भारतीय मानक IS 3177 : 2020

Indian Standard (Superseding IS 4137 : 2015)

इस्पात कार्य एवं अन्य ससं ्थानों पर उपयोग

के लिए विशेष प्रयोजन के लिये क्रे न सहित
इलेक्ट्रिक शिरोपरि यात्रा क्रे न तथा
गैन्ट्री क्रे न — रीति सहं िता
( तीसरा पनु रीक्षण )

Electric Overhead Travelling

Crane and Gantry Crane for all
Applications — Code of Practice
( Third Revision )

ICS 53.020.20

© BIS 2020

भारतीय मानक ब्रयू ो

B U R E A U O F I N D I A N S TA N D A R D S
मानक भवन, 9 बहादरु शाह ज़फर मार्ग, नई िदल्ली – 110002
MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI-110002
         www.bis.gov.in  
www.standardsbis.in

February 2020  Price Group 17

Cranes, Lifting Chains and its Related Equipment Sectional Committee, MED 14

FOREWORD
This Indian Standard ( Third Revision ) was adopted by the Bureau of Indian Standards, after the draft finalized by
the Cranes Lifting Chains and its Related Equipment Sectional Committee had been approved by the Mechanical
Engineering Division Council.
This standard was originally published in 1965 and subsequently revised in 1977 and 1999. In this revision all the
amendments have been incorporated and the following major changes have been made:
a) To help standardization, as far as possible, relating requirements for components to basic duty factor for
class of mechanisms.
b) Recommended selection of group mechanism (duty class) of the crane for purchaser.
c) Simplified graphical method for calculating permissible fatigue stress.
d) Selection of wheel and giving due consideration of duty class, travel speed and wheel material.
e) Selection of sizes for wire rope, rope drum, sheave and allowable fleet angle using graphical method.
f) Provision of compacted rope, seamless pipe for rope drum, case carburized gearboxes, geared brake
motor, etc. have been made.
g) Motor selection with thermal adequacy, use of service factor and RMS method has been prescribed.
h) The mechanism duty is classified in eight groups M1 to M8 based on their total duration of utilization
applying upto the time of replacement of mechanism and load spectrum that is, life load cycle.
j) Certain other changes for better implementation of the standard.
The requirements of IS 4137 : 2015 ‘Heavy duty electric overhead travelling cranes including special service
machines for use in steel work — Code of practice’ has been covered in this revision. This Indian Standard
supersedes the IS 4137 : 2015.
This standard covers design, manufacture and erection of electric overhead traveling cranes and gantry cranes
for use in steel works and other locations. The standard also covers mechanical, electrical, inspection and testing
aspects as related to design, manufacture and erection of electric overhead traveling cranes in order to secure
safe, efficient and reliable working of these heavy duty cranes during service. Structural design aspects of all
types of cranes and hoists are covered in IS 807 : 2006 ‘Design, erection and testing (structural portion) of cranes
and hoists — Code of practice. Cranes are broadly classified into eight classes in IS 807 depending on duty and
number of hours in service per year.
The new classification of cranes now coming into effect and the classification presently in use can approximately
be compared as follows:

Old Equivalent New Classification Average Working Average Total Life in

Hours Per Day Working Hours, Min
I M1 0.5-4 400
M2 800
M3 1 600
II M4 4-6 3 200
M5 6 300
III M6 6-9 25 000
IV M7 6-9 35 000
M8 12 75 000

NOTE ― The running time per day and total life relate to mechanism class only.

(Continued on third cover)

 IS 3177 : 2020

CONTENTS

Page No.

SECTION 1 GENERAL

1 SCOPE ... 1

2 REFERENCES ... 1

3 TERMINOLOGY ... 1

4 TECHNICAL INFORMATION TO BE PROVIDED ... 1

5 IDENTIFICATION ... 1

6 WORKMANSHIP, MATERIAL AND INSPECTION ... 4

SECTION 2 MECHANICAL COMPONENTS

7 DESIGN PROCEDURE ... 5

8 HOOKS ... 12

9 WIRE ROPES ... 12

10 SHEAVES ... 16

11 EQUALIZER BARS OR SHEAVES ... 16

12 TRACK WHEELS ... 16

13 BUFFERS ... 18

14 SHAFTS ... 18

15 PRESS FITS AND KEYS ... 19

16 BEARINGS ... 19

18 MACHINING REQUIREMENTS OF GEARS ... 20

19 GEAR BOXES ... 20

20 CRANE LUBRICATION SYSTEM ... 20

21 LINE SHAFTING AND COUPLINGS ... 20

22 RAILS ... 21

23 OPERATOR’S CABIN ... 21

i
IS 3177 : 2020

Page No.

24 GANGWAYS AND PLATFORMS ... 22

25 GUARDING ... 22

26 WEATHER PROTECTION ... 23

27 PAINTING ... 23

28 HANDLING FACILITIES ... 23

29 BRIDGE AND TROLLEY DRIVES ... 23

30 TORSIONAL, DEFLECTION AND VIBRATION ... 25

31 MOTION LIMITING DEVICES ... 25

32 CROSS TRAVEL AND LONG TRAVEL LIMITING DEVICES ... 25

33 LOAD LIMITING DEVICES ... 25

34 DRAWINGS AND DOCUMENTS ... 25

SECTION 3 ELECTRICAL EQUIPMENT

35 POWER SUPPLY ... 25

36 CABLES AND CONDUCTORS ... 29

37 ELECTRICAL PROTECTIVE AND SAFETY EQUIPMENT ... 30

38 CONTACTORS ... 33

39 CONTROL SWITCH FUSE ... 33

40 EMERGENCY SWITCHES ... 33

41 OFF-POSITION INTERLOCKING ... 33

42 PILOT LAMP ... 33

43 MAIN FEATURE OF BUILT-IN CRANE WEIGHING SYSTEM IF SPECIFIED ... 33

44 AUXILIARY SUPPLY ... 33

45 DISTRIBUTION BOARD ... 34

46 AUXILIARY SWITCHES OTHER THAN ISOLATION SWITCHES ... 34

47 IDENTIFICATION OF CIRCUITS ... 34

48 DISPOSITION AND HOUSING OF ELECTRICAL EQUIPMENT ... 35

49 SAFETY FEATURES ... 35

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 IS 3177 : 2020

Page No.

50 DESIGN AND SELECTION OF MOTORS ... 37

51 CYCLIC DURATION FACTOR AND NUMBER OF CYCLES PER HOUR ... 41

52 DESIGNING THE CRANE CONTROLS ... 42

53 CRANE CONTROLLING ARRANGEMENTS ... 42

54 RESISTORS ... 46

55 CRANE CONTROLS ... 47

56 BRAKING ... 49

57 FLOOR CONTROL ─ WITHIN CONTROL FEATURES ... 51

58 AUXILIARY REQUIREMENTS ... 52

59 HEATING AND AIR-CONDITIONING ... 52

60 AUXILIARY CIRCUIT ... 52

61 LIFTING MAGNETS AND LOAD HOLDING DEVICES ... 52

62 ELECTRICAL EQUIPMENTS LOCATED ON THE CRANE BRIDGE ... 53

63 DRAWINGS ... 54

SECTION 4 INSPECTION AND TESTING

64 INSPECTION PROCEDURE ... 54

65 GENERAL REMARKS ... 59

66 TESTING ... 64

67 CRANE-RECOMMENDED/PREFERRED PARAMETERS ... 65

ANNEX A
A-1 LIST OF THE STEEL PLANT CRANES AND SPECIAL SERVICES
MACHINES COVERED BY THE CODE ... 67

ANNEX B
B-1 TYPICAL CLASSIFICATION OF CRANE MECHANISM ... 68
B-2 OVERHEAD TRAVELLING INDUSTRIAL TYPE CRANES (O.T.C) ... 68
B-3 OVERHEAD TRAVELLING STEEL WORKS CRANES AND
TRANSPORTERS ... 69

ANNEX C
LIST OF REFERED INDIAN STANDARDS ... 71

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IS 3177 : 2020

Page No.

ANNEX D
D-1 GENERAL ... 73
D-2 CRANE PERFORMANCE ... 73

ANNEX E
E-1 GENERAL ... 74
E-2 CRANE AND COMPONENTS WEIGHT ... 74
E-3 STRUCTURAL DETAILS (see Fig. 18) ... 74
E-4 OPERATOR’S CABIN DETAILS ... 74
E-5 MECHANICAL DETAILS ... 75
E-6 ELECTRICAL DETAILS ... 75
E-7 PROTECTION OF CRANE STRUCTURE AND MACHINERY ... 77
E-8 ADDITIONAL REQUIREMENTS ... 77

ANNEX F
F-1 GENERAL ... 78
F-2 FATIGUE REFERENCE STRESS, Pf,r ... 78
F-3 DETERMINATION OF FATIGUE REFERENCE STRESS FACTOR (Cf,r) ... 78
F-4 FATIGUE LIMIT FACTOR (Clim) ... 78
F-5 DETERMINATION OF C1, C2, C3 and K FACTORS ... 78

ANNEX G
G-1 GENERAL ... 82
G-2 DEFINITION OF DIFFERENT RATINGS ... 82

LIST OF FIGURES

Fig. 1 Typical Crane Types ... 3

Fig. 2 Illustraiton of typical Attachments in Relation to Safe Working Load ... 5
Fig. 3 Permissible Fatigue Bending Stress, Pbc ... 7
Fig. 4 Permissible Fatigue Stress in Axial / Tension, Pfa ... 8
Fig. 5 Permissible Fatigue Stress, Pfs ... 9
Fig. 6 Maximum Allowable Fleet Angle ... 13
Fig. 7 Drum Groove Design ... 15
Fig. 8 Typical Arrangement of Bridge and Trolly Drive ... 24
Fig. 9 Main Isolating Switches and Fuses Required for Fixed-Cabin Crane ... 31
Fig. 10 Main Isolating Switches and Fuses Required for Moving-Cabin Crane ... 31
Fig. 11 Recommended Arrangement of Controllers ... 45
Fig. 12 Recommended Arrangement of Controllers ... 45
Fig. 13 Torque Speed Curves Characteristics ... 48
Fig. 14 Crane Dimensions ... 55
Fig. 15 Spacing Dimensions ... 56

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 IS 3177 : 2020

Page No.

Fig. 16 Trolley Dimensions ... 56

Fig. 17 Weld Profiles ... 60
Fig. 18 Overhead Travelling Crane ... 73
Fig. 19 Fatigue Referecnce Streess Factor Cfr ... 79
Fig. 20 Size Factor C2 ... 80
Fig. 21 Surface Finish Factor C3 ... 80
Fig. 22 Notch Sensitivity Curves ... 81

LIST OF TABLES

Table 1 Factor for Mechanical Design (for Fatigue Analysis) ... 5

Table 2 Values of Co-efficient, Cdf ... 10
Table 3 Values of Coefficient, Cbf ... 10
Table 4 Values of Coefficient, Csf ... 11
Table 5 Value for L ... 14
Table 6 Values of PL ... 17
Table 7 (Value of c1 ) ... 17
Table 8 ( Values of c2 ) ... 17
Table 9 Minimum Flange Dimensions ... 18
Table 10 Load Diversity Factor fD ... 26
Table 11 Duty Cycle Factor fED ... 26
Table 12 Equivalent Continuous Current of DSL ... 27
Table 13 Normal Requirements for Number of Protective Devices for Circuit ... 33
Table 14 Recommended Cyclic Duration Factor and Starting Class ... 38
Table 15 Number of Cycles per Hour and the Cyclic Duration Factor for the
Vertical Motions ... 42
Table 16 Number of Cycles per Hour and the Cyclic Duration Factor for
the Horizontal Motions ... 43
Table 17 Rating of Resistors ... 47
Table 18 Braking Path ... 50
Table 19 Brake Magnet Coil Ratings ... 51
Table 20 Brake Magnet Operating Voltages and Currents ... 51
Table 21 Information for Enclosures ... 54
Table 22 Certificate ... 59
Table 23 Certificate ... 59

v
 IS 3177 : 2020

Indian Standard
ELECTRIC OVERHEAD TRAVELLING CRANE AND
GANTRY CRANE FOR ALL APPLICATIONS —
CODE OF PRACTICE
( Third Revision )

SECTION 1 GENERAL possibility of applying the most recent editions of the

standards indicated in Annex C.
1 SCOPE
3 TERMINOLOGY
1.1 This standard covers requirements for design,
manufacture, inspection and testing of electric 3.1 General ― For the purpose of this standard the
overhead travelling cranes and gantry cranes for use in definitions given in IS 13473 (Part 1) and following text
steel works and other locations. Its provisions where shall apply. If there are common terms, the definitions
applicable, shall also apply to special purpose cranes, given in this standard shall prevail.
such as, those listed in Annex A including steel plant
crane and other overhead travelling cranes, portal 3.2 Normal Service Condition ― Normal service
and semi-portal cranes, single girder, double girder or condition shall satisfy the following conditions:
mono-box type (Fig. 1). It is recommended that, the a) Indoor and outdoor applications should with
crane should be designed based on the duty classes and normal air of normal humidity and free from
application, irrespective of usage in steel works or at contamination;
other locations. Classification of the crane as a whole b) Ambient temperature should be 0°C to 40°C and if
shall be taken as defined from classes A1, A2, ...... A8 the service conditions those beyond this, suitable
and as defined as from mechanism classes M1, M2, ..... derating factors shall be applied; and
M8 classification as defined in foreword. Structural
c) Altitude should not exceed 1 000 m above mean
design aspects of all types of cranes and hoists are
sea level.
covered in IS 807.
4 TECHNICAL INFORMATION TO BE
1.2 The duty class of crane preferably be selected as
PROVIDED
per 1.1.
1.3 Annex B gives guidance which may be referred by 4.1 Information to be Supplied with Enquiry or
purchaser while specifying the duty class. Order
Information regarding the conditions under which
1.4 This standard is not intended for application to the crane is to be used, together with the information
cranes for use in areas where sparks from cranes could required in Annex D, shall be supplied with the enquiry
lead to explosions. or order.
1.5 It is recommended that IS 13367 (Part 1) to be 4.2 Information to be Supplied by the Manufacturer
referred for safe usage of crane. with Offer
1.6 Risk assessment and risk reduction to be carried out The manufacturer shall supply all technical details/
as per IS 16819 and IS 16504 (Part 1) if agreed between documents together with the information required in
the manufacturer and the purchaser. Annex E including drawings giving the over all sizes,
clearance, end approaches, structural features, travel
2 REFERENCES wheel loads, type of buffers, impact forces, wheel
The standards listed in Annex C contain provisions, spacing, etc.
which through reference in this text, constitute
provisions of this standard. At the time of publication, 5 IDENTIFICATION
the editions indicated were valid. All standards are
subject to revision, and parties to agreements based 5.1 A small plate shall be located in a prominent
on this standard are encouraged to investigate the position in the cabin or suitable location bearing the

1
IS 3177 : 2020

1A TOP RUNNING CRANE (DOUBLE GIRDER)

1B TOP RUNNING CRANE (SINGLE GIRDER)

1C SEMI GOLIATH (GANTRY) CRANE

2
 IS 3177 : 2020

1D GOLIATH (GANTRY) CRANE (WITH CANTILEVERED EXTENSION)

1E OFFSET CRAB CRANE

Notes
1 The classification given in foreword is for guidance only. However, while correlating between earlier
classifications and proposed M1 to M8, the new classification shall prevail with clear understanding of customer
requirements,keeping in view the interests as protected by the earlier classification.
2 The classification of the individual motions of a crane may not necessarily be the same as those of crane
structure. The classification of one motion of a crane may differ from the another motion of the same crane.
3 In the case, where a crane mechanism is required to perform a duty that falls beyond the group classification M8,
either the mechanism shell be designed for higher hook load or other parameters shall be charged so that it
satisfies requirement for the group classification M8.
.
FIG. 1 TYPICAL CRANE TYPES

Fig. 1 Typical Crane Types

3
IS 3177 : 2020

following inscription: 5.3 Manufacturer’s Name Plate

a) Manufacturer’s name; The manufacturer’s name plate shall contain the
b) Manufacturer’s serial number; following details:
c) Year of manufacture; a) Name of manufacture;
d) Safe working load; and b) Year of manufacture;
e) Nomenclature of crane. c) Manufacturer serial number; and
d) Safe working load of each hoist shall be
5.1.1 In general purpose cranes, X/Y indicates the
permanently marked on each side of crane in such
following:
a manner as to be easily legible from the floor and
a) X — Capacity of the main hook, in tonnes; and in tonnes;
b) Y — Capacity of the auxiliary hook, in tonnes.
5.4 Warning Notices
Both the hoists are mounted on one trolley (double
The following warning notices shall be suitably located
girder).
so as to be clearly visible:
5.1.2 X + Y indicates the following: a) Do not stand under the load;
a) X — Capacity of the main hoist in tonnes; and b) No access for unauthorized personnel; and
b) Y — Capacity of the main auxiliary hoist, in c) Danger-crane; by means of warning colour strips
tonnes. (as applicable).
Main hoist is mounted on main trolley and the auxiliary
hoist on a separate auxiliary trolley and both the trolleys 6 WORKMANSHIP, MATERIAL AND
may be on same girder (double girder) or on different INSPECTION
girders (four girders).
6.1 Workmanship and material shall be subject to the
5.1.3 X/Y/Z indicates the following: inspection of the owner or his representative at all
times. Weldments of carbon steel (except bridge girder,
a) X — Capacity of the main hoist, in tonnes;
trolley structure, boggie, end carriage) shall be stress
b) Y — Capacity of the auxiliary hook 1; and relieved by uniformly heating in a furnace, wherever
c) Z — Capacity of the auxiliary hook 2. applicable. Field welds shall likewise be stress relieved
All hooks are mounted on one trolley (double girder). unless other means agreeable to the owner as specified
in the information sheet. The temperature of the
5.1.4 X + Y / Z indicates the following: furnace when the weldment is placed in it shall not be
a) X — Capacity of the main hoist, in tonnes; over 150°C at the start and increased to 650°C at a rate
not exceeding 95°C/h, and then held at the temperature
b) Y — Capacity of the main hook of the auxiliary for 1 h/25 mm of thickness of material. It shall then be
trolley; and cooled in the furnace at a rate (not exceeding 95°C/h)
c) Z — Capacity of the auxiliary hook of the auxiliary to 260°C, before being removed from the furnace.
trolley. Weldments of alloy material shall be welded and stress
Main hoist hooks are mounted on one trolley and both relieved using a procedure as per IS 16003 or ASME,
the hooks of auxiliary trolley are mounted on another Sec - IX.
trolley and both the trolleys may be on same girder
6.2 The stress relieving shall be applicable for the
(double girder) or on different girders (four girders for
plate thickness of more than 40 mm as per AWS 14.1
ladle cranes).
or ASME Section VIII, Div I. For larger components
5.2 Rating Plate where the thermal stress relieving is not possible, as
an alternative, the mechanical vibratory method shall
a) The lifting capacity shall be permanently marked
be applied. To stress relieve the field weld, local flame
in a visible position and shall be easily legible
heating shall be applied.
from the ground;
b) In case of grabbing cranes, the lifting capacity 6.3 Safety Clearances
shall be permissible total weight of the grab and All moving parts of the cranes shall be at least 100 mm
the lifting capacity; and from any fixed part of a building/structure and minimum
c) In the case of cranes with more than one hoist, the of 600 mm from human access area. Alternatively, the
lifting capacity of each hoist shall be indicated on safety clearances shall be as per agreement between the
the relevant hook block. purchaser and the manufacturer.

4
 IS 3177 : 2020

SECTION 2 MECHANICAL 7.3 Loadings to be Considered in the Design of

COMPONENTS Mechanisms
7.3.1 Loads
7 DESIGN PROCEDURE
The following loadings shall be taken into account
7.1 General when designing a mechanism and its components:
The design of the component parts of the mechanism Rd = Loads due to the dead weight of the mechanism
relating to each crane motion shall be included with or component and dead weight of those parts
due allowance for the effects of the duty which the of the crane acting on the mechanism or the
mechanism shall perform in service. The design of component under consideration.
the component parts will be in accordance with the Rh = Loads due to the weight of the hook load with
provisions given in this section. reference to Fig. 2 and also it is defined as
SWL of the hook.
7.2 Load Amplifying Factor
Rhi = Loads due to the weight of the hook load
The load amplifying factor applied to the motion of
increased by the load amplifying factor given
the hook in a vertical direction covers inertia forces
in 7.2.
including shock. In calculating fatigue analysis in the
components of the mechanism the live loads, the rated Rm = Dynamic loading arising from the acceleration
hook load shall be multiplied by the load amplifying or braking of the motion and from skewing
factor, given in Table 1. interaction between the crane and track. These
loads include those loads due to the following
NOTE — Load amplifying factor for structural design shall be
as per IS 807. Table 1 refers for fatigue design of mechanical
reasons:
components only. a) inertia of the mechanism, associated crane
Table 1 Factor for Mechanical Design parts and hook load;
(for Fatigue Analysis) b) its prime mover and brakes; and
( Clauses 7.2 and 7.4.3.2 ) c) concurrent operation of other motions, etc,
as applicable.
Sl No. Group Classification of the Load Amplifying Rf = Loads arising from frictional forces.
Mechanism Factor
Rw1 = Loads due to the service wind acting
1) (2) (3)
horizontally in any direction where applicable
i) M1 1.00 according to IS 807.
ii) M2 1.04
Rw2 = Loads arising out of wind pressure during
iii) M3 1.08 out of service condition with wind acting
iv) M4 1.12 horizontally in any direction where applicable
v) M5 1.16 according to IS 875 (Part 3).
vi) M6 1.20 RC = Loads due to collision with end buffers.
vii) M7 1. 25
viii) M8 1.30

SAFE WORKING
LOAD OF CRANE

SLINGS LIFTING MAGNET GRAB BUCKET

BEAM
SAFE WORKING LIFTING ATTACHMENT
LOAD OF LIFTING
ATTACHMENT

FIG. 2 ILLUSTRATION OF TYPICAL ATTACHMENTS IN RELATION TO SAFE WORKING LOAD

Fig . 2 Illustraiton of typical Attachments in Relation to Safe Working Load

5
IS 3177 : 2020

7.3.2 Loading Condition and Load Combinations consideration shall be given to the consequences of
failure. For example, failure in hoisting mechanism
Each mechanism of the crane shall be designed to component is usually more dangerous occurrences than
operate satisfactorily under the most unfavourable failure of a horizontal motion mechanism.
combination of loadings that can occur under different
conditions and that could also actually occur in practice. 7.4.2 Basis of Design
7.3.2.1 Case I - Normal service without wind where Mechanism components are checked depending on the
crane capacity equal to Rh ultimate strength by verifying that the calculated stress
does not exceed a permissible stress dependent on the
a) Vertical Motion — Hoisting or lowering: breaking strength of the material used.
1) Rd + Rh + Rm + Rf; or NOTE ― If, Cdf is considered in calculation of allowable
2) Rd + Rhi strength then load amplifying factor as mentioned in 7.2 need
not to be considered.
b) Horizontal Motion — Traverse or travel:
7.4.3 Permissible Stress
Rd + Rh + Rm + Rf
Mechanism component shall be checked for strength
7.3.2.2 Case II - Normal service with wind under case I, II, III and IV loading conditions and
a) Vertical Motion — Hoisting or lowering: load combinations specified in 7.3.2. The value of the
permissible stress Fa is given by following formula
1) Rd + Rh + Rm + Rf + Rw1; or where unit of stress was defined as N/mm2:
2) Rd + Rhi + Rw1.
b) Horizontal Motion — Traverse or travel: Fa = Fult
——————
Rd + Rh + Rm + Rf + Rw1 Cdf × Cbf ×Csf

7.3.2.3 Case III Crane out of service Where,

a) Vertical Motion — Hoisting or lowering not Fult = ultimate tensile strength of the material;
applicable. Cdf = duty factor for the appropriate mechanism
b) Horizontal Motion — Traverse or travel : class. For the values see Table 2;
Cbf = basic stress factor corresponding to each case
Rd + Rw2 of loading. For the values see Table 3; and
7.3.2.4 Case IV — Exceptional loading condition Csf = safety factor depending on the material used.
The combination of loads to be considered for this For the values see Table 4.
case of loading will depend upon the type of crane, 7.4.3.1 Permissible stress Fa should be reduced by
application and the crane motion. Account shall be 20 percent in the crane component for reverse bending.
taken of any loading condition that are known to apply
but which are not covered under the other three cases 7.4.3.2 Normally, the steel plant cranes are designed for
of loading. A few cases of exceptional loading are as M6, M7 and M8 class duty which need to be checked
follows: against fatigue / endurance limit. The working stress is
to be calculated based on below formula,
a) Loads due to collision of cranes with each other or
with end stoppers that is buffer loads; Working stress = Stress due to rated load × stress
b) Loads due to testing of cranes; concentration factor × load amplifying factor.
c) Erection loads; and That is, for bending:
d) Loads due to the maximum load that the motor can
actually transmit to the mechanism while starting, fb Max = fbc × K × Load amplifying factor (as per Table 1)
stalling or due to higher actual power.
Where,
7.4 Design Procedure K = Stress concentration factor.
7.4.1 General As load amplification factor has been considered Cdf is
Mechanism components shall be proportioned by not being consider.
checking that they have adequate safety against
The permissible fatigue stresses in bending Pfb is
becoming unserviceable as a result of a single
obtained from Fig. 3, permissible fatigue stresses in
combination of extreme loading conditions causing
tensile Pft is obtained Fig. 4 and for permissible fatigue
fracture, bending or other type of failures. They
stress in shear Pfs obtained from Fig. 5 based on the
shall also be checked whenever appropriate against
ultimate strength of the selected material.
fatigue, deflection or over heating. In this connection,

6
 IS 3177 : 2020

MPa kg/cm2 ksi

199.1 2030 29
192.3 1960 28 20%

1.0
185.4 1890 27

TO
.3
178.5 1820 26

-O

STRESS FLUCTUATION RATIO = fb MIN, (MINIMUM VALUE OF STRESSES IN BENDING)

.4
-O

fb MAX, (MINIMUM VALUE OF STRESS IN BENDING)

171.7 1750 25
PERMISSIBLE FATIGUE BENDING STRESS

.5
164.8 1680 24

-O
157.9 1610 23

.6
-O
.7
151.1 1540 22

-O
.8
144.2 1470 21 -O

.0 .9
137.3

-1 -O
1400 20
130.5 1330 19
123.6 1260 18
116.7 1190 17
109.9 1120 16
103.0 1050 15
96.1 980 14

EXAMPLE - 1
89.3 910 13
82.4 840 12
75.5 770 11
68.7 700 10
61.8 630 9
ksi 60 70 80 90 100 110 120 130 140 150 160
kg/cm2 4200 4900 5600 6300 7000 7700 8400 9100 9800 10500 11200
MPa 412 481 549 618 687 755 824 893 961 1030 1099

MINIMUM ULTIMATE TENSILE STRENGTH AT MID RADIUS

Example shown in above Fig indicates that, the material with 117 ksi minimum UTS have maximum allowable bending stress 16.1 ksi for
stress fluctuation ratio -1.0 and 23ksi for stress fluctuation ratio -0.3 and 1.0 For determining stress fluctuation ratio. it should be observed that
the stress
Example having
shown in the maximum
above figure absolute
indicatesmagnitude ( regardless
that, the material withof117
whether it is a tension,
ksi minimum UTS compression,
have maximum shear, combined
allowable or equivalnet
bending stress stress
16.1) isksi
to be
forconsidered positive ratio
stress fluctuation in all -1.0
cases. The
and 23minimum stressfluctuation
ksi for stress is to be considered
ratio -0.3positive
and 1.0.if itFor
is of the same sense
determining stressasfluctuation
the maximum stress.
ratio,
otherwise it is to be taken as negative. Referring Fig. 3 to Fig. 5, in regions of combined stress fa Max. or f, Max or f Max should be taken as
it should be observed that the stress having the maximum absolute magnitude (regardless of whether it is a tension, compression,
the maximum combined or equivalent stress having the maximum absolute magnitude. fa Min or fib Min. or f Min, shall be taken as the
shear, combined or equivalnet stress ) is to be considered positive in all cases. The minimum stress is to be considered positive
absolute minimum stresses which do occur at the same location as the maximum stress.
if it is of the same sense as the maximum stress, otherwise it is to be taken as negative. Referring Fig. 3 to Fig. 5, in regions
of combined stress fa Max. or fb Max. or fs Max. should be taken as the maximum combined or equivalent stress having the maximum
absolute magnitude. fa Min. or fb Min. or fs Min. shall be taken as the absolute minimum stresses which do occur at the same location
as the maximum stress. FIG. 3 PERMISSIBLE FATIGUE BENDING STRESS, Pbc

Fig. 3 Permissible Fatigue Bending Stress, Pbc

7
IS 3177 : 2020

MPa kg/cm2 ksi

199.1 2030 29

192.3 1960 28

fs MAX, (MAXIMUM VALUE OF STRESS IN AXIAL TENSION / COMPRESSION)

STRESS FLUCTUATION RATIO = fa MIN, (MINIMUM VALUE OF STRESS IN AXIAL TENSION / COMPRESSION)
185.4 1890 27

178.5 1820 26

171.7 1750 25

164.8 1680 24

157.9 1610 23

0
1.
PERMISSIBLE FATIGUE STRESS IN AXIAL TENSION / COMPRESSION

TO
.5

6
151.1 1540 22

-0

.
-O
- O .8 .7
-O -O
144.2 1470 21

137.3 1400 20

.9
.0
130.5 1330 19

-1
123.6 1260 18

116.7 1190 17

109.9 1120 16

103.0 1050 15

96.1 980 14

89.3 910 13

82.4 840 12

75.5 770 11

68.7 700 10

61.8 630 9
ksi 60 70 80 90 100 110 120 130 140 150 160
kg/cm2 4200 4900 5600 6300 7000 7700 8400 9100 9800 10500 11200
MPa 412 481 549 618 687 755 824 893 961 1030 1099
MINIMUM ULTIMATE TENSILE STRENGTH AT MID RADIUS

FIG. 4 PERMISSIBLE FATIGUE STRESS IN AXIAL / TENSION , Pfa

Fig. 4 Permissible Fatigue Stress in Axial / Tension, Pfa

8
 IS 3177 : 2020

MPa kg/cm2 ksi

103.0 50 15

96.1 980 14

1 .0
TO

fs max., (MAXIMUM VALUE OF TORSIONAL SHEAR STRESS)

.6

STRESS FLUCTUATION RATIO = fs min., (MINIMUM VALUE OF TORSIONAL SHEAR STRESS)

-O
89.3 910 13

.7
-O
.8
-O
82.4 840 12

.9
-O
.0
-1
75.5 770 11
PERMISSIBLE FATIGUE STRESS IN SHEAR

68.7 700 10

61.8 630 9

54.9 560 8

48.0 490 7
EXAMPLE

41.2 420 6

34.3 350 5

ksi 60 70 80 90 100 110 120 130 140 150 160

kg/cm2 4200 4900 5600 6300 7000 7700 8400 9100 9800 10500 11200
MPa 412 481 549 618 687 755 824 893 961 1030 1099
MINIMUM ULTIMATE TENSILE STRENGTH AT MID RADIUS

FIG. 5 PERMISSIBLE FATIGUE STRESS, Pfs

Fig. 5 Permissible Fatigue Stress, Pfs

9
IS 3177 : 2020

The allowable stress coming from Fig. 3 to Fig. 5 is to e) Combined bending and compression
be compared with Fa value as per 7.4.3.1 and the lower
value should be considered in the calculations. fc + fbc ≤Fa
f) Pure shear
7.4.3.2.1 Alternatively value of permissible fatigue
stress Pfr (Pfb and Pfs) can also be calculated as per √3 fs ≤ Fa
Annex F. g) Combined bending, tension and shear
7.4.3.3 The static bearing stress in any part of a crane √[(1.25 ft + fbt)2 +3 f 2] ≤ Fa
component, calculated on the net area of contact shall
not exceed the value of determined by the following h) Combined bending, compression and shear
formula: √[(fc + fbc)2 +3 fs2] ≤ Fa
σp = 0.75 fy Where,
where, ft = calculated axial tensile stress,
σp = Maximum permissible static bearing stress; fc = calculated axial compressive stress,
and fbt = calculated maximum tensile stress due to
fy = Yield stress of selected material. bending about both principal axes,
fbc = calculated maximum compressive stress due to
7.4.4 Relation between Calculated and Permissible
bending about both principal axes, and
Stresses
fs = calculated shear stress.
According to the type of loading to be considered the
following relations shall be verified: 7.4.5 Checking for Fatigue
a) Pure tension 1.25 ft ≤Fa 7.4.5.1 General
b) Pure compression fc ≤Fa
Where it is necessary to check a component for fatigue,
c) Pure bending either compression or tension recognized techniques available for calculation of
fatigue properties shall be used. The choice of the
fbt or fbc ≤Fa
methods used shall be left to the manufacturer, however,
d) Combined bending and tension he shall specify the origin of the methods to be adopted,
if asked by the customer.
1.25 ft + fbt ≤Fa

Table 2 Values of Co-efficient, Cdf

( Clauses 7.4.3 and 7.4.5.6 )

Sl Group Classification For Mechanism For Mechanism For Mechanism Used for Vertical Motion or While
No. of Mechanism used for Horizontal Used for Vertical Handling Dangerous Material for Example, Molten
Motion Motion Metals, Highly Radioactive or Corrossive Products
(1) (2) (3) (4) (5)
i) M1 1.00 1.18 1.32
ii) M2 1.06 1.25 1.40
iii) M3 1.12 1.32 1.50
iv) M4 1.18 1.40 1.60
v) M5 1.25 1.50 1.70
vi) M6 1.32 1.60 1.80
vii) M7 1.40 1.60 1.90
viii) M8 1.50 1.70 2.00

Table 3 Values of Coefficient, Cbf

( Clause 7.4.3 )

Case of Loading I II III and IV

Cbf 3.15 2.5 2.0

10
 IS 3177 : 2020

Table 4 Values of Coefficient, Csf

( Clause 7.4.3 )

Sl No. Safety Factor Depending on the Material Used Values of Coefficient

(1) (2) (3)
i) For ordinary grey cast iron or for cast or forged components where blow holes or 1.25
internal cracks can not be detected.
ii) For mild steel E 250, E 350 and E 410 1.12
iii) For heat treated and tested material (for example, 42CrM04, C45, C55Mn75) 1.00

7.4.5.2 Loading condition Pfa = Permissible fatigue, in axial tension;

Case I of loading condition as specified in 7.3.2 shall be fa Max, fa Min = Extreme values of axial tensile
used as the basis for all fatigue checks. stress;
fb Max, fb Min = Extreme values of stress, in bending;
7.4.5.3 Factors affecting fatigue strength
fs Max, fs Min = Extreme values of torsional shear
For any component, the magnitude of the permissible stress; and
fatigue stress ( pf) depends upon the following factors:
fMin/fMax = Maximum degree of stress
a) Total number of stress cycles during the service fluctuation.
life of the component ‘n’;
b) Type of stress cycles (that is, degree of stress 7.4.5.5 Permissible fatigue stress
fluctuation); When single nature of stresses are applicable, then the
c) Quality of the material; working stress should be less than permissible fatigue
stress which is to be calculated as per 7.4.3.2 .
d) Size of the component;
e) Surface finish of the component; The stress combination occurring most frequently in
practice in a component detail is that of bending and
f) Configuration of the individual details under torsion. The details subjected to this combination shall
consideration; and be designed so that:
g) Miscellaneous effects such as the effects of
corrosion, residual stress, electrolytic plating, ( fb Max/Pfb )2 + (fs Max/Pfs)2 < 1.0
metal spraying, etc, where under certain conditions
7.4.5.6 Checking for crippling
reduce the permissible fatigue stress. 7.4.5.4 gives
a method for calculating the fatigue reference Component subjected to crippling that is overall
stress (pfr) which takes account from the factor (a) flexural buckling due to axial compression shall be
to (g). checked so that the calculated stress does not exceed
NOTE — A check for fatigue need not be made in the cases, a limit stress determined as a function of critical stress
where experience shows that the ultimate strength check as per above which there is a risk of crippling occurring. For
7.4.3 is sufficient. this check coefficient Cdf, as given in Table 2 shall be
taken into account.
7.4.5.4 Stresses
The following characteristics shall be determined for 7.4.5.7 Checking for wear
each type of fluctuating stress, for example, tension, In the case of parts subjected to wear, the specific
compression, bending or shear, occurring during an physical quantities, such as, surface pressure or
appropriate stress cycle in the component detail having the circumferential velocity must be determined.
regard to the loading that it will experience: The figures must be such that on the basis of OEM/
fMax, fMin = Extreme values of stress occurring international practices they will not lead to excessive
in the stress cycle; wear.
fMin =  Considered as negative if it is of 7.4.5.8 Means of access
opposite sense to fMax;
pfb = Permissible fatigue stress, in 7.4.5.8.1 General requirements
bending; In front of the panel the working place shall be
pfs = Permissible fatigue stress, in shear; minimum of 500 mm or width of the door of the panel
or whichever is more. Safe means of access shall be
pfr = Fatigue reference stress at which a
provided to the driver’s cabin and to every place where
component detail has a 90 percent
any person engaged on the inspection, repair and
probability of survival;

11
IS 3177 : 2020

lubrication of the crane will be called upon to work, of qualified welding engineer and performed prior
adequate handholds and footholds being provided to initial heat treatment. The capacity of hook may
where necessary. be stamped on the hook nose. The hook shall not be
painted.
7.4.5.8.2 Platforms
Every platform shall be securely fenced with double 8.4 Hook Body
tiered guard rails having a minimum height of 1.1 m Hook bodies shall be of standard design where the
and toe boards, unless parts of the crane structure line of resultant load on the hook passes through the
provided safely. The platform normal width with only centre of curvature of the inside edge of the hook and
chequered plates shall be of sufficient to enable normal coincides with the centerline of the shank.
maintenance work to be carried out safely. On bridge
platform, minimum clear width which shall be not less 8.5 Testing
than 0.50 m in normal width, the fencing shall extend A certificate of compliance showing static load testing
along the full length of the outer edge. Guard rails on (proof load test ) covering the configuration of the hook
the trolley side of the bridge platform may be provided, body and the hook shank shall be provided.
if required.
8.6 Latches
7.4.5.8.3 Ladders Hook latches and swivel lock plates shall be provided
Sides of ladders shall extend about 1 m above top rung, when specified.
unless some other appropriate handhold is provided.
Ladders shall if possible, slope forward. Vertical ladders 8.7 Mounting
exceeding 3 m in length shall be provided with back Swiveling hooks shall be mounted on thrust bearings.
safety guards. The ladders over 5 m in height should A protective skirt shall be provided to enclose the
be provided with safety hoops starting at a height of bearings. The thrust bearings shall be provided with
2.5 m. The distance between safety hoops shall not be facilities for lubrication.
greater than 0.9 m. The strength of safety hoops must
be adequate to withstand a force of 100 kg distributed 9 WIRE ROPES
over 100 mm acting on any point of the loop. The
ladders must be provided with rest platforms spaced so 9.1 The hoisting ropes shall be of the grade and type
that the first stretch does not exceed 10 m and there are specified in IS 2266. Steel cored ropes shall be used
then rest platforms at every 8 m. for cranes handling hot metal or where the rope has
to be used under water or in corrosive atmosphere.
7.4.5.8.4 Stair ways All wire ropes shall generally be of ordinary lay, right
Slope of stairways should preferably be 45º, however hand, pre-formed and ungalvanized. For grab cranes
shall not exceed 60º (with horizontal), the height of one rope may have left hand lay and the other right
individual steps shall not exceed 250 mm and their hand lay or non-rotating rope according to IS 2266.
depth shall not be less than 150 mm the surface of treads The compacted ropes suitable for crane duty may be
shall be anti-slip. The stair ways shall be provided with used as per agreement between the purchaser and the
guard rails on each side. supplier based on various crane’s application. Ropes
working under water and in corrosive atmosphere shall
NOTE ― In case of space constraint, slope of stairways may
be mutually decided by the purchaser and the manufacturer. be galvanized. Reverse bend in the rope reeving shall
be avoided as far as possible. The sheave arrangement
8 HOOKS should be reeved so as to eliminate reverse bends
preferably except at the drum and equilizer.
8.1 The hook material and rated capacity shall be selected
from IS 15560, IS 5749, and DIN 15407-1 or AISE 7 9.2 The maximum allowable fleet angle for frequent
(for Laminated hooks). DIN 15400 for single point working positions shall be 3° for all classes of cranes.
and Ramshorn hooks are also acceptable. Radiography However, maximum allowable fleet angle for seldom
test may be done for forged hook, if mutually agreed reach position may be permitted upto 5°. Fig 6 may be
between the purchaser and the manufacturer. referred for further guidance with respect to rope speed.
The negative fleet angle can be calculated based on
8.2 General
below formula: Negative fleet angle = Allowable
Hooks shall be designed for the rated load. The design positive fleet angle –tan -1 ( Pitch of the groove / 3.14 ×
shall be established by analysis or testing as per relevant rope PCD on the drum )
standards.
When special reeving, such as, a stabilized reeving
8.3 Details arrangement is used, consideration must be given to
geometry and dynamics to maintain the appropriate
Hooks shall be forged from fine grained material. safety factors. Provisions should be made to prevent
Any welding on the hook shall be with the approval the twisting of the hook block.
12
 IS 3177 : 2020

ROPE SPEED

100
5.6° PITCH(p)

90

PCD (D)
5.0°

4.5° 80 t1
Maximum allowable fleet angle (Ø)= tan-1 ( t1 /1000 )

25
m/ β
mi
4.0° 70 n Ø
1000mm
30
40
50
3.5° 60
60
10 75
0
12
5
3.0° 15 UP TO
0 25 m/min
50
30
25
0m 40
t1 (in mm)

/m
in 50
2.5°
60
75
40 100
EXAMPLE-1
EXAMPLE-2

125
150
200 m/min
2.0°
20 30 40 50 60 70 80
D/d (Drum PCD/ Rope Dia)

Example 1 : Input data Example 2 : Input data

FIG.6 MAXIMUM ALLOWABLE FLEET ANGLE
Crane capacity : 225 t Crane capacity : 35 t
Hoisting speed : 1.25 m/min Hoisting speed : 8 m/min
Rope drum dia., D : 1 400 mm Rope drum dia., D : 550 mm
Number of fall : 20 Number of fall : 8
Rope dia. : 36 mm Rope dia. : 22 mm
Pitch of groove : 39 mm Pitch of groove : 26 mm
Rope PCD on drum : 1 436 mm Rope PCD on drum : 572 mm
Calculation, Calculation,
The D/d ratio = 1400/36 = 38.88 The D/d ratio = 550/22 = 25
Rope speed = 20/2 × 1.25 = 12.5 m/min Rope speed = 8/2 × 8 = 32 m/min
( Minimum 25 m/min rope speed to be considered )
As per Fig. 6 , maximum allowable fleet angle ( ø ) = 4.35 Degree As per Fig. 6, Maximum allowable fleet angle ( ø ) = 5.18 Degree

Now, allowable negative fleet angle (β) Now, allowable negative fleet angle (β)
= ø - tan -1( p / πD ) = ø - tan -1( p / πD )
= 4.35 - tan -1 ( 39 / π × 1436 ) = 3.854 Degree = 5.18 - tan -1 ( 26 / π × 572 ) = 4.35 Degree

Fig. 6 Maximum Allowable Fleet Angle

9.3 Where load swinging can occur due to the crane formula given below, however load amplifying factor
service, rope lead angles shall be set, or other provisions shall not be considered while calculating the rope
made, to minimize or eliminate the possibility of tension:
the rope skipping grooves on the hoist drums. When
designing hoist drums the following should be taken Fo = S × Zp
into consideration.
Where,
9.4 The minimum breaking load Fo of the rope intended S = maximum rope tension considering inclination
for a particular duty shall be determined from the of the rope in the upper most position; and

13
IS 3177 : 2020

Zp = minimum practical coefficient of utilization.

Value of Zp shall be obtained as given below:
Value to Zp

Group classification Hoisting Boom hoisting or luffing

of mechanism in Single-layer spooling Multi-layer spooling
accordance with
ISO 4301-1 : 1986 Standard Rotation- Standard Rotation- Standard Rotation-
rope resistant rope rope resistant rope rope resistant rope
M1 3.15 3.15 3.55 3.55 3.55 4.5
M2 3.35 3.35 3.55 3.55 3.55 4.5
M3 3.55 3.55 3.55 3.55 3.55 4.5
M4 4.0 4.0 4.0 4.0 4.0 4.5
M5 4.5 4.5 4.5 4.5 4.5 4.5
M6 5.6 5.6 5.6 5.6 5.6 5.6
M7 7.1 7.1 - - 7.1 -
M8 9.0 9.0 - - 9.0 -

9.5 Rope Drum

The diameter of the drum / sheave / equalizer measured 9.6 Strength of Rope Drum
at the axis of the rope shall be not less than the value
calculated as follows: Drums shall be designed to withstand the compressive
stress caused by the wound of wire rope, bending stress
Dd ≥ L × d × Crc due to beam action and torsional stress.

Where, All rope drum shall be checked against crushing stress

and permissible compressive stress at the groove when
Dd = Winding diameter on pulleys, drums or comp­ rope is wound on drum.
ensating pulleys measured at the axis of rope;
d = The nominal rope diameter; The rope drum which manufactured from E-250 grade
of IS 2062 or ASTM A 106 Gr. A or B material or any
L = Coefficient depending upon mechanism group. other equivalent standard, the minimum permissible
The minimum values of L, for drums, pulleys crushing stress will be 1100 kg/cm2 for M7 and
and equalizer pulleys, as per given Table 5; and M8 duty cranes and 1250 kg/cm2 for M1 to M6 duty
Crc = factor dependent on the construction of wire cranes.
rope.
If rope drum manufactured from E-350 grade of
For wire rope construction: IS 2062 than the minimum permissible crushing
stress will be 1 350 kg/cm2 for M7 and M8 duty cranes
a) 6 × 36 or 6 × 37 or compacted : Crc =1.0,
and 1 500 kg/cm2 for M1 to M6 duty cranes.
b) 6 × 24 : Crc =1.12
Normally, the rope drum is safe in bending and torsion
c) 6 × 19 : Crc =1.25
but longer rope drum should be checked against
Table 5 Value for L bending and torsion.
( Clause 9.5 ) The seamless pipe has more strength against fabricated
drum manufactured from steel plates. The grain
Mechanism Group Drums Sheave Equalizer
structures are in circumferential direction in seamless
M1 11.2 12.5 11.2 pipe, which is better for withstanding compressive
M2 12.5 14 12.5 stress. As compressive stress is the prime criteria in
M3 14 16 12.5 rope drum design.
M4 16 18 14 9.7 General
M5 18 20 14
Drums shall be designed for single layer of ropes
M6 20 22.4 16 only and can be designed with multilayer guided rope
M7 22.4 25 16 when agreed to between the manufacturer and the
M8 25 28 18 purchaser.

14
 IS 3177 : 2020

9.8 Length of the Drum 9.10 Grooving of the Drum

The drum shall be of such length that each lead of Rope drums shall have machined grooves and the
wire rope has a minimum of two full turns on the contour at the bottom of the grooves shall be circular
drum when hook is at its lowest position not taking over a minimum angle of 130°. The lead of the rope
into consideration the turns covered by the wire rope shall not exceed 5º ( 1 in 12 ) on either side of the helix
anchorage and one spare groove for each lead of the angle of the groove in the drum.
wire rope on the drum when hook is at its highest Grooving shall be finished smooth and shall be free
position. from surface defects likely to injure the wire rope. The
In the case where the drum flanges are not provided, edges between the grooves shall be rounded. The radius
a free length not less than 4 times to the diameter of of the groove shall be between 0.525d to 0.550 d (with
the wire rope or 100 mm dia whichever is more is to 0.537d as the optimum see Fig. 7) times the diameter
be provided beyond the last groove center line at the of the wire rope rounded off upwards to the nearest
anchorage point. 0.5 mm. The depth of the groove shall not be less than
0.35 (for crane duty upto M 5) or 0.4 (for crane duty
9.9 Flanges above M 5) times the diameter of the wire ropes for
The drums shall be flanged at one or both ends in the drum with single layer of the wire rope.
following conditions such as: The grooves of the drum shall be so pitched that there
a) For single flange drum, at the end where wire rope is a clearance between adjacent turns of the rope of not
is released. less than:
b) For drums having handed grooves at both ends if a) 1.5 mm for ropes up to and including 12 mm
wire ropes are released from the end of drums. diameter,
c) For multi-layer wire ropes at both ends. b) 2.5 mm for ropes above 12 mm diameter and
d) If required by the purchaser. including 28 mm diameter, and
c) 3.0 mm for ropes above 28 mm diameter.
Where provided, the flanges shall project above the
wire rope to a distance not less than 2 times of the wire The depth of the groove shall not be less than 0.2 times
rope diameter or 50 mm whichever is less beyond the the diameter of the wire rope for multiple layers of wire
wound rope. rope on the drum. The pitch of the grooves of the drum

Ød Ød

r
r

ØD1

KEY
Ød Nominal diameter of rope
h Depth of groove
p Pitch of groove
r Radius of groove
ØD1 Pitch Circle Diameter of rope drum

FIG. 7 DRUM GROOVE DESIGN

Fig. 7 Drum Groove Design

15

LONG TRAVEL CONDUCTORS

IS 3177 : 2020

shall not be less than 1.05 times the diameter of the utilize equalizer bars to provide two independent rope
wire rope for multiple layers of the wire rope on the systems, not equalizer sheaves. For increased rope life,
drum. consideration shall be given to using equalizer sheaves
9.11 Material for the Drum with the same diameter as the running sheave. The
diameter shall be selected from the below preferred
Drums shall be made of seamless pipe as per ASTM A values, 125, 160, 200, 250, 320, 400, 500, 560 and
106 GR A or B, cast iron of minimum Grade 25, cast 630 mm.
steel, rolled steel of welded construction and in case of
welded drum this should be stress relieved. 12 TRACK WHEELS
9.12 Rope Anchorage 12.1 General
The end of the wire rope shall be anchored to the drum All track wheels shall be double flanged. Incase of
in such a way that the anchorage is readily accessible. under slung crane bridge wheel and in single girder
Each wire rope shall have not less than two full turns on cross travel wheel may be of single flange.The wheel
the drums when the hook is at the lowest position not shall be made by roll forming, forging or casting from
taking into consideration the turns covered by the wire grades of steel appropriate to the forming process.
rope anchorage. The wheel can also be made from forged tyre shrunk
on cast steel, if agreed between the purchaser and the
10 SHEAVES
manufacturer. Bridge track wheels shall have either
10.1 The minimum pitch diameter of sheaves for all straight or tapered treads. The material of the wheels
crane class shall be selected based on formula given in shall be of grade C55Mn75 of IS 1570 (Part 1 and
9.5. Use the next larger size diameter for lead sheave. Part 2/Sec 2) or 42CrMo4 or equivalent. Bridge
Sheaves shall be enclosed by guards which fit close wheel loads (Pmax and Pmin) shall be determined with
to the flanges to prevent the ropes from coming out the maximum lifted load on the trolley, which shall
of the grooves. The material of the sheaves shall be be positioned at the closest working approach that
as per IS 1030. The bearing assembly in each sheaves produces the maximum wheel load. Trolley wheel
shall be individually lubricated. The fittings and grease loads shall be determined with the maximum lifted
lines shall be located so that they will be protected loads:
from damage. Where possible, upper sheave block Maximum lift load = (WT + WL + WA)
mountings shall be above the trolley deck. The upper
sheaves block shall be removable as a unit from the Where,
above. The diameter at the bottom of the groove may WT = Total weight of trolley including mast if any,
be selected from the preferred values that is, 125, 160,
200, 250, 320, 400, 500, 560, 630, 710, 800, 900, 1 000 WL = weight of the lifted load, and
and 1 120 mm. WA = Weight of lifting appliances if any.

10.2 Grooving 12.2 Wheel Hardness

Sheaves shall have machined groove. The contour The hardness of the wheel rim shall be maintained
at the bottom of the groove shall be circular over a between 300 and 350 BHN with minimum depth of 10
minimum angle of 130° and shall have an included mm. If hardness of the wheel rim more than 350 BHN is
angle of 45° to 60 ° proportional to fleet angle of rope. required, it shall be decided as per agreement between
The depth of the groove shall not be less than 1.5 times the purchaser and the crane supplier. The limiting
the diameter of the rope. The radius of the groove shall pressure value (PL) of wheel materials are mentioned
be between 0.525 to 0.550 times the diameter of the in Table 6 which is to be considered while selection of
wire rope rounded of upwards to the nearest 0.5 mm wheel diameter.
on higher side. In case, if crane wheels are to be manufactured from
alloy steel or high tensile steel and treated to ensure
11 EQUALIZER BARS OR SHEAVES very high surface hardness, the value of PL is limited
Where required, either an equalizer bar or sheave to that for the quality of the steel comprising the
will be acceptable. In either case the bar or sheaves wheel prior to surface treatment according to Table 6.
shall be positioned to be accessible from the floor of The higher value of wheel hardness will give better
the trolley and made in such manner that it can turn life however, would risk causing wear of the rail and
or swivel to align itself with the pull of the ropes. The possibility of crack generation during shock loads. The
minimum pitch diameter of equalizer sheaves shall be hardening of the wheel tread at the depth of 0.01 D
selected based on formula given in 9.5. Cranes having may be taken into account when selecting the value
hoists which handle hot metal or critical loads should of PL.

16
 IS 3177 : 2020

Table 6 Values of PL Table 7 (Value of c1 )

( Clauses 12.2 and 12.3 ) ( Clause 12.3 )

Ultimate Tensile Strength PL Minimum Wheel c1 Wheel c1 Wheel c1

for Metal Used For Rail Strength for Rotation Rotation Rotation
In N /mm2
Wheel N /mm2 the Rail, Speed in Speed In Speed in
in N /mm2 RPM RPM RPM
σr > 500 5.0 350 200 0.66 50 0.94 16 1.09
σr > 600 5.6 350 160 0.72 45 0.96 14 1.10
σr > 700 6.5 510 125 0.77 40 0.97 12.5 1.11
σr > 800 7.2 510 112 0.79 35.5 0.99 11.2 1.12
σr > 900 7.8 600 100 0.82 31.5 1.00 10 1.13
σr > 1 000 8.5 700 90 0.84 28 1.02 8 1.14
80 0.87 25 1.03 6.3 1.15
71 0.89 22.4 1.04 5.6 1.16
12.3 Diameter of the Wheels 63 0.91 20 1.06 5 1.17

Wheels may be either double flanged or flangeless with 56 0.92 18 1.07 — —

guide rollers.
The tread diameter of wheels shall be standardized to Table 8 ( Values of c2 )
sizes 160, 200, 250, 320, 400, 500, 630, 710, 800, 900, ( Clause 12.3 )
1 000, 1 120 and 1 250 mm. While doing selection of
the rail wheel, following points to be checked, Group Classification of Mechanism c2
a) It should be capable of withstanding the maximum M1 and M2 1.25
load to which it will be subjected. M3 and M4 1.12
b) It will allow the crane / trolley to perform its M5 1.00
normal duty without abnormal wear.
M6 0.90
The minimum diameters of wheel can be determined
M7 and M8 0.80
based on below formula:

Pmean
D ≥ ——————— 12.4 Determining the Mean Load
  PL × w × c1 × c2
In order to determine the mean loads, the procedure
and the maximum allowable load can be verified based is to consider the maximum and minimum loads with
on below formula. stood by the wheel in the loading cases considered,
that is, with the crane in normal duty but omitting the
Pmax ≤ 1.9 × PL × D × w dynamic factor
Where, The values of Pmean shall be determined by the following
formula and it is applicable for all cases of loading
D = Minimum wheel diameter, in mm; conditions mentioned in 7.3.2:
w = Useful width of rail, in mm;
PL = Limiting pressure of wheel depending on Pmean = ( Pmin + 2 Pmax ) / 3
wheel material, in N / mm2 as mentioned in Where, Pmin and Pmax depends on loading condition.
Table 6;
c1 = A coefficient depending on the speed of 12.5 Determination of Wheel Bearing Surface/
rotation of the wheel and are given in Table 7; Useful Width of Rail
c2 = A coefficient depending on the group a) Flat bearing surface : w = B – 2r
mechanism and given in Table 8; and b) Convex bearing surface : w = B – 4r/3
Pmean = The mean wheel load, in N.
where,
While calculating wheel load amplifying factor is not B = width of the rail, and
applied.
r = radius of the rounded corners of the side.

17
IS 3177 : 2020

12.6 Flanges 13.4 The design of all bumpers shall include safety
Dimensions of flanges for guiding tread wheels at the cables to prevent parts from dropping to the floor. For
base shall not be less than the values given in Table 9. computing bridge bumper energy, the trolley shall be
placed in the end approach which will produce the
Table 9 Minimum Flange Dimensions maximum end reaction from both bridge and trolley.
( Clause 12.6 ) This end reaction shall be used as the maximum weight
All dimensions in millimeters portion of the crane that can act on each bridge bumper.
The energy absorbing capacity of the bumper shall be
Sl Diameter of Wheels Depth of Thickness of based on power-off and shall not include the lifted load,
No. Flange Flange if free to swing. Bridge bumpers shall have a contact
(1) (2) (3) (4) surface of not less than 125 mm in diameter, be located
i) 160, 200, 250, 16 16 on the rail centreline and mounted to provide proper
clearance when bumpers of two cranes come together
ii) 315, 400, 500 20 20
and both are fully compressed. Where practical, they
iii) 630, 710, 800, 25 25 shall be mounted to provide for easy removal of bridge
iv) 900, 1 000 , 1 250 30 30 track wheels.
13.5 If required by the customer, buffer may be
12.7 Width of Tread designed at 0.7 times of the rated speed.
The width of the wheel tread shall be greater than the 14 SHAFTS
rail head by an amount which shall suitably allow for
the variations in the gantry rail alignment, gantry track 14.1 General
span dimensions and crane span dimensions. Hoist shafting design torque shall be based on the torque
12.8 Adhesion of the Drive Wheels required to lift the rated load plus hook block and/
or lifting beam and shall take account of mechanical
To eliminate slipping of the drive wheels of the travelling efficiencies. Design torque for all travel drives shall
mechanism of the crane or crab, the design shall be be based on 2 times the 60 min motor rating for series
checked for adhesion under the most unfavourable wound, constant potential d.c. drives, and 1.7 times
combination of loads producing maximum and the 60 min motor rating for a.c. motors and adjustable
minimum loads on the drive wheels. The co-efficient voltage d.c. drives without motor field weakening,
of adhesion (friction) shall be taken as 0.2 for dry rails or wheel slip at maximum wheel load (0.20 friction
and 0.15 for damp rails. factor), whichever is lower. Due consideration shall
be given to the maximum brake torque which can be
13 BUFFERS
applied to the drive. Axles or shafts which are provided
13.1 Provisions in the design of the runway and the with sleeve bearings are to be surface or case-hardened
design of the runway stops shall consider the energy and ground.
absorbing or storage device used in the crane bumper. 14.2 Shaft Material
The device may be non-linear (for example, hydraulic
bumpers) or a linear device, such as, a coil spring. All shafts shall be made of low alloy steel in addition to
Other types of buffers like hydraulic and resilient C 45 and axles shall have strength, rigidity and required
plastic buffers may also be used subject to agreement the bearing surfaces. All rigid shafts shall be supported
between the manufacturer and the purchaser. on two bearings. Angular deflection of the line shaft
at torque corresponding to 1.5 times the motor torque
13.2 Buffers shall have sufficient energy absorbing during the acceleration period shall not be more than
capacity to bring unloaded crane / trolley ( loaded crane 0.3° / m of shaft length. The drive for line shaft shall
in the case of stiff masted cranes ) to rest from a speed be mounted as close as practicable to the centre of the
of 50 percent of the rated speed at a deceleration rate span.
not exceeding 5 m/s2.
14.3 Stress Calculations
13.3 Between cranes or trolleys (if two trolleys are All shafting shall be designed to meet the stresses
located on one bridge) bumpers shall be capable of uncounted in actual operation. Due consideration shall
absorbing the energy from 70 percent of full load rated be given to the maximum torque which may be applied
speed of both cranes or trolleys travelling in opposite to the shaft. When significant stresses are produced
directions, or the energy from 100 percent of full load by the other forces, these forces shall be positioned
rated speed of either crane or trolley, whichever is the to provide the maximum stresses at the section under
greatest. consideration. Impact shall not be included wherein Cdf
value has been considered.

18
 IS 3177 : 2020

14.4 Fatigue Stress Check for Normal Operating bearing shall be arranged to allow for expansion or float
Conditions of the axle.
Any shafting subjected to fluctuating stresses, such as, 16.3 Lubrications
the bending or rotating shafts or the torsion in reversing
drives must be checked for fatigue. The bearing stress Provisions shall be made for the service lubrication of
must not exceed 50 percent of the minimum yield all the bearings unless sealed and lubricated for life.
strength for non-rotating shafting. Ball and roller bearings shall be lubricated before
assembly. Gear housings shall be split or designed to
15 PRESS FITS AND KEYS permit easy removal of the shaft. Gear reduction units
should be designed so that gears, shafts and bearings,
All gears, pinions and couplings shall be pressed and can be pre-assembled as a spare.
keyed and/or shrunk onto shafts. All press fits shall
be made in accordance with IS 2048. All keys and 16.4 Bearing Brackets and Housing
keyways shall be radiused and/or chamfered according Bearing brackets, if not integral with the frame, shall
to relevant Indian Standard. be mounted on a machined surface and be kept in
alignment by fitted bolts or other equally effective
16 BEARINGS
methods. When shafting is geared together the support
16.1 Anti-friction bearing shall be used throughout structure for all bearing cartridges should, where
except where specified otherwise or mutually agreed. practical, be integral and located as close as possible
Anti-friction bearing shall be self aligning spherical to the gears and pinions. Heavy caps shall be provided
roller for wheel and self aligning spherical roller/ taper with a means for lifting.
roller/ ball bearing for all gear boxes and cylindrical 17 GEARING
roller/ ball bearing for pulley as per duty class. Anti-
friction bearing shall be selected for minimum 10 years 17.1 Gearing Types
life. The minimum bearing life (in hours) as per their Gearing shall be spur, herring bone, helical as specified
class duty are mentioned below: in the IS 4460 (Part 1 to 3), IS 7504. No split gears
shall be used. As far as possible overhung gears should
Duty Class Minimum Bearing Life be avoided.
(in hours)
M1 1 250 17.2 Gearing Design
M2 1 250 Horsepower ratings for all spur and helical involute
gearing shall be based upon American Gear
M3 2 500
Manufacturers Association or IS 4460 (Part 1 to 3).
M4 6 300
17.3 Gear Design Loading
M5 10 000
Hoist gear loading for bending strength and pitting
M6 15 000
resistance shall be based on the torque required to lift the
M7 30 000 rated load plus hook block and/or lifting beam. Travel
M8 50 000 drive gear ratings for bending strength and pitting
resistance shall be based on 2 times the 60 min motor
Antifriction bearing to be checked for the static load to rating for series wound constant potential d.c. drives,
which it can be subjected under whichever of loading and 1.7 times the 60 min motor rating for a.c. motors.
cases I, II or III (see 7.3.2 ) is the most unfavourable. Due consideration shall be given to the maximum brake
Bearing selection in this specification is based on the torque which can be applied to the drive.
total number of cycles which it is expected the bearing
17.4 Dynamic Response
will undergo during the number of hours service the
crane will be used in a 10 year period. Where unusual drive arrangements are employed the
dynamic response of the system should be analyzed
16.2 All bearings selected shall meet the required to ensure that any additional loadings are identified
life at bearing load (at rated speed) based on bearing and mitigated for operational requirements and life
manufacturer. If the load on the bearing is essentially expectancy of crane.
constant, the bearings must meet a required life of
100 percent of the maximum load at rated speed. In 17.5 Drum Gear Alignment
some cases axle sizes establish bearing sizes. With The effects of trolley frame and rope drum deflections
wheel bearings of the antifriction type, one bearing on on the alignment of the hoist drum gear and pinion shall
each wheel axle shall be of the fixed type. The other be considered.

19
IS 3177 : 2020

18 MACHINING REQUIREMENTS OF GEARS and the boxes shall be oil tight. They shall be of rigid
construction and fitted with inspection covers and
18.1 Machining and Inspection lifting lugs, where necessary. The inspection covers
shall be so positioned that the first and second pinion
All gears shall be preferably 20º pressure angle full
shafts can be inspected. Minimum and maximum oil
depth tooth form and shall have a full root radius unless
level indicators and facilities for oil filling, oil drainage
this compromises other design considerations. The wall
and air breathing shall be provided. All gear boxes
thickness over the keyway of pinions shall be at least
shall be in totally enclosed construction. Teeth shall be
equal to the tooth depth and the rim thickness of gears
machine cut, suitably hardened and tempered and shall
shall be at least 1.2 times the tooth depth. Gears shall
conform to IS 4460 (Part 1 to 3) or AGMA. The surface
not have a shoulder or step left in the fillet area.
hardness of pinion shall be minimum 270 BHN and
18.2 All gears shall be hardened and machine cut that for gear shall be minimum 220 BHN. Difference
and may be profile ground. The gears shall confirm of hardness of pinion and gear shall not be less than 20
to relevant Indian Standards. The gearing shall be BHN (except for case carburized gears). The gear box
designed for a service life compatible with the service mounting shall be machine cut, seated and positively
life of the mechanism, the class of utilization and state located on machined surface. Material of the gear box
of loading used for the mechanism, and having regard housing shall be cast or fabricated. The fabricated gear
to the prime mover and brake. boxes shall be stress relieved before machining. The
internal surfaces of the gear box shall be painted with
19 GEAR BOXES oil resisting paint.

19.1 Material 19.7 If desired by purchaser, molten metal handling

crane, main hoist mechanism shall be provided with
All gears shall be of cast or wrought steel or forged planetary gearbox with dual drive system to facilitate
steel of low or medium carbon steel or alloy steel and uninterrupted operation without overloading of the
suitably heat treated and/or case carburized. hoist mechanism, so that the main hoist can be operated
19.2 All gears shall be completely enclosed in gear with one motor at half the rated speed when other motor
boxes which shall be attached to rigid supports. All fails.
gear boxes except for drum ring gears shall be oil-tight 19.8 Shaft mounted geared brake motor for travel drive
and sealed with compound or gaskets. The bottom of in CT and LT may also be used.
the gear boxes shall be split horizontally above the oil
level. Easily accessible drain plugs and breathers shall 20 CRANE LUBRICATION SYSTEM
be provided. Oil level dipsticks shall go directly into
the main body of gear box. 20.1 Following types of lubrication system may be
considered as per requirement:
19.3 Openings shall be provided in the top section
for the inspection of gearing at mesh lines. Gear box a) Point lubrication;
inspection cover plates should provide reliable sealing b) Semi centralized ( Bunched ) lubrication;
and be easily opened and re-sealed. c) Dual line centralized motorized lubrication
19.4 Splash oil lubrication of bearings may be used system;
unless otherwise specified. Oil pumps shall be used, if d) Dual line centralized lubrication system with
vertical gearing exceeds two reductions. On horizontal manual pump;
gearing, the oil level shall be above the smallest gear. e) Rail track lubrication system; and
Oil seals shall be sized to allow replacement with split f) Wire rope lubrication system.
seals. Through bolts should be used to hold the gear
cases together and to mount the gear box to its base. All lubrication lines shall be suitably located to prevent
All gear cases shall be mounted on machined surfaces. any mechanical damage.
Shims shall not be used.
20.2 Provisions shall be made for lubricating all
19.5 Gear box seats shall be of sufficient size to allow bearings unless sealed or lubricated for life, mating
the installation of shear blocks to locate the gear box gears and chain and sprockets arrangements, where
positively. Gear boxes shall be provided with lifting necessary easy access shall be provided.
lugs that are suitable for use in lifting the whole gear
case assembly without tilting. 21 LINE SHAFTING AND COUPLINGS

19.6 All pair of gearboxes shall be preferably helical, 21.1 Floating Shaft
except for planetary portion of gearboxes shall be
spur. The gears shall be automatically splash /forced Where possible, the flexible halves of half flexible
oil lubricated. The gears shall be readily removable couplings shall be mounted on the floating shaft.

20
 IS 3177 : 2020

Couplings shall be located close to the bearings and be 23 OPERATOR’S CABIN

provided with substantial removable guards which shall
extend beyond the ends of the hubs and overlap with 23.1 Type and Location
the coupling hub outer diameter. Where half-flexible Based on purchaser’s requirement, the operator’s
couplings are used, the couplings shall be located close cabin may be of the fixed / moving type, open / enclosed
to the bearing on the end track and the adjacent line type.
shaft bearing shall not be closed than 1 250 mm.
23.2 Structure
21.2 The load shall be transmitted between couplings
half by means of fitted bolts. For shaft speed below 400 The cabin shall be rigidly built of structural steel and
rpm, the following maximum bearing spacing shall be fire proof material for molten metal crane and shall
permitted: be braced to prevent movement between cabin and
supporting members. It shall be supported by rivets or
a) 3.5 m for 75 mm diameter;
bolts in shear. The head room of the cabin shall not be
b) 4.25 m for 90 mm diameter; less than 2 m.
c) 4.5 m for 100 mm diameter; and
23.2.1 Driver’s Cabin
d) 4.85 m for 115 mm diameter .
21.3 For shaft speed in excess of 400 rpm, the above 23.2.2 Driver’s Visibility
spacing shall be reduced as necessary to avoid harmonic Driver’s cabin shall be designed so that the driver has a
vibrations. Supports for motor and gear reduction units clear view of all working areas.
shall be welded structural steel, rigidly connected to
the crane girder. Bolts for fastening bearing brackets, 23.2.3 Cabin Dispositions
motors and gear reduction unit shall be accessible from The driver’s cabin shall have sufficient room for the
above the foot walk. Angular deflection of bridge line driver to be able to reach or leave the controls without
shafts at torque shall not exceed 0.3°/m of shaft length. hindrance. Controls shall preferably be operated from
a sitting position, but also from a standing, when
21.4 For connection between the hoist gear box and
necessary.
rope drum the following options may be considered as
required: 23.2.3.1 Driver’s cabin shall have a minimum head
a) Built in geared coupling; room of 2 m and shall be fitted with a guardrail of at
b) Barrel coupling; and least 1.0 m high.
c) Any other suitable flexible transmission system as a) A protective shield shall be installed above the
per requirement of the purchaser or design. driver’s cabin when there is any danger of falling
object.
22 RAILS b) The layout of the cabin and controls shall be
ergonomically designed.
22.1 Rail shall be as per IS 3443 or equivalent,
rectangular bar or square bar of weldable steel (of high 23.2.4 Heat Insulated Material (For Molten Metal
tensile steel) may also be used depending on capacity Handling Crane, if Required by Purchaser)
and duty of crane. Rail joint shall be secured by The structural frame work of the driver’s cabin shall
clamping or welding. be non-combustible material, and the side panels and
22.1.1 Joints on trolley rail shall be clamped /welded roof may optionally be of fire resistance materials. The
/ made by using standard joint bars. There shall be no floor of the driver’s cabin shall be covered with non-
bolt holes adjacent to the welded joint. metallic, heat-insulating material.

22.2 For box girders, rails shall be fastened in place 23.2.5 Glazed Windows and Entrances
by suitable clamps or square / rectangular bars can be Entrances shall be protected against accidental opening
welded to top of girder. Suitable wear plate may be sliding doors and out ward opening doors of driver’s
provided below rail so as to avoid wear and tear or cabin must lead on the landing. The drivers cabin’s
girder top flange, if agreed between the manufacturer windows shall be provided with suitable safety glass to
and the purchaser. avoid the risk of breakage.
22.2.1 The rail clamping may be of soft mounting 23.2.6 Anti-glare Lighting and Heating
system consist of pad and clips, if agreed between
manufacturer and purchaser in lieu of standard steel rail Driver’s cabin shall be provided with adequate anti-
clamps. The clamps shall be spaced at not more than glare lighting to allow handling of the controls and, if
900 mm between centres. necessary, may be ventilated.

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IS 3177 : 2020

23.2.7 Heat-proof 23.10 The cabin shall have a robust seat with a fixed
Driver’s cabin which are exposed to radiant heat shall or hinged or swivelling base and a durable upholstered
be protected heat radiation, and of a heat proof design, squab. The seat shall be capable of withstanding severe
and if required by the purchaser air-conditioned may be braking force.
provided to ensure tolerable working conditions.
24 GANGWAYS AND PLATFORMS
23.2.8 Following shall be provided at the appropriate
location: 24.1 Cabin Access
a) Emergency stop and reset device; 24.1.1 Easy and safe access to the driver’s cabin
b) Electrically operated audio warning device, must possible in any position under normal working
audible at minimum distance of 30 m; and conditions.
c) Adequate illumination. 24.1.2 The driver’s cabin shall be fitted with suitable
23.3 In ladle cranes, other cranes handling hot materials emergency exit.
and outdoor cranes, cabins shall be totally enclosed, 24.1.3 Entry to the driver’s cabin should be preferably
unless otherwise specified. from a platform at the same level as the floor of the
23.4 The cabin of outdoor cranes shall be weather proof. cabin and provided with guard rails.
If the cabins are fitted with opening windows, these 24.2 Access to Gang Ways, Stair Ways and Platforms
shall be hinged or made to slide as per manufacturer’s
standard practise. If special vision panels are provided Gangways, stair ways and platforms must have safe
in the floor, they shall be suitably guarded. Arrangement access in any position.
shall be made to ensure that the whole exterior of the 24.3 Maintenance Areas
cabin glazing can be safely cleaned. Glasses shall be
mounted with proper rubber seals/ beadings and shall All operating locations and all equipment of the crane
be able to with stand vibration. All glazing shall be which requires regular inspection or maintenance must
toughened plate glass of 6 mm minimum thickness be provided with safe access. Arrangement shall be
conforming to IS 2553 (Part 1) and shall be installed provided to ensure that whole exterior of the cabin
from inside. Heat shield shall be provided below the glass shall be safely cleaned without any additional
cabin of hot metal handling crane. scaffolding.

23.5 Cabin Access 24.3.1 Head Room

Access to open cabins via rung ladder or staircase from Stair ways, gang ways and platforms shall have a head
walkway, the entrance to the cabin shall be fitted with room of not less than 2 m and clear passage way of not
a door located for safe access. The cabin floor shall be less than 600 mm wide must be provided.
extended outside the cabin on the side containing the 24.3.2 Guard Rail
door, and if necessary, sideways also to form a platform
unless otherwise required. Suitable hand railing should Guard rails shall be not less than 1 m height and shall
be provided on the platform. be provided with toe guards and intermediate rails.

23.6 Accessibility to the bridge platform shall be 24.3.3 Slip-proof Surfaces

through the stairs. However, in case of space constraints Platform surfaces shall be suitably slip-proof. Holes,
ladders may be provided, if required. gaps and openings in the flooring shall be restricted in
size so that a 20 mm diameter ball can’t pass through.
23.7 Visibility and Field of Vision
Cabins shall be so designed that under all operating 24.3.4 Power Line Protections
conditions the field of vision of the driver is adequate. When gang ways are located adjacent to power lines,
these lines must be protected against accidental contact.
23.8 Lighting, Heating, Ventilation and Air-
conditioning 25 GUARDING
Fixed service lighting shall be installed to provide glare
free illumination in the crane cabin. All cabins shall be 25.1 All gear wheels, pinions and chain drives shall be
provided with an air circulating fan of minimum sweep totally enclosed. Effective guards shall be provided for
400 mm. All air-conditioned cabins shall be fitted with revolving shafts and couplings. Long travel cross-shafts
a suitable hydraulic door closer and temp in the cabin and couplings above the top platform shall be guarded
shall be around 25ºC. wherever necessary. The sheaves of hook blocks shall
be guarded to prevent the trapping of a hand between
23.9 A suitable carbon dioxide (CO2) type fire a sheave and the in-running rope and shall be enclosed
extinguisher shall also be provided. except for rope opening.

22
 IS 3177 : 2020

25.2 Safety features in hook blocks, pulleys and other However, for all outdoor goliath and semi-goliath
load carrying devices. cranes, this facility shall be provided.
25.2.1 Prevent to Jumping 28.2 All cranes shall be provided with jack pad on both
Adequate means shall be provided to prevent the rope end carriages and trolley structures in such a way so
from jumping of the pulleys. as to facilitate removal of wheels, wheel bogie and
compensating bogie.
25.2.2 Hand Guard
29 BRIDGE AND TROLLEY DRIVES
An adequate guard shall be provided where there is any
danger of a hand being trapped between the rope and 29.1 Bridge and trolley drives arrangements may cover
the pulley of the hook block. most types of crane drives regardless of the number of
25.2.3 Maintenance wheels.
Rope pulleys shall be designed so as to be accessible 29.2 Bridge and Trolley Drive
for maintenance. Bridge and trolley drive may consist of one of the
25.2.4 Working Load Name Plate following typical arrangements (see Fig. 8) and these
arrangements cover most four or eight wheel crane
Inter changeable load carrying devices, such as, grabs, drives:
lifting magnets, tongs and lifting beams shall be
permanently marked with their safe working load and 29.3 A1 Drive
dead weight and also, in case of grabs and buckets their The motor is located near the centre of the bridge/
capacity and name of manufactures. trolley and connected to a self-contained gear reduction
unit located near the centre of the bridge/trolley. Output
26 WEATHER PROTECTION
of the gear reduction shall be connected directly to
For outdoor cranes, all electrical equipment shall be the track wheel axle by means of suitable shafts and
adequately protected from weather. All weather proof couplings.
covers shall be easily removable.
29.4 A2 Drive
27 PAINTING The motor is connected to a self contained gear
reduction unit located near the centre of the bridge/
27.1 Before dispatch of the crane, the complete crane trolley. The track wheels shall be driven through gears
covering structural, mechanical and electrical parts pressed and keyed on their axles or by gears fastened
shall be thoroughly cleaned of all dirt, grease, scale to, or integral with, the track wheels and with pinions
and rust by shot blasting or chemical cleaning methods. mounted on the end section of the cross-shaft. The
Suitable number of coats of primer shall be given to end sections of the cross-shaft shall be connected by
all parts exposed to the weathering effects and if are suitable couplings.
not already treated earlier or effectively lubricated. At
least two additional finishing coats of paint for indoor 29.5 A3 Drive
cranes/outdoor cranes of colour of customer’s choice The motor is located at the centre of the bridge/trolley
shall be given on all primer painted surfaces. and is connected to the cross-shaft and gear reduction
27.2 All moving parts up to the height of 5.0 m from units with suitable coupling. Self-contained gear
working level or ground shall be painted in ‘Golden reduction units located near each end of the bridge/
Yellow’ colour. The bright exposed parts of the crane trolley shall be either directly connected to the wheel
shall be given one coat of rust inhibitor. Interior of all axle extension or connected to wheel axles by means of
gear boxes shall be painted with one coat of oil resisting shafts in the suitable couplings.
paint. Areas that are inaccessible after assembly or 29.6 A4 Drive
erection shall be treated before assembly or erection.
The motors are located near each end of the bridge/
27.3 Where the cranes are supplied for use in abnormal trolley without torque shafts. The motors shall be
working conditions special protection may be necessary. connected to self-contained gear reduction units.
Any additional requirements regarding painting shall be The gear reduction unit shall be applied to the
as agreed between the purchaser and the manufacturer. track wheels by means of both suitable shafts and
couplings or directly mounted to the wheel axle
28 HANDLING FACILITIES shaft extension. Another variation of this drive
would separate the high speed and final reductions
28.1 Suitable structure at all four corners for handling by locating the motors near each end of the bridge
the track wheels shall be provided for outdoor cranes. without torque shafts.

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IS 3177 : 2020

A 1 DRIVE

℄ CRANE

A 2 DRIVE

℄ CRANE

A 3 DRIVE

℄ CRANE

A 4 DRIVE

℄ CRANE

A 5 DRIVE

℄ CRANE

A 6 DRIVE

℄ CRANE
A7 DRIVE

Note - Other arrangement may also be considered if required.

FIG. 8 TYPICAL ARRANGEMENT OF BRIDGE AND TROLLY DRIVE

Fig. 8 Typical Arrangement of Bridge and Trolly Drive

29.7 A5 Drive 29.8 A6 Drive

The motor is located near the centre of the bridge/ The motors are located near each end of the bridge/
trolley and is connected to a self-contained gear trolley and connected with a torque shaft. On the drive
reduction unit located near centre of the bridge/trolley. end, the motors shall be connected to self-contained
This reduction unit shall be connected by sections of gear reduction units by suitable couplings. The output
cross-shaft having suitable couplings to self-contained of the gear reduction units shall be connected directly
gear reduction units located near each end of the crane, to the track wheel axle by means of suitable shafts and
and these in turn connected to track wheel axle by couplings.
means of shafts with suitable coupling.

24
 IS 3177 : 2020

29.9 A7 Drive 34 DRAWINGS AND DOCUMENTS

The geared brake motors are mounted on the wheel Depending on the extent of agreement with purchaser,
shaft with torque arm to transmit the torque to the following drawings and documents shall be submitted
driving wheel. This arrangement is an alternative of A4 for approval of the purchase before manufacturing of
drive (see 29.6) which is compact and ensure life time the crane:
alignment of the drive.
a) GA drawings of the crane;
29.10 Percentage of driving wheels may be 16.66, 25, b) GA drawings of crab/trolley;
33.33, 50 or 100 depending on the requirement. While c) GA drawings of individual mechanisms;
selecting the percentage of driving wheels, it shall be
ensured that there is no skidding. d) Drawings of bridge, end girder and their
connection;
30 TORSIONAL, DEFLECTION AND e) Sub-assembly drawing for wheels, hook blocks
VIBRATION and hoist drums;
Natural frequency and amplitude of total torsional f) Calculation for selection of motor, reducer, brake,
deflection of the drive system should be determined. couplings, etc.;
Low frequencies and large total torsional deflections g) Layout of cabin showing the location and fixing of
are undesirable for crane operation. all the equipment inside it;
h) Lubrication arrangement for the complete crane;
31 MOTION LIMITING DEVICES and
Positively operated hoisting motion limiting devices j) Quality assurance plan for inspection
shall be provided that stops the upward and downward
motion when predetermined level is reached to prevent
over winding or over unwinding. Pre-limit switch shall
SECTION 3 ELECTRICAL
also be provided for slowing down before the final
limits are actuated wherever control system permits EQUIPMENT
variable speed.
35 POWER SUPPLY
NOTE ― The limiting device shall be regarded as a safety
feature and not as a routine operational means of stopping. 35.1 General
Where normal operation of the crane necessitates frequent
approach to the upward limit, an additional motion limiting This standard deals with a.c. low voltage systems up
device shall be provided that operates independently and to 1 000 V. The power supply system should comply
require manual settings. with relevant Indian Standards. Voltage variation at the
point of supply to crane DSL system be limited to ±
32 CROSS TRAVEL AND LONG TRAVEL
5 percent of the rated voltage under normal operating
LIMITING DEVICES
conditions. The end user shall ensure this with respect
The limiting devices shall prevent the following to number of cranes in the bay with dedicated feeding
conditions: transformer or feeder, etc. For applications with very
a) Over traversing and over travelling, or long cabling distances it may be necessary to limit the
voltage variation further. The allowed voltage drop
b) Collision where two or more crane/trolleys (percent) in the different parts of the power supply need
operating on the same track/ different track at to be considered case by case. The type of the power
different level in the same bay (if specified). supply grounding may have significant effects on the
Pre-limit switch shall also be provided for slowing requirements of the crane electrification. The type
down before the final limits are actuated wherever should always be as agreed to between the purchaser
control system permits variable speed. and the supplier. For cranes with incoming power
requirement higher than 1 000 kVA, for example,
33 LOAD LIMITING DEVICES ladle crane, the system voltage should be designed
preferably at 415/ 690 V a.c. in order to optimize the
Load limiting devices are recommended, if weights sizes of conductor, cables , motors and controls.
of objects to be lifted are not known accurately. When
fitted, they shall sense the load on the crane by means 35.2 DSL Systems and Accessories for Cranes
other than the current consumed by the hoist motor. If
the load lifted is more than SWL, load limiting devices 35.2.1 General
shall stop further hoisting operation till the load is Down shop lead arrangement using GI, copper,
removed or reduced. If required by purchaser, load aluminum or steel sections with or without shrouding
indication may be suitably provided. This arrangement or by using flexible trailing cable arrangement or with
is to be provided, if specifically asked by purchaser. drag chain/cable reeling drum may be used.

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IS 3177 : 2020

35.2.2 Conductors an “X”, plus basic loads for auxiliary load are added
Current conductor system or DSL system shall be together i.e. IDA = Ʃ ID + Ʃ IG
provided either by the purchaser or by the crane Current rating of runway conductor = Total load current
manufacturer as agreed by them. Cranes operating on as per Table 12 X fED × fD
bare conductors shall be equipped with suitable guards
to prevent ropes or suspended load coming in contact The selected current rating of the runway conductor
with the live conductors due to swing of the hook may be derated by the temperature correction factor as
block. Down-shop conductors also shall be screened per the manufacturer as applicable.
to prevent contact while handling long lengths of NOTES
conducting materials from floor. 1 In this clause, the rated current (IN) should be considered
not necessarily to mean the name plate current of the motor
35.2.3 Current Collectors but the current drawn by the motor at full rated load (that is,
FLC corresponding to mechanical kW at rated ambient and
Unless otherwise agreed to, all collector assembly shall duty) .
be supplied by the crane manufacturer. The purchaser 2 When squirrel cage motor is operated by variable voltage
shall furnish relevant details depending upon the variable frequency converter, the full load current drawn from
manufacturer’s scope of work. Collector rollers or shoes supply source by VFD line current should be considered for
shall be so designed as to minimize/avoid sparking, sizing of runway conductor
shall be spring loaded/gravity type and shall be easily
35.3 Cross Travel Current Collecting System
replaceable. Collector assembly shall be mounted on a
rigid structure on the crane bridge. Necessary safe and 35.3.1 General
convenient access shall be provided for maintenance
or replacement of the collectors. Minimum two current Cross travel current collecting system shall be with
collectors shall be provided per trolley line. Each bare conductors or with shrouded conductors or
collector shall be of 100 percent rating of crane total with trailing cable arrangement or with cable drag
current load. chain. The collection system shall be provided by the
manufacturer.
35.2.4 Rating and size of DSL / Runway Conductor
35.3.2 Conductors
The total ampere load is determined with full load
currents reduced by load diversity factor and duty cycle Cross travel conductors for the main trolley shall be
factor given in Table 10 and Table 11 respectively. The mounted on the main bridge platform and not inside
total ampere load shall be considered as per Table 12. the main girders. Conductors for auxiliary crabs shall
After determination of the sequence of the motors with be mounted suitably above the level of auxiliary trolley
the largest output (ID), the amperages marked with rails. Cross travel conductors shall be arranged so that

Table 10 Load Diversity Factor fD

( Clause 35.2.4 )

Sl Duty Class Diversity Diversity Diversity Diversity Drive Drive Drive

No. Factor for 1 Factor for 2 Factor for 3 Factor for 4 Diversity Diversity Diversity
Crane Cranes Cranes Cranes Factor for 5 Factor for 6 Factor for 7
Cranes Cranes Cranes and
More
(1) (2) (3) (4) (5) (6) (7) (8) (9)
i) M6, M7, M8 1.0 0.95 0.91 0.87 0.84 0.81 0.78
ii) M5 0.7 0.8 0.65 0.5 0.5 0.5 0.5
iii) M1 to M4 0.5 0.7 0.5 0.4 0.4 0.4 0.4
NOTE ― In case the cranes are of different duty classes, then diversity factor of higher duty class shall be considered.

Table 11 Duty Cycle Factor fED

( Clause 35.2.4 )

Duty Cycle Factor (fED)

Running period ED 20 percent 30 percent 40 percent 50 percent 60 percent 80 percent 100 percent
Reduction Factor fED 0.45 0.54 0.63 0.71 0.78 0.89 1

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 IS 3177 : 2020

Table 12 Equivalent Continuous Current of DSL

( Clause 35.2.4 )

No. of Cranes
1 2 3 4 5
FLC of FLC of FLC of FLC of FLC of
Largest Largest Largest Largest Largest
Summation of
Motor Motor Motor Motor Motor

Aux. load

Aux. load

Aux. load

Aux. load
load current

Aux.load
2nd largest

2nd largest

2nd largest

2nd largest

2nd largest
1st largest

1st largest

1st largest

1st largest
1st largest

∑ X X X n.a n.a n.a n.a n.a n.a n.a n.a n.a n.a n.a n.a
∑ X X X X X X n.a n.a n.a n.a n.a n.a n.a n.a n.a
∑ X X X X X X X X X n.a n.a n.a n.a n.a n.a
∑ X X X X X X X X X X X X n.a n.a n.a
∑ X X X X X X X X X X X X X X X
X Applicable
n.a not applicable
NOTES
1 With double drives corresponding to 2 X ID , lifting magnet and hoisting unit are counted as one joint drive.
2 Aux. load such as lighting, A.C, magnet, rotating trolley, brakes etc. as applicable
3 For multiple motors on single crane or hoist, the minimum current rating of power supply conductors shall be the full load ampere
rating of the first largest motor or group of motors for any single crane motion, plus current rating of second largest motor or group
of motors operating simultaneously with the first largest motor or group of motors.

they are all accessible for maintenance from at least one effectively earthed through a fourth lead or through a
side along the whole length. Bare conductors mounted set of collectors sliding on the gantry rail with reference
on the bridge adjacent to a walk way along the bridge to IS 3043.The purchaser shall arrange for the earthing
shall be completely screened from the walkway. of the gantry and/or the long travel earth conductor.
35.3.3 Collector Assembly 35.4.2 Control Circuit Earthing
Collector assembly shall be rigidly mounted on One end of the secondary winding of control circuit
the trolley and shall be provided with reasonable transformer shall be earthed. One end of the coil of all
accessibility to all parts for maintenance purpose. relays and contactors shall be connected to earth side of
35.4 Earthing the control circuit supply and this connection shall not
be interrupted by any fuse or contact. In the case of d.c.
35.4.1 General control circuits one pole of the rectifier shall be earthed.
The crane structure, motor frames, and metal cases 35.4.3 Magnet Earthing
of all electrical equipment including metal conduit or
cable guards shall be effectively connected to earth The magnet frame shall be bonded to the trolley by
complying with Indian Electricity Rules,1956 (see IS the earth connection via the magnet lead, the magnet
3043). Preferably a ring earthing system to be provided coupling, the magnet cable and an extra slip-ring on the
on the crane. Each and every electrical equipment shall cable drum.
be connected to this earthing ring atleast at two points. A 35.5 Conductor Bars, Cable Reels and Flexible
flexible metallic tube or duct may not form an effective Cables
earth connection. The crane wheels shall not be used
as means of earthing. Where the crane is connected to The following five important considerations shall be
the supply by flexible cord or flexible cable, the crane taken into account in dimensioning insulated wires or
shall be connected to earth by means of a separate cables:
earthing conductor enclosed with the current carrying a) Temperature rise in normal condition;
conductors. Travelling cranes connected to the supply b) Temperature rise in faulty operation and on short-
through collectors (minimum two numbers) shall be circuit;

27
IS 3177 : 2020

c) Voltage drop; b) Where the over current protective device is

d) Cable grouping; and intended to provide overload protection, the
following relationships shall exist:
e) Motor full load current.
Ib < In < Iz
35.5.1 The following clauses in IS 16504 (Part 32)
define the basic requirements: I2 < 1.45 × Iz
a) Flexible cable (see 13.7);
Where,
b) Collector wires, collector bars and slip ring
assemblies (see 13.8); and I2 is the minimum current, that when maintained
for 1 h will cause the protective device to open the
c) Connections to cranes and between moving parts
circuit, in A.
of the crane (see 14.4.3).
c) Where the over current protective device is
According to IS 16504 (Part 32), wherever collector intended only to provide short circuit protection:
wires, conductor bars and slip-ring assemblies are In may be greater than Iz , and
installed as part of the protective bonding circuit, they
shall not carry current in normal operation. Therefore, I2 may be greater than 1.45 Iz
the protective conductor (PE) and the neutral conductor However, it should be remembered that the higher In is in
(N) shall each use a separate collector wire, collector bar relation to Iz , the greater is the possibility of exceeding
or slip-ring. The continuity of the protective conductor the ultimate short-circuit conductor temperature in
circuit using sliding contacts shall be ensured by taking the event of a short circuit. That is particularly true
appropriate measures (for example, duplication of the in the case of the smaller conductors ranging in size up
current collector, continuity monitoring). The continuity to 16 mm2.
of any protective bonding connection with sliding
contacts shall be ensured for example, by duplication 35.6.3 Short Circuit Protection of Conductors
of the current collector (one set). Additionally, when The conditions to be met for short circuit protection is:
sliding contacts are used to supply power to electronic
drives, double collectors should be used to avoid noise t xI
and hardware failures which may occur, if a contact CS =
k
cuts off momentarily (2 sets of current collectors).
35.6 Calculation of Cross-Section of Conductors Where,
CS = conductor cross section, in mm2;
35.6.1 These requirements apply both to the power
supply to the crane and also to cabling within the crane. t = switch off time for protection against hazardous
In general the selection of cable/conductors depend on shock currents shall be decided based on
the following: tripping time of protective device selected;
a) General operating conditions; I = effective short circuit current at fault point in
amperes expressed for a.c. as the rms.; and
b) Ambient air temperature;
K = factor for conductor [Amp × sec / mm2 ] when
c) Methods of installation; insulated with the following material,
d) Grouping; and = 76 for PVC insulated aluminium conductors.
e) Intermittent duty applications. = 115 for PVC insulated copper conductors.
35.6.2 Co-ordination Between Conductors and = 141 for Rubber insulated copper conductors.
Protective Devices = 132 for SiR insulated copper conductors.
a) In all cases, the following relationships shall exist: = 143 for XLPE insulated copper conductors.
Ib < In = 143 for EPR insulated copper conductors.

Ib < Iz 35.6.4 Calculation of the Cross-section in Relation to

the Admissible Voltage Drop
Where,
The voltage drop must be considered, paying attention
Ib = steady state design current; to the fluctuation and the voltage drop within the
In = nominal current or current setting of the over power supply. For very long supply lines, not only
current protective device, in A ; and the resistive but also the inductive part of the supply
Iz = effective current carrying capacity of a cable impedance need to be taken into account. Drop due to
for continuous service under the particular reactance should also be checked. The cross-section
installation conditions concerned in it, in A. of the conductors should be determined by taking

28
 IS 3177 : 2020

into account the mechanical strength required and NOTES:

the electrical load to be carried. Looping cable may 1) In this clause, the rated current (IN) should be considered not
be provided in parallel after checking the limit of necessarily to mean the nameplate current of the motor but the
voltage drop. When calculating the voltage drop, the current drawn by the motor at full rated load.
most unfavourable position of the hoisting appliance in 2) In case number of motors (n)>1 are driven in parallel,
consider: IN = n × IN (IN = current drawn by the motor at full
relation to the supply point must be considered.
load).
The voltage drop shall be limited to 3 percent on DSL 3) In case two or more hoisting appliances are working together,
and 2 percent on the crane (from current collector to they should be handled as one by using the sum current of each
motor terminals). The conductor size and/or number of joint motion.
feed points should be increased or even booster cables 4) In case the power supply also feeds other (continuous)
should be used in parallel to runway conductors in case loads such as lighting, hydraulic pumps, lifting magnets, AC
the voltage drop is exceeding the limit value. in e-room or other cranes, the current drawn by these devices
need to be taken into account.
Unless otherwise specified the maximum current
density shall not exceed 0.42 A/mm2 for rolled steel 36 CABLES AND CONDUCTORS
sections. The size of shrouded conductor, copper /
aluminum headed conductor/GI conductor type DSL, 36.1 General
the current rating as per manufacturer shall be followed. Cables used for crane wiring shall comply with relevant
Indian Standard. Unless otherwise agreed, only copper
35.6.5 For a three phase power supply, the required or aluminum cables shall be used for power wiring and
minimum cross-section (CS1) of conductor can be only copper cables shall be used for control wiring.
calculated with the formula: Single strand cables shall not be used where cable cross
   √3 × l × Itot × cos φ mm2 sectional area is more than 6 mm2. Festoon or rubber
CS1 = —————————— cable with low capacitance values are recommended
for cranes using ac VFD.
Δu × K
36.2 Minimum Size
Where,
While selecting cables consideration shall be given
l = effective length of the line, in m;
to factors like ambient temperature, grouping and
I tot = sum of the above calculated (ID and IN) disposition of cables, and the limitation of the voltage
currents, in A; drop. The cables selection, testing shall be as per
Δu = admissible voltage drop, in V; IS 694, IS 1554 (Part 1 and Part 2), IS 9968 (Part 1 and
k = electric conductivity, in [Ω × mm2 × m-1]-1; and Part 2) and IS 7098 (Part 1).
cos φ = power factor. Conductors for power wiring/control circuits to electric
motors shall have a sectional area not less than the
Calculation for voltage drop (for reference purpose):
values given below of copper or equivalent material:
Δu = √ 3 × I tot × l × Z a) [2.5 mm2 for Power] and [1.5 mm2 for control
Where, wire] should be up to M5 class.
I tot = Net current load on DSL, b) [4.0 mm2 for Power] and [2.5 mm2 for control
wire] should be M6 class and above.
l = Effective length depending upon number and
arrangement of feed points, c) For instrumentation cables shall be minimum 0.75
mm2.
Z = Impedance = (Rcosφ + Xsinφ)(Ω/m),
R = resistance of the DSL conductor, and 36.3 Protection
X = Impedence of the DSL conductor. All cables shall be adequately protected against
mechanical damages as given below:
35.6.6 Calculation of the Minimum Cross-section in
a) By running in conduits complying with relevant
Relation to the Thermal Capacity of the Conductors
Indian Standards, trunking or on trays with top
When calculating the cross-section for the conductor cover;
bar, which supplies several hoisting appliances, the b) By being clipped to the crane structure in a
actual simultaneous operation of the drive motors must position where they are protected from mechanical
be taken into account. damage; and
The maximum allowed conductor temperature shall not c) By being of armoured construction.
be exceeded during normal operation. Conductor cross-
section should be selected according to manufacturers’ If cables are drawn into a steel tube, the tube shall be
specifications. medium gauge welded or solid drawn or screw jointed.

29
IS 3177 : 2020

For outdoor cranes except where flexible unarmoured ingress or collection of water or oil in any part of a
cables are essential, cables shall be either armoured or conduit or trunking system. For three phase a.c.
enclosed throughout their length in galvanized trunking power cables, if single core cables are used due to size
or conduit. Taped and braided varnished cambric limitations, efforts shall be made to lay the cables in
insulated cables shall not be used for outdoor cranes. trefoil formation.
36.4 Current Rating 36.6 Termination
The current rating of the cable given in the relevant Where trunking is used it shall extend into the electrical
Indian standard / declared by cable manufacturer is compartment or enclosed units. It shall be terminated
for continuous duty. As the cranes are operating with as close as practicable to motors, collector gears and
intermittent duty motors, the continuous rating of cable controllers. Junction boxes shall be rigidly fixed to
shall be up-rated by intermittent duty factor. the crane structure close to the end of the trunking.
The operative rating of the cable shall be computed Conducting systems shall be continuous to switch boxes
giving due consideration of ambient temperature, and conduit outlets. Cable tails shall be adequately
grouping and disposition of cable and intermittent duty insulated and mechanically protected.
factor.
37 ELECTRICAL PROTECTIVE AND SAFETY
Irequired = Iequipment / (C1 × C2 × C3) EQUIPMENT

Where, 37.1 Protective Equipment

C1 = Ambient temperature correction factor 37.1.1 General
(recommended by cable manufacturer);
Suitably located efficient means shall be provided to
C2 = Group rating factor (recommended by cable protect every part of a system from excess current
manufacturer); and and voltage to prevent danger or damage. Enclosures
C3 = 10/√CDF for intermittent duty rated motor having minimum degree of protection IP 52 (except for
(25 percent, 40 percent, 60 percent etc. inside e-room panels with minimum IP 42 enclosure or
= 1.7 for 1/2 h rated motor IP 00 open execution with protective cover, hand rail
= 1.4 for 1 h rated motor to prevent accidental contact) shall be provided for all
electrical equipment except for motors, transformers
36.5 Installation and resistors.
36.5.1 The cable and wiring system for each motion 37.1.2 Main Isolating Switches
shall be independent and common return shall be
avoided. Main cables and control cables shall be 37.1.2.1 Main switches used for isolating shall comply
effectively separated wherever possible. Cables shall as per relevant Indian Standard. The main metal-clad
be adequately secured to the main structure of the crane isolating switch shall be provided on the crane bridge
having due regard for the weight of the cable and the in an accessible position and connected directly to the
possibility of vibration. Cable runs shall not be installed long-travel collectors or terminal box in case flexible
in a place where they will impede the crane driver’s cables are used. The switch shall be located as close as
view or hamper the movement of persons on the crane. possible to the long-travel collectors or terminal box,
The cables shall be placed so that they are easily unless its position be otherwise specified. On fixed cabin
accessible. Due consideration shall be given during cranes (see Fig. 9), it shall isolate all circuits, except
the design of the crane to make adequate provision for the crane lighting circuits, warning lighting circuits,
cable runs and to avoid cable runs in locations where communication circuits; and in a.c cranes, the circuit of
mechanical damage or high temperatures are likely to the transformer supplying the portable lighting socket
be experienced. The segregation of power and control outlets. On moving cabin cranes, it shall isolate all
cables shall be made as far as possible depending circuits except bridge lighting circuits, warning lighting
upon the space available on the crane and keeping or circuits and in ac cranes the circuit of the transformer
maintenance point of view. supplying the portable lighting outlets. This isolating
switch shall be unfused/MCCB/ACB/Isolator.
36.5.2 Where there is incidence of direct radiation of
heat, the cables shall be protected by metallic shield. 37.1.2.2 On moving cabin cranes (see Fig. 10) an
Where mineral insulated metal cables are subjected additional main unfused metal-clad isolating switch
to the effects of high transient voltage they shall be shall be provided on the cabin structure in an accessible
suitably protected by the use of surge limiting devices. position outside the crane cabin and connected directly
Cables remaining alive, when main isolator is opened, to the cross travel collectors or terminal box in case
shall be separately installed and adequately protected. flexible cables are used. The switch shall be located as
Adequate precaution shall be taken to prevent the close as possible to the cross-travel collectors, unless

30
 IS 3177 : 2020

LONG TRAVEL CONDUCTORS

MAINS

CRANE LIGHTING, WARNING LIGHT

MAIN AND AND ON A.C.- CRANES
CONTROL CIRCUITS TRANSFORMERS FOR PORTABLE
LIGHTING SOCKET OUTLETS
MAGNET

MAGNET CIRCUITS

FIG. 9FMAIN
ig. 9 M ain Isolating
ISOLATING Switches
SWITCHES AND Fuses REQUIRED
FUSES
and Required for
FORFixed -Cabin Crane
FIXED-CABIN CRANE

LONG TRAVEL CONDUCTORS

MAINS
CROSS
TRAVEL
CONDUCTOR

BRIDGE LIGHTING, WARNING LIGHT

AND ON A.C.- CRANES TRANSFORMERS
FOR PORTABLE LIGHTING SOCKET
OUTLETS ON THE CRAB / TROLLEY

CRAB LIGHTING, WARNING CIRCUIT AND ON A.C.- CRANES

TRANSFORMERS FOR PORTABLE LIGHTING SOCKET
OUTLETS ON THE CRAB / TROLLEY

MAIN AND CONTROL CIRCUITS

MAGNET CIRCUITS

Fig. 10 Main Isolating Switches and Fuses Required for Moving-Cabin Crane
FIG. 10 MAIN ISOLATING SWITCHES AND FUSES REQUIRED FOR MOVING-CABIN CRANE

31
N
N
IS 3177 : 2020

its position be otherwise specified. It shall isolate all comply with scheme B. Also it is more often required
circuits, except the trolley lighting circuits, circuits that in master controller operated crane, overload of any
arranged to operate warning devices and on ac cranes motion should not trip the complete crane circuit, but
the circuit to the transformer for the portable lighting should trip the individual circuit. In general, overload
socket outlets on the trolley. Alternatively, subject protection shall be of electromagnetic / electronic type
switch may be avoided by providing additional with time delay.
emergency stop push buttons on the trolley and cabin Operation of any of the above protective devices shall
so that crane main contactor can be switched off during automatically apply the electro-mechanical brakes
emergency. The selection, maintenance and installation on the relevant motion. If other systems of control or
shall be as per IS 10118 (Part 1 to Part 4). Each of the mixed systems are specified, the protective equipment
above main isolating switches shall be rated to carry at shall be in accordance with the recommendations of the
least 150 percent of the combined full-loads currents control gear manufacturer. An indelible circuit diagram
of the two motions of the crane using the largest power of the protective equipment shall be provided in the
(kW) working together with auxiliary loads such as electrical equipment compartment.
lifting magnets and shall be provided with a means
for locking it in the ‘OFF’ position of the switch. The 37.2.2 Protective Device Common to all Motions
switch cover shall be interlocked with the operating Protective devices common to all motions shall have
handle, so that it may not be removed or opened when all necessary incoming and outgoing feeders along with
the switch is closed. minimum equipment for protection.
37.1.2.3 Live terminals inside the switch shall be a) Incoming feeder shall have manually operated
shielded to prevent accidental contact. A pair of neon SFU/MCCB/ACB and electromagnetically
type pilot lamps or other device in duplicate, indicating operated contactors.
when the supply to the crane control circuits is live, b) MCCB/ACB shall have short circuit and overload
shall be provided in a position visible to the driver protection.
from his normal working position. If specified, the
c) The current rating of SFU/MCCB/ACB and
main isolating switch on the bridge shall be fitted with
contactors shall be at least the combined full
a pair of auxiliary contacts which will be closed when
load current of motors (at mechanical kW) for
the main switch is open and vice-versa, to operate the
any two motions having largest power operating
crane warning lights
simultaneously and auxiliary load.
NOTE ― Instead of fuse and isolator, MCB/MCCB/ACB may
also be used d) If required current rating is very high and single
contactor can not handle the load, motorized
37.2 Electrical Protective Device
e) ACB in place of SFU/MCCB/ACB and contactor
37.2.1 General with remote operation facility may be provided.
Motorised ACB shall have short circuit, overload
If electrically operated contactor/ VFD is used for and shunt trip facility.
control of all crane motions, the protective equipment
shall be in accordance with either: f) The outgoing feeder to all motion control circuit
shall be provided with adequate short circuit
a) Scheme A ─ Each motion has separate protection. protection., there will be HRC fuses or MCCB
For conventional crane control system, electronic HRC fuses/MCCB/ACB suitably in each isolating
motor protection relays with instantaneous over-current position. For conventional crane control, HRC
release and inverse time overload release shall be fuses may lead to single phasing; therefore
provided. Manual reset provision shall be considered. MCCB/ACB shall be provided in each isolating
position. However cranes with a.c. VFD control,
For cranes with VFD control, the in-built overload semiconductor fuses with switch isolators can
protection (settable) of the drive shall be used for be provided at the converter and inverter inputs.
protection of the motor in case of single motor drive. The circuit breaker or main line contactor should
However, in case of multi motor drive, individual motor not be rated to carry magnet full load current as
protection thermal overload relay /MPCB shall be used. magnet supply is taken before the circuit breaker/
main line contactor. The breaker shall have
For cranes with VFD and common DC Bus adequate rupturing capacity to withstand and clear
configuration, isolation between the bus and inverter fault current of the system. If specified a suitable
shall be provided. control circuit may be provided for this circuit-
b) Scheme B ─ An overload condition of any motion breaker to prevent it from being closed when the
trips off the supply of respective motion. main contactor of a particular motion has failed
to open, although the corresponding controller has
If drum controllers or master controllers are used for the been brought to its ‘zero’ position.
control of all motions, the protective equipment shall

32
 IS 3177 : 2020

37.2.3 Ac Instantaneous Release Single Pole over operating coil circuit of the contactor. Miniature circuit
Load: Protective Device for Individual Motions breaker as an alternative to control switch fuse may
Any motor having its power less than one-third that also be used.
of the largest motor and served by the same common
40 EMERGENCY SWITCHES
overload release, shall be protected by a separate
overload release. However, normally instantaneous A mushroom head push button (with rotate to release
release of overload relays are not used for individual facility) or a prominent switch for emergency stop shall
motion and circuit breaker is tripped by its own overload. be provided at each control facility to switch ‘off ’ the
In crane with circuit breaker overload protection is total crane supply or to de-energize the main contactor
provided by circuit breaker. The minimum provision common to all the motion drives. In the case of d.c.
for over current protection shall be as given below: cranes, rheostat braking shall be applied to the hoist
a) One instantaneous release in a common line motions. When any circuit breaking device is open no
feeding all motions set to trip the main contactors main pole on the nominally dead side shall be made
or circuit breakers instantaneously when the alive by a parallel circuit in emergency. The emergency
current rises to 250 percent of the value specified switch shall be so located as to be readily available for
above; and prompt use by the operator in case of emergency. If
specified by the purchaser or when the crane span is
b) One inverse time-lag release in each other line
larger than 20 m, the number of emergency stops shall
feeding each motion, set to trip the respective
be more than one. A reset button shall be provided, if
motion when carrying 200 percent of the full
required by the purchaser. The emergency stop push-
load current of the line, after a time-lag of
buttons or switches shall be connected in the operating
approximately 10 s.
coil circuit in the case of a contactor and in the under
It shall not be possible to reinstate the current supply to voltage release circuit in the case of a circuit breaker.
the common main contactor closing coils, or complete
the under voltage circuit of the circuit breakers until the 41 OFF-POSITION INTERLOCKING
master controllers for all motions are returned to the Electrical interlocking shall be provided to prevent
‘off’ position. inadvertent starting of the motions, in the case when
power is lost, without the controller being brought to
37.2.4 Protective Devices for Motor Circuits
the ‘off’ position on restoration of the supply.
The number of overload devices and their position
shall normally be in accordance with the arrangements 42 PILOT LAMP
shown in Table 13. If specified by the purchaser, other
arrangements giving protection not less than any A red pilot lamp (LED type) shall be connected to
of these shall be considered as complying with the indicate that the crane is ready for operations and it shall
specification. be so located that it is visible to the operator. The pilot
lamp shall be connected so that it indicates whether
Table 13 Normal Requirements for Number of the control supply is ON or OFF or the contactor is
Protective Devices for Circuit CLOSED or OPEN.
( Clause 37.2.4 ) 43 MAIN FEATURE OF BUILT-IN CRANE
WEIGHING SYSTEM IF SPECIFIED
d.c. Supply 3-phase a.c. supply
No line earthed One line earthed a) Overall accuracy of the system shall be ± 3.0
percent or better;
2 per motion in 1 per motion 3 per motion in
separate lines connected in the separate lines b) The system shall have the provision of tripping
non-earthed line. the circuit in case of overloading the cranes and
should serve on an additional overload safety
device; and
38 CONTACTORS
c) Load display unit shall be provided in the operator
Reversing power contactors shall be interlocked, cabin and crane girder
preferably mechanically as well as electrically so that
only one directional contactor can be in the closed 44 AUXILIARY SUPPLY
position.
Auxiliary switches used for isolating shall comply with
39 CONTROL SWITCH FUSE the relevant Indian Standards. If specified, an isolating
switch shall be provided to isolate all supply lines to the
Operating coil circuit of the main contactor or control main circuits of each motion. If specified single pole
contactor in case of cranes with circuit breaker. A double isolating switch with HRC fuse/MCB shall be provided
pole control switch fuse/MCB shall be connected in the on each motion panel. MCB/MCCB shall be provided

33
IS 3177 : 2020

to isolate all supply lines to each of the following 45.2 Moving Cabin Cranes
distribution boards or circuits where they exist. a) One Distribution Board for Bridge Lighting
44.1 Fixed Cabin Cranes Circuits — Warning or signal lights; in ac cranes,
the step down transformer supplying the bridge
a) Distribution board for all crane lighting circuits socket outlets, and walkways and bridge lighting.
including warning lighting circuits,
b) One Distribution Board for Trolley Lighting
b) Distribution board for auxiliary circuits other than Circuits — Cabin service and maintenance
lighting circuits, and lighting; cabin and bridge approaches and
c) Magnet circuits. electrical equipment lighting and in ac cranes,
the step-down transformer supplying the trolley
44.2 Moving Cabin Cranes socket outlets.
a) board for bridge lighting circuits including c) One distribution board for cabin heating circuits,
warning lighting circuits, fan and air-conditioning circuits.
b) Distribution board for all trolley lighting circuits,
c) Distribution board of boards for auxiliary circuits 46 AUXILIARY SWITCHES OTHER THAN
other than lighting circuits, and ISOLATION SWITCHES
d) Magnet circuits. 46.1 Each auxiliary circuit shall be provided with a
44.2.1 In fixed cabin cranes, the crane lighting circuit totally enclosed lighting switch component complying
isolating switch shall be connected directly to the long with relevant Indian Standard. These auxiliary switches
travel collectors and located in the immediate vicinity shall be located as follows:
of the main isolating switch on the bridge. In moving a) For the equipment in the cab, such as, fans and air-
cabin cranes, the bridge lighting circuit isolating switch conditioners (in cabin or e-room);
shall be connected directly to the live side of the main b) For the electrical compartment lighting, at the
isolating switch with cables as short as possible. The door of the compartment;
switch shall be located on the bridge in the immediate
c) For the cabin approaches, bridge approaches, and
vicinity of the main isolating switch. The trolley
bridge walkway lighting such that an operator can
lighting circuit isolating switch shall be connected
illuminate the approaches or walkways without
directly to the cross-travel collectors and located in
traversing them;
the immediate vicinity of the main isolating switch
on the crab. Molded case circuit breaker can be used d) For the bridge lights on the crane bridge, at the
as alternate to the switches and fuses, where ever is crane entrance platform in fixed-cabin cranes and
possible in the power circuit on the bridge in moving cabin cranes; and
e) Non-fusible double pole emergency switches
45 DISTRIBUTION BOARD should be connected in series for opening the
Metal clad distribution boards incorporating adequate circuit breaker or main contactors on the protective
protection in all lines, except those directly connected panel.
to earth shall be provided as detailed below to feed 46.2 Switches mentioned at 46.1 e), when ‘OFF’ will
the following auxiliary circuits where they exist. open both the main lines of the protective panel control
Distribution boards shall comply with relevant Indian circuit and will be located at the following places one
Standards, except that semi-enclosed fuses shall not be in driver’s cabin within the easy reach of the driver and
used. one on each of the landing corners of the end carriages
to be easily accessible to a person when boarding the
45.1 Fixed Cabin Cranes
crane or getting down from it. Additional switches shall
45.1.1 One Distribution Board for Crane Lighting be provided, if found necessary and when asked for.
Circuits
47 IDENTIFICATION OF CIRCUITS
a) Cabin service and maintenance lighting;
b) Cabin and bridge approaches and electrical All switches and fuses shall be adequately labelled to
equipment compartment lighting; facilitate the identification of the circuits. All panels,
controller and resistors are to be properly marked for
c) Warning lights; each motion. All main and control wires shall be ferruled
d) In a.c. crane, the step down transformer supplying at both ends, as per drawing for quick identification. All
the socket outlets and walkway, and bridge elements of the controller and panels are to be clearly
lighting for illuminating the floor area; and marked by furnishing functional nomenclature at the
e) One distribution board for cabin heating circuits, devices. All equipment terminals shall be numbered
fan and air conditioning circuits, if provided. and tagged.

34
 IS 3177 : 2020

48 DISPOSITION AND HOUSING OF The trigger limit of the over-speed protection shall be
ELECTRICAL EQUIPMENT set so that the mechanical brake is capable to stop the
motion safety in all conditions. In general, the trigger
48.1 Electrical Equipment other than Resistor limit should not exceed 1.05 to 1.1 times the specified
Assemblies speed at nominal load. For over speed sensing in
If electrical equipment is mounted in the open, it shall case of non-hot metal handling cranes without load
be of the enclosed type in weatherproof enclosure with free fall arresting protection, the speed mismatch
provision for easy access to the parts inside. obtained from encoder feedback shall be adequate.
However, in case of hot metal handling, separate
48.1.1 Control panels and other electrical equipment over speed sensor like centrifugal switch/electronic
should be so located that there is no chance for oil from over speed switch/proximity type over speed sensor,
the gear boxes, to drip on them. shall be provided to avoid free fall of the load. The
speed switch can either be attached to the encoder
48.1.2 The compartment or units shall neither impede mounted on the motor or at the hoisting drum. The
the maintenance of the long-travel drives, nor be emergency stopping with any possible speed and load
mounted on the bridge platform occupied by the cross- combination shall not cause any hazard including the
travel collector gear. The thoroughfare between the cases where the drive is intended to operate above the
different parts of the crane or between any portion of nominal speed.
the crane and the exit platform shall not entail passage
through the compartment or be impeded by any control
49.2 Devices for Switching off for Prevention of
unit.
Un-Expected Start Up
48.1.3 Control panels or units shall be so spaced that Devices for switching off for the prevention of
efficient maintenance may be performed, and shall unexpected start up shall be provided. The main
withstand the mechanical forces imposed by the crane incoming switch (crane-disconnector) fulfils that
under service conditions. function for the complete crane. Where it is necessary
to work on individual parts of a crane motion,
48.1.4 The compartment shall be constructed of steel
additional disconnecting device shall be provided
sections and plates, or other fireproof material of
for each part requiring separate disconnection.
adequate mechanical strength. It shall be drip proof,
Disconnectors, withdrawable fuse links, contactors
adequately ventilated and lit, and in addition for outdoor
can be used as hardware. Alternatively this protection
cranes, weatherproof. If windows are provided, wired
can be provided by VFDs, in accordance with of
or toughened glass shall be used and it shall be possible
IS 16504 (Part 32), if the discharge of stored energy
to clean all glass surfaces without danger.
would significantly restrict the availability of a
48.2 Resistor Assemblies machine, additional devices must be installed to
reliably buffer the remaining energy. For instance, this
Resistor assemblies shall be so mounted as to ensure involves a multi-motor drive with inverters connected
an adequate flow of cooling air and shall be mounted to a common d.c. link. In this case, suitable resources
outside the main contactor compartment. must ensure that the “stored energy”, that is the energy
48.2.1 Resistor assemblies shall not impede the stored in the d.c. link capacitors of the individual
maintenance of the long-travel drives or access to inverters, is reliably buffered with the d.c. link voltage
the platforms of the crane, and shall be arranged so still available.
that efficient maintenance may be performed on each
unit. 49.3 Limit Switch
Generally except the ultimate hoist limit switch, all
48.2.2 Resistor assemblies for each motion shall
other limit switches trip individual motions, when
be stacked separately for the facility of inspection,
cranes are operated using VFD.
maintenance and safety.
49.3.1 Limit Switches in Hoist Motion
49 SAFETY FEATURES
49.3.1.1 Cranes with d.c. series motors
49.1 Motor Over Speed Protection
The final switches to be provided in the power
All electronically controlled hoisting motions shall be circuit shall be of self-resetting type and shall initiate
equipped with over-speed protection. The over-speed dynamic braking when tripped. If specified by the user,
protection shall prevent: provisions shall be made in the control circuit to have
a) uncontrolled and unintentional motions, and an audio-visual annunciation to indicate that the final
b) all parts of the mechanism from reaching its limit switch has operated.
mechanical limit speed.

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IS 3177 : 2020

49.3.1.2 Cranes with a.c.motors 49.4 Safeguarding Motors against Overheating

a) Final limit switch should trip the main contactor Motor overload protection shall fulfill the requirements
supplying power to all drive panels and shall be of of relevant Indian Standards. Protection methods
manual reset type. Provision shall be made to by- based on actual temperature measurement of the
pass the limit switch temporarily for emergency motor are preferred. The overload protection can also
lowering of hot metal. While by-passing only be implemented by electronic devices, which may be
lowering motion shall be possible; either separate devices or integrated in the control or
b) In case where final limit switch is used in the drive unit. Motor thermistor inside motor winding with
power circuit the same may be of manual or thermistor relay in control panel may be provided.
self-resetting type. If self-resetting type is 49.5 Over-Current Protection of Conductors
used, there shall be a provision for audio-visual
annunciation to indicate its operation, if specified All conductors are required to be protected against
by the user; over-current by protective devices inserted in all live
conductors so that any short-circuit current flowing
c) If the ultimate limit switch is shunt-connected it
in the cable is interrupted before the conductor has
shall control the protective panel circuit breaking
reached the maximum allowable temperature as per
device. No two-shunt limit switches shall control
the relevant Indian standards . For selection of the
the same circuit-breaking device; and
correct protective device for switching off in case of a
d) If occasional abnormally high lifts are required, short circuit (see 37). The cross-section of a conductor
arrangements may be made for by passing the should be determined according to the current intensity
first limit switch. Under such condition, hoisting to which it is subject during both normal running of the
should be possible at slow speed only when by motor and starting-up or electrical braking. Whether the
passing button is kept pressed. loads (motors) are overload protected or not, all wires
49.3.2 Track Limit Switches should be safeguarded against any over current, which
could result from a short circuit or faulty insulation.
If specified, one or more track switches shall be fitted to The protective device shall be rated for the anticipated
the bridge to give warning of approach to a danger area. short-circuit currents.
They shall be operated by suitable devices to be fixed to
the crane gantry as required and shall either operate an 49.6 Safeguarding Against Absence or Inversion of
audible warning signal or trip the main circuit-breaker Phases
on the crane, as specified in 37. Track switches shall Where an incorrect phase sequence of the supply
be so arranged that they can be readily tested. Strikers voltage can cause a hazardous condition or damage to
shall be so arranged as to prevent damage of the limit the hoisting machine, protection should be provided.
switch on over travel due to impact. If the absence of phases may occasion a danger, the
49.3.3 Proximity Sensing / Anti-Collision Devices appropriate safety measures must be taken.
If specified, one or more devices shall be fitted to the 49.7 Action of Safety Devices
bridge of the crane to give warning of the approach When several motors drive the same motion, the action
to danger, or another crane. Anti-collision devices of a safety device should stop all of the motors for this
are relevant to safety. Their failure will result in high movement. After a safety device has been activated, it
impact forces, which may cause damage to the loads should be possible for the equipment to be started up
transported or to system components, or personal again only manually.
injuries. Strict requirements are to be met with respect
to reliability and safe functioning of anti-collision 49.8 Protection Against the Effects of Lightning
devices. They shall be failsafe under the specified For very tall pieces of hoisting equipment which are
environmental conditions (such as, temperature limits, erected in particularly exposed locations, the effects of
dust, alternating electromagnetic fields). Note that lightning must be considered on:
‘emergency stop functions’ of electrical limit switches
can be realized using mechanically actuated switches a) pieces of vulnerable structure (for example, jib
which function according to the positive-opening support cable); and
principle. Non-contact or proximity limit switch b) anti-friction bearings or runners which form a link
systems only afford the desired operational reliability, if between large parts of the frame (for example,
combined with a safe circuit including self-monitoring slewing rings, travel runner).
and plausibility check. Where the ‘emergency stop
function’ is undesirable, monitoring devices will be When necessary, safeguarding against the effects of
required for clear and unambiguous indication of any lightning should be carried out.
fault. UPS may also be provided for the control system For the safety of personnel, it is recommended that the
if required by purchaser. runner rails for the lifting equipment are earthed.

36
 IS 3177 : 2020

49.9 Electrical Safety Features f) Speed regulation;

49.9.1 Wiring of the cranes where high ambient g) Type of power system;
temperature and radiant heat from an open-top ladle h) Ambient temperature;
are exposed shall be with high temperature insulation j) Altitude; and
cables. k) Suitability of motor for VFD operation.
49.9.2 Motors and controls shall be de-rated based on NOTES:
their ambient temperature. 1) Derating factor (if any) on account of losses due to
harmonics shall be declared by the manufacturer.
A crane disconnecting means, either a current rated 2) Highest calculated ratings of the motor as per service factor
circuit breaker or main isolator switch, lockable in the formula or thermal adequacy rating shall be the basis of the
open position shall be provided in the lead from the run selection
way contact conductors or other power supply.
50.2 Sizing of a.c. Motors for Hoist Motion
Each motor shall be provided with overload and short
circuit protection. For hoisting motor the power required shall be equal to
or greater than that computed from the following:
49.9.3 Control circuits shall be protected with over load
protection. Pmech (kW) = M × V / (6.12 × E)
Under voltage protection shall be provided as a function Pcomp (kW) = Pmech × S / Camb
of each motor controller, or an enclosed protective
panel, or a magnetic main line contactor, or a manual Where,
magnetic disconnect switch, and on automatic cranes, Pcomp kW = power rating of motors as in table given
all motions shall be disconnected, if the crane does below table;
not operate in accordance with automatic sequence of
M = mass of the rated load on the hook plus
operations.
weight of the hook block and the wire ropes,
50 DESIGN AND SELECTION OF MOTORS in tonnes;
V = Specified hoisting speed, in m/min or actual
50.1 General speed based on gear box ratio whichever is
The selection and testing of the motors shall be as per higher;
IEC 60034-25 or IS 12615 or any other equivalent E = Combined efficiency of gears and sheaves;
Indian standard. The following details needs to be = (0.93)n × (0. 98)m for sleeve bearings,
checked by the crane designer while selecting the = (0.95)n × (0. 99)m for anti-friction bearings (for
motors for the corresponding motions: spur and helical gears:
a) Required power (thermal rating of the motor Efficiency to be taken as 0.95 per reduction),
calculated as per 5.8 of FEM 1.001);
= (0.985)n × (0.99)m for hardened profile ground
b) Required maximum rated torque and maximum and oil splashed lubricator;
acceleration torque (considering motor and load
GD 2 values); n = number of pairs of gears;
c) Cyclic duration factor; m = total number of rotating sheaves passed over
by each part of each moving rope attached to
d) Number of cycles/h; the drum; and
e) Type of control (includes type of electrical braking S = Service Factor
also);
Values of Service Factor (S) for a.c.
No. of Electrical Mechanism Slip ring motor Squirrel cage motor
Round Service Classification ( Rheostatic / Thyristor Control) / Sq. Cage Motor with DOL Starter (VFD control)
Trips/ Class
Hoist Bridge Service Factor Trolley service Hoist, bridge and
percent
With Plugging Without Plugging factor trolley service
Time
factors
Operation
per Hour
15 / 20 E1 M1-M2-M3 1.0 1.1 1.0 1.2 1.0
25 / 30 E2 M4-M5 1.0 1.2 1.1 1.3 1.0
35 / 40 E3 M6- 1.1 1.3 1.2 1.4 1.1
45 / 50 E4 M7-M8 1.2 1.4 1.3 1.5 1.2
45 / More 1.2 1.5 1.4 1.5 1.2
than 50

37
IS 3177 : 2020

Where, A cycle of a bridge or trolley consist of two moves, one

Pmech = Mechanical power; loaded and one unloaded
Pcomp = Required motor power; and Table 14 Recommended Cyclic Duration Factor
C amb = Derating/uprating factor for ambient and Starting Class
temperature. ( Clauses 50.2.1, 50.3.2 and 50.5.8 )
NOTES:
1) derating/uprating factor for ambient temperature higher Sl No. Mechanism Number of Recommended Starting
or lower than design ambient of motor shall be as per motor Class Operating Cyclic Duration Class (C)
manufacturer declaration for their standard crane duty motor Cycle / hour Factor Percent Equivalent
rating. Starts 1 h
2) Altitude variation factor shall be as per motor manufacturer. (1) (2) (3) (4) (5)

50.2.1 For a.c. Slip Ring Type Hoist Motor i) M1 Up to 5 25 90

For an a.c. hoist motor, the specified full load hoist

speed must be obtained at not more than rated torque, ii) M2 6 to 10 25 90
therefore, the calculated full load kW must be multiplied iii) M3 11 to 15 25 150
by: iv) M4 16 to 20 25 150

( 100 – Rated slip percent) v) M5 21 to 30 25/40 150/300

———————————————— vi) M6 31 to 40 40 300
( 100 – Total ohms at full speed percent) vii) M7 41 to 50 60 300/600
viii) M8 51 to 60 60 300/600
Where sufficient information is not available values
given in Table 14 for duty cycles, cyclic duration factor
and starting class corresponding to mechanism class
shall be used. 50.3 a.c Motor for Crane Travel or Trolley Traverse

The values given are based on the following formula: 50.3.1 General
It is assumed that the drive mechanism from the motor
           Operating time × 100 to the track wheels will use enclosed gearings mounted
Cyclic duration factor = ——————————— on anti-friction bearings. The actual efficiency of the
           Operating time + Idle time drive will be adopted in making calculations. Where
actual efficiency values are not available the efficiency
50.2.2 The starting class (C) assumes numbers of
of the drive shall be taken in the range of 0.85 to 0.9.
complete starts (S), jogging operations (J) and electrical
braking operations (B) as follows: For the track wheel with anti-friction bearings the rolling
friction at these bearings plus the friction between the
C = S + K1J + K2B track wheels with an average drive efficiency of 0.875
shall give an overall friction factor of 8.0 kgf per tonne
Where, of the mass moved for calculation of the motor horse
K1 = 0.20 squirrel cage motor operated by VFD power or torque. In the case of wheels with the plain
control bearings an overall friction factor of 13.0 kgf per tonne
= 0.25 for slip ring motors. of the mass moved may be used.
= 0.5 for squirrel cage motors for DOL starting. 50.3.2 Sizing of a.c Motors for Crane Travel or Trolley
K2 = 0.8 for slip ring motors. Traverse
= 0.50 squirrel cage motor operated by VFD For bridge travel or trolley traverse, the power of the
control motor required shall not be less than that computed
= 3.0 for squirrel cage motors for DOL starting. from the following:
a) For indoor cranes:
For computation of number of starts/hour can be done
using number of operating cycles/hour and number of      M × V × F
moves in each cycle for hoist and travel motion the PR (kW) = ————
hoisting cycle constitutes four motions:      6117
a) Full load hoisting,
     M × V (1100 × a)
b) Full load lowering,
PA (kW) = ——— × ————
c) No load hoisting, and       6117   (981 × N)
d) No load lowering.

38
 IS 3177 : 2020

     (PR + PA) T = factor introduced by the permissible motor

Pmech (kW) = ————— torque during acceleration, exceeding the
    T motor-rated torque. As a general guidance
value of T may be taken as 1.7 for motors
Pcomp is computed power of motor
having pull out torque of 275 percent full load
Pcomp (kW) = Pmech × S/ Camb torque for slip ring motor and 1.5 for motors
having pull out torque of 225 percent of full
b) For outdoor cranes:
load torque corresponding to Pmech for squirrel
    M × V × F cage motor fed from VFD. Lower values of
PR (kW) = ————— T should be taken for corresponding lower
    6117 values of pull out torque.
= 1.7 for a.c. Slip Ring Induction motors
     M × V (1100 × a) = 1.6 for a.c. motors , fed from DOL
PA (kW) = ——— × ———— = 1.5 for a.c. motors when operated from VFDs
      6117   (981 × N)
F = overall friction factor
     RW × V = 8 kgf per tonne for wheels on anti-friction
Pwind (kW) = ——— bearings
      6117 = 13 kgf per tonne for wheels on plain bearings
Rw = load due to service wind acting horizontally
     (PR + Pwind + PA) as defined in 7.3.1 which can be obtained by
Pmech (kW) = ——————— multiplying the horizontal exposed area by the
     T service wind by taking drag co-efficient into
Pcomp (kW) = Pmech × S/Camb consideration;
a = average linear acceleration of the crane or
If travel resistance to wind is not specified, consider the trolley in cm/s2 till the mechanism reaches
wind force (RW) corresponding to 8 kgf/m2 for sizing 90 percent of free running speed. For the
of motor. values of average linear acceleration as given
in 50.5.5; and
If travel resistance to wind is specified, consider the
same in the above calculation. The limiting value of S = service factor aimed at providing adequate
working wind force (RW) as per IS 807 is 25 kgf/m2. motor heat dissipation capacity as given
in 50.5.2.
Where, NOTES:
PR =Running power; 1) Duty cycle per hour (number of operating cycles per hour),
recommended cyclic duration factors for the mechanism class
PA =Acceleration power; can be taken from Table 14.
Pmech =
Average mechanical power; 2) At free running speed, the acceleration becomes zero.
Pcomp =
Required motor power; 3) The gear reduction ratio actually used should be reasonably
close to the ideal reduction ratio =
Pwind =
Power required to overcome wind force; Motor rev/min at free running
RW =W8 × area exposed to wind, in m2; —————————————————————
Track wheel rev/min at specified free running speed
W25 × area exposed to wind, in m2;
=
4) In order to limit the acceleration to the specified value and
W8 =Wind load 8 kgf/m2; also to take full advantage of the service factor the electrical
W25 =Wind load 25 kgf/m2; control should be designed to suit the values of ‘S’ and ‘T’
actually adopted or values of ‘S’ and ‘T’ should be selected
kW = one hour power rating for d.c. motors and based on electrical controls to be provided.
power rating minimum at (S3– 40 percent) 5) Since the wheels must transmit all acceleration forces to
cyclic duration factor for a.c. motor; the crane, to prevent wheel skidding due consideration should
M = mass of crane or trolley plus mass of max rated be given on percent driven wheels after acceleration rate has
been fixed. The wheel skidding should be checked at no-load
load, in tonne;
conditions considering 20 percent adhesion between wheel and
V = Specified travel speed in m/min or actual speed rail.
based on gear box ratio whichever is higher; 6) The skewing force arising during the running of the crane
N = mechanical efficiency of gearing. For spur needs to be considered by the designer while designing/
configuring the electronics controls. This is usually a function
and helical gears, efficiency to be taken as of the ratio of span to the wheel base.
0.95 per reduction. For hardened and ground 7) The gradients of the track and the necessary forces for CRD
gears, efficiency to be taken as 0.985 per fed cranes has to be taken into consideration when designing
reduction; the travel motor.

39
IS 3177 : 2020

50.4 Sizing of d.c Motors for Hoist Motions 50.4.3 For voltages other than 230 volts, use the one-
hour ratings at the selected voltage, as established by
50.4.1 Direct Current Motors the motor manufacturer.
The motors shall be so selected that their one hour
power rating is not less than that computed from the 50.4.4 For duty cycle of more than 50 percent time
following formula: ‘ON’ or 45 cycles per hour, the requirements must be
submitted to the motor manufacturer for selection of
Pmech (HP) = M × V / (4.56 × E) adequate ratings.

Pcomp (HP) = Pmech × K 50.5 Sizing of d.c. Motors for Bridge Travel or
Trolley Traverse
Where,
50.5.1 The selected motor shall have the one hour
M = weight or the rated load on the hook plus
power rating which is not less than that computed from
weight of the hook block and the wire ropes, in
the following formula:
tonnes;
V = specified hoisting speed, in m/min; and Selected Power (HP) = F × M × V × S
E = combined efficiency of gears and sheaves, Where,
= (0.93)n × (0.98)m for sleeve bearings
F = a factor which includes for power to overcome
= (0.95)n × (0.99)m for anti-friction bearings friction, to give linear acceleration to the mass
= (0.985)n × (0.99)m for hardened profile ground moved, and the angular acceleration to the
and oil splashed lubricator motor armature and the rotating parts;
n = numbers of pairs of gears; M = mass moved, in tonnes;
m = total number of rotating sheaves between drum V = specified free running speed, in m/min; and
and equalizer passed over by each part of the S = a service factor aimed at providing adequate
moving rope attached to the drum; and motor heat dissipation capacity to cover for the
K = Service factor depending on the electrical severity of the expected duty cycle.
service class of crane.
50.5.2 Recommended values for F and S are given in
50.4.2 Recommended values of K for series motors tables below.
operated at 230 volts as given below.
Values of Service Factor ‘K’ for Hoist Motor
(Series Motor) Values of Friction Factor (F)

Electrical Service Acceleration Track Wheels Track Wheels

Duty Cycle Service Factor Whilst on the on Anti-friction on Plain
Class K Resistor cm/s2 Bearing Bearing
Not more than 20 percent 15 0.002 5 0.003 3
time ON and not more than 1 0.75 30 0.003 5 0.004 4
15 cycles per hour
21-30 percent time ON or 45 0.004 3 0.005 4
2 0.75
16-25 cycles per hour 60 0.005 1 0.006 3
31-40 percent time ON or 75 0.005 8 0.007
3 0.82
26-35 cycles per hour
41-50 percent time ON or
4 0.96
36-45 cycles per hour

Values of Service Factor (S) for d.c. Motor

No. of Round Electrical Mechanism DC Motor

Trips/Percent Service Classification (Resistance/Thyristor Control)
Time Operation Class Hoist Bridge Service Factor Trolley Service Factor
per Hour
With Plugging Without Plugging
15 / 20 E1 M1-M2-M3 1.0 1.1 1.0 1.2
25 / 30 E2 M4-M5 1.0 1.2 1.1 1.3
35 / 40 E3 M6- 1.1 1.3 1.2 1.4
45 / 50 E4 M7-M8 1.2 1.4 1.3 1.5

40
 IS 3177 : 2020

50.5.3 For other values of acceleration between two considering 20 percent adhesion between wheel and
figures, intermediate values of K may be taken. rail.
50.5.4 At crane or trolley free running speed, the 50.5.7 It is essential that the gear reduction ratio
acceleration becomes zero and hence the power to be actually used be reasonably close to the ideal reduction
furnished by the motor is: ratio (motor speed when developing calculated free
a) Case I — Track wheels on anti-friction bearings, running power) / (track wheel speed to give specified
running speed).
Required Power (HP) = 8 × M × V/4562
Required Power (HP) = 0.00175 × M × V 50.5.8 For limiting the acceleration to the specified
value and also to take full advantage of the service
b) Case II — Track wheels on plain bearings,
factor actually used, it is essential that whilst the motor
Required Power (HP) = 13 × M × V/4562 is on the resistor, the electrical control shall limit the
Required Power (HP) = 0.00285 × M × V average current to a value corresponding to 1.33 times
the torque which the selected motor would furnish
50.5.5 If the acceleration values are not specified by the when developing power of KMV, that is, KMVS with
user, this may be chosen corresponding to the speeds S taken as unity.
to be reached according to the three following working
NOTES:
conditions:
1 Duty cycle, recommended cyclic duration factors and
a) Appliances of low and moderate speed with a recommended starting class for the mechanism class can be
great length of travel; taken from Table 14.
b) Appliances of moderate and high speed for normal 2 At free running speed the acceleration becomes zero.
applications; and 3 The gear reduction ratio actually used should be reasonably
close to the ideal reduction ratio:
c) High speed appliances with high acceleration.
Motor rev/min at free running
The values of acceleration for the above three conditions = ———————————————————
are given below: Track wheel rev/give specified running speed
4 In order to limit the acceleration to the specified value and
Acceleration Values ‘a’ also to take full advantage of the service factor the electrical
control should be designed to suit the values of ‘S’ and ‘T’
actually adopted or values of ‘S’ and ‘T’ should be selected
Speed Acceleration Acceleration Acceleration
based on electrical controls to be provided.
to Be in cm/s2 for in cm/s2 for in cm/s2 for
5 Since the wheels must transmit all acceleration forces to the
Reached Low and Moderate High Speed crane, to prevent wheel skidding due consideration should
M/Min Moderate and High With High be given on percent driven wheels after acceleration rate has
Speed with Speed Acceleration been fixed. The wheel skidding should be checked at no-load
Long Travel (Normal conditions considering 20 percent adhesion between wheel and
Application) rail.
6 The skewing force arising during the running of the crane
240 — 50 67
needs to be considered by the designer while designing /
190 — 44 58 configuring the electronics controls. This is usually a function
of the ratio of span to the wheel base.
150 — 39 52
7 The gradients of the track and the necessary forces for CRD
120 22 35 47 fed cranes has to be taken into consideration when designing
the travel motor.
100 19 32 43
8 The horizontal forces arising due to the swaying of the
60 15 25 33 load also needs to be considered for designing of the motor
40 12 19 — especially for a high load inertia.

25 10 16 —
51 CYCLIC DURATION FACTOR AND
15 8 — — NUMBER OF CYCLES PER HOUR
10 7 — — Table 15 indicates the number of cycles per hour and
the cyclic duration factor for the vertical motions as a
50.5.6 Since the wheels must transmit all acceleration guideline.
forces to the crane, to prevent wheel skidding due
consideration should be given on percent driven 51.1 Table 16 indicates the number of cycles per hour
wheels after acceleration rate has been fixed. The wheel and the cyclic duration factor for the horizontal motions
skidding should be checked at no-load conditions as a guideline.

41
IS 3177 : 2020

Table 15 Number of Cycles per Hour and the Cyclic Duration Factor for the Vertical Motions
( Clause 51 )

Sl Type of Appliance Particulars Number of Type of Mechanism ED Percent

No. Concerning Cycles per
Nature of Use Hour
Reference Designation Lifting Derricking Derricking
hinged boom boom
(1) (2) (3) (4) (5) (6) (7) (8)
i) 1 Hand-operated (non — — — — —
motorized) appliances

ii) 2 Erection cranes — 2 - 25 25 - 40 — —

iii) 3 Erection and dismantling — 2 - 15 15 - 40 — —
cranes for power stations,
machine shops, etc.
iv) 4 Stocking and reclaiming Hook duty 20 - 60 40 S2 (2) —
transporters 15 - 30 min
v) 5 Stocking and reclaiming Grab or magnet 25 - 80 60 - 100 S (2) —
transporters 15 -30 min
vi) 6 Workshop cranes Grab or magnet 10 - 50 25 - 40 — —
vii) 7 Overhead traveling cranes, — 40 -120 40 - 100 — —
pigbraking cranes scrapyard 60
cranes
viii) 8 Ladle cranes — 3 - 10 40 - 60 — —
ix) 11 Forge cranes — 6 40 — —
x) 12 a) Bridge cranes for a) Hook or 20 - 60 40 - 60 S (2) —
unloading, bridge spread 15 - 30 min
cranes for containers. duty
b) other bridge cranes b) Hook duty 20 - 60 40 - 60 S (2)
(with trolley and/or 15-30 min
slewing
xi) 13 Bridge cranes for unloading, Grab or magnet 20 - 80 40 - 100 S (2) —
bridge (with trolley and /or 60 15 - 30 min
slewing jib crane)
xii) 14 Drydock cranes, shipyard Hook duty 20 - 50 40 — —
jib cranes, jib cranes for
dismantling.

52 DESIGNING THE CRANE CONTROLS be provided with means to prevent operation from more
than one facility at any one time.
The following crane control schemes are used in the
steel mill depending on the type of motor: NOTE — Main circuits are those which carry main motor or
magnet current. Control circuits with brake circuit mechanism
a) d.c. motor with thyristor based controls; are those which are used for control equipment for main motor
b) a.c. slip ring motors with conventional controls or magnet.
using rotor resistances and plugging braking; 53.2 Controllers
c) a.c. Slip ring motors with thyristor based controls; Controllers shall be rated to comply with
and IS/IEC 60947-2, IS/IEC 60947-4-1. Controllers shall
d) a.c. squirrel cage motors with VFDs. be suitably protected to prevent accidental contacts
with the live parts. Controllers in ‘off’ position shall
53 CRANE CONTROLLING ARRANGEMENTS open all supply lines of the respective motors, unless
otherwise agreed to, in which case a warning notice
53.1 General shall be fixed to the controllers. On or adjacent to
The type of controls to be used shall be as agreed to each control device, there shall be a clear marking
between the manufacturer and the purchaser. Cranes identifying the motion controlled and the direction of
having alterative control or brake circuit facilities shall movement.

42
 IS 3177 : 2020

Table 16 Number of Cycles per Hour and the Cyclic Duration Factor for the Horizontal Motions
( Clause 51.1 )

Sl Type of Appliance Particulars Number of Type of Mechanism ED Percent

No. Concerning Cycles Per
Nature of Use1) Hour
Reference Designation Rotation Crab Travel
(1) (2) (3) (4) (5) (6) (7) (8)
i) 1 Hand-operated (non — — — — —
motorized) appliances
ii) 2 Erection cranes — 2 - 25 25 25 - 40 25 - 40
iii) 3 Erection and dismantling 2 - 15 25 25
cranes for power stations,
machine shops, etc
iv) 4 Stocking and reclaiming Hook duty 20 - 60 15- 40 40 - 60 25 - 40
transporters
v) 5 Stocking and reclaiming Grab or magnet 25 - 60 40 60 15 - 40
transporters
vi) 6 Workshop cranes — 10 - 50 — 25-40 25 - 40
vii) 7 Overhead traveling cranes, Grab or magnet 40 - 120 40 - 60 60 - 100
pigbraking cranes Scrapyard
cranes
viii) 8 Ladle cranes — 3 - 10 — 40 - 60 40 - 60
ix) 9 Soaking pit cranes 30 - 60 40 40 - 60 40 - 60
x) 10 Stripper cranes, open-health — 30 40 60
furnace-charging cranes 10 40 40
xi) 11 Forge cranes — 6 100 25 25
xii) 12 a) Bridge cranes for a) Hook or 20 - 60 15 - 40 40 - 60 15 - 40
unloading, bridge spread 20 - 60 25 - 40 40 -60 25 - 40
cranes for containers. duty
b) other bridge cranes b) Hook duty
(with trolley and/or
slewing
xiii) 13 Bridge cranes for unloading, Grab or magnet 20 - 80 40 40 - 100 15 - 60
bridge (with trolley and /or
slewing jib crane)
iv) 14 Drydock cranes, shipyard Hook duty 20 - 50 25 40 25 - 40
jib cranes, jib cranes for
dismantling
v) 15 Dockside cranes (slewing, Hook duty 40 25 - 40 40 15 - 25
on gantry, etc.), floating 20
cranes and pontoon derricks
xvi) 16 Dockside cranes (slewing, Grab or magnet 25 - 60 40 - 60 25 - 40
on gantry, etc), floating
cranes and pontoon derricks
xvii) 17 Floating cranes and pontoon — 2 - 10 15 - 40 — —
derricks for very heavy loads
(usually greater than 100)
xviii) 18 Deck cranes Hook duty 30 - 60 40 — —
xix) 19 Deck cranes Grab or magnet 30 - 80 60
xx) 20 Tower cranes — 20 40 - 60 25 15 - 40
xxi) 21 Derricks — 10 25 — —
xxii) 22 Railway cranes allowed to — 10 25 — —
run in train
1)
This column comprises only some indicatory typical cases of utilization.

43
IS 3177 : 2020

53.2.1 Control Equipment for d.c. Motors selected accordingly. For master control operated
Contactors, switches and allied electrical components cranes the control voltage preferably 110 a.c. and
shall be selected on the basis of calculated power (in shall not exceed 240 for a.c. or d.c. supply. Typical
kW) of the motor. location of various motion controller of the crane
with respect to operator are given in Fig. 11 and
53.2.2 Control Equipment for a.c. Motors Fig. 12.
The rating of the control gears, such as, switches, 53.4 Pendant Controllers
overloads etc, shall be selected according to the
computed motor power without the service factor of the Cranes with pendant controls shall not have long
motion served and not on the motor power computed travel speed in excess of 40 m/min. Pendant control
by the thermal requirements. may directly descend from the trolley or from the
independently traveling trolley or from a convenient
The contactors selected under 53.2 shall have the position on the crane bridge. Push-buttons or other
stipulated contact life as may be specified by the switching devices, which automatically return to their
user. ‘off’ position as soon as they are released, should be
53.3 Controllers Provided in the Cabin provided for the control of all motions by pendant
control units. Housings of pendant control units
All control handles and pedals shall be placed in should preferably be of fully insulating material or
convenient position to allow the driver ample room of material with protective insulation. Metal parts
for operation and permit an unrestricted view of the accessible from the outside, which pass through the
load. They shall be so disposed that the contacts insulation, should be separately earthed. The surface
and terminal arrangements are readily accessible of the housing must be a vivid colour. For indoor
for inspection and maintenance purposes. The operation, the degree of protection should be at least
controls should be so arranged that the operator IP54, and for outdoor operation at least IP65. Pendant
has an adequate view of the crane’s working area. control units shall be suspended with a strain relief
The control for hoisting appliances shall preferably arrangement.
be arranged on the right-hand side of the operator’s
seat. 53.4.1 Pendent Switches

53.3.1 Marking Direction of Operation of Controllers The pendant switches shall be capable of
withstanding rough handling without being damaged
Where practicable controller handles shall move in the and the cover shall be effectively secured. If control
direction of resultant load movement. Each controller is from the floor, the electrical control circuit to the
shall be marked in a permanent manner to show the pendant shall be energized at not more than 110 V
motion controlled and direction of movement. For a.c. supply.
vertical lever, handle operating hoist controllers,
movement towards operator shall indicate hoisting 53.4.2 Pendant Control
and movement away from operator shall indicate On all pendant controlled cranes means shall be
lowering. provided to prevent inadvertent operation from the
53.3.2 Notching floor while maintenance work is being carried out on
the crane. An isolator fitted on the crane bridge, which
The notching for the controller handle in the ‘off’ can not be operated from the floor will comply with this
position shall be more positive than the notching in requirement.
other positions. The handle may be provided with a lock,
latch, dead man or spring return feature, if specifically 53.4.3 Pendant Control Station
requested by the customer. The control lever shall be If the control is by push buttons or switches, they shall
provided with stops and/or catches to ensure safety automatically return to the ‘off’ position immediately
and facility of operation. A controller drum fitted with after they are released. One lockable type push button
a star wheel shall be regarded as complying with the shall be provided to switch off control power when the
requirement. crane is not in use and if other means of switching off
53.3.3 Master Controller is not available.

Master controller operated cranes shall be provided 53.4.4 Suspension of Pendant Switch
with automatic control of acceleration. Accelerating The weight of the pendant shall be supported
torque/current peak shall be limited during controller independently of the electric cables by means of chain
handle movement from one notch to the other with or wire rope. If the pendant enclosure is of metal it
due consideration to the pullout torque of the motor shall be effectively earthed. A chain or hook does not
and number of rotor accelerating contactors shall be provide effective earth connection.

44
 FIG. 10 MAIN ISOLATING SWITCHES AND FUSES REQUIRED FOR MOVING-CABIN CRANE

IS 3177 : 2020

DOWN
DOWN
BRIDGE DRIVE GIRDER
BRIDGE A. HOIST

TROLLEY
M. HOIST
DOWN UP

A. HOIST
BRIDGE
TROLLEY M. HOIST
DOWN UP
M. HOIST TROLLEY
UP DOWN
A. HOIST BRIDGE
UP DOWN

LEFT HAND CABIN RIGHT HAND CABIN

UP
UP
CENTER CABIN
4 MOTOR CRANE

FIG. 11 RECOMMENDED ARRANGEMENT OF CONTROLLERS

Fig. 11 Recommended Arrangement of Controllers
DOWN

BRIDGE DRIVE GIRDER

BRIDGE M. HOIST
TROLLEY
M. HOIST
BRIDGE

DOWN UP
TROLLEY TROLLEY
M. HOIST BRIDGE
UP DOWN

LEFT HAND CABIN RIGHT HAND CABIN

UP

CENTER CABIN
3 MOTOR CRANE

Fig . 1212RRECOMMENDED
FIG. ecommended AARRANGEMENT Controllers
rrangement ofOF CONTROLLERS

53.5 Remote Control will not result in operation of any motion of the crane.
The crane must not take off on its own or respond to
53.5.1 Main features of radio remote control system or generate false commands. In case electricity failure
consist of: occurs, the crane must stop.
a) a portable transmitter; MAXIMUM A key switch or equivalent security device on the
b) an antenna and receiver on 2.5
the bridge; and transmitter that can be used to prevent unauthorized use
c) an intermediate relay panel on the bridge to of the transmitter.
amplify the signals for the crane
2
contactors. The sending of a continuous or continuously repeating
secure signal when transmitter is in use, which the
53.5.2 Radio controls should be designed so that
crane receiver can identify. A secure signal includes at
if the control signal for any crane motion becomes
least three characteristics separately recognizable by
ineffective, that crane motion will stop, and conversely
the receiver.
signals received any source other thanNORMAL
the transmitter

45

0 0 0 0 1 1 1 2

CONSTANT FLUX FIELD WEAKENING

IS 3177 : 2020

An emergency stop device shall be used for emergency 3 It is recommended that a device is fitted to the crane to give
stop. warning that the crane is under non-conductive control.
4 Incorporate a limited range feature, present by means not
A carrying harness, belt, shoulder strap or lanyard on available to the operator so that the crane will stop when the
the transmitter. extent of that range is reached.
5 If more than one crane are provided with this type of controls,
53.5.3 The arrangement of the operating levers on only the intended crane and its motion is operated at one time.
the radio transmitter should conform to figures given The transmitter shall be constructed so that it is capable of
below. The manufacturers should supply motion withstanding rough handling.
switches with different shaped knobs so that the motion
can be selected by feel and the operator’s vision remain 53.5.5 Remote control may be by means of radio or
on the load. Modular construction shall be preferable infrared transmission or an off-crane control station
for easy replacement. connected to the crane through wiring. The control
station may consist of pushbuttons, master switches,
53.5.4 Typical frequencies used for radio controls are: computer keyboards or combination thereof. For
a) in between 450 - 470 MH for which license is definition of remote control, see the applicable ASME
required; and standards. The selection and application of the remote
control system shall be done to assure compatibility
b) any license free frequency band. between the remote control and the crane control
The recommended crane controls for operating are of system and eliminate interference. When more than
maximum 100 metre range. one control station is provided, electrical interlocks
shall be included in the system to permit operation
Radio crane control transmitter lever arrangement of from only one station at a time. Electrical interlock
four motions, namely, are given below: is defined as effective isolation of the control circuits
Four Motion: with the use of rotary switch contacts, relay contacts
or with the use of a programmable logic controller and
Bridge Trolley Main Hoist Aux Hoist its input/output modules. Due consideration should be
given to elimination of interference between electronic
X Y Down Down signals and power circuits. This includes physical and
electrical separation, shielding, etc. Due consideration
should also be given to the following:
a) operating range of the remote control equipment;
b) operating speeds of the crane;
c) application of end travel limit switches; and
W Z Up Up d) wiring of magnet and vacuum circuits to the
line side of the disconnecting means and use of
Radio crane control transmitter lever arrangements of latching controls.
three motions, namely, are given below:
54 RESISTORS
Three Motion:
54.1 General
Bridge Trolley Hoist
Resistors shall be adequately protected to prevent
X Y Down accidental contact with live parts. The elements shall
be protected against corrosion.
54.2 Rating
Resistors shall be rated such that the temperature does
not exceed the limits specified in the relevant Indian
Standard specification, during the operation of the crane
W Z Up under service condition. The resistance and current
capacity of the resistors shall be computed according
NOTES: to the actual torque requirements of the motion served
1 Markings on the crane visible from the floor, shall indicate and not on the motor size which may be set by thermal
the direction of bridge and trolley travel corresponding to the requirements. The effect of using plugging as a service
W, X, Y and Z designations on transmitter. brake shall be taken into account in determining the
2 The maximum working range of radio control shall be limited size of resistors. Resistors shall be rated according to
to 40 – 50 m from the transmitter. This limitation reduces the the service conditions and the mechanical class of the
likelihood of an accident caused by the crane operating beyond crane and shall preferably be intermittent and short
the operator’s visibility.

46
 IS 3177 : 2020

time rated. The rating of the resistors shall not be less b) The thyristor shall be suitable to carry at least
than that given in the Table 17. 200 percent of the drive motor current rated
NOTE — For definitions of different intermittent rating, see S3-40 percent. The PIV of the thyristor shall by
Annex G. 2.5 times the system peak voltage appearing across
the thyristors. The factor 2.5 has been selected
Table 17 Rating of Resistors taking into account the line voltage variations;
c) Each thyristor shall be protected by RC snubber
( Clause 54.2 )
circuits so as to absorb the surges generated out of
Sl Mechanism Class Short Rating for Time Rated external line surges in consultation with the user;
No. Resistors, Min d) The drive system shall be protected against
overload by means of thermal overload or oil
(1) (2) (3)
dash pot of magnetic overload type with inverse
i) M1, M2 2 characteristics having adjustable setting range.
ii) M3, M4, M5 5 It shall also be protected against over current by
iii) M6, M7 10 means of instantaneous acting over current relays
having a setting range of 200 to 400 percent of the
iv) M7, M8 To suit the service condition
drive rated current. Solid state overload protection
may be used subject to the agreement of the
54.3 Fittings purchaser;
Resistors shall be enclosed in the well ventilated f) Switching-off of reversing contactors shall be
housings and, wherever necessary be fitted with done at near zero current. This is to be done by
suitable covers. They shall be mounted outside the main ensuring that the stop/tripping command first
contactor compartment. Resistors shall be mounted inhibits the thyristor controller and then switches
on steel frames to withstand forces imposed by the ‘off’ the reversing contactors. This requirement
crane under service conditions. They will be arranged will not be applicable, if the reversing is through
in such a way that boxes can be easily replaced. thyristors;
The connections to the resistor terminals should be g) In the case of overloading or the single phasing
accessible and adjustable. Resistor assemblies shall of the synchronizing supply, the circuits shall be
not impede the maintenance of the long travel drives or tripped immediately;
access to any part on the crane. Resistor assemblies for
each motion shall be stacked separately for the facility h) Whenever armature reversal (in case of the dc
of inspection maintenance and safety. drive) or stator reversal (in case of the a.c drive)
is to be done through the reversing contactors,
54.4 Degree of Protection the drive shall be protected against the free
fall conditions at the time of switching on and
Minimum degree of protection for the resistors shall be
reversals by having the preferred switching state
IP 22 or as specified by the purchaser.
of the reversing contactor. The drive controller
55 CRANE CONTROLS shall have suitable provisions for preventing load
drifts at the time of start and stop;
Various types of crane speed controls are as follows: j) For achieving smooth acceleration of the drive
a) d.c. motor with thyristor based controls; mechanism suitable ramp generator circuit shall
b) a.c. slip ring motors with conventional controls be available with the controller;
using rotor resistances and plugging braking; k) Wherever necessary, suitable de-ration would be
c) a.c. slip ring motors with thyristor based controls; considered for a.c./d.c. motors in consultation
with the thyristor controller manufacturer and
d) a.c. squirrel cage motors with gear arrangements
the motor manufacturer;m) The control circuits
called ‘geared motors’ for standard hoists and
shall be so designed that the brakes are applied at
travel motions; and
around the zero speed;
e) a.c. squirrel cage motors with VFDs.
n) Test points shall be available in the cards.
55.1 Thyristor Control Alternatively for digital device the HMI should
Main features are as under: have necessary display facility;
p) In case of wide deviation of the speed in actual
a) The thyristor shall be protected by fast acting
value from the set value, the circuit shall trip the
semiconductor fuses having 12 × t value
mechanism immediately. During acceleration
considerably lower than that of the thyristor. These
or deceleration period such tripping shall be
fuses shall be continuously of any fuse shall result
prevented by adjustable time setting;
in tripping of the power circuits;

47
IS 3177 : 2020

q) Thyrist or control shall be suitable for operation at be selected corresponding to F.L. current at electrical
vibration levels and environments encountered in kW. Rating of each thyristor (for example, Itan ) shall
the crane operation; be minimum 0.45 times Irms. The current rating of rotor
r) If specially required by the purchaser, the drive contactors and resistance grids shall preferably be about
motor shall be protected against overheating by 125 percent to 150 percent of rated current (depending
means of thermistors embedded in the motor upon minimum speed required to achieve) which may be
winding. Matching thermistor for trip relay shall confirmed by thyristor drive manufacturer. The thyristor
be provided by in the control panel. The embedded controller should be rated at maximum of (+) 65ºC and
thermistors are best for preventing overloads and should be operational for a supply voltage variation of
subsequent overheating of the motor as these –15 percent to (+) 10 percent. The commissioning and
thermistors give the correct thermal image of the trouble shooting should preferably be done through the
motor irrespective of the current carried.; and in-built key pad on the drive for ease of operation and
maintenance in steel plant cranes. If possible the key pad
s) Wherever a.c. phase controllers are to be
should be detachable type with provision to store the
paralleled for load sharing, the converter outputs
drive data sets and parameters, allowing user flexibility
shall be paralleled only at the load end and not at
to upload / download data. However, provision for
the converter end.
programming / trouble shooting from LAPTOP / PC
55.2 Special Protection for Direct Current Drive should also be available.
System
55.4 Variable Frequency Drives
a) To minimize excessive rate of rise of armature
current and radio frequency interference, When asynchronous motors are fed from VFDs, the
commutating chokes with sufficient inductance speed can be changed by changing the frequency

DOWN
shall be provided on the a.c. side so that PU of the supply (to the motor). Up to, the base speed/
frequency of the motor (50 Hz), the constant flux is
(inductive drop) across the choke lies between BRIDGE DRIVE GIRDER
maintained (see Fig. 13) thereby allowing the motor
2 and 4 percent. Where isolating transformer isBRIDGE
to deliver constant torque through out the range M.
from
HOIST

TROLLEY
M. HOIST
used, commutating chokes are not necessary;
BRIDGE
DOWN UP
0 - 50 Hz. The complete pull out torque of the motor
TROLLEY TROLLEY
b) To prevent excessive wear and tear of theM. HOIST is available at the time of starting. The normal torque
BRIDGE
commutator, the ripple content of theUPd.c. output speed DOWN characteristics of the motor (at 50 Hz) shifts
shall be minimized by providing smoothening towards the origin with the lowering of frequency. In
chokes of sufficient inductance depending LEFTupon the field weakening region above the nominal RIGHT
HAND CABIN motorHAND CABIN
motor design;
UP

speed / frequency, the motor’s rated torque decreases

c) In case of the quadrant drives, to protect against proportional to theCENTER increase of frequency and the
CABIN
3 MOTOR CRANE
inverter commutation failure during regenerating maximum torque (pull out torque) decreases inversely
mode, branch thyristor fuses shall be used. proportional to the square of the speed. The frequency
FIG. 12 RECOMMENDED ARRANGEMENT OF CONTROLLERS
However, where it is not possible to use branch above the rated, sets the limitations to the use of field
thyristor fuses, there shall be at least one fast weakening. The motor is operated ensuring constant
acting semiconductor fuse on the d.c. side of the power in field weakening zone as well as availability of
converter in addition to the semi-conductor fuses pull out torque for required operation.
on the a.c. side;
d) While switching on the system, the following
sequence shall be adhered to: MAXIMUM
2.5
1) Synchronizing supply is switched ‘ON’,
2) Field circuits are established, and
2
3) a.c./d.c. contactors are switched ‘ON’.
e) The drive shall be protected against field failure
with suitable circuits; and
NORMAL
f) The field current shall be reduced to a safe value
during the crane idling time to reduce the heating
of the motor. The normal field current shall resume
at the start of the drive operation.
55.3 Thyristor Controllers for Slip Ring Motors 0 0 0 0 1 1 1 2
The thyrist or controller should be a dedicated controller
for crane application. It should be with microprocessor CONSTANT FLUX FIELD WEAKENING
based closed loop, thyristor controlled adjustable a.c.
voltage control. The current rating of thyristor drive shall Fig. 13 Torque Speed Curves Characteristics
FIG. 13 TORQUE SPEED CURVES CHARACTERISTICS

48
 IS 3177 : 2020

55.4.1 VFD Selection q) For cranes under operation in steel melting shop
a) The VFDs selected for crane application should be having high ambient temperature of more than
insulated gate bipolar transistor (IGBT) / diode/ 50○C as well as dusty condition for example,
thyristor based, converter and inverter both. charging crane, ladle crane, hot slab handling
cranes, VFDs should be provided with A/C unit
b) Inverter selection shall be based on inverter with filter arrangement and be suitably protected
manufacturer’s recommendation given due with proper enclosure protection to tune of IP-54 /
consideration of the following: 55 degree or should be housed inside crane girder
1) Application, or electrical room on crane platform.
2) Power factor and efficiency of the motor at the r) Rating of VVVF drives, however be selected
load point, with sufficient margin, to take care of steady state
3) Power supply, and accelerating torque demand at maximum
4) Actual current at mechanical kW (Pmech), and operating point i.e. full load current at full speed
of respective motion.
5) Operating ambient temperature.
s) VFD rating for M7 and M8 duty class (charging
c) VFDs should always be selected based on the crane, ladle crane and hot slab handling cranes)
heavy duty current rating mentioned in the application is recommended to be 150 percent of
manufacturer’s catalogue. In case of dual current motor full load current at mechanical kW.
rating mentioned in the catalogue, the current
rating corresponding to ‘constant torque’ or ‘heavy 55.4.2 Dynamic Braking Selection for VFDs
duty’ should be selected for crane applications. For the hoisting motion, the braking occurs when the
d) The continuous current rating of the VFD shall be load is lowered. The braking resistor of a hoisting drive
at least equal to the motor current at the highest shall be selected considering the possible lowering
speed maintaining torque. The current required height of the load being lowered at the maximum
by the motor at any foreseen loading, including speed. The calculated regenerative energy and the
dynamic situations shall not exceed the short time lowering time can be used for designing the braking
rating of the VFDs. resistor. The hoisting drive should preferably have the
e) The squirrel cage motors shall be of inverter flexibility of connecting external braking units (IGBT
duty. These motors may not be suitable for DOL based) along with the resistors. The hoisting drive
starting, hence, same shall not be used for direct along with the register may also have inbuilt IGBT
online starting with bypassing VFDs. as the chopper. For horizontal motions, the braking
resistor shall be capable of absorbing the regenerative
f) VFDs shall be provided with dynamic braking
energy during deceleration of the motion also taking
facility with braking resistor or fully regenerative
into account the possibility of a swinging load and the
capability (active front end type).
wind push (the load and load attachment included). The
g) VFDs shall be provided with proper branch circuit braking resistor shall be thermally capable to absorb
protection on the line side. the generative energy during successive drive cycles of
h) Distorted waveforms on the line and/or short the application.
circuit current may require the use of line reactors,
isolation transformers or filters. 56 BRAKING
j) Line contactor shall be used with VFDs for
56.1 Electro-Mechanical Braking
hoisting applications to disconnect power from
drive in case of over speed or fault. 56.1.1 General
k) A minimum of two collectors for each runway Brakes shall be provided for each drive. At least one
conductor shall be furnished with inverter use. brake shall be mounted on the input pinion shaft of
m) The cranes using VFD controls shall adhere to the gear train. Cranes, which require particular safety,
the crane safety standards mentioned by IS 16504 for example, in steel works or with dangerous or
(Part 32). melted loads, should be provided with a second brake.
n) Starting current of motor shall be limited within The operation of the second brake shall be arranged
150 percent of the maximum operating motor full according to the design of the drive. It is recommended
load current or more if required. that under normal operating conditions, the second brake
is always being applied on stopping, after the motion
p) VVVF drive should be selected suitably so that the
has been brought to a halt by the main brake. In some
drive can perform under overload of 150 percent
applications for example, if waiting for the releasing of
of maximum operating full load current of motor
the second brake would cause unacceptable time delay
(that is, FLC corresponding to mechanical kW)
at each starting, it may be necessary to apply the second
for 60 s in every 300 s.
brake only when the crane switch (main contactor) is

49
IS 3177 : 2020

de-energized. In the event of an emergency stop, the should be selected based on minimum 150 percent of
second brake should be applied immediately. hoisting torque and be actuated through over speed
sensor mounted near or on rope drum extended shaft.
56.1.2 Hoist Motion Brake selection should be cross checked with respect
Electro-mechanical brake/brakes used for hoist motion to specified braking path or within 65 mm, whichever
shall apply automatically when the power supply fails or is less so that the load stops within safe distance to
when the circuit brake is opened or when the controller prevent any fatal accident or damage to any equipment.
handle is brought to the ‘off’ position. For hoists not Hydraulic disc brake is applied by release of hydraulic
handling molten metal and having single brake only pressure during emergency. With accumulator assisted
the minimum braking torque shall be 150 percent of hydraulic system application time of brake shall
computed full load “computed full load torque, which be longer which may not be acceptable in case of
is to be derived from below formula: emergency as such requirement pressure accumulator
may be reviewed. Speed encoder/transducer must be
Braking torque (in kg.m) = 975 × Pmech / N provided on the rope drum shaft, to compare the motor
shaft encoder for generating signal for actuation of the
Where,
e<mergency braking:
Pmech = Mechanical KW ( as per 50.2 ); and
a) Any other disc brake arrangement; and
N = Motor RPM.
b) These are to be suitably designed with the
When two brakes are fitted each shall have braking manufacturer.
torque not less than 125 percent of the computed full
56.1.5 Long Travel and Cross Travel Motions
load torque. Hoists handling molten metal shall have
two brakes on each drive and each brake shall have Braking torque shall be checked so that it is capable of
minimum braking torque of 125 percent of computed arresting the motion within a distance, in metre, equal
full load torque. For a.c. cranes when two brakes per to 10 percent of speed, in m/min, when travelling with
motor are used, the second brake may be fitted with a rated load at rated speed, provided there is no skidding.
time lag in which case the braking torque shall not be Long travel motions of outdoor cranes shall be provided
less than 125 percent of the computed full load torque with an additional storm brake. The combined braking
for each brake. torque of the service brake shall not be less than the
skidding torque assuming a coefficient of friction
56.1.3 Braking Path (μ) = 0.2. For long travel drives anchoring device
The braking path of the hoist motion should be within shall also be provided for outdoor cranes in addition
the distance as per Table 18 with all the brakes applied to storm brakes. All other motions, such as, slewing
simultaneously, except the effect of brakes with time shall be provided with effective braking system which
lag: can be applied in an emergency or would be applied
automatically in the event of failure of power supply.
Table 18 Braking Path
Each drive shall be fitted with an electro-mechanical
( Clause 56.1.3 )
brake having braking torque not less than 100 percent
of computed full load torque, which is to be derived
Sl No. Speed of Hoist Max. Braking Path
(v in m/min) (in m) from below formula:
(1) (2) (3) Braking torque (in kg.m) = 975 × Pmech /N .
i) v<6 v/100
Where,
ii) 6 < v < 12 v/120
iii) v > 12 v/150
Pmech = Mechanical KW ( as per 50.3.2 ); and
N = Motor RPM.
56.2 Electrical Braking
56.1.4 Emergency Braking for Ladle Cranes, if Asked
by Purchaser In addition to specific requirements of this code in
regard to the provision of electro-mechanical brakes,
This is for the failures of any mechanism in between and irrespective of the supply current system, electrical
motor shaft to rope drum shaft, including internals braking is permissible and recommended on all motions
of gear boxes. If emergency disc brake of hydraulic of electrically operated cranes. When electrical braking
caliper type is provided on hoist rope drum, then is used, provision shall be made to limit the current
pressure accumulator should be built-in on hydraulic on reversal to a safe value. Effective means shall be
power pack to avoid any mal-operation in the event provided for stopping the motion in the event of power
of failure of the motor of the power pack. This brake failure and in the case of emergency.

50
 IS 3177 : 2020

56.3 Brake Magnet Coils transformer or an isolating transformer and rectifier.

All magnet coils shall be fed from d.c. or a.c. supplies, The transformer frame and one pole of this supply
and the rating of brake magnet coils shall be as given shall be earthed and the contactor and relay coils shall
in Table 19. The brake shall operate at the voltage and be connected to this pole. An earthed screen shall be
current values specified in Table 20 given below. Shunt provided between the primary and secondary winding.
magnets shall meet the requirements when the coils The primary winding and unearthed pole of secondary
are at a temperature which corresponds to energization winding of the transformer shall be protected by fuse in
under rated conditions. line connection. Effective means shall be provided to
prevent mal-operation owing to short circuits or earth
The temperature rise of coils shall not exceed that faults.
permitted by relevant Indian Standard for the class of
insulation employed. 57.2 Rectifiers
NOTE: On a.c. cranes, if d.c. supply is required, rectifiers
Brake Surfaces — The rubbing surfaces of brakes shall be shall be provided for supplying the control circuit,
smooth and free from defects. The temperature attained by the brakes and magnets. These rectifier units shall be of
rubbing surfaces under service conditions shall be such that
adequate capacity to supply the full d.c. loads required
their operation is not impaired.
continuously. They shall be of suitable construction and
mounting to withstand heat, dust, shock and vibration.
Table 19 Brake Magnet Coil Ratings Silicon type rectifier units shall be preferred. Adequate
( Clause 56.3 ) fuse protection shall be provided for the rectifiers.
Rectifiers/thyristors used for magnets shall be protected
Sl No. Winding Brake Duty Rating against switch surges.
(1) (2) (3) (4)
57.3 Control for d.c. Supply
i) Shunt Emergency Conditions (with
economy resistance When a d.c. supply circuit is used, motor acts as a
inserted where generator in the lowering direction, the control shall be
necessary such that:
ii) Shunt Intermittent 1h a) motor shall not exceed a pre-determined maximum
operation, any
motion
revolutions per minute;
iii) Series Hoist 30 min
b) progressive degrees of braking is provided;
c) adequate light hook lowering speed is provided;
d) brake is prevented from being released by back
Table 20 Brake Magnet Operating Voltages and emf of the motor when power supply is interrupted;
Currents and
( Clause 56.3 ) e) electro-mechanical brake is automatically applied
when circuit breaker or contactor is opened.
Sl Winding d.c. Magnets a.c. Magnets
No. 57.4 Braking Controls
(1) (2) (3) (4) When an electro-mechanical brake is used as an
i) Shunt Lift at 80 percent Lift at 80 percent emergency or parking brake or when such an emergency
rated voltage rated voltage or parking brake is used with hand or foot operated
Hold at 50 percent Hold at 50 percent travel service brakes, the brake actuating device shall
rated voltage rated voltage remain in the circuit when the main circuit breaker is
ii) For series Lift at 40 percent — closed. The brake shall apply automatically when the
resistor rated current power supply fails or when the circuit breaker is opened
iii) Series or Hold at 15 percent — or on operating an emergency stop push button or
potentiometer rated current switch, but not when the controller handle is brought to
control the ‘off ’ position. The brake shall lift off when voltage
at the coils is a minimum of 85 percent of rated voltage.
57 FLOOR CONTROL ─ WITHIN CONTROL Provision shall be made for emergency application of
FEATURES this brake by means of the emergency stop push button
or switch. In the arrangement of connections to the
57.1 Control Circuits hoisting motion brake coils, means shall be provided
to ensure that when associated drive motors are de-
If the mains supply is a.c. and the control circuits are
energized, the stored electrical energy in these motors
supplied at reduced voltage, the supply to these circuits
will not delay the application of the brake.
shall be from the secondary winding of an isolating

51
IS 3177 : 2020

57.5 Acceleration Control They shall not interfere with the driver’s vision and
Automatic control of acceleration shall be provided shall be readily visible to the concern persons.
for all crane motions, unless for any motion another
59 HEATING AND AIR-CONDITIONING
control system is specified. The hoist motion circuits
shall enable any load to be lowered with safety and 59.1 Machinery House
the hoist motors shall remain under effective control
with the controller in all positions. While calculating Natural or forced ventilation should be provided to
the number of rotor contactors, peak accelerating/ disperse thermal power generated by the machinery
decelerating torques and pull out torque of the motor and its equipment. Where electronic equipment is used
should be taken into account. and working conditions do not guarantee an ambient
temperature for proper functioning of the electronic
For creep lowering speed on hoisting motion, relatively equipment, an air conditioning unit should be provided.
flat speed control shall be provided. Peak accelerating/
decelerating torque shall be considered as minimum 59.2 Operator Cabin
180 percent of full load torque for cranes under M6 to
If necessary, heating appliances should be provided
M8 mechanism class.
in the cabin. This apparatus of black heat/non radiant
58 AUXILIARY REQUIREMENTS type shall be securely fixed. It must be provided
with a thermostat and must have such a power to
58.1 Lighting on the Crane assure a minimum temperature of 25 ± 2°C, taking
into account the environment in which the equipment
Necessary lighting arrangement for approaches and for is installed. This apparatus must be fed independently
carrying out maintenance work without danger shall of the principal circuits of the hoisting appliance. If
be provided by the crane manufacturer in consultation required by the environment an air conditioning unit
with the purchaser. The nominal voltage of lighting should be installed in the cabin to maintain a maximum
circuits shall not exceed 250 V. 220 V a.c. can be used acceptable temperature. This apparatus must be fed by
for hand lamp if circuit is protected with earth fault. a circuit independent of the principal circuits of the
If hand lamp is provided it shall not be connected to a hoisting appliance.
circuit exceeding 250V d.c. or 25V a.c. supply. In the
case of an a.c. circuit hand lamp shall be fed through a 60 AUXILIARY CIRCUIT
double wound isolating transformer with some part of
the secondary winding earthed. The primary winding If there is no possibility of supply in the proximity,
of the transformer shall be controlled by a double auxiliary circuits should be provided for maintenance
pole switch. Fuses or MCB shall be provided in each purposes, as follows:
pole of the primary circuit and one pole of each of the a) A circuit for portable lighting, if the ambient
secondary circuits. lighting is not sufficient to carry out maintenance;
58.2 Cabin Lighting b) A circuit for portable tools according to agreement
between customer and supplier; and
The cabin and the panel room shall be provided with
adequate lighting. c) These circuits should be protected by a differential
circuit breaker of high sensitivity and they shall
58.3 Under the Bridge Lighting be independent of the principal circuits of the
hoisting appliance.
Under bridge lighting, if required by the purchaser shall
be mounted on shock absorbers and so installed that 61 LIFTING MAGNETS AND LOAD HOLDING
they can be serviced easily. DEVICES
58.4 Other Provisions in the Cab
61.1 General
As required by the purchaser fans, air conditioners or
The requirements given in this clause apply to all load
cabin heating arrangements shall be provided by the
holding devices, such as, lifting magnets and vacuum
crane manufacturer.
lifters. Load holding devices are normally designed
58.5 Crane Warning Signals to a cyclic duration factor of 50 percent. Other cyclic
duration factors should be as agreed to between the
If required by the purchaser, the crane shall be equipped
manufacturer and the user.
with warning lights on both sides of the crane and/
or sound signals to indicate approach of the crane or The tear-off force should be at least twice the lifting
hook. Each warning light fitting shall contain two LED capacity. If there is a stand-by power supply from
connected in parallel. Each fitting shall be provided batteries, the holding time should be at least 20 min.
with an anti-vibration mounting and shall be accessible. In this case, an automatic charging unit and a charge

52
 IS 3177 : 2020

level indicator should be provided. Use of the stand- 61.5 Cable Drum
by supply should be indicated visually and audibly The magnet cable drum shall be as follows:
for general warning. If the battery voltage level is not
adequate, a device preventing the installation from a) Arranged so that magnet cable does not foul with
being used should come into effect. If required by the the hoisting ropes;
purchaser, the crane shall be fitted or provision shall be b) Such that the cable will become neither unduly
made to permit in the future fitting of lifting magnets, taut, nor slack enough to touch the hoist ropes or
magnet control and protective gear. get entangled; and
c) Capable of accommodating and paying out the
61.2 Magnet
length of cable necessary for the magnet to reach
The type and size of magnet shall be decided based on its lowest position.
the details given by the purchaser. The type and size of
magnets shall preferably be in accordance with details Cable drum when attached to the hoist drive, a
specified in Annex D. disengagement device shall be provided. Where
power is fed to the magnet by a brush and slip ring
Each magnet will be water tight and shall be provided arrangement on the magnet cable drum, two brushes
with a water tight terminal box having the under per slip-ring shall be provided and the rings shall
mentioned features, however rectangular magnets are have adequate clearance. The slip ring insulation
normally of fabricated construction type also can be shall be of non- tracking material and the assembly
used as follows: shall be enclosed by an easily removable cover, oil-
a) Integral construction with magnet casing; proof for indoor cranes and weather proof for out
b) A gland through which the magnet load is brought door cranes. A spare slip ring complete with brush
to the magnet terminals; gear arrangement shall be provided, if required by the
purchaser.
c) A cover which shall be easily removable without
interfering with the magnet lead inlet; 61.6 Magnet Control and Protective Equipment
d) Adequate thickness of box and cover; and The magnet shall be controlled either by direct-online
e) Non-linear type discharge resistor of adequate control or potentiometer control as required by the
rating and the rectangular magnets are fabricated purchaser. In both methods of control the magnet shall
constructions and nice fabricated type of magnets. be demagnetized by current reversal. In direct-on-line
control, the magnet shall be energized by switching it
61.3 Magnet Lead and Cable
across full mains voltage and discharge resistance shall
The magnet lead and cable shall be flexible three be connected on switching ‘OFF’. The control shall be
core cables. If specified by the purchaser, the magnet affected by means of a master controller and magnetic
lead shall be protected by rubber hose complying contactor panel.
with the relevant Indian Standard. The magnet lead
shall be so arranged that it does not become unduly 61.7 Battery Back up System
slack or taut during normal operation of the crane. If required by the purchaser, necessary and adequate
It should be so located that magnet cable does not battery back up system shall be provided by the
foul with the rope. The use of sheaves and rollers for supplier. The rechargeable battery shall keep the
the cable should be avoided as far as possible. The magnet energized till the time the lifted load is brought
magnet cable shall be rigidly attached to the bottom to a safe location, in the case of power failure. If
block by a suitable cable clamp at a point above there is a stand-by power supply from batteries, the
magnet coupling. holding time should be at least 20 min. In this case,
an automatic charging unit and a charge level indicator
61.4 Magnet Couplings
should be provided. Use of the stand-by supply should
The type of magnet coupling shall be as agreed to be indicated visually and audibly for general warning.
between the purchaser and the supplier. The coupling If the battery voltage level is not adequate, a device
shall comply with the following requirements: preventing the installation from being used should
a) Couplings shall be of rugged construction; come into effect.
b) At the moment of breaking, the contacts shall 62 ELECTRICAL EQUIPMENTS LOCATED
be enclosed by insulating material and earth ON THE CRANE BRIDGE
connection shall break last;
c) Provision shall be made to fasten the coupling in 62.1 General
the closed position; and Electrical equipments mounted on bridge platform
d) Socket shall be connected to the supply and plug shall be enclosed in suitable enclosure with provision
to the magnet or magnet lead. for easy access to the parts inside. The units shall not

53
IS 3177 : 2020

impede the maintenance of the long travel drives. The SECTION 4 INSPECTION AND
control panels or units shall be so spaced that efficient TESTING
maintenance is possible. They shall withstand the
mechanical forces imposed by the crane under service
conditions. For cranes working in open yard, electrical 64 INSPECTION PROCEDURE
equipments shall be of weather-proof construction for
64.1 General
the duty. Control panels and other electrical equipment
shall be so located that there is no chance for oil or If required by purchaser and specified in the contract,
grease falling on them. The thorough fare between any the purchaser or his authorized representative shall have
portion of the crane and the exit platform shall not be access to the manufacturer’s works at all reasonable
impeded by any control unit. However, also refer the times for the purpose of witnessing the manufacturer,
below given Table 21 for information may suitably inspection and testing of all products concerned and/or
used for the enclosures, where discussed. the complete crane.
Any work found defective or which is not in accordance
62.2 Identification of Circuits
with the drawings or of the terms of this code and/or
All switches, fuses, panels, controllers, resistors contract may be rejected by the inspector (see Fig. 14,
connectors and other electrical elements of controller 15 and 16).
panels shall be adequately labelled or marked by
furnishing functional nomenclature to facilitate 64.2 Test at Manufacturer’s Works
identification of the circuit. All main and control All electrical and mechanical equipment shall be tested
wires and conductors shall be ferruled and numbered in accordance with the appropriate Indian Standard at
at both ends as per drawing for quick identification. either the crane maker’s or equipment manufacturer’s
All equipment terminals shall be numbered and works and test certificates provided, if required by the
tagged. purchaser.
Table 21 Information for Enclosures If required by the purchaser and specified in the contract,
the crane shall be tested at manufacturer’s works under
( Clause 62.1 ) full load and 25 percent overload of hoisting and cross
traverse motions. Travelling gear may be run light to
Sl No. Equipment In-Door Out-Door check shaft and gear alignments. The load test shall
(1) (2) (3) (4) be carried out at the manufacturer’s premises and/or
i) Control panel IP 54 IP 55 (with purchaser’s premises as mutually agreed between the
double door) manufacturer and the purchaser.
ii) Limit switches IP 54 IP 55 Any test required by the purchaser beyond those called
iii) Resistances IP 22 IP 33 for in the appropriate Indian Standard shall be subject
to mutual agreement and shall be carried out at the
iv) Motor IP 54 IP 55
purchaser’s expense.
(without cover) (with cover)

64.3 Trolley Movement Over Bridge Girder

63 DRAWINGS Whether all the 4 wheels are in contact with the rails at
A wiring diagram of the crane shall be supplied by all places……………………….
the manufacturer. The diagram shall give the rating of
each motors, the cable sizes and such other information 64.3.1 Checking of Axial and Angular Misalignment
which will facilitate inspection and maintenance of
the crane. All electrical elements shall be designated Quality of Axial Angular
by functional nomenclature and numbered for Alignment of Misalignment Misalignment
identification. All main and control wires and terminals Geared Couplings mm degree
shall be numbered to facilitate wiring and identification a) Main hoist .................... ....................
while maintaining. A schematic diagram shall also be
supplied for contactor controlled cranes along with b) Auxiliary hoist .................... ....................
the list of parts used. In addition to the drawings
the following drawings and documents may also be c) Cross traverse .................... ....................
provided as given below: d) Long travel .................... ....................
a) External termination drawings and cable schedule;
and
b) GA drawings of control panels.

54
 IS 3177 : 2020

S2

CD 2 TS 4

ED 3 ED1
W2
W4 W 3 TS 7 TS 6 TS 5 TS3 TS 2 TS 1 W1
ED 4 ED2

CD1

S1

DATA W1 W2 W3 W4 ED1 ED2 ED3 ED4 S1 S2 CD1 CD2

SPECIFICATION
ACTUAL

TOLERANCE

DATA TS1 TS2 TS3 TS4 TS5 TS6 TS7 REMARKS

SPECIFICATION
ACTUAL
TOLERANCE

CRANE LOCATION :
CAPACITY AND TYPE :
CRANE MANUFACTURER :
ORDER NUMBER :
DATE OF INSPECTION :
PLACE OF INSPECTION :

Fig. 14 Crane Dimensions

FIG. 14 CRANE DIMENSIONS

55
IS 3177 : 2020

CL
h4 h3 h2 h1 H1 H2 H3 H4

GIRDER h4 h3 h2 h1 L H1 H2 H3 H4
DRIVING
TRAILING

a) DEFLECTION DUE TO DEAD LOAD OF BRIDGE GIRDER :

b) DEFLECTION DUE TO TROLLEY :
C) DEFLECTION DUE TO RATED LOAD :
d) ACTUAL CAMBER :
e) ACTUAL DEFLECTION :

REMARKS:

NOTE:- USE WATER LEVEL TO TAKE READING

Fig. 15 Spacing Dimensions

FIG. 15 SPACING DIMENSION

w2

D2

S2 S1
D1

w1

DATA W1 W2 S1 S2 D1 D2 REMARKS

SPECIFICATION
ACTUAL

TOLERANCE

REMARKS :

FIG. 16 TROLLEY DIMENSIONS

Fig. 16 Trolley Dimensions

56
2000 mm min. TO THE TOP OF
BRIDGE PLATFORM T2
P1 P2
T1
 IS 3177 : 2020

64.3.2 Condition of Cable Trolleys 64.3.7 Checking of Protective Coating

a) Are they provided with ball bearings: ...................
Painting Actual As per Specification
.................
a) Prime coat ............. .............
b) Are they fitted with single flanged wheels:
............................ b) Finishing first ............. .............
coat
c) How many wheels per trolley: ..............................
.................. c) Second coat ............. .............
d) Number of trolleys: ..............................................
.................. 64.3.8 Checking of Nut and Bolt

64.3.3 Performance of Mechanisms (Each Mechanism Bolt Holes Alignment Fit bolts
should be Run for 30 min Continuously for this Test) (Tolerance level of bolts and holes) (Reamed holes)
a) Long Travel (No load running on sleepers or on a) Bridge girder splice ..................
test bench)
b) Gantry leg spice ..................
1) Noise level from gear box................................ c) End carriage splice ..................
.......……………..
d) End connection (end carriage ..................
2) Oil leakage through input and output and girder)
shaft................................ ..
3) Linear speed of wheel treated at full speed. 64.3.9 Idle Running and Speed of the Motor
............................
a) Main hoist ..................................
4) Hardness of gears/ pinion................................
b) Auxiliary hoist ..................................
5) Material of gears/ pinion.................................
c) Cross traverse ..................................
b) Main Hoist d) Long travel ..................................
1) Noise level from gear box ........................
64.3.10 Electrical
2) Oil leakage through shafts .....................
Motors (idle running and measuring the no load and
3) Surface speed of wire rope drum ............ full load current):
4) Hardness of gears/pinion ....................... a) Main hoist ..................................
5) Material of gears/pinion .......................... b) Auxiliary hoist ..................................
c) Auxiliary Hoist c) Cross traverse ..................................
1) Noise level from gear box ........................ d) Long travel ..................................
2) Oil leakage through shafts ..................... (variable speeds of different motion under no load and
3) Surface speed of wire rope drum ............ load condition)
4) Hardness of gears/pinion ........................
Main Auxiliary Cross Long
5) Material of gears/pinion .......................... Hoist Hoist Traverse Travel
d) Cross Traverse I notch .......... .......... .......... ..........
1) Noise level from gear box ........................ II notch .......... .......... .......... ..........
2) Oil leakage ............................................... III notch .......... .......... .......... ..........
IV notch .......... .......... .......... ..........
3) Linear speed ............................................
V notch .......... .......... .......... ..........
4) Hardness of gears/pinion ........................ Rated speed .......... .......... .......... ..........
5) Material of gears/pinion .......................... as per specification
64.3.4 Hardness 64.3.11 Checking of Controls
a) Long travel wheels ........................................ Control Panel As per Actual
b) Cross traverse wheels ................................... Drawing (IP 54 or
c) Permissible values ........... IP55)
a) Size ............... ...............
64.3.5 Material of Wheel for LT, CT ................... b) Power contractor size
64.3.6 Hardened ....................... (Process of hardening) and rating ............... ...............

57
IS 3177 : 2020

c) Rotor contractor size and 64.3.15 Check the Functioning and Observe
rating ............... ...............
Main Auxiliary Cross Long
d) Terminal blocks size ............... ............... Hoist Hoist Traverse Travel
e) Types of wiring ............... ............... a) Contractors ........ ........ ........ ........
f) Cable (aluminium/copper) ............... ............... b) Timers ........ ........ ........ ........
g) Spacing of the contractors c) Limit switches ........ ........ ........ ........
and timers ............... ...............
d) Overload ........ ........ ........ ........
h) Multi hinged doors ............... ............... protection
j) Type of beeding provided ............... ............... e) Controllers ........ ........ ........ ........

64.3.12 Wiring 64.3.16 Check the Functioning of Accessories

Crane Trolley Cabin a) Ceiling fan ..............................................
a) Any defect noticed ? ........... ......... ........ b) Warning bell ………………………………
c) Under bridge lighting ……………………..
b) What type of wiring ? .......... .......... ........
d) Operator’s seat ……………………………
c) Rectification needed ? .......... .......... ........
d) Whether cabin wiring 64.3.17 Insulation Tests
completed ? .......... .......... ........ After erection but before the crane is connected to
e) Are the different the supply, the insulation of the electrical equipment
motions as per wiring shall be tested by a suitable instrument and any
diagram ? .......... .......... ........ defects revealed shall be rectified. The voltage
required for the insulation resistance test shall be
64.3.13 Checking of Functions d.c. voltage not less than twice the rated voltage of
the system concerned and all phase shall be checked
a) Is plugging and reversing functioning?.................
for each crane motion or system. Any reading less
b) Is creeping functioning? ………………………… than 0.5 MΩ obtained with an insulation resistance
c) Is counter torque lowering working satisfacto­ tester shall be verified. The wiring under test shall
rily? ………………… be subdivided until a reading higher than 0.5 MΩ is
d) Is zero speed monitor functioning ? ……………… obtained. Failure to obtain higher reading shows an
unsatisfactory state of the insulation and hence shall
64.3.14 Resistors be rectified.
NOTE — A reading below 0.5 MΩ obtained with such a tester
Main Auxiliary Cross Long may indicate that unduly low proportion of the prescribed test
Hoist Hoist Traverse Travel voltage is in fact being applied. If an installation has been
a) Rating and ........ ........ ........ ........ sub-divided for test purposes each sub-division shall meet the
requirements. The insulation resistance of each wiring circuit
value of
exclusive of connected apparatus shall be not less than 2 MΩ.
resistance in If necessary, it shall be permissible to disconnect individual
each step items of equipment making this test.
b) Type of ........ ........ ........ ........
64.3.18 Test Certificate
resistor used
c) Is resistor ........ ........ ........ ........ If specified by the Government of the State in which
as per the crane is to be installed, the tests shall be carried out
specification? in the presence of the competent authority appointed,
by the concerned industrial safety department of the
d) Lugs to be ........ ........ ........ ........ government. The crane shall be put in use only after
provided in clearance and acceptance certificate is issued by the
the terminals competent authority. The purchaser shall arrange to
e) Heating ........ ........ ........ ........ ensure presence of the competent authority at the time
condition of testing. The manufacturer shall issue a test certificate
during no clearly indicating the tests carried out and results
load and full obtained.
load testing

58
 IS 3177 : 2020

65 GENERAL REMARKS 65.1.2 Proforma for Welding Profiles Certificate

(see Table 23)
65.1 Welding Inspection Procedures
Table 23 Certificate
65.1.1 Visual Examination (see Table 22 for ( Clause 65.1.2 )
verification)
Sl Condition Acceptable/ Reason
Not for Not
No.
Table 22 Certificate Acceptable Acceptable
( Clause 65.1.1 ) (1) (2) (3) (4)
i) The faces of the fillet welds
Sl Condition Acceptable/ Reason (a) Convex
No. Not for Not
(b) Flat
Acceptable Acceptable
(c) Slightly concave
(1) (2) (3) (4)
(concavity must not exceed
i) The weld has no cracks the sum of 0.1s + 1 mm
ii) Complete fusion exists where is the actual size of
between adjacent layers of the fillet in mm)
weld metal, and between ii) a) Groove welds must be
weld metal and base metal free of the discontinuities.
iii) All crates are filled to full b) In case of butt and corner
cross section of the weld joints, the reinforcement
height R, must not exceed
iv) Weld profiles are in
3 mm for metal thickness of
accordance with Fig. 17
51 mm and under 5 mm for
v) Permissible frequency and metal thickness over 51 mm
size of piping porosity in
iii) Where the surface of butt
fillet welds shall be limited
joints are required to be
as follows:
flush, the thickness of the
a) For primary welds thinner base metal or weld
not more than 1 mm metal shall not be reduced
pore in each 102 mm by more than 0.8 mm
length and no larger in
diameter than 2.4 mm
iv) Under cut depth shall not
b) For secondary welds
exceed 0.8 mm or 7 percent
the sum of the
of the base metal thickness
diameters of piping
porosity shall not v) Welds shall be free from
exceed 9.5 mm overlap
in any linear mm
of weld and shall
not exceed 19 mm
in any 305 mm length 65.1.3 Radiography Procedure and Acceptability
of weld
a) Radiographic Procedure
vi) The actual size of a portion
of continuous fillet weld, 9.5 1) Radiographic shall be made by either X-ray or
mm or larger, can be under isotope radiation methods.
the normal required fillet
weld size by 1.6 mm without
2) The quality level of inspection for radiographs
correction, provided that the shall be 2.2 T, except that the diameter of the
under size portion does not 2T penetrate meter hold need not be less than
exceed 10 percent of the 1.6 mm for X-ray or 2.4 mm for gamma ray
weld length radiographs.
vii) Primary groove welds must
3) Radiographs shall have a H and D density
have no piping porosity
between 1.5 and 3.5.

59
 IS 3177 : 2020

45°
SIZE SIZE SIZE SIZE

C
SIZE SIZE SIZE SIZE

DESIRABLE FILLET WELD PROFILES ACCEPTABLE FILLET WELD PROFILES

SIZE SIZE SIZE SIZE SIZE SIZE

INSUFFICIENT EXCESSIVE EXCESSIVE OVERLAP INSUFFICIENT INCOMPLITE
THROAT CONVEXITY UNDERCUT LEG FUSION

UNACCEPTABLE FILLET WELD PROFILES

R
METAL THICKNESS
WELD REINFORCEMENT SMOOTH WASH UNDER CUT
t (mm) R (mm) SHALL NOT BE EXCEED
t
0.80 mm OR A MAXIMUM 0.07t
50 OR LESS 3.18
OVER 50 4.77
R
ACCEPTABLE BUTT JOINT WELD PROFILE

EXCESSIVE INSUFFICIENT EXCESSIVE OVERLAP

CONVEXITY THROAT UNDERCUT

WELD SIZE TOLERANCE

WELD SIZE WELD SIZE
IN (mm) TOLERANCE IN (mm)
UNDER 10 +1.6
0

10 OR LARGER +3.18
- 1.6

UNACCEPTABLE BUTT JOINT WELD PROFILES

All dimensions in millimetres.

FIG. 17 WELD PROFILES

Fig. 17 Weld Profiles

60
 IS 3177 : 2020

4) Two or more penetrate meters shall be used b) Acceptability of Radiographic Welds

for each radiographs on a film 254 or more in 1) Welds subject to radiographic examination
length. Only one penetrate meter need be used shall first be visually examined to check the
for radiographs on film less than 254 mm in cracks and welding profiles.
length.
2) The greater dimensions of the porosity or
5) Radiographs shall be made with a single fusion type discontinuity indications that are
source of radiation approximately centred 1.6 mm or larger shall not exceed the size.
with respect to the length and width of the area
3) Discontinuities meeting requirements of 1 and
being examined. The distance from radiation
2 and having a greatest dimensions of less than
source to the film shall not be less than 7
1.6 mm are nevertheless not acceptable if the
times the maximum thickness of weld being
sum of their greatest dimensions 9.5 mm in
examined, and the rays shall not penetrate the
any linear 25 mm of weld.
weld at an angle greater than 26.5° from a line
perpendicular to the weld surface. The film, 4) The limitations for 38 mm groove weld
during expose, shall be as close as possible to effective throat shall apply to all welds with
the surface of the weld opposite to the source larger effective throats.
of radiation. 5) A recommended form for reporting the results
of radiographic examination is shown as per
65.1.3 c).
c) Report of Radiographic Examination of Welds

Project ..............................................................................................................................................
Quality requirements — Section No. ...............................................................................................
Reported to ......................................................................................................................................
WELD LOCATION AND IDENTIFICATION SKETCH
Technique source ...............................
Film to source ....................................
Exposure time ....................................
Screens ...............................................
Film type ............................................
(Describe length, width and thickness of all joints radiographed)

Date Weld Identification Area Interpretation Repairs Remarks

Accept Reject Accept Reject

We, the undersigned, certify that the statements in this record are correct and that the welds were prepared and
tested in accordance with the requirements of AWS Specification D-14.1

Radiographer(s) .............................................. Manufacturer or contractor ...........................

Interpreter ...................................................... Authorized by ..................................................
Test date .......................................................... Date .................................................................

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IS 3177 : 2020

65.1.4 Ultrasonic Test, Magnetic Particle and Liquid c) Magnetic particle examination of welds A,
Penetrant Tests as per IS 4620, IS 5334, IS 3658 d) Liquid penetrant examination of welds, and
respectively.
e) The recommended forms for reporting the
a) Ultrasonic examination of welds, results of the above tests as shown in the formats
b) Ultrasonic testing procedures acceptance criteria, below:

REPORT OF MAGNETIC PARTICLE EXAMINATION OF WELDS

Project ..............................................................................................................................................
Quality requirements — Section No.
...............................................................................................................................................
Reported to ................................................................................................................................................

WELD LOCATION AND IDENTIFICATION SKETCH

Date Weld Identification Area Interpretation Repairs Remarks

Accept Reject Accept Reject

We, the undersigned, certify that the statements in this record are correct and that the welds were prepared and
tested in accordance with the requirements of AWS Specification D-14.1

Inspector…..................................................... Manufacturer or contractor ...........................

Test date .......................................................... Authorized by ..................................................
Date .................................................................

Method of Inspection :
1. Dry 2. Wet 3. Residual 4. Continuous 5. A.c. 6. D.c. 7. Half-wave

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 IS 3177 : 2020

DYE PENETRANT INSPECTION REPORT

Customer .......................................................... Date...................................................................

Order No. .......................................................... Material ............................................................
Drawing No. ..................................................... Specification .....................................................

Places Description Comments

Soak time .........................................................................................

The above parts have been carefully tested with dye penetrant. This inspection is limited to defects of the type
which can normally be located with the dye penetrant inspection method.

65.1.5 Repair and Correction of Discontinuities 65.1.6 Base Material Repairs

a) Overlap or excessive convexity — Remove excess a) Defects in edges of plate — If a defect is found in a
weld metal; plate edge that excess the limits, shall be removed
b) Excessive concavity of weld or crater and under and repaired;
size welds — Prepare surfaces and deposit b) Arc strikes and temporary attachment — Areas :
additional weld metal. All slag shall be removed Arc strikes or severed temporary welds in critical
and the adjacent base metal shall be cleaned locations, must be ground smooth to ensure that
before additional welding; no abrupt change in section exists;
c) Cracks in weld or base metal — Determine the c) Removal of defective areas — The removal of
extent of the cracks by dye penetrant magnetic weld metal or portions of the base metal may be
particle inspection or other suitable means. done by machining, grinding, chipping, oxygen
Remove the crack and adjacent sound metal for gouging or air carbon arc gouging. It shall be done
a 51 mm length beyond each end of the crack and in such a manner that the remaining weld metal or
then reweld; and base metal is not nicked or undercut.
d) Under cutting — Under cutting may be repaired Unacceptable portions of the weld shall be
by grinding and blending or by welding. Grinding removed without substantial removal of the base
should be performed with a pencil type grinder. metal. Additional weld metal, to compensate for
Blending shall be done with a slope not to exceed any deficiency in size, shall be deposited using
1 in 3 on plates of 13 mm thickness and above, up low hydrogen electrodes;
to 7 percent reduction of base material thickness d) Distortion and camber — Members distorted
is permitted. When undercut is to be repaired by by welding shall be straightened by mechanical
welding, prepare the surfaces and then deposit means or by carefully supervised application of a
additional weld metal. limited amount of localized heat. The temperature

63
IS 3177 : 2020

of heated areas, as measured by approved methods c) Allow trolley to move entire length of bridge span,
shall be limited to that imposed by the materials are fully watching alignment of trolley collector
exposed to the heat, but it shall not exceed 590°C pole and bridge conductors and also watching
for quenched and tempered steel nor 890°C for for any interference with building and building
other steel; and equipment. Do not run trolley into end stops;
e) Correction of improperly fitted and welded d) Adjust end limit switch trip;
members — If a weld is found to be e) Reverse master switch and repeat (a) to (d); and
unacceptable after additional work has
f) Reset trolley timers, if needed.
rendered it inaccessible, or new condition make
correction of the unacceptable weld dangerous 66.1.3 Bridge Motion (Long Travel)
or ineffectual, or original conditions shall be
a) Place master switch in 1st point ‘bridge travel’
resorted by removing welds or both, before the
position;
corrections are made.
b) Observe contactor sequence and direction of
66 TESTING travel through full range of master switch. Reverse
phasing, if necessary;
66.1 Preliminary Tests c) Allow crane to move entire length of travel,
The preliminary tests shall be done before the hoist carefully watching alignment of bridge collector
block is reeved. Test the various methods as follows. pole and bridge conductors and also watching
Close the runway, disconnect the switch, the main for any interference with building and building
crane disconnect switch, and the individual motor and equipment. Do not run crane into end stops;
accessory switches in that order. d) Adjust end limit switch trip;
66.1.1 Hoist (Main Hoist and Auxiliary Hoist) e) Reverse master switch and repeat (a) to (d); and
a) Place master switch in 1st point ‘hoist’ position; f) Reset bridge timers, if needed.
NOTE ― At manufacturer premises idle run of bridge motion
b) Observe the contactor for proper sequence and
drive can be tested with no load.
direction of hoist drum rotation. If operating
correctly the speed may be gradually increased; 66.1.4 Check all Accessories for Proper Function
c) If hoist contactor and rotation is not correct, shut 66.2 No-Load Test
off power, reverse two leads on the main line
collectors or on the hoist motion (whichever is 66.2.1 After reeving the hoist, the operation of the hoist
incorrect), to obtain the correct phasing. Restore limit switches are to be tested as follows:
power the repeat step (a) and (b);
a) Raise empty blocks to within about 500 mm of its
d) After checking hoisting, return master switch upper position and stop;
to neutral position and observe braking action,
b) Raise the empty block at the lowest control speed
readjust if needed;
until the limit switch trips and stops the hoisting
e) Place master switch in ‘lower’ 1st point and motion. During this operation watch for proper
observe, if correct motion and contactor sequence alignment between load block and limit switch
occurs; trip;
f) Reset hoist timers, if needed; c) Check that block stops at correct height as shown
g) Speed points shall be for accelerating only on drawings. Adjust limit switch, if necessary;
and shall not be used for running any distance. d) Lower the block suitably to reset the upper limit
Maximum time for acceleration is 15 s, unless switch;
special equipment is provided. If held any longer,
e) Raise block at about half speed;
resistor damage may occur; and
f) Check for adequate clearance between block and
h) The above steps (a) to (g) shall be repeated for
trolley frame (or upper sheaves);
auxiliary hoist same as main hoist.
g) Repeat points (d), (e) and (f) with block being
66.1.2 Cross Travel Motion raised at full speed;
a) Place master switch in I point ‘trolley travel’ h) Check for one spare groove available on drum in
position; top most position; and
b) Observe contactor sequence and direction of travel j) Ensure that at least two rope turns are still wounded
through full range of master reverse phasing, if on drum before rope clamp to avoid chances of
necessary; load coming on rope clamp.

64
 IS 3177 : 2020

66.2.2 If crane is equipped with a lower limit switch 66.4 The actual hoisting and travelling speed shall be
proceed as follows: within ± 10 percent of specified speed. In shop test
a) Lower the empty block until one wrap rope long travel speed may be verified in idle condition by
remains on each end of the drum; and revolution of wheels.
b) Set lower limit switch to trip at this point (or any 66.5 Overload Tests
higher elevation).
66.5.1 After full load test but before putting crane into
66.2.3 Never lower block beyond the point at which service, crane shall (with overload relays appropriately
one wrap remains at each end of the drum. set) be tested to lift and sustain a minimum test load
of 125 percent of the working load, when the load is
66.3 Load Test
located at the center of the span.
After the no-load running test has been completed,
the crane should be tested with loads in the following 66.5.2 During the overload test each motion in turn shall
manner: be maneuvered in both directions and the crane shall
sustain the load under the full control. The specified
66.3.1 Raise a load equal to about 50 percent of the speeds need not be attained but the crane shall show
rated load not higher than required to clear its supports itself capable of dealing with the overload without
and stop adjust brake, if necessary. Raise load about difficulty.
1 m above its supports and stop. Lower the load
about 300 mm and stop. Check drift of load during 66.5.3 Duration of overload test should be kept as
stopping. If load drifts, brakes should be corrected. minimum as possible.
Repeat this operation until proper adjustment of NOTES:
brakes is obtained. Lower load carefully back to its 1 Test load and necessary lifting tackles shall be provided by
supports. the purchaser or as per contract.
2 If the load test is to be carried out at crane manufacturer’s
66.3.2 Load the hoist motion with 100 percent of rated premises the same should be agreed by both manufacturer and
capacity and follow the same procedure as mentioned purchaser. The limitation of load test should be discussed and
in 66.3.1. finalized during finalization of order.

a) Hoist the load high enough to clear all obstructions

but not higher than necessary. Move trolley across 67 CRANE-RECOMMENDED/PREFERRED
the entire span of bridge. Transport the test load by PARAMETERS
means of the bridge for full length of the runway in
one direction with the trolley at the extreme right 67.1 General
hand end of the crane, and in the other direction To aid economic manufacture it is recommended that
with the trolley at the extreme left hand end of the the crane parameters given in 67.2 to 67.4 be selected
crane. from a progression based upon the preferred number
b) The deflection test shall be carried out with the series.
safe working load at rest in air and with the trolley 67.2 Preferred Lifting Capacities
in a central position. The measurement shall not
be taken on the first application of the load. The Preferred series R10 shall be used for capacities up to
datum line for measuring the deflection should and including 125 tonne and R20 for capacities above
be obtained by placing the trolley without live 125 tonne. The preferred lifting capacities (in tonne)
load on the extreme end of the crane span with are as follows:
smaller hook approach ( see IS 807 for allowable
deflection limit ). 1.0 3.2 10 32 100 225 400
c) Measure the ‘no-load’ and ‘full load’ current 1.25 4.0 12.5 40 125 250 450
of the motor and verify whether it is as per the 1.6 5.0 16 50 140 280 500
recommendations of motor manufacturers. Check
2.0 6.3 20 63 160 320 560
the resistors in the circuit whether any over-
heating of the element occurs. 2.5 8.0 25 80 200 360 etc.
d) If separate creep speed control is provided it
should be run for check-out over a distance of
about 500 mm. 67.3 Preferred Lifting Height
e) Check overload relays (if any) for proper Preferred series R5 shall be used for lifting heights
function. up to and including 16 m and R10 for heights above

65
IS 3177 : 2020

16 m. The preferred lifting heights (in metres) are as 67.4 Preferred Speed of Operation (Full Speeds)
follows: Preferred series R5 and R10 shall be used for full
speed of operation respectively. The preferred speeds
2.5 10 25 50 of operation (in m/ min) are as follows:
4.0 16 32 63
6.3 20 40 etc 0.63 1.6 4.0 10 25 63 160
0.8 2.0 5.0 12.5 32 80 200
1.0 2.5 6.3 16 40 100 -
1.25 3.2 8.0 20 50 125 -

66
 IS 3177 : 2020

ANNEX A
( Clause 1.1 )

A-1 LIST OF THE STEEL PLANT CRANES g) Bucket handling cranes at various raw and scrap
AND SPECIAL SERVICES MACHINES material stock yards, trolley cranes and bridges
COVERED BY THE CODE handling, coal, ore, limestone, etc, or by-product
or waste materials, such as slag, cinder and mill
This specification applies to the following types of
scale;
cranes and special service machines (the list is not
exhaustive): h) Magnet cranes used for skull cracking, and for
handling and preparing steel scrap;
a) Coke ovens charging;
j) Magnet and cradle cranes for handling semi-
b) Coke ovens drawing (coke pushers); finished steel (such as, slabs, blooms and billets)
c) Blast furnace cast house; and for stocking and shipping finished products
d) Pig machine; (such as, structurals, rails, plates and sheets) in the
e) Ladle cranes used in the charging and/or tapping various mills and departments.;
of hot metal mixer vessels, bessemer converters k) Ingot and ingot mould handling cranes at stripper
of LD vessels, open hearth and electric furnaces, yards, ingot stock yards and soaking pit buildings,
etc.; etc;
f) All cranes and machines (either floor mounted m) Mill building cranes for changing stands and rolls
or running on over-head gantries) used to cold in the various mills; and
charge open hearth or electric furnace, etc, or n) Cranes and repair trolleys on fixed high level
used to charge and draw all types of reheating gantries for the servicing and repair of furnaces or
furnaces; of ladle cranes or stripper cranes, etc.

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IS 3177 : 2020

ANNEX B
( Clause 1.3 )

B-1 TYPICAL CLASSIFICATION OF CRANE MECHANISM

This Annex shows the range of crane mechanism classifications normally associated with particular types of
crane. It should not considered as substitute for the process of determining classification.

B-2 OVERHEAD TRAVELLING INDUSTRIAL TYPE CRANES (O.T.C)

Type of Crane Motion Mechanism Classification

Class of State of Group of
Utilization Loading Mechanism
Power station O.T.C Hoist and aux. hoist T3 L1  L2 M3
Cross traverse T3 L1  L2 M3
Long travel T3 L2 M3
O.T.C for assembly and dismantling Hoist and aux. hoist T3 L1  L2 M3
machinery Cross traverse T3 L1  L2 M3
Long travel T3 L2 M3
O.T.C stores Hoist and aux. hoist T4  T5 L1  L2 M3   M5
Cross traverse T4  T5 L1  L2 M3   M5
Long travel T4 L2  L3 M4   M5
O.T.C workshop Hoist and aux. hoist T4 T5 L1 L2 M3 M5
Cross traverse T4 T5 L1 L2 M3 M5
Long travel T4 L2 L3 M4 M5
O.T.C grabbing Hoist T5  T7 L3 M6   M8
Closing motion T5  T7 L3 M6   M8
Cross traverse T5  T7 L3 M6   M8
Long travel T5   T6 L3 M6   M7
O.T.C. scrapyard or magnet Hoist and aux. hoist T5   T6 L3 M6   M7
Cross traverse T5   T6 L3 M6   M7
Long travel T5 L3 M6
O.T.C. with magnet for transporting Hoist T5   T6 L3 M6   M7
plates and like Cross traverse T5   T6 L3 M6   M7
Long travel T5 L3 M6
O.T.C. for containers Hoist T5  T7 L2  L3 M5   M8
Cross traverse T5  T7 L3 M5   M8
Long travel T5  T7 L2  L3 M5   M8
O.T.C. foundry ladle (for the Hoist T5   T6 L2  L3 M5   M7
selection of hoist rope for Cross traverse T5   T6 L2  L3 M5   M7
dangerous handling operation,
see 8.5.) Long travel T5 L3 M6
O.T.C. process cranes Hoist T6   T7 L2  L3 M6   M8
Cross traverse T5 L3 M6
Long travel T6 L3 M7

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 IS 3177 : 2020

B-3 OVERHEAD TRAVELLING STEEL WORKS CRANES AND TRANSPORTERS

Type of Crane Motion Mechanism Classification

Class of Class of Class of
Utilization Loading Mechanism
Ladle crane (for the selection of Hoist and aux. hoist T6   T7 L4 M8
hoist rope for dangerous handling Cross traverse T5   T6 L4 M7   M8
operation, see 8.5.)
Aux. traverse T5   T6 L3 M6   M7
Long travel T6   T7 L4 M8
Pig/scrap, breaking crane Hoist T5   T6 L4 M7   M8
Cross traverse T5   T6 L4 M7   M8
Long travel T5 L3 M6
Stripper, vertical ingot charger and Hoist T7   T8 L3 M8
soaking pit mould handling crane Aux. hoist T5   T6 L2 M5   M6
Cross traverse T6   T8 L4 M8
Long travel T6   T7 L4 M8
Slewing T6   T7 L3 M7   M8
Closing tong motion T6   T7 L4 M8
Furnace charging crane Hoist and aux. hoist T7   T8 L3 M8
Cross traverse T7   T8 L3 M8
Aux. traverse T5   T6 L2 M5   M6
Long travel T7   T8 L3 M8
Forging crane Hoist T6   T8 L3 M7   M8
Cross traverse T5   T6 L3 M6   M7
Long travel T6   T8 L3 M7   M8
In line process crane Hoist T7 L3 M8
Cross traverse T5 L3 M6
Long travel T6 L3 M7
Off line process crane Hoist T6   T7 L2 M6   M7
Cross traverse T5 L2 M5
Long travel T6 L2 M6
Heavy mill service Hoist T5   T6 L2 M5   M6
Aux. hoist T4 L2 M4
Cross traverse T5 L2 M5
Long travel T5   T6 L2 M5   M6
Service and maintenance crane Hoist and aux. hoist T4  T5 L1-L2 M3   M5
Cross traverse T4  T5 L1-L2 M3   M5
Long travel T4 L2-L3 M4   M5
Transporter: medium duty general Hoist T5 L2-L3 M5   M6
use Cross traverse T5 L2-L3 M5   M6
Long travel T5 L2-L3 M5   M6
Boom hoist T4 L1 M3

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IS 3177 : 2020

B-4 OVERHEAD TRAVELLING STEEL WORKS CRANES AND TRANSPORTERS

Type of Crane Motion Mechanism Classification

Class of Class of Class of
Utilization Loading Mechanism
Transporter; heavy duty Hoist (hold and close) T6   T7 L3  L4 M7   M8
intermittent grabbing and magnet Cross traverse T6   T7 L3  L4 M7   M8
work
Long travel T6 L2  L3 M6   M7
Boom hoist T4 L1 M3
Transporter; extra heavy duty Hoist (hold and close) T8   T9 L4 M8
continuous grabbing and magnet Cross traverse T7   T8 L4 M8
work
Long travel T7 L3 M8
Boom hoist T4 L1 M3

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 IS 3177 : 2020

ANNEX C
( Clause 2 )

LIST OF REFERED INDIAN STANDARDS

IS No. Title IS No. Title

694 : 2010 Polyvinyl chloride insulated 3658 : 1999 Code of practice for liquid penetrant
unsheathed and sheathed cables/ flaw detection
cords with rigid and flexible 3658 : 1999 Code of practice for liquid penetrant
conductor for rated voltages up flaw detection (second revision)
to including 450/750 V (fourth 4260 : 2004 Recommended practice for
revision) ultrasonic testing of butt welds in
807 : 2006 Code of practice for design, ferritic steel (third revision)
manufacture, erection and testing 4460 (Part 1 Gears — Spur and helical gears —
(structural portion) of cranes and to 3) : 1995 Calculation of load capacity
holes (second revision)
5334 : 2014 Magnetic particle flaw detection of
875 (Part 3) : Design loads (other than earthquake) welds — Code of practice
2015 for buildings and structures — Code
of practice: Part 3 Wind loads (third 5749 : 1970 Specification for forged ramshorn
revision) hooks
1030 : 1998 Carbon steel castings for 7098 (Part 1) : Crosslinked polyethylene insulated
general engineering purposes — 1988 pvc sheathed cables: Part 1 For
Specification (fourth revision) working voltages up to and
including 1100 V (second revision)
1554 Specification for PVC insulated
(heavy duty) electric cables: 7504 : 1995 Gears — Cylindrical gears —
Accuracies — Method of inspection
(Part 1) : 1988 For working voltages up to and (first revision)
including 1 100 V (third revision)
9968 Specification for elastomers
(Part 2) : 1988 For working voltages from 3.3 kV insulated cables:
up to and including 11 kV (second
revision ) (Part 1) : 1988 For working voltages up to and
including 1 100 V (first revision)
1570 (Part 1) : Schedules for wrought steels: Part 1
1978 Steels specified by tensile and/or (Part 2) : 2002 For working voltages from 3.3 kV
yield properties up to and including 33 kV (first
revision)
1570 (Part 2) : Schedules for wrought steels: Part 2
1979 Carbon steels (unalloyed steels) 10118 Code of practice for selection,
installation and maintenance of
2048 : 1983 Specification of parallel keys and switchgear and control gear:
key-ways ( second revision )
(Part 2) : 1982 Selection
2062 : 2011 Hot rolled medium and high tensile
structural steel (Part 3) : 1982 Installation
2266 : 2002 Steel wire ropes for general (Part 4) : 1982 Maintenance
engineering purpose — (Part 1) : 2018 General (first revision)
Specification (fourth revision) 12615 : 2018 Line operated three phase a.c. motors
2553 (Part 1) : Safety glass: Part 1 General purpose (IE Code) ‘efficiency Classes and
1990 (third revision) Performance Specification’ (third
3043 : 2018 Code of practice for earthing revision)
(second revision ) 13367 (Part 1) Safe use of cranes — Code of
3443 : 1980 Specifications for crane rail sections : 1992 practice: Part 1 General
(first revision)

71
IS 3177 : 2020

IS No. Title IS No. Title

13743 (Part 1) Cranes — Vocabulary: Part 1 IS/IEC 60947- Low-voltage switchgear and
: 2015 General 4-1 : 2012 controlgear: Part 4 Contactors
13834 (Part 1) Cranes — Classification: Part 1 and motor-starters, Section 1
: 2018 General ( first revision ) Electromechanical contactors and
motor-starters (first revision )
15560 : 2005 Point hooks with shank up to 160
tonne — Specification IS/IEC 60947- Low-voltage switchgear and control
2 : 2016 gear: Part 2 Circuit breakers (first
16003 : 2012 Specification and qualification of revision)
welding procedures for metallic
materials — General rules AWS 14.1 : Specification for welding of
1997 industrial and mill cranes and other
16504 (Part 1) Safety of machinery — Electrical material
: 2019 equipment of machines: Part 1
General requirements (first revision) DIN 15407-1 Lifting hooks; laminated hooks with
: 1970 a point for spigot ladles, assembly,
16504(Part Safety of machinery — Electrical principal dimensions
32) : 2017 equipment of machines: Part 32
DIN 15400 : Lifting hooks; materials, mechanical
Requirements for hoisting machines 1990 properties, lifting capacity and
16819 : 2018 Safety of machinery — General stresses
principles for design — Risk
assessment and risk reduction

72
 w2 IS 3177 : 2020

ANNEX D
( Clause 4.1 )

INFORMATION TO BE SUPPLIED BY THE BUYER

D2
D-1 GENERAL D-1.4 Gantry or Track Rail (see Fig. 18)
2 S a) Size and weight
S1 tonne; or
D-1.1 Number of Cranes: .................................
D1 b) Width of head (B) mm.
D-1.2 Duty or Class of Crane: ……………....
D-1.5 Ambient Conditions
a) Crane structure
a) Ambient temperature, in °C (Max ); or
b) Main hoist
b) Relative humidity ( Max ).
c) Auxiliary hoist (see IS 807)
d) Cross-traverse D-1.6
w1
Number of tender documents, including
drawings and relevant technical literature required
e) Long-travel
...................................……………………………….
D-1.3 Safe Working Load, in Tonne:
DATA W1 W2 S1 S2 D1 D2 REMARKS
a) Main hoist tonne D-1.6.1 Any Requirement For
SPECIFICATION
b) Auxiliary hoist tonne a) Detailed drawings for approval ........................….
ACTUAL
c) Second auxiliary hoist tonne
TOLERANCE D-2 CRANE PERFORMANCE
d) Stripping and extracting capacity
REMARKS :
in case of stripper cranes tonne D-2.1 Operating Speeds (Loaded), Not Less Than
NOTE — In case of magnet and grabbing cranes, the a) Main
FIG. 16 TROLLEY hoist...............………………. m/ min;
DIMENSIONS and
specification and physicals condition of the material to be
handled shall be given. b) First auxiliary hoist..............……….m/min.

2000 mm min. TO THE TOP OF

BRIDGE PLATFORM T2
P1 P2
T1

X
C

E
B
F
M N

K D H
RAIL SECTION 1
L
A1 S A2

H2

FLOOR LEVEL

FIG. 18 OVERHEAD TRAVELLING CRANE

Fig. 18 Overhead Travelling Crane

73
IS 3177 : 2020

ANNEX E
( Clause 4.2 )

INFORMATION TO BE FURNISHED BY THE MANUFACTURERS ( SELLER )

E-1 GENERAL E-3.3 End Clearances:

( P1 ) ... ... . .. . . .. . .. . . . . .. ... ... ... .. . .. . .. .metre
E-1.1 Number of Cranes
( P2 ) .. . . .. . .. ... ... ... .. . .. . . . . . . . ... ... .. .... metre
E-1.2 Duty or Class of Crane ( T1 ) ... ... . .. . . .. . .. . . . . .. ... ... ... .. . .. . .. . metre
E-1.3 Span of the Crane, in mm ( T2 ) ... ... . .. . . .. . .. . . . . .. ... ... ... .. . .. . .. . metre
( R1 ) ... ... . .. . . .. . .. . . . . .. ... ... ... .. . .. . .. . metre
E-1.4 Safe Working Load, in Tonne
( R2 ) ... ... . .. . . .. . .. . . . . .. ... ... ... .. . .. . .. . metre
a) Main hoist . . . . . . . . . . . m/min
b) Auxiliary hoist . . . . . . . . . . . . m/min E-3.4 Vertical clearance to underside of bridge:
( K ) .. . .. . .. . .. . .. . .. . . .. .. . .. . .. . . .. . .. . metre
E-1.5 Crane Speed
a) Main hoist . . . . . . . . . . . . . . . . . m/min E-3.5 Operator’s Cabin:
b) First auxiliary hoist . . . . . . . . . . . m/min a) Clearance height to under side of cabin (L) .. metre
c) Second auxiliary hoist . . . . . . . . . m/min b) Length of cabin (N) ………………………. metre
d) Cross-traverse (main). . . . . . . . . . m/min c) Distance from back of cabinto nearest gantry rail
(for fixed cabin) ( M)... .. . . .. . .. . .. .. . . .. . ... .. ... ..
e) Cross-traverse (Auxiliary) . . . . . . m/min
. . . . . .. ... . .. ... .... . . . . . .. ... . .. ... ... ..... .... metre
f) Long travel . . . . . . . . . . . . . . . . . m/min
E-3.6 Lift of hook above floor level:
E-2 CRANE AND COMPONENTS WEIGHT a) Main hook (HI ) metre
a) Total weight of the crane . . . . . . . . . . . . . . . . tonne b) First auxiliary hook metre
b) Total weight . . . . .. . . . . . . . . . . . . . . . . . . . . tonne c) Second auxiliary hook metre
c) Girders weight . . . . . . . . . . . . .. . . . . . . . . . . tonne
E-3.7 Drop of hook below floor level:
d) End carriage weight . . . . . . . . . . . . . . . . . . .. tonne
a) Main hook (H2) metre
e) Wheel loads:
b) First auxiliary hook metre
1) Maximum wheel load . . . . . . . . tonne
c) Second auxiliary hook metre
2) Minimum wheel load . . . . . . . . tonne
3) Mean wheel load . . . . . . ……... tonne E-3.8 Nearest position of hook to centre of gantry rail:
a) Main hoist:
E-3 STRUCTURAL DETAILS (see FIG. 18)
1) Cabin end ( E )... ... ..... .. ... ...... metre
E-3.1 Distance between centre lines of gantry or track 2) Cabin end ( F )... ... ..... .. ... ...... metre
rails (S).. . .. . .. . .. . .. . .. . .. . .. . .. . .. ….. .. .. . .. . .. . .. . b) First auxiliary hoist:
.. . .. . .. . . .. . .. .. . .. . .. . .. . .. . metres (span) 1) Cabin end ( E )... ... ..... .. ... ...... metre
NOTE — It is recommended that the span of the track shall
not vary by more than ±12 mm. When the track span does not
2) Cabin end ( F )... ... ..... .. ... ...... metre
satisfy this requirement the maxi­mum and minimum span for c) Second auxiliary hoist:
which the crane has to be designed shall be specified by the
1) Cabin end ( E )... ... ..... .. ... ...... metre
purchaser.
2) Cabin end ( F )... ... ..... .. ... ...... metre
E-3.2 Side Clearance
E-3.9 Any other site restrictions ... ... ... ... ... ...
a) Distance from centres of gantry or track rails to
nearest side: E-4 OPERATOR’S CABIN DETAILS
1) ……………………………(Al) metre
I. (A2 ) metre E-4.1 Type of Cabin
b) Distance from top of gantry rail to: a) Fixed or moving.........................................
1) Lowest overhead obstruction (C)…….. .metre b) Location on bridge, if fixed....................................
2) Floor level (D).........................................metre E-4.2 Open or Closed Type ... ... ..... .. ... ......

74
 IS 3177 : 2020

E-4.3 Any Requirement for: h) Centralized lubricating system

a) Steel plate of thicknesses other than 3 ‘15 mm j) Locking device on swiveling hooks
........................ k) Closing fingers on the hooks
b) Insulated cabin walls .............................................
............. E-6 ELECTRICAL DETAILS
c) Insulated floors ...................................................... E-6.1 Electric Supply
.........
a) d.c. supply
d) Window opening on hinges.. ... ... ... ... ... ... ... ...
... ... ... ... ... ... ... Volts ..................... No. of wires ..............
e) Dispensing with platform outside cabin door Supply (rectifiers or not) ...... ... ...... …….­
.......................... b) a.c. supply
f) An extraction fan ( door should open inwards Volts ..................... No. of wires ..................
where platform is not provided ) .. . ... ... .. . .. . .. . Frequency ............. No. of phases ………..
. .. . .. .. . .. . ... .. . .. ... .. . ...
Neutral (earthed or dot).........................................
g) A circulating fan.....................................................
E-6.2 Braking
h) Air-conditioning for totally enclosed cabin .........
...... Any requirements for:
j) Fire extinguishers ....................................................... a) Electromechanical shunt brake(s) on hoist
motion(s)............
E-5 MECHANICAL DETAILS
b) Emergency brake(s) on hoist motion(s) of moving
E-5.1 General cabin cranes (electromechanical shunt, mechanical
or hydraulic )..............
a) Type of long travel drive .......................................
c) Emergency electro-mechanical shunt brake(s) on:
b) Make and type of flexible couplings.....................
1) Hoist motions of fixed cabin cranes.................
c) Type of any overload slip device (fluid coupling,
2) Coss-travel motion(s) of moving cabin
plate-clutch, or cone clutch) ..................................
cranes...............
.............................
3) the Long travel motion of fixed cabin
E-5.2 Type of Hooks cranes……..
a) Main hoist ...…………………………….............. d) Emergency lowering of load by hand operation
b) First auxiliary .…….............................................. of brakes........
c) Second auxiliary................................................... e) Aa mechanical drag brake on crab...........................
f) Brake magnet coils to be fed from a.c. .................
E-5.3 Any Requirement For
g) Alternative brake magnet coil ratings...................
a) A lifting beam on outdoor cranes
h) Additional brakes for other motions or
b) Built in jacks on end carriages purposes.................……
c) Built in jacks on crabs
E-6.3 Motors
d) Special rail wheel tyres
a) Manufacturer of main motors : ……....................
e) Special gearing arrangements or details
b) Class of insulation of main motors........................
f) Bearing other than ball or roller type
c) d.c. mill motor details (if not selected from any
g) Bearings having full ring cartridge housings
standard specification)

Motion Motor kW STR* or Voltage Class of Temperature Rev/Min

frame IDF insulation rise

Series Compound Shunt

* STR = short time rating.

IDF= intermittent duty factor

75
IS 3177 : 2020

d) Any special motor lead or terminal requirements E-6.6.1 Location of Electrical Equipment Compartment
..................... for
E-6.4 Main Control Gear a) Fixed cabin cranes (below or above the bridge
platform, or above the cab)
E-6.4.1 Type of Control Panels (open or separate closed .. .. .. . .. . .. .. . .. . .. . .. . . .. . .. .. . . .. .. . . .. .. . ... ..
units)............ . . .. ... . .. ... .. . ... .. . .. .. .
E-6.4.2 Short Time Rating or Duty Cycle Ratings of b) Moving cabin cranes (above the bridge platform
Resistors: level, or above the cab), ... ... ... ... ... ...
a) Hoist motions ....................................................... E-6.7 Long-Travel System
b) Cross-travel motions ............................................
E-6.7.1 Provision of long-travel collectors (purchaser
c) Long-travel motions .............................................. or manu­facturer) ..............................
E-6.4.3 Scheme of Protection for Main Control E-6.7.2 Details of mountings on bridge structure for
Circuits: long-travel collectors, if these are to be provided by the
a) Protection of each motion, or................................. purchaser..................................
b) Tripping out crane supply if overload on any
E-6.7.3 Details of long-travel conductors, if
motion ..................................................
long-travel collectors are to be provided by the
E-6.4.4 Any Requirement for: manufacturer.................................................
a) A special control system, or a control system E-6.7.4 Type of long-travel collectors if these are to be
other than auto­matic control of acceleration for provided by the manufacturer................................
any motion (for example, drum or mechanically
operated contactor controller) E-6.8 Cross-travel System
b) Emergency rheostatic braking on travel motions: E-6.8.1 Any requirement for flexible cable type of
1) cross-travel ....................………………….. cross-travel system... ... ... ... ... ... ... ... ... ... ... ... ... ...
2) long-travel …………………………………
E-6.8.2 Type of cross-travel conductors (rolled steel
c) an electrically operated main circuit-breaker section or wires)
...........................…..
d) special clearances of creepages .......……………. E-6.8.3 Maximum current density for cross-travel
conductors (if higher than that recommended in this
E-6.5 Auxiliary Switching specification ).............................
E-6.5.1 Any Requirement for: E-6.8.4 Provision of cross-travel collectors (purchaser
a) special position of: or manufacturer)
1) main isolating switch ……………….............. E-6.8.5 Details of mountings on the trolley for cross-
2) additional main isolating switch ........................ travel collectors, if these are to be provided by the
b) HBC fuse protection for main isolators purchaser ......................
c) auxiliary contacts on the main isolating switch to E-6.8.6 Type of cross-travel collectors, if these are to
operate the crane warning hights be provided by the manufacturer .…………….............
d) an isolating switch on the main circuit of each
E-6.9 Lifting Magnet and Equipment
motion
e) an isolating switch on the control circuit of each E-6.9.1 If lifting magnets and magnet control and
motion protective gear are to be provided:
f) special creeping button to by-pass lower hoist a) Type and size of magnets... ... ... ... ... ... ... ... ... ...
limit switches ... ... ... ...... ...
g) track switches (number, details and whether to b) Type of magnet control ( direct-on-line or
operate a warning signal, or trip the main circuit- potentiometer )... ......
breaker) c) Type of master controller for direct-on-
h) proximity warning devices (number, location and line control (hand or foot­ operated)............
duty) ……………………………………………........
E-6.6 Disposition and Housing of Electrical d) Type of potentiometer control (master drum or
Equipment mechanically operated contactor controller).

76
 IS 3177 : 2020

E-6.9.2 Any requirement for: E-6.11 Earthing

a) provision for future fitting of a lifting magnet Any requirement for:
(number of extra cross-travel conductors) a) earthing other than through crane gantry................
b) rubber hose protection of magnet lead................... b) the magnet to be earthed by a connection via the
.................. magnet lead, coupling and cable and an extra slip-
c) special type of magnet coupling .......................... ring on the magnet cable drum... ... ... ... ... ... ... ...
... ... ... ... ... ... ...
E-6.10 Crane Illumination and Warning Lights
Any requirement for: E-7 PROTECTION OF CRANE STRUCTURE
a) lighting of the bridge walkway and the cabin and AND MACHINERY
bridge............ approaches………..
E-7.1 Any Requirement for Special Painting
b) underslung lighting (number, type and location of Schemes ...........................................................
lamps and lamp fittings) .............………………
c) warning light .....................................................… E-8 ADDITIONAL REQUIREMENTS
1) if so, give details of their function ................... E-8.1 Any Additional Requirements ........................

77
IS 3177 : 2020

ANNEX F
( Clause 7.4.3.2.1 )

DETERMINATION OF FATIGUE REFERENCE STRESS

F-1 GENERAL C3 = is a surface finish factor; and

Clause 7.4.3.2 sets out the procedure for checking Kf = is a fatigue notch factor equal to Kbf for bending
the fatigue strength of a mechanical component stresses and Kqf for torsional shear Stresses.
and outlines the factors which affect its fatigue life.
F-5 DETERMINATION OF C1, C2, C3 AND K
A fatigue reference stress is used in the process of
FACTORS
evaluating the fatigue strength. This annex outlines a
method of determining the fatigue reference stress for F-5.1 Stress Factor C1
a component detail.
The value of C1 is given in accordance with the nature
F-2 FATIGUE REFERENCE STRESS, PF,R of the stress cycles as follows:
Unidirectional bending 0 < fmin./fmax. < 1
Pf,r = Cf,r × Fult C1 = 0.85
Where, Reversing bending – 1 < fmin./fmax.. < 0
C1 = 0.50
Fult is the minimum ultimate tensile stress of the material
Unidirectional torsion (shear) 0 < fmin./fmax. < 1
Cf,r is a fatigue reference stress factor that depends on C1 = 0.50
the: Reversing torsion (shear) – 1 < fmin./fmax. < 0
a) number and characteristics of the stress cycles to C1 = 0.30
which a component is subjected; and
F-5.2 Size Factor C2
b) value of the fatigue limit factor Clim.
The size factor is derived from Fig. 20.
F-3 DETERMINATION OF FATIGUE
REFERENCE STRESS FACTOR (C F,R) F- 5.3 Surface Finish Factor C3
The surface finish factor is dependent on the ultimate
For steels having a minimum ultimate tensile stress not tensile stress of the material and the machining process
greater than 1 100 N/mm2, the value of Cf,r is given in used in manufacture. The value of C3 is given in Fig.
Fig. 19(a) for cases of bending stress and in Fig. 19(b) 21 in which Rt is the peak-to-valley height of surface
for cases of torsional shear stress. The value of Cf,r is roughness (in μm).
determined in accordance with the appropriate number
of stress cycles and with the appropriate value of the F-5.4 Fatigue Notch Factor Kbf, Kqf
fatigue limit factor Clim.
F-5.4.1 Derivation of Fatigue Notch Factor
Alternatively the factor Cf,r can be determined from the
following formulae, in which N is the total number of The presence of such details as shoulders, grooves, holes,
cycles. keyways, threads, etc. results in a modification of the
simple stress distribution that would occur in members
For N >= 106 Cf,r = Clim
which have a constant cross section with gradual changes
For 103 < N < 106 Cf,r = A Clim (1/3 l°g N-1 ) of contour. The resulting localization of high stresses is
where for bending stresses A = 1; and known as the stress concentration or notch effect and is
for torsional shear stresses A = 3(1/6 l°g N-1 ) measured by the stress concentration factor.
The stress concentration factor is defined as:
F-4 FATIGUE LIMIT FACTOR (CLIM)
f b max
The fatigue limit factor Clim is the value of Cf,r
       Kb = ———— for bending stress
corresponding to the fatigue endurance limit.
fb nom
C1
      f q max
Clim = ——————
Kq = ———— for torsional shear stress
   C2 × C3 × Kf
      f q nom
Where,
Where, fb max and fq max are the maximum stresses in a
C1 = is a stress state factor; component detail and fb nom and fq nom are the nominal
C2 = is a size factor; stresses at the corresponding location.

78
 IS 3177 : 2020

1.0
0.9
0.8
0.7
0.6 Clim= 0.50
0.5
0.4 0.40
0.3 0.30
0.20
Cf,r
0.2
0.15

0.1 0.10
0.09
0.08 0.07
0.07
0.06 0.05
0.05
0.04
0.03
0.02

0.01
103 104 105 106 107 108

TOTAL NUMBER OF CYCLES

19A BENDING STRESS

1.0
0.9 0.8
0.7
0.6
0.5
0.4 Clim= 0.30
0.3
0.20
0.2
Cf,r

0.15
0.10
0.1
0.09 0.08 0.07
0.07 0.06
0.05
0.05 0.04
0.04
0.03
0.03
0.02

0.01
103 104 105 106
107 108
TOTAL NUMBER OF CYCLES
19B TORSIONAL SHEAR STRESS
FIG. 19 FATIGUE REFERENCE STRESS FACTOR Cfr

Fig. 19 Fatigue Referecnce Streess Factor Cfr

79
IS 3177 : 2020

1.5

1.4

1.3

C2 1.2

1.1

1.0
10 20 30 50 100 200 300
DIAMETER (mm)
FIG. 20 SIZE FACTOR C2

Fig. 20 Size Factor C2

1.5

)
0 µm
=3
1.4 (R T
E D
RN
TU
H
UG
RO

1.3
m)
1 2µ
(R T=
U ND
GRO
C3

U GH
/ RO
1.2 ED
RN m)
TU .5µ
=6
RT
D(
R NE
E TU )
FIN 2. 5µm
(R T=
UND
1.1 GRO
FINE
= 1µm
)

OLIS HED (R T
UGH P
D / RO
LAPPE

0
400 500 600 700 800 900 1000 1100
2
ULTIMATE TENSILE STRENGTH OF STEEL ( N/mm )

FIG.21 SURFACE FINISH FACTOR C3

Fig. 21 Surface Finish Factor C3

STEEL

}
USE THESE VALUES WITH BENDING AND AXIAL LOAD S1 Ksi
USE THESE VALUES WITH TORSION AND Bhn
80 AS MARKED
1.0
( 3 60 Bh n )
Bh n ) 18 0
0.9 00
(4 )
00 4 0 Bhn
20 ( 2
TOR q

n) 1
2

0.8 Bh hn )
80 60 B
(2 0( 1 Bh n )
 )
0 µm
=3
1.4 (R T
ED IS 3177 : 2020
RN
TU
U GH
The effect of a notch on the fatigue strength of a part F-5.4.3
RO Notch Sensitivity Factor
varies considerably with material and notch geometry For ductile materials the value of q may be obtained
and is normally less than would be predicted by the
1.3 from published reference works or from experimental
m)
use of the stress concentration factor. The general data. = 12µ
(R T
phenomenon is denoted “notch sensitivity”. ND
OU exist, then a value of q = 1.0 should be
Where noGRdata
For design purposes the following relations apply:
C3

H
used Uin deriving Kbf and Kqf.
G
RO
D/
1.2 Kbf = q (Kb – 1) + 1 R NEFor brittle materials
) q = 1.0 shall be used in all cases.
TU µm.5
=6
(R T
Kqf = q (Kq – 1) + 1 F-N5.4.4
E D Stress Concentrations which are Superimposed
UR
N E Tor in Close Proximity .5µm)
Where, F I =2
D (R T
1.1 q = is the notch sensitivity factor as per Fig. TreatmentGRof multiple
OUN stress concentrations in close
22; FINE
proximity is outside of the scope of this annex and
Kbf = is the fatigue notch factor (bending stress); and 1µm)
where this situationOLarises
H E D (R T =
reference should be made to
IS
Kqf = is the fatigue notch factor ( torsional shear established/ UGH P
reference
RO works.
APP E D
L
stress).
0
F-5.4.2 Stress Concentration Factor
400 500 600 700 800 900 1000 1100
The stress concentration factors Kb and Kq are to be
ULTIMATE TENSILE STRENGTH OF STEEL ( N/mm2 )
taken from established reference works.
FIG.21 SURFACE FINISH FACTOR C3

STEEL

}
USE THESE VALUES WITH BENDING AND AXIAL LOAD S1 Ksi
USE THESE VALUES WITH TORSION AND Bhn
AS MARKED
1.0
( 3 60 Bh n )
Bh n ) 18 0
0.9 00
(4 )
00 0(2 4 0 Bhn
NOTCH SENSITIVITY FACTOR q

) 12
hn
2

B
0.8 80 Bhn )
(2 160
0 ) 80 ( 0 Bh n )
n 2
4 Bh 6 0( 1
0.7 0
1

20 hn
)
0( 0B
10 6 n )
(1 Bh
0.6 80 2 0 n )
(1 Bh
60 00
(1 ALUMINIUM ALLOY
0.5 50
(BASED ON 2024-T6 DATA)
0.4

0.3

0.2

0.1

0
0 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 ( IN inch )

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 ( IN mm )

NOTCH RADIUS r.

FIG.22 NOTCH SENSITIVITY CURVES

Fig. 22 Notch Sensitivity Curves

81
IS 3177 : 2020

ANNEX G
( Clause 54.2 )

INTERMITTENT RATINGS FOR RESISTORS

G-1 GENERAL G-2.2 Five Minute Rating

The basis of the rating shall be the ratio of the running A resistor having a 5 min rating shall be capable of
time to a total time of 15 min and the resistors are rated being left in circuit for a period not exceeding 2 min
to carry the rated full load motor current in any section on the first section and for a further period of 3 min
or sections except where current is restricted to lower equally divided between the remaining sections of
value by the amount of resistance in the circuit in which the resistor, followed by a period of rest of 10 min,
case the resistor shall be rated to carry the current this cycle being repeated until a stable temperature is
passed with the motor at stand still. reached.

G-2 DEFINITION OF DIFFERENT RATINGS G-2.3 Ten Minute Rating

A resistor having a 10 min rating shall be capable
G-2.1 Two Minute Rating of being left in circuit for a period not exceeding
A resistor having a 2 min rating shall be capable of 4 min on the first section and for a further period
being left in the circuit for a period not exceeding of 6 min equally divided between the remaining
30 s on the first section and for a further period of 90 s sections of the resistor, followed by a period of rest
divided between the remaining sections of the resistor, of 5 min, this cycle being repeated until a stable
followed by a period of rest of 13 min. This cycle being temperature is reached.
repeated until a stable temperature is reached.

82
(Continued from second cover)

The Committee kept in view the manufacturing and trade practices prevailing in the country while formulating
the standard.
For the purpose of deciding whether a particular requirements of this standard is complied with the final value,
observed or calculated expressing the result of a test or analysis shall be rounded off in accordance with IS 2 : 1960
‘Rules for rounding off numerical values (revised)’. The number of significant places retained in the rounded off
value should be the same as that of the specified value in this standard.
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Review of Indian Standards

Amendments are issued to standards as the need arises on the basis of comments. Standards are also reviewed
periodically; a standard along with amendments is reaffirmed when such review indicates that no changes are
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should ascertain that they are in possession of the latest amendments or edition by referring to the latest issue of
‘BIS Catalogue’ and ‘Standards: Monthly Additions’.
This Indian Standard has been developed from Doc No.: MED 14 (13932).

Amendments Issued Since Publication

Amend No. Date of Issue Text Affected

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