RAILWAY ENGINEERING

Lecture Number 59
Track Maintenance I

RAJAT RASTOGI
CIVIL ENGINEERING

1
Discussed in Previous Lecture

• Stations
• Yards
• Level Crossing

2
Today’s Discussion

• Track Maintenance
– Maintenance categories
– Maintenance parameters
– Track Indices

3
Track Maintenance

• Ideal requirements
– It should show the health of the track
– It should be independent of the speed of recording
– It should not include design deviations as defects
– It should show the effect of loading also https://iricen.gov.in/iricen/books_jquery/track_mo
nitoring.pdf · PDF file
– It should be recorded, keeping in view the purpose of
each types of results

4
Track Maintenance

• Three maintenance categories:

– Planned Maintenance Limit (PML)
– Need Based Maintenance Limit (NBML)
– Urgent Maintenance Limit (UML)
• Planned Maintenance Limit
IRPWM 2020
– Maintenance is decided in complete block section
based on the permissible tolerances
– PML for unevenness and alignment are based on
Standard Deviation values (affecting ride quality)
– It is carried out using track machines
5
Track Maintenance
• Need based Maintenance Limit
– Maintenance is done timely before the defects size
necessitates UML.
– NBML for unevenness and alignment are based on
Standard Deviation values (affecting ride quality)
and peak values (for gauge and twist)
– Traffic need to be slowed down during NBM IRPWM 2020

• Urgent Maintenance Limit

– The need is based on acceleration limits on comfort
consideration and peak values for Gauge and Twist
– The speed need to be reduced during maintenance

6
Maintenance Limits: Speed up to 100 kmph
Parameter PML NBML UML UN – Unevenness
UN-1 SD 5.0 mm SD 6.8 mm AL – Alignment
Peak 20 mm SD – Standard
Vertical and Deviation of readings
UN-2 - - lateral
taken at every 30 cm
AL-1 SD 3.3 mm SD 4.0 mm acceleration peak
of 0.30g interval using TRC
Peak 15 mm
IRPWM 2020

AL-2 - -
Mean gauge over 200 m section over normal gauge
Straight - -8 mm to +10mm -10mm to +12mm
Curve R - -5mm to +14mm -7mm to +17mm
440m
7
Maintenance Limits: Speed up to 100 kmph
Parameter PML NBML UML Gauge: -5mm means
slack and +18mm means
Mean gauge over 200 m section over normal gauge
tight with respect to
Curve R< - -5mm to +18mm -7mm to +20mm 1676mm gauge;
440m
measured at every 30
Isolated defects – Nominal track gauge to peak values cm interval using TRC
Straight - -10mm to +12mm -12mm to +15mm IRPWM 2020

Curve R - -7mm to +17mm -11mm to +20mm

440m
Curve R< - -6mm to +22mm -8mm to +25mm
440m
Twist TW-1 - 5mm/m 7mm/m

8
Maintenance Limits: Speed 100 to 110 kmph
Parameter PML NBML UML
UN-1 SD 3.8mm SD 5.5mm
Peak 17mm
UN-2 SD 5.4mm SD 7.5mm Vertical and
Peak 23mm lateral
https://iricen.gov.in/iricen/books_jquery/track_mo
AL-1 SD 2.5mm SD 3.9mm acceleration peak nitoring.pdf · PDF file

Peak 12mm of 0.30g IRPWM 2020

AL-2 SD 4.1mm SD 6.7mm

Peak 20mm
Mean gauge values are same as for speed up to 100 kmph
Twist TW-1 - 4mm/m 7mm/m

9
Maintenance Limits: Speed 110 to 130 kmph
Parameter PML NBML UML Twist = Relative
UN-1 SD 3.3mm SD 4.9mm movement of axle on
Peak 15mm left and right rail
UN-2 SD 5.1mm SD 7.4mm LL = Left low, left rail
Vertical and
Peak 22mm lateral lower than right rail
AL-1 SD 2.5mm SD 3.6mm acceleration peak RL = Right low, right
Peak 11mm of 0.25g rail lower than left rail
AL-2 SD 3.5mm SD 5.3mm
Peak 16mm
Mean gauge values are same as for speed up to 100 kmph
Twist TW-1 - 4mm/m 6mm/m
IRPWM 2020

10
Maintenance Limits: Speed 130 to 160 kmph
Parameter PML NBML UML Twist = (1-2 X-level) –
UN-1 SD 2.9mm SD 4.4mm Vertical and (3-4 X-level) / 3.6 or
Peak 13mm lateral 4.8 (i.e. length of
UN-2 SD 4.4mm SD 6.6mm acceleration peak bogie)
Peak 20mm of 0.20g Algebraic values are
AL-1 SD 1.9mm SD 3.6mm taken
IRPWM 2020
Peak 11mm
AL-2 SD 2.5mm SD 4.9mm
Peak 15mm
Mean gauge values are same as for speed up to 100 kmph
Straight - -6mm to +10mm -8mm to +12mm

11
Maintenance Limits: Speed 130 to 160 kmph
Parameter PML NBML UML
Curve R - -5mm to +13mm -7mm to +15mm
440m
Curve R< - -5mm to +18mm -7mm to +20mm
440m
Isolated defects – Nominal track gauge to peak values https://iricen.gov.in/iricen/books_jquery/track_mo
nitoring.pdf · PDF file
Straight - -8mm to +12mm -10mm to +15mm IRPWM 2020

Curve R - -6mm to +16mm -9mm to +20mm

440m
Curve R< - -6mm to +22mm -8mm to +25mm
440m
Twist TW-1 - 3.5mm/m 5mm/m
12
Maintenance Limits: For Low Speeds & Parameters
Speed kmph Peak value of UN Peak value of Permissible Standard chord length
(on 3.6 m chord) Twist (on 3.0 m Gauge range for unevenness
in mm chord) in mm measurement on IR is
Up to 45 22 18 -10 to +27mm 3.6 m or 9.6 m; done on
top of rail head
Up to 30 24 21 -10 to +27mm
Up to 15 33 25 -12 to +27mm IRPWM 2020

Standard chord
length for TRC on IR
is 7.2 m or 9.6 m;
done on side of rail
head
https://iricen.gov.in/iricen/books_jquery/track_mo
nitoring.pdf · PDF file

13
Track Maintenance: Measurement of Parameters
Twist/ alignment measurements are taken by
shifting the chord by 30 cm every time thus
resulting in 667 readings in 200 m distance
These are done for left and right rail
Thus, for all four parameters there will be
4000 readings for a block distance of 200 m
https://iricen.gov.in/iricen/books_jquery/track_mo
nitoring.pdf · PDF file

14
Track Maintenance: Track Indices

• Composite Track Record (CTR value)

– This gives overall condition of a track, allows
assessment of/for improvements between two
runs of TRC, and enables comparison of two
sections of the track https://iricen.gov.in/iricen/books_jquery/track_mo

– It is calculated for each km of the track as: nitoring.pdf · PDF file

– CTR = 75 – (ULA + URA + GA + TA + ALB + ARB)

– Where, measures are taken as number of peaks
exceeding category limits

15
Track Maintenance: Track Indices

• Composite Track Record (CTR value)

– CTR = 75 – (ULA + URA + GA + TA + ALB + ARB)
– ULA = No. of peaks exceeding 6 mm in unevenness
on a chord of 3.6 m for left rail per km of track.
– URA = No. of peaks exceeding 6mm in unevenness
https://iricen.gov.in/iricen/books_jquery/track_mo
on a chord of 3.6 m for right rail per km of track nitoring.pdf · PDF file

– GA = No. of peaks exceeding 3mm in gauge per km

of track
– TA = No. of peaks exceeding 5mm in twist on base
of 3.6.m per km of track

16
Track Maintenance: Track Indices
• Composite Track Record (CTR value)
– CTR = 75 – (ULA + URA + GA + TA + ALB + ARB)
– ALB = No. of peaks exceeding 5 mm in alignment on
7.2 m chord for left rail per km of track
– ARB = No. of peaks exceeding 5 mm in alignment on
7.2 m chord for right rail per km of track
https://iricen.gov.in/iricen/books_jquery/track_mo
– Unevenness peaks and alignment peaks of both the nitoring.pdf · PDF file

rails are counted; all peaks on points and crossings

are counted
– This is done wrt ‘A’ category defects
– Average CTR is reported for all km under jurisdiction
of an authority

17
Track Maintenance: Track Indices

• Composite Track Record (CTR value)

– It was observed that CRT is very sensitive to ‘A’
category defects. Considering this weightage of
‘B’ Category defects was used and formula
changed https://iricen.gov.in/iricen/books_jquery/track_mo

– RCTR = 1 0 0 - (ULB + URB + TB + GB + 0.5*ALB + nitoring.pdf · PDF file

0.5*ARB) - 0.25*(ULA + URA + TA + GA)

– With the introduction of TQI / TGI the use of CTR
has discontinued though TRC can be set to give its
value
18
Track Maintenance: Track Indices

• Track Quality Index (TQI value)

– This aligned with the measurement of four
parameters on a block length of 200 m and working
with SD-based approach
– The evaluation is based on the chord length of 4.8 m
https://iricen.gov.in/iricen/books_jquery/track_mo
for twist and 9.6 m for alignment and unevenness, nitoring.pdf · PDF file

giving 11 SD values for block of 200 m

– TQI = 40*(U + 2*T + G + A)/5
– Where, U = Average of SD values of unevenness of
left and right rails on 9.6 m chord

19
Track Maintenance: Track Indices

• Track Quality Index (TQI value)

– TQI = 40*(U + 2*T + G + A)/5
– T = SD values of twist on 3.6 m base
– G = SD value of gauge
– A = Average of SD values of alignment of left and https://iricen.gov.in/iricen/books_jquery/track_mo
nitoring.pdf · PDF file

right rails on 7.2 m chord

– This formula is found to be directly proportional
to SD values and no benchmark is used to
calculate the value

20
Track Maintenance: Track Indices

• Track Geometry Index (TGI value) m = measured

– This is based on the index values related to four r = restricted for new
track
parameters for a block of 200 m using SD values
ur = required for urgent
of defects on specified chords maintenance
– TGI = (2UNI + TWI + GI + 6ALI)/10 https://iricen.gov.in/iricen/books_jquery/track_mo
nitoring.pdf · PDF file
– UNI = 100 exp [–(SDUm – SDUr)/(SDUur – SDUr)]
– TWI = 100 exp [–(SDTm – SDTr)/(SDTur – SDTr)]
– GI = 100 exp [–(SDGm – SDGr)/(SDGur – SDGr)]
– ALI = 100 exp [–(SDAm – SDAr)/(SDAur – SDAr)]

21
Track Maintenance: Track Indices
• Track Geometry Index (TGI value) TGI for a km = Average
– SDUm = (SDU2L + SDU2R)/2 – Average measured of TGI for 5 blocks in a
value of SD for unevenness km
– SDU2L = Measured value of SD of Unevenness of left
rail on 9.6 m chord
– SDU2R = Measured value of SD of unevenness of
right rail on 9.6 m chord https://iricen.gov.in/iricen/books_jquery/track_mo
nitoring.pdf · PDF file

– SDTm = Measured value of SD of twist on the base of

3.6 m
– SDGm = Measured value of SD of gauge
– SDAm = (SDA1L + SDA1R)/2 – Average measured
value of SD for alignment

22
Track Maintenance: Track Indices

• Track Geometry Index (TGI value)

– SDA1L= Measured value of SD of alignment of left
rail on 7.2 m chord
– SDA1R = Measured value of alignment of right rail
on 7.2 m chord
– SDUur = SD prescribed for urgent maintenance of https://iricen.gov.in/iricen/books_jquery/track_mo
nitoring.pdf · PDF file
unevenness at 9.6 m chord
– SDUr = SD prescribed for newly laid track for
unevenness at 9.6 m chord
– SDTUr = SD prescribed for urgent maintenance for
twist at base of 3.6m

23
Track Maintenance: Track Indices

• Track Geometry Index (TGI value)

– SDTr = SD prescribed for newly laid track for twist at
base of 3.6 m
– SDGur = SD prescribed for urgent maintenances for
gauge
https://iricen.gov.in/iricen/books_jquery/track_mo
– SDGr = SD prescribed for newly laid track for gauge nitoring.pdf · PDF file

– SDAur = SD prescribed for urgent maintenance for

alignment on 7.2 m chord
– SDAr = SD prescribed for newly laid track for
alignment on 7.2 m chord

24
Track Maintenance: TGI values
parame Chord New Up to 110 kmph > 110 kmph < 130 Priority I: for UML
ter m track SD values mm kmph SD values Priority II: for PML
tolerance mm Bold values are used to
SD values
P II PI P II PI calculate UNI, TWI, GI
mm
and ALI
UN 3.6 1.2 2.5 3.3 2.3 3.0
https://iricen.gov.in/iricen/books_jquery/track_mo
9.6 2.5 6.5 7.4 5.1 6.2 nitoring.pdf · PDF file

TW 3.6 1.75 3.8 4.2 3.4 3.8

4.8 2.5 4.2 5.0 3.8 4.5
AL 7.2 1.5 2.7 3.8 2.3 3.0
9.6 2.5 5.0 6.3 3.3 4.0
G - 1.0 2.5 3.6 1.8 2.6
25
Track Maintenance: TGI values

• Maintenance Guidelines based on TGI

Band width of TGI Maintenance Requirements
80 and above No maintenance required
50 to 80 Need based maintenance
36 to 50 Planned maintenance https://iricen.gov.in/iricen/books_jquery/track_mo
nitoring.pdf · PDF file

Below 36 Urgent maintenance

26
Track Maintenance: Track Indices

• Sperling’s Ride Index

– Based on OMS readings taken every 10 milliseconds
10 3 1 Caused due to vertical
– 𝑅𝐼 = 0.896 ∗ σ𝑛𝑖=1 𝑏𝑖𝑓𝑖 ∗ 𝐹(𝑓𝑖) and lateral acceleration
𝑛
– Where, n = number of completed half waves (cycles https://iricen.gov.in/iricen/books_jquery/track_mo
nitoring.pdf · PDF file
– bi = Peak value of amplitude for the ith half wave /
cycle (cm/s2)
– fi = frequency of the ith half wave (Hz) = 1/2Ti
– Ti = time of ith half wave/cycle

27
Track Maintenance: Track Indices

• Sperling’s Ride Index

– F(fi) = Correction factor for the ith half wave
– Correction factors are given below 10
𝑛
𝑏𝑖 3 1
𝑅𝐼 = 0.896 ∗ ෍ ∗ 𝐹(𝑓𝑖)
𝑓𝑖 𝑛
For vertical mode For lateral mode 𝑖=1

https://iricen.gov.in/iricen/books_jquery/track_mo
0 for f < 0.5 Hz 0 for f < 0.5 Hz nitoring.pdf · PDF file

0.325 f2 for 0.5 < f < 5.4 Hz 0.8 f2 for 0.5 < f < 5.4 Hz
400/f2 for 5.4 < f =< 20.0 Hz 650/f2 for 5.4 < f =< 20.0 Hz
1 for f > 20 Hz 1 for f > 20 Hz

28
Track Maintenance: Track Indices

• Ride Index (RI) values

RI Interpretation RI Interpretation
1.0 Very good 3.5 Just satisfactory 10
𝑛
𝑏𝑖 3 1
𝑅𝐼 = 0.896 ∗ ෍ ∗ 𝐹(𝑓𝑖)
1.5 Almost vey good 4.0 Tolerable 𝑓𝑖 𝑛
𝑖=1

2.0 Good 4.5 Not tolerable https://iricen.gov.in/iricen/books_jquery/track_mo

nitoring.pdf · PDF file
2.5 Almost good 5.0 Dangerous in service
3.0 Satisfactory
Type of vehicles Preferable Limiting
Diesel and electric locomotive 3.75 4.00
Carriages 3.25 3.50
Wagons 4.25 4.50 29
Track Maintenance:
TRC Report Output

https://iricen.gov.in/iricen/books_jquery/track_mo
nitoring.pdf · PDF file

30
Track Maintenance: TRC Measuring Gauge

https://iricen.gov.in/iricen/books_jquery/track_mo
nitoring.pdf · PDF file

31
Track Maintenance: TRC – Measurement of Alignment

Accelerator

https://iricen.gov.in/iricen/books_jquery/track_mo
nitoring.pdf · PDF file

32
Track Maintenance: CFD Plots of Parameters

https://iricen.gov.in/iricen/books_jquery/track_mo
nitoring.pdf · PDF file

33
Track Maintenance: Blocks Requiring PM and UM

https://iricen.gov.in/iricen/books_jquery/track_mo
nitoring.pdf · PDF file

34
Today we started discussing the maintenance of tracks. We
discussed the classification of maintenance, tolerances
related to four parameters, their measurement process,
and track indices used to identify the maintenance
requirements.
Thank You

35
RAILWAY ENGINEERING
Lecture Number 58
Stations, Yards, Level Crossings

RAJAT RASTOGI
CIVIL ENGINEERING

1
Discussed in Previous Lecture

• Train Control Systems

– Automatic Block System
– Centralized Train Control System
– Automatic Train Control
– Absolute Permissive Block System
– Moving Block System
– Non-Block Train Movements

2
Today’s Discussion

• Stations
• Yards
• Level Crossing

3
Stations

• Purpose:
– Controls movement of trains
• Reception, Departure of trains, Crossing of trains,
Passing of faster trains
– Allows passenger and goods movement
– Provide facilities for enroute passengers
– Enable sorting of trains and wagons on sidings
– Provide maintenance facilities for rolling stock,
especially at terminal stations or junctions
– Facilitate movement or changeover of train crew

4
Stations

• Classification: Operational
– Block stations: Class-A, Class-B, Class-C
– Non-Block station: Class-D
– In the case of block station, the driver need an
authority to proceed enter the block section S1P.pdf (railnet.gov.in)

– In non-block stations, stopping places are between

two consecutive block stations
– Special Class: These need approval of Commissioner
Railway Safety (CRS)

5
Stations

• A-Class Stations
– At these stations, the line shall not be considered
clear and Line clear shall not be given, unless:
• The whole of the last preceding train has arrived
completely
• All signals have been put back to ON position behind
the said train S1P.pdf (railnet.gov.in)

• The line on which it is intended to receive the

incoming train is clear up to the Starter signal
• All points have been correctly set and all facing points
have been locked for the admission of the train on the
said line

6
Stations

• A-Class Stations
– Conditions for line Clear:
• Where line clear cannot be given for a train unless
the line on which it is intended to receive the train
is clear for at least 400 m beyond the Home signal,
or up to the Starter signal S1P.pdf (railnet.gov.in)

– Signals used: Warner, Home, Starter, Advanced

starter

7
Stations

• B-Class Stations
– Conditions for line Clear: for double line
• The whole of the last preceding train has arrived
completely
• All necessary signals have been put back to ON
position behind the said train and the line is clear
S1P.pdf (railnet.gov.in)
at stations equipped with MAS up to the
outermost facing points or the BSLB, if any
– Conditions for line Clear: for single line
• The whole of the last preceding train has arrived
completely

8
Stations

• B-Class Stations
– Conditions for line Clear: for single line
• The whole of the last preceding train has arrived
completely
• All necessary signals have been put back to ON
position behind the said train and the line is clear S1P.pdf (railnet.gov.in)

up to the SLB or Advanced starter if any at the end

of the station nearest to the expected train, or up
to the outermost facing points if there is no SLB or
Advanced starter

9
Stations

• C-Class Stations
– Conditions for line Clear: for single/double line
• The whole of the last preceding train has passed
completely at least 400 m beyond the Home signal
and is continuing its journey
• All signals taken OFF for the preceding train have
S1P.pdf (railnet.gov.in)
been put back to ON position behind the said train
• Provided that on a single line, the line is also clear
of trains running in the opposite direction towards
the block hut from the block station at the other
end

10
 Station Signals

Class-B Station

Class-C Station
Class-A Station Railway Engineering by Chandra and Agarwal

11
Stations: Comparison
Class-A Class-B
Exist only in TAS Exist in TAS and MAS
Now obsolete Most stations are Class-B
No station section Definite station section
No shunting after LC given Shunting possible
LC cannot be given to both No such restriction S1P.pdf (railnet.gov.in)

side simultaneously
LC cannot be given unless No such restriction
reception line is clear
Obstruction is protected by 2 Obstruction is protected by 1
signals signal
12
Stations: Non-Block

• Halt:
– A simplest form with same shelter for booking of
tickets and waiting, platform is at rail level
• Flag station:
– Provided with a station building and staff; equipped
with a Morse telegraph or a control phone for
communication with nearby stations
• Wayside or Crossing station:
– Basic idea is to allow crossing of trains, especially on
single lines; mail/express trains stop at major
stations; deals with parcel traffic only; points and
13
Stations: Non-Block

• Wayside or Crossing station:

– Switches are controlled by one cabin or two
cabins (one on either side); performs reception
and departure of trains

Railway Engineering by Chandra and Agarwal

14
Stations: Non-Block

• Junction station:
– Station with three or more lines merging/
diverging from/in different directions

Railway Engineering by Chandra and Agarwal

15
Stations: Non-Block

• Terminal station:
– Station where a line or a branch line terminates; station
is equipped with facilities for passengers, wagons and
locomotives; usually FOB is not provided

Railway Engineering by Chandra and Agarwal

16
Yards

• Types of Yards
– Coaching yard: It deals with reception and
dispatch of passenger trains; related facilities are
provided
– Goods yard: This deals with the reception,
stabling, loading, unloading and dispatch of goods
wagons; no sorting, marshalling and reforming is
done; separate goods sidings are provided
– Locomotive yard: This yard provides facilities
related to the locomotives; space is based on the
number of locomotives to be handles together

17
Yards

• Types of Yards
– Sick Line yard: This yard deals with the wagons
which are declared defective; repair related
facilities and workshop are provided
– Marshalling yard: This is a yard where goods
trains are received, sorted, new trains are
formed, and dispatched; deals with loaded and
unloaded wagons/trains; marshalling is done in
such a way that wagons can be conveniently
detached without mush shunting enroute at
wayside stations

18
Marshalling Yards
• Functions
– Reception of trains
– Sorting of trains
– Departure of trains
• Principle of Design:
– Trains should be received and dispatched as quickly
as possible
– Directional movement of wagons shall be
unidirectional
– There shall be no conflicting movement of wagons
and engines

19
Marshalling Yards

• Principles
– Lead for movement of wagons and trains should
be short as possible
– It should be well lighted
– Scope should be there for further expansion
• Types
– Flat yard: All tracks are laid almost at level and
the wagons are relocated using engines; require
frequent shunting; takes more time during back-
and-forth operations

20
Marshalling Yards – Types
• Flat yard: This is adopted when,
– There is limitation of space
– There is severe limitation of funds
– Number of wagons dealt are less
• Gravitational yard: Some tracks are laid at a gradient;
wagons move to sidings for sorting under action of
gravity; engine assistance is need for some operations
• Hump yard: A hump is provided, wagons are pushed
to hump by an engine, and they slide to the sidings
under gravity; topography of location plays an
important role in this

21
Marshalling Yards
Item Gradient to be adopted for Mechanized yard
Mechanical yard Non-mechanical uses retarders to
yard control the speed of
wagons on a
Rising gradient of 1 in 50 to 1 in 125 1 in 50 to 1 in 100 gradient and to stop
approach at specified location
Top of hump Level Level
First falling grade 1 in 17 to 1 in 20 1 in 25 to 1 in 35
after apex of hump
Intermediate grade 1 in 50 to 1 in 60 1 in 80m to 1 in
up to the point 200
where the train starts
22
Marshalling Yards
Item Gradient to be adopted for Non-Mechanized
Mechanical yard Non-mechanical yard uses hand
yard brakes to control the
speed of wagons on
Final falling gradient 1 in 200 to level 1 in 80 to 1 in 200 a gradient and to
up to clearance of stop at specified
points location
Gradient of the Down gradient Falling gradient 1
sidings eased off and then in 400 to 1 in 600
an up gradient
given to stop
wagons at the end

23
Marshalling Yards

Hump
Yard

24
Marshalling Yards
• Spacing: 400 km if lead is 500 km and train section is
100 km
• Length of a siding: 700 m for BG
• Number of sidings: based on 3-4 trains per siding
• Shunting neck: Longer than the longest train
• Average height of ordinary hump: 2.5 to 3 m
• Average height of mechanized hump: 3.5 to 6 m
• Average gradient from the hump to the end of
switching zone: 2% for empty and 1.5% for loaded
wagons

25
Level Crossings

• When road traffic crosses the rail traffic at the

same level it is known as level crossing
• At LC, the road is brought up to the level of rail
table and guard rails are provided to ensure
clearance for wheel flanges
• LC become necessary because the alternative of S1P.pdf (railnet.gov.in)

providing over/under bridge is very costly

• A LC will have an arrangement to stop road
traffic on either side of the crossing (except at D-
class crossing)

26
Level Crossings

• The arrangement can be as swing gates, lifting

barriers or even a chain across the road
• It will have check rails to keep the flangeway
clear
• Provision of warning signs are mandatory on
either side of the LC for warning the road users
• Classification of a LC is made after conducting
the LC census of TVU for seven days once in 3
years and based on that average per day is used

27
Level Crossings
• Classification is based on nature of road, number of
road vehicles passing and number of trains passing
• TVU (Train vehicle Unit) = No of trains × No of road
vehicles (both for 24 hours)
• Train, motor vehicle, bullock carts and tongues – 1
unit
• Cycle rickshaw and auto rickshaw – ½ unit
• Motorised two-wheelers: ¼ unit
• TVU over 20000 qualifies for interlocking
• Minimum TUV for ROB/RUB on cost sharing basis
should be 1 Lakh, with relaxation on suburban
sections
28
Level Crossings
Class Criteria TVU is more than 6000
Special TVUs greater than 50,000 of LC visibility is poor –
Convert un-manned
‘A’ Class TVUs from 50000 and up to 30000 or gate into Manned gate
Line capacity utilization 80% (on single line) and
number of road vehicles greater than 1000
‘B’ Class TVUs less than 30000 and up to 20000 and IRPWM 2020
number of road vehicles greater than 750
B1 Class: TVUs less than 30000 and up to 25000
B2 Class: TVUs less than 25000 and up to 20000
‘C’ Class All other level crossings for road, not covered in
above classes

29
Level Crossings
• Road and railway line should cross preferably at right
angles. Angle of crossing should not be less than 45o
• All interlocked LC shall be kept ‘Normally Open to
Road Traffic’
• In case of non-interlocked LC, the gates must
normally be kept closed. They can be kept open
IRPWM 2020
during the busy season with proper permission
• Height gauges should be located at a minimum 8 m
from gate posts at LC located at electrified sections
• LC should not fall within the breathing length of LWR

30
Level Crossings
• Rail joints should be avoided in check rails and on the
running rails, within the level crossings and 3 m on
either side from the end of level crossing
• In case of LWR, avoiding fish plated joint on the level
crossing and within 6 m from the end of level crossing
• On NH, SH and other important roads, only grade
IRPWM 2020
separators shall be provided instead of LC
• Visibility of manned gate shall be minimum 5 m and
gate post shall be 3 m from center of the track
• Fencing shall be done for 15 m parallel to the track on
either side

31
Level Crossings

IRPWM 2020

32
Level Crossings

Distant Gate cum Distant Home Remarks

Yellow Red --- Stop at gate signal
Green Yellow Red Stop at Home
signal
Green Double yellow Yellow / Going to be S1P.pdf (railnet.gov.in)

Yellow with received on main

route line / loop line
Green Green Green Train is on run
through via main
line
33
Today we discussed the classification of block and non-block
stations and their features, station yards, their types and
salient features of marshalling yards, and level crossings,
the classification and important features related to
them.
Thank You

34
RAILWAY ENGINEERING
Lecture Number 60
Track Maintenance II

RAJAT RASTOGI
CIVIL ENGINEERING

1
Discussed in Previous Lecture

• Track Maintenance
– Maintenance categories
– Maintenance parameters
– Track Indices

2
Today’s Discussion

• Track Maintenance
– Annual Maintenance Schedule
– Mechanised Track Maintenance
– Systematic packing
– Picking up slacks
– Through packing

3
Regular Track Maintenance

• Annual programme of track maintenance

– Post monsoon attention schedule
• Picking of slacks – 1 to 2 days a week
• On remaining days systematic planned / NBM from
one end of the section to the other. It includes:
• Through gauging, Sleeper spacing/squaring, casual IRPWM 2020
renewals of rails/sleepers, attention to bridge
approaches, level crossings and points & crossings,
SEJs, Glued Joints, lubrication of rail joints, weld
collar painting, Destressing of track, Cold weather
patrolling, etc.

4
Regular Track Maintenance

• Annual programme of track maintenance

– Pre-monsoon attention schedule
• 2 to 3 days a week: clearing of side and catch water
drains, earthwork repairs to cess, clearing
waterways and picking up slacks
• Rest of the days: normal systematic planned / NBM
IRPWM 2020
which includes:
• Through gauging, Sleeper spacing/squaring, casual
renewals of rails and sleepers, Shallow screening of
specified lengths, Destressing of track, Hot weather
patrolling etc.

5
Regular Track Maintenance

• Annual programme of track maintenance

– Attention during monsoon schedule
• Picking up slacks or NBM with attention to side and
catch water drains and waterways
• During abnormally heavy rains, patrolling of the
line by gangs should be carried out in addition to IRPWM 2020

regular monsoon patrolling

6
Regular Track Maintenance

• Mechanised Track maintenance

– On-track Machines Unit (OMU)
– Mobile Maintenance Gang (MMG)
– Sectional Gangs
Universal Tamping machine starbag-rail.com

IRPWM 2020

7
Mechanised Track Maintenance

• On-track Machines Unit (OMU)

– Machines used are: Tie – tamping machines for
plain track and points and crossings, shoulder
ballast cleaning machines, ballast cleaning
machines, ballast regulating machines, dynamic
track stabilizers and UTV Tie-tamping machine Blogspot.com

IRPWM 2020
– Maintenance taken up are:
• Systematic tamping of plain track as well as Points
& Crossings
• Intermediate tamping of plain track as well as
Points & crossings

8
Mechanised Track Maintenance

• On-track Machines Unit (OMU)

– Maintenance taken up are:
• Shoulder ballast cleaning;
• Ballast profiling/redistribution;
• Track stabilization;
• Periodical deep screening; Ballast Cleaning machine technology.plassertheurer.com

IRPWM 2020
• Picking up and transportation of Material
• Mobile Maintenance Gang (MMG)
– One MMG has a jurisdiction on 70-80 km in single
line section and 30-50 km in double/multi-line
section

9
Mechanised Track Maintenance

• Mobile Maintenance Gang (MMG)

– A Rail Borne Maintenance Vehicle (RBMV) is used
for mobility
– The functions of MMG are:
• Repair to rail/weld fracture including in-situ AT Ballast Cleaning machine technology.plassertheurer.com

IRPWM 2020
welding.
• Attention to SEJs.
• Scattered replacement of switches and crossing
components, glued joints, SEJs, etc.
• Rail cutting, drilling and chamfering

10
Mechanised Track Maintenance

• Mobile Maintenance Gang (MMG)

– Functions contd.:
• Spot renewals of rails and sleepers.
• Spot attention by tamping of few sleepers with off-
track tampers or any other approved equipment. Rail Borne maintenance Vehicle facebook.com

• Loading and unloading of material required for IRPWM 2020

spot attention.
• Driving of RBMV
– RBM vehicle carries all the equipment and
accessories required for maintenance works

11
Mechanised Track Maintenance

• Sectional Gangs (SG)

– Functions:
• Systematic through packing of track
• Overhauling of track
• Patrolling of track (Keyman’s daily patrol, Hot/cold Rail Borne maintenance Vehicle facebook.com

IRPWM 2020
weather patrolling, monsoon patrolling)
• Watching vulnerable locations
• Need-based attention to bridges, turnouts, SEJs, LC
• Greasing of ERCs, lubrication of joints, casual
changing of rubber pads, fittings

12
Mechanised Track Maintenance

• Sectional Gangs (SG)

– Functions:
• Minor cess repairs
• Cleaning of drains
• Attention to loops Rail Borne maintenance Vehicle facebook.com

IRPWM 2020
• Creep and gap adjustment not involving use of
machines
• Pre and post tamping attention
• Examination of rails, sleepers and fastenings
including measurement of toe load of ERCs

13
Mechanised Track Maintenance

• Sectional Gangs (SG)

– Functions:
• Inspection of and attention to insulated joints, SEJs
• Weld collar painting, cess cleaning, cutting of tree
branches/shrubs for improving visibility Rail Borne maintenance Vehicle facebook.com

IRPWM 2020

14
Track Maintenance

• Systematic Tamping (Plain track, P&C)

– Decided based on results of Track Recording Car
(TRC) and Oscillation Monitoring System (OMS)
– TRC records four track parameters, accelerations
and ride indices
Track Recording car indiarailinfo.com
– OMS measures acceleration in vertical and lateral IRPWM 2020

direction and calculates the ride indices

– Oscillograph Car can be used at higher speeds up
to 150 kmph (TRC has a speed limitation of 110
kmph)

15
Track Maintenance

• Systematic Tamping (Plain track, P&C)

– Past history of deterioration of tracks, traffic GMT,
type of formation, condition of track and its
components is considered before deploying
tamping machines Output of TRC
https://iricen.gov.in/iricen/books_jquery/track_monit

– Pre-requisites: oring.pdf · PDF file

• A minimum depth of 150 mm of clean ballast

cushion below the bottom of the sleepers
• Adequate ballast available in the shoulders and
cribs
IRPWM 2020

16
Track Maintenance

• Systematic Tamping (Plain track, P&C)

– Pre-requisites:
• Deep screening of ballast and running out of
ballast should be done in advance
• Time allowance for work shall be incorporated in
the block time for the operation of trains
• Heaping of ballast should be ensured in the
tamping zone and wherever it is short
• Low cess should be made up, ballast should be
clean
• Pumping joint should be cleaned
IRPWM 2020

17
Track Maintenance

• Systematic Tamping (Plain track, P&C)

– Pre-requisites:
• Hogged joints, tightening of fastenings should be
given attention
• Damaged and broken sleepers be removed,
squaring of sleepers be done and spacing adjusted
• Adjust creep, expansion gaps and gauge
• Removing of signal rods, cables, pipes, level
crossing check rails, joggled fish plates etc. which
may get damaged due to tamping
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18
Track Maintenance
• Systematic Tamping (Plain track, P&C)
– The tamping depth i.e. gap between the top edge of
the tamping blade and the bottom edge of the
sleeper in closed position of the tamping tool should
be adjusted to 15 mm to 20 mm
– Tamping tools shall be inserted centrally between
the sleepers into the ballast (to avoid damage) Ballast Tamping Machine railgeelong.com

– The tamping (squeezing) pressure (110–120 Kg/cm2

for plain track and 125-135 Kg/cm2 for P&C) and
squeezing time (0.8 second to 1.2 second) should be
adjusted
– One insertion is sufficient. Two insertion may be
used if lift is above 30mm
IRPWM 2020

19
Track Maintenance

• Systematic Tamping (Plain track, P&C)

– A run-off ramp of 1 in 1000 should be given
before closing the days work
– Checking of alignment, levels, tightening of
fastenings, breaking of fittings or sleepers be Ballast Tamping Machine railgeelong.com
done once the tamping is over and remedial
measures be taken appropriately

IRPWM 2020

20
Track Maintenance

• Picking Up Slacks
– Slacks usually occur on:
• Stretches of yielding formation
• High banks and cuttings
• Approaches of bridges, LC, SEJs, P&C zones, Glued Using Crowbar on track Storyblocks video
Joints
• Badly aligned curves, axle counter locations and
other electrical and S&T installations
• Locations where ballast is poor in quality or
quantity or where drainage is defective
IRPWM 2020

21
Track Maintenance
• Picking Up Slacks
– Attention shall be given as per the results of TRC /
OMS / Oscillograph car
– For spot attention, multi-purpose tampers or Off-
track handheld tampers or crowbars are used
– In the case of a low joint, the fishplates should be
slightly loosened and the joint tapped, so that the Off-track handheld tampers svjcorporation.com

rail ends are rendered free and can be lifted

– After the joint is thoroughly packed the fishplates
should be tightened again
– When joints are picked up, at least three sleepers on
either side of the joints should be packed
IRPWM 2020

22
Track Maintenance

• Picking Up Slacks
– If the affected length of the track is more than 1
km then track machines should be used
Defects Symbol Place of indication
Cross levels C-2 On the sleeper inside gauge face
Track Tamping Machine railway-supply
Loose packing H or P On the sleeper outside the gauge face
Gauge G± On the sleeper inside gauge face
Unevenness →  On the rail web on gauge face side
Alignment  → On the foot of the rail inside gauge
face IRPWM 2020

23
Track Maintenance
• Through Packing: Convention method
– Manual through packing is not done on concrete
sleeper tracks
– Steps:
• Opening of the road.
• Examination of rails, sleepers and fastenings.
• Squaring of sleepers. Manual maintenance rediff.com

• Slewing of track to correct alignment.

• Gauging.
• Packing of sleepers.
• Repacking of joint sleepers.
• Boxing of ballast section and tidying
IRPWM 2020

24
Track Maintenance

• Through Packing: Convention method

– Opening of Road:
• Ballast is taken out for a depth of 50mm below the
packing surface and up to 450mm inside of the rail
seat
• Racking pf ballast inwards should not form ridge
Manual maintenance freepressjournal.com
higher than 50mm above the rail levels
– Examination of rails, sleepers and fastenings
• Rails are examined for corrosion on foot/web,
cracks at ends, wear at top and side of rail head,
wear at rail joint, tightening of fish bolts, etc.
IRPWM 2020

25
Track Maintenance

• Through Packing: Convention method

– Examination of rails, sleepers and fastenings
• Lubricate the gauge face (if wear on curve is
unusually high); remove rust and dust from
corroded rails, remove kinks in rails
• Sleepers and fastenings should be checked for their Manual maintenance thestatesman.com

condition and soundness

– Squaring of sleepers
• Spacing of sleepers be checked and marked
correctly using chalk. Same marking is done on rails
IRPWM 2020

26
Track Maintenance
• Through Packing: Convention method
– Squaring of sleepers
• Out-of-square sleepers are picked with pick end of
beaters, fastening loosened, and the sleepers are
levered and squared to position
• Squaring should be done using mechanical or
hydraulic spacer or using crowbars
– Slewing of track to correct alignment Manual maintenance thestatesman.com

• Heavy slewing is done at the time of track

realignment
• Under normal maintenance, road is opened, cores at
ends are loosened, sufficient ballast is drawn at the
ends of the sleepers
IRPWM 2020

27
Track Maintenance

• Through Packing: Convention method

– Slewing of track to correct alignment
• Gang Mate shall check slewing from a distance 30
to 60 m on straight track and on outer rail on
curves
• It is done in the morning, as later the sighting
Manual maintenance blogspot.com
becomes difficult
• It is done using hydraulic / mechanical jacks or
TRALIS. If crowbar is used, then the angle with
vertical shall not be more than 30o as at higher
angle it will lift the track
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28
Track Maintenance

• Through Packing: Convention method

– Gauging
• It is done once the squaring of sleepers is over
• Gauging is done within specified permissible limits
• The track gauge cum level should be held firm with
one lug against the base rail, and the other end being Manual maintenance tklink.co.uk

swiveled over the opposite rails

• The tightest position obtained determines the correct
point to test the gauge
On straight track -6mm to +6mm
On curves with R  440 m -6mm to +15mm IRPWM 2020

On curves with R < 440 m Up to +20mm 29

Track Maintenance
• Through Packing: Convention method
– Packing of sleepers
• The Gang Mate shall sight the base rail with eye along
the lower edge of the head of rail and any dip or low
joint is lifted correctly
• The adjacent sleepers should then be packed and the
top checked
• After two rail lengths have been attended to, the rail Manual maintenance railfastners.com

on the other side should be brought to the correct

level by checking cross level with the gauge-cum-level
at every rail joint and at every fourth sleeper
• The next two rail lengths should then be taken up and
the process continued
IRPWM 2020

30
Track Maintenance

• Through Packing: Convention method

– Packing of sleepers
• No joint or dip should be lifted higher than the proper
level
• Packing of all sleepers should be taken up in a
systematic manner commencing from one end
• Four men should deal with every sleeper successively, Off-track handheld tampers svjcorporation.com

two at each rail seat

• The ballast under the sleeper should be packed by the
men standing back-to-back and working their off-track
handheld tampers diagonally under the rail seat at the
same time to ensure firm packing
IRPWM 2020

31
Track Maintenance

• Through Packing: Convention method

– Packing of sleepers
• If crowbars are used, then all men should work the
crowbar to the same height to ensure uniform packing
• After packing the rail seat, the packing should be
continued outwards and inwards (450mm inside) Off-track handheld tampers svjcorporation.com

• The strokes should be kept as nearly horizontal as

possible
• Before final dressing, check should be made that no
sleeper in center bound and adjoining sleepers are
not lifted off their bed (of packed sleeper)
IRPWM 2020

32
Track Maintenance

• Through Packing: Convention method

– Repacking of joint sleepers
• The joint and ‘shoulder’ sleepers should be
repacked, before boxing is done and the cross-
levels at joints checked
– Boxing of ballast section and Tidying Off-track handheld tampers svjcorporation.com

• Clean ballast should be worked in with ballast forks

or rakes
• Hemp cords 6 mm dia. of sufficient length should
be used for lining the top and bottom edges of the
ballast section
IRPWM 2020

33
Track Maintenance

• Through Packing: Convention method

– Boxing of ballast section and Tidying
• If the quantity of ballast is inadequate, full section of
ballast should be provided near the rail seat
• The cess should then be tidied up
• Earth ridging, if exists at the edge of the bank, should Boxing of ballast and tidying depositphotos.com

be removed
• Cess should be maintained to the correct depth below
rail level according to the ballast-section and
formation profile. Too high a cess affects drainage; too
low a cess results in ballast-spread and wastage
IRPWM 2020

34
Today we continued discussion on track maintenance. We
discussed annual schedule of maintenance and regular
maintenance. Along with mechanized maintenance,
packing of ballast, picking up of slacks and through
packing we discussed.
Thank You

35
RAILWAY ENGINEERING
Lecture Number 61
Track Maintenance III

RAJAT RASTOGI
CIVIL ENGINEERING

1
Discussed in Previous Lecture

• Track Maintenance
– Annual Maintenance Schedule
– Mechanised Track Maintenance
– Systematic packing
– Picking up slacks
– Through packing

2
Today’s Discussion

• Track Maintenance
– Systematic overhauling
– Lubrication of rail joints
• Insulated rail joints
• Glued insulated rail joints
– Deep screening of ballast
• Manual and mechanical
– Lifting and Lowering of track

3
Track Maintenance
• Systematic Overhauling
– The overhauling should be done using SBCM for
cleaning of shoulder ballast
– The length of the section to be overhauled shall be
such that complete overhauling of track will be
accomplished within a specific period (normally 3 to
5 years) Shoulder ballast cleaning machine rail-news.com

– The crib ballast should also be shifted to shoulders

for screening by the machine, which should again be
put back in crib portion
– All the loop lines should be shallow
screened/overhauled once in 7 years or more
frequently as required
IRPWM 2020

4
Track Maintenance
• Systematic Overhauling
– Operations:
• Shallow screening and making up of ballast
• All items as done in through packing
• Making up the cess
– Shallow screening and making up of ballast
• For good drainage periodical screening of ballast is Shallow screening

essential
• The ballast in the shoulders opposite to the crib as
well as between the sleepers is removed to the full
depth
• A slope is given at the bottom sloping away from the
sleeper end
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5
Track Maintenance

• Systematic Overhauling
– Shallow screening and making up of ballast
• In case of manual overhauling, the crib ballast in the
shoulders should be opened out to a depth of 75 to
100 mm below the bottom of sleepers, sloping from
the center towards sleeper end
• The ballast is then screened and put back Shoulder ballast cleaning machine plassertheurer.com

• Two contiguous spaces between sleepers should not

be worked at the same time
• Screening should be progressed in alternate panels of
one rail length. Not all panels be stripped of ballast
simultaneously
IRPWM 2020

6
Track Maintenance

• Systematic Overhauling
– Shallow screening and making up of ballast
• Where drains across the track exist, they should be
cleaned and filled with boulders or ballast to
prevent packing from working out and forming
slacks Shoulder ballast cleaning machine plassertheurer.com

• After screening, full ballast section should be

provided, extra ballast being run out in advance for
the purpose
– Through packing of the ballast: already discussed
IRPWM 2020

7
Track Maintenance

• Systematic Overhauling
– Making up of cess
• Cess when high should be cut along with
overhauling and when low should be made up
• Overhauling should be completed before the end
of March Shoulder ballast cleaning machine plassertheurer.com

IRPWM 2020

8
Track Maintenance

• Lubrication of Rail Joint

– This helps in the expansion of rails and reducing
wear on the fishing planes and fish plates
– A stiff paste of plumbago (Graphite) and kerosene
oil, made in the proportion of 3 kg of plumbago to 2
kg of kerosene oil may be used as lubricant
Lubrication of rail joint rail-system.net
– Black oil or reclaimed oil may be used for fish bolts
and nuts
– All rail joints should normally be lubricated once a
year usually from October to February. It should not
be done during extreme hot and cold weather
IRPWM 2020

9
Track Maintenance

• Lubrication of Rail Joint

– In case of non-running lines the period can be 2
years
– Creep in excess of 150 mm should be adjusted before
the work of lubrication
– Procedure: Lubrication of rail joint rail-system.net
• Unscrew the nuts, remove the fish bolts and fish
plates
• clean the fishing surfaces and fish plates with wire
brush
• Check rail ends for cracks and fish plates for wear
IRPWM 2020

10
Track Maintenance
• Lubrication of Rail Joint
– Procedure:
• The fishing surfaces of the rails and fishplates are then
lubricated
• The fish bolts are then put back in reverse position
and tightened using a standard fish bolt spanner, the
inner two bolts being tightened first
• While tightening overstraining of bolts shall be Lubrication of rail joint rail-system.net

avoided
• During all works such as relaying, rail renewals and
renewals of turnouts, etc. rail joints should be
lubricated
• Insulated joint fishplates should not be greased
IRPWM 2020

11
Track Maintenance

• Insulated Rail Joints

– Insulated joints, wherever provided, shall be
maintained as square joints
– Rail ends shall be square and the gap between the
rails should be equal to the thickness of the end post
– The metal burrs at the end, if any, should be Insulated rail joint Goldschmidt.com
removed well in time to avoid short-circuiting
– Fish bolts must be kept tight, and the sleepers well
packed in the vicinity of the joints
– Rail ends shall be kept free from brake dust, dirt,
sand, rust, other foreign Materials etc.
IRPWM 2020

12
Track Maintenance
• Glued Insulated Rail Joints
– The ballast used in track in the vicinity of glued
insulated joints shall be clean to ensure efficient
packing and drainage.
– Ballast is clear of rails and rail fastenings.
– In glued joints, normally no relative movement occurs
between rails and fishplates.
– In case, failure of joints occurs by separation of rail,
Glued Insulated rail joint indiamart.com

fishplate surfaces with consequent relative movement,

fishplates crack/breakages etc., the damaged glued
joint shall be refurbished/replaced.
– The track at glued joint and its vicinity shall be kept
clean with efficient drainage
IRPWM 2020

13
Track Maintenance
• Deep Screening of ballast
– Track, on which deep screening is to be done, shall
be well drained
– Due to presence of bad formation, ballast attrition,
excessive rainfall and dropping of fines and ore,
ballast gets choked up and track drainage is
impaired
– In such situations, it becomes necessary to screen
the entire ballast right up to the formation level
/sub-ballast level
– Through screening restores the resilience and
elasticity of the ballast bed. This is called deep
screening
IRPWM 2020

14
Track Maintenance

• Deep Screening of ballast

– Criteria
• Prior to complete track renewal.
• Prior to through sleeper renewal.
• Where the caking of ballast has resulted in
unsatisfactory riding.
• Before converting existing track, fish plated or SWR
into LWR or CWR, unless the ballast was screened
in recent past.
• After 500 GMT or 10 years, whichever is earlier.
IRPWM 2020

15
Track Maintenance

• Deep Screening of ballast

– Criteria
• For loop lines, once in 15 years
• If the existing clean ballast cushion is less than
150mm
– Procedure (manual, not for LWR section)
• Take longitudinal section of the track with rail
levels at every 30 m. in station yards and run
through lines it is taken as 50 m
• Longitudinal and cross sections are taken
• Humps, sags, unevenness shall not be present
IRPWM 2020

16
Track Maintenance

• Deep Screening of ballast

– Procedure (manual, not for LWR section)
• Arrange additional ballast at site. New ballast
should not mix with unscreened ballast
• Bring cess level to the correct level in relation to
the final rail level
• Provide pegs at an interval of 30 m
• Slewing of curves be completed in advance
• Sleeper renewal be carried out in advance

IRPWM 2020

17
Track Maintenance

• Deep Screening of ballast

– Procedure (manual, not for LWR section)
• Ballast should be removed from space on either
side of the sleeper down to final formation level
and wooden blocks are provided to support the rail
for passing the trains
• Now remove the ballast from under the sleeper 1
down to formation/sub-formation level
• Screen the ballast and place back under the
sleeper 1 and pack the ballast
• Remove wooden block from first space
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18
Track Maintenance

• Deep Screening of ballast

– Procedure (manual, not for LWR section)
• Now remove the ballast from next adjacent space
• After screening the ballast, place it in previous-to-
previous space up to the bottom of the sleeper
• Extra ballast be removed and rail in new space be
supported by a wooden block
• Remove the ballast from under the sleeper 2 down
to the formation level
• Screened ballast be placed under sleeper 2 and
sleeper is packed well
IRPWM 2020

19
Track Maintenance

• Deep Screening of ballast

– Procedure (manual, not for LWR section)
• Now ballast from 4th space be removed down to
formation level and after screening place the
ballast in space 2 upto the bottom of the sleeper.
• Extra ballast is removed from the track.
• Wooden block is removed from space 2 and placed
in space 4th to support the rail
• Ballast under the sleeper 3 is removed and the
procedure is repeated
IRPWM 2020

20
Track Maintenance

• Deep Screening of ballast

– Procedure (manual, not for LWR section)
• Lift the track to provide additional cushion where
required. Pack the track in final position and then box.
– Precautions
• No unscreened length should be left between
screened lengths of the track at the same time
• When ballast is being removed from any sleeper,
there should be at least four fully supported sleepers
• Lifting should be limited to 50mm at a time
IRPWM 2020

21
Track Maintenance

• Deep Screening of ballast

– Precautions
• It should be checked that packing, cross-levels and
grade run-off are satisfactory before closing the
day
• Speed restriction of train should be 20 kmph. It can
be raised gradually and restored on the 21st day
• With machine packing, normal sectional speed be
resumed on the 10th day

IRPWM 2020

22
Track Maintenance

• Deep Screening of ballast (manual packing)

Day Sequence of events Speed, kmph
1st Deep screening and initial packing 20
2nd 1st through packing 20
3rd 2nd through packing 20
4th to 9th Picking up of slacks as required 45
10th 3rd through packing 45
11th to 19th Picking up of slacks as required 75
IRPWM 2020

23
Track Maintenance

• Deep Screening of ballast (machine packing)

Day Sequence of events Speed, kmph
1st Deep screening and initial packing 20
2nd 1st machine packing 20
3rd to 5th Picking up of slacks as required 45
6th 2nd machine packing 45
7th and 8th Picking up of slacks as required 75
9th 3rd machine packing 75
10th Normal IRPWM 2020

24
Track Maintenance

• Deep Screening of Ballast (with BCM)

Details of work Days of work Speed BCM: Ballast Cleaning
Machine
Deep screening by BCM, ballast 1st day 40 kmph TTM: Tie Tamping Machine
equalization followed by initial packing DTS: Dynamic Track
and initial stabilization by DTS Stabilizer
First round of tamping followed by 2nd day (1st 40 kmph
stabilization of track by DTS tamping)
Survey of track for design tamping mode, 3rd day 40 kmph
boxing, ballast section and tidying
Second round of tamping followed by 4th day (2nd 40 kmph
stabilization of track by DTS tamping) IRPWM 2020

25
Track Maintenance

• Deep Screening of Ballast (with BCM)

Details of work Days of work Speed BCM: Ballast Cleaning
Machine
Survey of track for design tamping 5th day 40 kmph TTM: Tie Tamping Machine
mode, boxing, ballast section and DTS: Dynamic Track
tidying Stabilizer
Third round of tamping in design 6th day (3rd 75 kmph
mode followed by stabilization of tamping)
track by DTS
Inspection of track, boxing of 8th day Normal
ballast section and tidying speed
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Track Maintenance

• Deep Screening of Ballast (with BCM)

– Precautions (BCM along with use of TTM and DTS) BCM: Ballast Cleaning
Machine
• Precautions taken in LWR/CWR track shall be
TTM: Tie Tamping Machine
strictly followed DTS: Dynamic Track
• The cutter bar shall be removed after completion Stabilizer
of day's work, ballast filled and packed & stabilized
by TTM/DTS
• Ramp shall not be located in locations like level
crossing, Girder Bridge, transition portion of curve
etc. It shall be kept minimum two rail length away
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Track Maintenance

• Deep Screening of Ballast (with BCM)

– Precautions (BCM along with use of TTM and DTS) BCM: Ballast Cleaning
Machine
• In case of malfunctioning of TTM/DTS, deep screening
TTM: Tie Tamping Machine
should be stopped and section of track which is not DTS: Dynamic Track
tamped and stabilized shall be attended manually by Stabilizer
ballast ramming and correction of track geometry to
ensure safety of running trains. Speed restrictions be
imposed.
• If traffic block in not available on subsequent day of
deep screening by BCM, speed restriction be imposed.
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Track Maintenance

• Deep Screening of Ballast (with BCM)

– Precautions (BCM along with use of TTM and DTS)
• When BCM is not deployed, adequate trackmen shall
be deputed to recoup ballast, particularly in shoulder
and maintain ballast profile after machine working
• Lifting of track shall be resorted to only after ensuring https://www.youtube.com/watch?v=v-jn9AKCN60

adequate availability of ballast for maintaining ballast

profile for planned lifting
• Arrangements for supply and training out of ballast
prior to deep screening should be ensured
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Track Maintenance

• Lifting of Track
– This may be needed:
• During re-grading
• For elimination of minor sags (caused due to improper
maintenance or yielding formation)
• To maintain good levels
– Before starting lifting, level pegs should be fixed at
suitable intervals
– Lifting should not exceed 50 mm at a time. This
allows proper consolidation
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Track Maintenance

• Lifting of Track
– The easement gradient for the passage of trains should
not be steeper than 25mm in one rail length of 13 m
– Lifting should commence from the downhill end carried
out in the direction of rising grade in case of single line
– It should proceed in the opposite direction to traffic, in
case of double line, care being taken not to exceed the
easement grade
– While lifting the track under bridges and overhead
structures and in tunnels, it should be ensured that
there is no infringement of standard dimensions
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Track Maintenance
• Lifting of Track
– In case of curves, it is usual to set the inner rail to the
correct level and grade and to raise the outer rail to
give the required super elevation, care being taken to
see that the cant gradient is within the permissible
limit
– The operation should be repeated until the required
level is attained when the track should be finally
ballasted, through packed and boxed, the cess being
made up to proper level
– Heavy lifting should always be carried out under
suitable speed restriction
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Track Maintenance

• Lowering of Track
– Usually, it should not be done
– When lowering is to be done, trenches should be
made across the track at every 30 m to the final
level to give a continuous indication
– The ballast should be removed sufficiently far away
from the track to prevent it getting mixed up with
excavated material
– Lowering should be restricted to maximum of 75mm
at a time
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Track Maintenance

• Lowering of Track
– Grade for passage of trains should not exceed
25mm in a rail length of 13 m
– Lowering should be carried out in the direction of
the falling grade
– Procedure:
• Clear the spaces between the sleepers
• Slightly lift the track, break the packing beneath
and level it into the space between the sleepers
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Track Maintenance

• Lowering of Track
– Procedure:
• Remove the material, repeat the operation until
the final level is reached
• Then the track is ballasted, through packed and
boxed
• Cess is cut down to the proper level

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Today we further discussed the track maintenance. We
covered systematic maintenance, lubrication of rail
joints, insulated rail joints and glued insulated rail joints,
manual and mechanical deep screening of ballast, and
lifting and lowering of a track.
Thank You

36
RAILWAY ENGINEERING
Lecture Number 62
Track Maintenance IV

RAJAT RASTOGI
CIVIL ENGINEERING

1
Discussed in Previous Lecture

• Track Maintenance
– Systematic overhauling
– Lubrication of rail joints
• Insulated rail joints
• Glued insulated rail joints
– Deep screening of ballast
• Manual and mechanical
– Lifting and Lowering of track

2
Today’s Discussion

• Track Maintenance
– Measured Shovel Packing
– Track Circuited Areas
– Electrified Areas of Track
– Permanent Way Renewals
– Through Sleeper Renewals

3
Track Maintenance

• Measured Shovel Packing

– This method is good for maintaining fish plated
and LWR tracks for speeds of up to 160 kmph
– It is used for mainly the following works:
• Through packing of flat bottom sleepers
• Packing of joint wooden sleepers in metal sleeper
tracks
• Through packing of turnout with wooden or steel
sleepers
• Dehogging of rail ends

4
Track Maintenance

• Measured Shovel Packing

– Procedure adopted:
• Measurement of voids fixation of high points
• Transferring high points to good points
• Longitudinal levelling
• Opening out of ballast
• Lifting and packing of track
• Provision of ramps
• Alignment fixing
• Boxing and dressing of ballast
• Majoration of joints and checking of work

5
Track Maintenance

• Measured Shovel Packing: Equipment Used

– Canne-a-boule
• This is used for assessing the extent of packing
voids under the sleeper
– Densometer
• This is used for measuring the packing voids under
the sleeper
• It has tripod legs which are fixed in the ballast
• Dancing rod is placed on the sleeper
• The shift of the friction sleeve helps in determining
the voids under the sleeper in dynamic condition

6
Track Maintenance

• Measured Shovel Packing: Equipment Used

– Fleximeter
• This is used to measure the depression of the rail
under the weight of plying traffic
• It is used along with Densometer to check the
tightness of the fastenings
• The difference between the readings of the two
meters indicates the extent of loosening of fastenings
– Viseur and Mire
• These are used to measure the unevenness of the rail
top and for rectifying the alignment

7
Track Maintenance

• Measured Shovel Packing: Equipment Used

– Viseur and Mire
• Viseur is a type of a telescope with magnifying
power of 12 and is supported on a stand which can
be fixed to the rail seat with the help of two
clamps
• Mire is a staff bearing five graduated scales, in mm
• It can be fixed to the rail head using bent clamps
– Gauge-cum-Level
• This is used to measure the gauge and cross-levels

8
Track Maintenance

• Measured Shovel Packing: Equipment Used

– Gauge-cum-Level
• A spirit level, 200mm long with sensitivity of 2’30’’,
is used to measure cross-levels to an accuracy of
1mm
– Packing Shovel
• This is used for placing the stone chips over the full
width of the sleeper under the rail seat
• It is around 1 m long and has a pan to collect chips
under the sleeper bed
• Throw of the blade is 100mm for BG

9
Track Maintenance

• Measured Shovel Packing: Equipment Used

– Non-infringing Track Jacks
• These are used for lifting the rail to a desired
height
• This jack brings back the lifted rail to its normal
position with little manipulation in case a train is
approaching on that track (without having a need
to remove the jack)
• These are designed for a safe working load of 5
tonnes and for a maximum lift of 200mm on a BG
track

10
Track Maintenance

• Track Circuited Areas

– Precautions to be taken:
• The two rails on the track should not be touched by
any tool or metal object that may cause short
circuiting
• All gauges, levels, trolleys used in the track-circuited
length should be insulated
• Steel or CI pipes placed under the track for different
reasons shall be sufficiently below the rails to prevent
short-circuiting
• Before taking up maintenance, all S&T/electrical
installations which may interfere shall be removed
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Track Maintenance

• Track Circuited Areas

– Precautions to be taken:
• Use of steel tapes shall be avoided
• Proper drainage should be ensured on tracks,
yards, etc. Washable concrete aprons shall be
provided on platforms lines in track circuited areas
• Ballast must be kept clean throughout the track
circuited section and care should be taken to see
that minimum ballast resistance per km of track
should not be less than 2 ohms per km in station
yard and 4 ohms per km in the block section
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Track Maintenance

• Track Circuited Areas

– Precautions to be taken:
• On PSC sleepers track, availability of insulated
liners upto a minimum level of 97% shall be
ensured
• Any hole drilled in the rail for providing S&T
fixtures should be at the neutral axis of the rail and
chamfered
• In case of curves in track circuited area, efforts
should be made to keep inner rail as positive rail
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Track Maintenance

• Track Electrified Areas

– Precautions to be taken:
• No work shall be done within 2 m distance from
the live parts of the O.H.E
• The section concerned should be isolated and
earthed on the date and at the time specified,
and ‘Permit-to-work’ should be taken
• Any branch of tree within 4 m of the live conductor
shall be cut or trimmed periodically
• No fallen wires or wires shall be touched unless power
is switched off and the wires are suitably earthed
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Track Maintenance
• Track Electrified Areas
– Precautions to be taken:
• In case wires drop at a level crossing, the gatekeeper
shall immediately arrange to stop the traffic on the
track
• Precaution be taken to prevent possible damage to
the traction underground feeder cables which are
located near the running lines
• Vertical and horizontal clearances of the wires should
be adhered to with respect to the center line of the
track
• No tool or part of the body shall come within 2 m of
OHE
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Track Maintenance

• Track Electrified Areas

– Precautions to be taken:
• While doing maintenance of the track, on removal
of fish plates or rails, temporary jumper shall be
used for bridging the gaps
• Temporary connections shall be made in case of
track renewals, defective or broken rails or
loosening of fish plates
• To omit the possibility of shock due to build up of
potential due to induction in the metallic bodies
situated close to OHE, the metallic structures shall
be bonded together and earthed
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Track Maintenance

• Track Electrified Areas

– Precautions to be taken:
• While unloading rails, care should be taken to ensure
that rails do not touch each other to form a
continuous metallic mass of length more than 300 m
• In case electrically hauled train is within 250 m, staff
shall remain clear of track and avoid contact with rails
• Normally all catch sidings, except, those which are
sanded, shall be kept alive
• On sanded catch siding, the rails shall be kept clear of
sand for a length of 21.5 m, beyond the section
insulators in the overhead lines
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Track Maintenance

• Track Electrified Areas

– Precautions to be taken:
• The switches controlling the sanded catch sidings
shall be kept in the neutral position
• The catch sidings shall not be made alive when an
electric engine or single or multiple unit train or
any vehicle coupled thereto are standing in the
sanded tracks

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Permanent Way Renewals
• Track renewal categories
– CTR(P): Complete Track Renewal (Primary)
– CTR(S): Complete Track Renewal (Secondary)
– TRR(P): Through Rail Renewal (Primary)
– TRR(S): Through Rail Renewal (Secondary)
– TSR(P): Through Sleeper Renewal (Primary)
– TSR(P): Through Sleeper Renewal (Secondary)
– TRT: Through Turnout Renewal
– TFT: Through Fitting Renewal
– TWT: Through Weld Renewal
– TBST: Through Bridge Sleeper Renewal
– TBR: Through Ballast Renewal
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Permanent Way Renewals
• Track renewal categories
– CTR(P): Complete Track Renewal (Primary)
– CTR(S): Complete Track Renewal (Secondary)
– TRR(P): Through Rail Renewal (Primary)
– TRR(S): Through Rail Renewal (Secondary)
– TSR(P): Through Sleeper Renewal (Primary)
– TSR(P): Through Sleeper Renewal (Secondary)
– TRT: Through Turnout Renewal
– TFT: Through Fitting Renewal
– TWT: Through Weld Renewal
– TBST: Through Bridge Sleeper Renewal
– TBR: Through Ballast Renewal
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Permanent Way Renewals

• Primary renewals:
– Renewals in which only new material are used
• Secondary renewals:
– Renewals using released serviceable materials
• Scattered renewals:
– In this case, unserviceable rails, sleepers and
fastenings are replaced by identical sections of
serviceable and nearly the same vintage track
components in isolated locations and not more than
10 rails and/or 250 sleepers in a gang beat in a year
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Permanent Way Renewals

• Scattered renewals:
– Such renewals are part of normal maintenance
operations
• Casual renewals:
– In this case, unserviceable rails, sleepers and
fastenings are replaced by identical sections of
serviceable and nearly the same vintage track
components in isolated locations of continuous but
small stretches
– This is not a part of normal maintenance operations
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Permanent Way Renewals

• Through Fitting Renewals:

– In this case, only liners and GRSPs/CGRSPs are
renewed without replacement of ERCs
• Factors governing renewal:
– Incidence of rail fractures/failures.
– Wear on rails.
– Maintainability of track to prescribed standards.
– Expected service life in terms of GMT of traffic
carried.
– Plan based renewals
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Permanent Way Renewals

• Incidence of rail fractures/failures.

– A spate of rail fractures on a particular section
having 5 withdrawals of rails per 10 km in a year due
to fracture and/ or rail flaws detected ultrasonically
falling in the category of IMR will have priority while
deciding rail renewals
– In case the rail failures at fish plated/welded joints
are pre-dominant, end cropping with or without
welding could be considered
– TRR is allowed in locations of track where more than
30 defective welds per track km are existing
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Permanent Way Renewals

• Wear on Rails:
– Limiting loss in rail section: 6% in 52 kg/m and 7%
in 60 kg/m rail section Vertical wear

– Corrosion beyond 1.5mm in the web or foot or WORN PROFILE

existence of the corrosion pits on the underside
of the foot and liner biting on the foot
– Vertical wear measured as a difference between
the height of the new rail and the height of the
worn-out rails; beyond 13mm on 60 kg/m and
8mm on 52 kg/m rail section
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Permanent Way Renewals

• Wear on Rails:
– Lateral wear limits: Lateral wear
• Curves: ‘A’ and ‘B’ routes 8mm; ‘C’ and ‘D’ routes New
Profile
10mm Wear measured
at a point 13-15
• Straight: ‘A’ and ‘B’ routes 6mm; ‘C’ and ‘D’ routes mm below rail Worn
table Profile
8mm
• Maintainability of track to prescribed standards
– Poor running quality of track in spite of extra
maintenance labour engaged
– Disproportionate cost of maintaining the portion of
track in safe condition
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Permanent Way Renewals

• Maintainability of track to prescribed

standards
– Poor running quality of track in spite of extra
maintenance labour engaged
– Disproportionate cost of maintaining the
portion of track in safe condition
– The condition of rails with regard to hogging/battering,
scabbing and wheel burns and other conditions such as
excessive corrugation of rail
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Permanent Way Renewals

• Based on service life as total GMT

– 60 kg/m rail: 72 UTS 550 GMT, 90 UTS 800 GMT
– 52 kg/m rail: 72 UTS 350 GMT, 90 UTS 525 GMT
– In case of the bridge proper and in approaches
(up to 100 m on either side) for all the important
bridges and such of the major bridges where
height of bank is 5.0 m or more, all tunnels and
their approaches (up to 100 m on either side) it
shall be half of the GMT specified above
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Permanent Way Renewals

• Plan Based Renewals

– As per pre-determined plan, with the objective of
modernization on the selected routes in the
quickest possible time
– This can be done even if it is premature renewals
• Renewal of special track components like
SEJ, Glued joints, etc.
– In case such components have degenerated to a
level where they are not able to serve their
desired purpose
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Permanent Way Renewals

• Through Sleepers Renewals

– Concrete sleepers will be considered for
replacement/renewal if:
• They have developed notches more than 3 mm at
rail seat locations
• Their inserts are broken or elongated
• They are not able to provide required toe load
• Sleeper themselves are broken or
• Any other reason for which they are not able to
hold gauge and level
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Permanent Way Renewals

• Through Sleepers Renewals

– Through sleeper renewal should be considered if the
percentage of such sleepers exceeds 20% in a patch
– On girder bridges when several sleepers are
defective, renewals should be carried out for the full
span
– PSC sleepers on Plain tracks, criteria: 2000 GMT or
35 years whichever is earlier or on condition basis
• 50% of the above for turnouts, CC aprons, curves
sharper than 6o, SEJ, gradient sharper than 1 in 100,
coastal areas, station yards including approaches, etc.
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Permanent Way Renewals

• Renewal of Track Fittings

– GFN-66 Liners on Plain tracks, criteria: 200 GMT or 4
years whichever is earlier or on condition basis
– Metal Liner on Plain tracks, criteria: 300 GMT or 8
years whichever is earlier or on condition basis
– ERC on Plain tracks, criteria: 300 GMT or 8 years
whichever is earlier or on condition basis
• 50% of the above for turnouts, CC aprons, curves
sharper than 6o, SEJ, gradient sharper than 1 in 100,
coastal areas, station yards including approaches, etc.
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Permanent Way Renewals

• Renewal of Track Fittings

– GRSP on Plain tracks, criteria: 200 GMT or 4 years
whichever is earlier or on condition basis
– CGRSP on Plain tracks, criteria: 300 GMT or 8
years whichever is earlier or on condition basis
• 50% of the above for turnouts, CC aprons, curves
sharper than 6o, SEJ, gradient sharper than 1 in
100, coastal areas, station yards including
approaches, etc.

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 Today we discussed other aspects related to track
maintenance. We discussed measured shovel packing,
maintenance precautions in track circuited areas and
electrified areas, permanent way renewals and through
sleeper renewals.
Thank You

34
RAILWAY ENGINEERING
Lecture Number 63
Track Renewals and Drainage

RAJAT RASTOGI
CIVIL ENGINEERING

1
Discussed in Previous Lecture

• Track Maintenance
– Measured Shovel Packing
– Track Circuited Areas
– Electrified Areas of Track
– Permanent Way Renewals
– Through Sleeper Renewals

2
Today’s Discussion

• Track Renewals
– Points and Crossings
– Track Renewal Train
• Track Drainage
– Requirements for a track
– Drainage between stations
– Drainage in station yards
– Drainage at platforms
– Sub-surface drainage

3
Permanent Way Renewals

• Points and Switches

– If wear on switches and crossings reaches the
limits as:
• Chipped length aggregates 200mm within a
distance of 1000mm from its toe (one chip is more
than 10mm over a continuous length of 10mm)
• It is badly twisted or bent and does not house
properly against the stock rail causing a gap of 5
mm or more at the toe
• Vertical wear on wing rails or nose of crossings
exceeds 10mm (after deduction for slope 1 in 20)
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Permanent Way Renewals

• Points and Switches

– When it crosses minimum total traffic in GMT as:
• Fabricated switch: 52 kg/m 150 GMT, 60 kg/m 200
GMT
• Thick web switch: 52 kg/m 500 GMT, 60 kg/m 500
GMT
• CMS crossing: 52 kg/m 300 GMT, 60 kg/m 300
GMT
– When through sleeper renewal is due
– When rail section on either side is changed to a higher
section in through running lines
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Permanent Way Renewals

• Points and Switches

– Points to be considered in station yards:
• Renewal should bring improvement in the layout
• Standard rail sections shall be used
• At least one rail length on either side of the turnout
should have the same section of rail as the turnout
• The intersection point of the turnout track and the
main line track shall be fixed accurately as these are
used as reference for measurement of other points
• Joints on the SRJ and lead rail should be welded
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Permanent Way Renewals

• Points and Switches

– Points to be considered in station yards:
• New gauge tie plates shall be used
• Before connecting stretcher bars, each tongue rail
should be checked regarding fitting properly
against the stock rail up to JOH, without applying
any pressure to bring it in position
– Procedure:
• Deep screen the ballast; place it up to the bottom
of the sleepers; keel extra ballast for boxing, etc.
• Keep rail cutting and rail drilling machines ready
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Permanent Way Renewals

• Points and Switches

– Procedure:
• Turnout can be assembled at site manually after
dismantling the old one or assembling manually by
the side of the existing layout at site or it can be
pre-assembled and lay using machines

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Track Renewal / Re-laying Train (TRT)

• TRT consists of:

– Main vehicle, which has:
• Sleeper handling device to remove old sleepers
and place new sleepers
• Rail lifting and guidance system for dissecting the
old rails at the side of the track
Constructionweekonline.com
• A triangular smoothing plough and compacting
plate to prepare the ballast
– Handling gantry, which can lift 20 sleepers at a
time and can travel at a maximum speed of 15
kmph
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Track Renewal / Re-laying Train (TRT)
• TRT consists of:
– A set of BFRs, used to handle sleepers, works with a
speed of 720 m/h when in use
• Working of TRT
– Removal of fastenings (from old rails)
– Placement of new rails (at 1.5 m from the track)
– Positioning on the track (using guidance sled) siyasat.com

– Lifting of old rails and screening of ballast (using rail

lifting and guidance system and BCM)
– Picking up of old sleepers (placed on conveyor
system)
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Track Renewal / Re-laying Train (TRT)

• Working of TRT
– Levelling and compaction of ballast bed (using
vibratory plough and compactor)
– Laying of new sleepers
– Laying of new rails plassertheurer.com

– Fixing insulators and elastic rail clips

– Picking up of old rails

https://www.youtube.com/watch?v=PWlZqdWc60U IRPWM 2020

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Track Drainage

• Need for Proper Drainage

– To avoid settlement of embankment or variation in
cross-levels of the rails
– To ensure the stability of the formation and the track
(in terms of bearing capacity and resistance to
shear)
– To avoid failure of an embankment (due to loss of BC
and self weight)
– To avoid formation of ballast pockets (due to
bouncing and pitching effects along with loosening
of components)

12
Track Drainage

• Need for Proper Drainage

– To ensure that the banks do not shrink and crack
(on account of drying of water; especially in poor
soils)
– To reduce the negative effects if the formation is
of black cotton soil (expansion/shrinkage, cracks)
– To avoid the formation of slush (causing clogging
of the ballast under dynamic loads)

13
Track Drainage
• Sources of Water
– Gravity water: Water which collects due to
precipitation and moves into the subgrade under
gravity. This can be controlled by:
• Provision of surface drainage, say cross-falls, side
drains
• Lowering of cess
• Turfing of side slopes of embankments
– Capillary action: This is the water which moves up
from the ground water table or seepage water
under the action of capillary effect
• It can be controlled by providing a pervious layer
which acts as a capillary break

14
Track Drainage

• Sources of Water
– From adjacent areas: Water seeping from sources in
the vicinity into the subgrade. It can be controlled
by:
• Diverting the water from the source away from
embankment
• Providing effective paved catch water drain in sloped
areas
• Providing inverted filters and underground drains
– Hygroscopic action from atmosphere: Absorbing the
moisture present in the atmosphere. Being less it
has little effect of subgrade moisture
15
Track Drainage

• Requirements for Good Track Drainage

– Surface water should not percolate to the track
– Side drains should have effective size and slope to
carry surface water
– Longitudinal drains provided between two tracks
shall have a Saucer shape so that it can collect water
from both sides
– Design of drain shall be such that it allows periodic
inspection and cleaning
– Top of the drain shall be below cess level to ensure
effective drainage of the ballast bed

16
Track Drainage

• Requirements for Good Track Drainage

– Sides and slope of the banks shall not get eroded
with flow of water
– Soil in the formation and subgrade should be such
that is more permeable, and do not help capillary
rise of water
– Proper sub-surface drainage measures shall be taken
– Longitudinal drains shall have a proper outfall
– Special arrangements shall be made for waterlogged
areas or other perennial problems

17
Track Drainage

• Drainage in mid-section between stations

– Side drains:
• These should be provided along the track in cutting
and in zero fill locations where the cess level is not
above the ground level
• These shall be provided with an adequate slope so
that collected water can flow freely
• Adequate opening shall be provided under level
crossing, around trolley refuges, and around the
OHE so that water do not accumulate at a location

18
Track Drainage

• Drainage in mid-section between stations

– Side drains:
• In general, the drains shall be provided with a
lining
• Based on the terrain condition, catch water drains
of adequate size should be provided to capture the
water
• Surplus ballast in the shoulders of the track retards
drainage and encourages vegetation growth.
Hence, all extra ballast should be removed from
the track, and stacked in small heaps beside the
track

19
Track Drainage

• Drainage in station yards

– Open surface drains:
• These shall be left open from top to allow inspection
and periodical cleaning
• In the case of earthen drains, the velocity shall be
taken in a range 0.50 m/s to 1.0 m/s, and for lined
drains it shall be 1.0 m/s to 2.0 m/s
– Saucer-shaped drains
• These are the longitudinal drains provided between
the two tracks with curved sides
• Drains with vertical sides can also be considered if
required

20
Track Drainage
• Drainage in station yards
– Normally the drain top should not be above the cess
level for effective drainage in the ballast
– In case the above is not feasible, weep holes can be
provided at the assumed cess level
– The slope shall be aligned based on the location of
the outfall. If it is available at both the ends, then
the slope of the drain shall move away towards the
ends from the center in the yard
– A network of longitudinal and cross drains shall be
provided to carry away the water in the least
possible time

21
Track Drainage

• Drainage in station yards

– The arrangement for drainage of water at water
columns and carriage watering points with washing
hydrants should be efficient and maintained
• Drainage at station platforms
– Platforms shall slope away from the track
– All drains from platform side should be enclosed in pipes
and that pipe should discharge the content toward non-
track side of the platform
– Covered longitudinal drains should be provided, if required

22
Track Drainage

• Drainage at station platforms

– In case of drainage from an island platform, the
pipes shall discharge the content towards less
important side of the track and not towards the run-
through lines
• Sub-surface drainage
– Inverted filter can be provided which is a blanket of
non-cohesive graded material. It acts as a capillary
cutoff
– It is provided on the entire width of the formation

23
Track Drainage

• Sub-surface drainage
– Inverted filter:
• Thickness of the layer can be 300mm on a clayey soil.
It may be increased as per the soil properties
• It may contain plastic fines not exceeding 5% and non-
plastic fines not exceeding 12%
• In macadam form, the LL should not exceed 35 and PI
should be below 10
• The uniformity coefficient should be above 4
(desirably above 7)
• The coefficient of curvature should be between 1 and
3

24
Track Drainage

• Sub-surface drainage
– Depth of blanket layer:
• For GP/SP soil with Cu > 2, GM, GM-GC: 450mm
• For GC, SM, SC, SM-SC: 600mm
• ML, ML-CL, CL, MI, CI, rocks susceptible to
weathering: 1000mm
– Sand Piles
• Sand piles of diameter 200mm can be used to
improve the sub-surface drainage
• The total cross-sectional area of sand piles is kept
as 20% of the formation area

25
Track Drainage
• Sub-surface drainage
– Sand Piles
• The depth of sand piles may be 2 to 3 m
• The water rises through the sand piles to the surface
through capillary action and evaporates
– Cement Grouting
• Cement grouting is used if water pockets are created
in the subgrade
• The slurry of cement and sand is pumped into the
embankment by pneumatic injection
• The grout of cement and sand is made in the ratio of
1:2 to 1:6 and is injected under the pressure of 4.2
kg/cm2

26
Track Drainage

• Sub-surface drainage
– Cement Grouting
• Pumping is continued till the grout appears
through the ballast and reaches its top surface
• It helps in filling the cracks thus preventing the
water to flow into the subgrade
• This method is expensive
– Paved catch water drains can also be provided to
stop the water to enter the subgrade

27
Track Drainage

• Sub-surface drainage
– Water Pockets in ballast
• If water pockets are just formed, then deep
screening and provision of pervious layer can help
• Cement grouting can be used to seal off the pocket
if the stretch is small
• In case water gets trapped in the ballast due to an
impervious layer lying over a pervious layer, the
drainage can be improved by puncturing a hole in
the impervious layer

28
Track Drainage

• Sub-surface drainage
– Water Pockets in ballast
• Perforated pipes can be inserted to drain off the
water
• Counterfeit drains can be provided to drain the
water. These are usually 600mm wide and spaced
at an interval of around 10 m

29
Today we discussed other aspects related to track
maintenance. We have continued with permanent
way renewals and through sleeper renewals then we
discussed about Track renewals and Track drainage.
Thank You

30
RAILWAY ENGINEERING
Lecture Number 64
High Speed Tracks

RAJAT RASTOGI
CIVIL ENGINEERING

1
Discussed in Previous Lecture

• Track Renewals
– Points and Crossings
– Track Renewal Train
• Track Drainage
– Requirements for a track
– Drainage between stations
– Drainage in station yards
– Drainage at platforms
– Sub-surface drainage

2
Today’s Discussion

• High Speed Tracks

– Effect of High speed
– Modernization Requirements
– Super High-Speed concepts
– Safety measures

3
High Speed Tracks

• These are the tracks which allow operation

of trains at speeds more than 120 kmph
• Need:
– Rapidly increasing demand of transportation
– Running heavy loads at faster speeds safely and
economically
– Better productivity
– Better service to customer
– Better social and economic development of an
area
IRPWM 2020

4
High Speed Tracks

• Classification:
– High Speed tracks
• Speeds over 120 kmph and up to 250 kmph
– Super High-Speed Tracks
• Speeds above 250 kmph
• To achieve the above conditions, it is
required to:
– Modernize the tracks to higher standards
– Use modified / advanced traction efforts

IRPWM 2020

5
High Speed Tracks: Effects of High Speed

• Track irregularities, resulting in pitching,

rolling, bouncing and lateral oscillations of
the vehicle (Parasitic movements)
• Pressure and stresses, due to resonance
between frequency of application of load
and elastic oscillations of the track (in whole
or component)
• Higher stresses, due to inertia or springing
action of track
IRPWM 2020

6
High Speed Tracks: Effects of High Speed

• Unbalanced weights
• Unsprung masses
• Suspension characteristics
• Wave formation
• Adhesion between wheel and rails
• Vibrational limitations
• Special problems on curves
• Power requirements
IRPWM 2020

7
High Speed Tracks: Wave Formation

• The propagation velocity of wave in a medium

sets the speed limit of a body moving in a
medium
• Higher speed than the speed in medium require
high power
• In tracks, as the vehicle speed increases and
approaches the velocity of wave propagation in
the rail, an extraordinary resistance comes into
play
• Rail deflects under the wheel
IRPWM 2020

8
High Speed Tracks: Wave Formation

• Wheel is accompanied by large amplitude

stationary waves, which can eventually
destroy the rail
• This propagation velocity of deflected wave
of the rail sets a speed limit for the train
running on it
• This limit was established as 1800 kmph with
no practical difficulties on New Tokaido Line
in Japan
IRPWM 2020

9
High Speed Tracks: Wave Formation

• Similar phenomenon exists between the

pantograph and the overhead wire of electrified
railway
• Pantograph deflects the overhead wire at the
point of contact thus causing wave formation in
it
• If the speed of pantograph exceeds the
propagation velocity of the transverse wave in
the wire, the rapid growth of amplitude may
destroy the overhead wire system IRPWM 2020

10
High Speed Tracks: Wave Formation

• This transverse propagation velocity of wave in

overhead wire sets a speed limit to the train
• This critical limit was established as 400 kmph on
New Tokaido Line in Japan
• The speed can be increased by increasing the
tension in overhead wire or by developing a
lighter wire material
• Restricting factors are strength and conductivity
of the wire
IRPWM 2020

11
High Speed Tracks: Adhesion between Wheels and Rails

• The tractive force works as the reaction of rail due to

adhesion between wheel and rail
• This adhesion force tends to decrease with the
increase in speed
• But the train resistance increases approximately with
the square of the speed
• If curves of adhesion force between wheel and rail,
and train resistance are plotted with respect to the
velocity of train then the two curves will intersect
each other.
IRPWM 2020

12
High Speed Tracks: Adhesion between Wheels and Rails

• If additional torque is applied above the

speed related to point of intersection, the
wheel slips on the rail and the torque cannot
be utilized for accelerating the train
• The point of intersection limits the speed of
the train
• For New Tokaido line in Japan, it was
estimated as 370 kmph under worst
conditions
IRPWM 2020

13
High Speed Tracks: Adhesion between Wheels and Rails

• The train speed can be increased by -

– Reducing the train resistance
• Innovative techniques like use of linear induction
motor, jet propulsion, etc.
– Raising the adhesion between rail and wheels
• This requires development of new material
superior to steel

IRPWM 2020

14
High Speed Tracks: Vibrations

• Track irregularities may cause vibrations. These

grow with an increase in speed
• There are unstable self excited vibrations in rail
vehicle, even if the rail is geometrically straight.
This phenomenon is called ‘hunting’.
• Even after taking measures to reduce the track
irregularities and improving the car body
suspension, the speed cannot be increased to a
high value.
IRPWM 2020

15
High Speed Tracks: Vibrations

• Due to vibrations, theoretically the speed

shall be limited to 350 kmph
• The train speed can be increased only by
making the train to float a little above the
surface of the track or rail table top

IRPWM 2020

16
High Speed Tracks: Curved Tracks

• Movement on the curve causes unequal

wheel loads on inner and outer rails which
affects the safety of the vehicle
• This unbalancing is countered by providing
superelevation on outer rail
• Inappropriate increase in SE may cause
unease to the passengers, vehicle
overturning, etc.
IRPWM 2020

17
High Speed Tracks: Curved Tracks

• Experiments on New Tokaido line in Japan

established that maximum lateral
acceleration of 0.05cm/sec2 do not cause
much discomfort and results in 180 mm of
cant.
• Cant of 180mm and curve radius 2000 m
results in a balancing speed of 200 kmph
• Train speed can be increased further with an
increase in the radius of the curve IRPWM 2020

18
High Speed Tracks

• Modernization of a track would require:

– Use of better designed rolling stock
– Use of higher standards for track components
– Better tele-communication and signaling
arrangement and standards
– Use of modern techniques of inspection and
maintenance

IRPWM 2020

19
High Speed Tracks

• Track components:
– Electric traction with higher power
– Heavy rail sections with higher wear resistance
(say 90 UTS / 110 UTS section)
– Use of SEJs with LWR/CWR
– Use of PSC sleepers
– Use of higher sleeper density as 1540, 1660 per
km or higher
– Ballast section as discussed for LWR/CWR
IRPWM 2020

20
High Speed Tracks

• Track components:
– Use of elastic fastenings
– Integrated track assembly with LWR/CWR
– Use of long curved switches as 1 in 16 and above
(on MAHSR it is 1 in 18)
– Higher cant deficiency
– Use of Cast Manganese Steel (CMS) rail for
crossings and curved switches
– Use of USFD to check flaws in rails before use
IRPWM 2020

21
High Speed Tracks

• Track Geometric: Maximum permissible speed 160 kmph

Degree Radius, Equi. Propose Cant Transitio
of curve m Cant, cant, defi., n curve
mm mm mm length,
m
½ 3492 100 40 60 48.5
¾ 2328 150 60 90 73
1 1746 200 100 100 120
1¼ 1395 250 150 100 180
IRPWM 2020

22
High Speed Tracks

• Track components:
– Strengthened formation as per requirement by:
• Providing topping layer with or without water
proofing membrane
• Providing sub-bullah piles
• Cement grouting of ballast pockets
• Lime treatment of formation
• Providing sub-bank or flattening of slopes
• Increase in depth of the ballast

IRPWM 2020

23
High Speed Tracks

• Traction Requirements
– Specific power, defined as the power required to
move 1 ton of passenger rolling stock, is correlated
with air resistance, gradient, speed and acceleration
– It is observed that with an increase in speed, the
requirement of power to overcome the resistance
and to accelerate the train goes up very steeply
– Tests indicated that at a speed of 300 kmph, air
resistance takes about 95% of the traction power
and only 5% of the power is devoted to suspension
and guidance
IRPWM 2020

24
High Speed Tracks

• Advanced Inspection of a track using GIT:

– GIT: General Inspection Train
– It has number of cars which are equipped with
equipment of the inspection and taking measures
of parameters related to track, power supply,
signaling and telecommunication systems
– The train can run up to a speed of 320 kmph

IRPWM 2020

25
High Speed Tracks: Super High-Speed Concepts

• Linear induction Motor:

– It helps in attaining very high speeds.
– The thrust is produced without physical contact
and therefore, it can be used with any type of
guidance system.
– This is free from adhesion and can take speed as
high as 350 kmph
• Linear Motor and Air Cushion System:
– This combination can allow super high-speed up
to 500 kmph
IRPWM 2020

26
High Speed Tracks: Super High-Speed Concepts

• Gas Turbine and Air Cushion (Jet propulsion):

– This is also known as Tracked Air Cushion vehicle
– Acceleration with Aero-propulsion is 200 kmph in
21/2 minutes
– Acceleration with Linear Induction Motor propulsion
system and core gas thrust is 380 kmph in 1¼
minutes with single motor and 480 kmph in 1¼
minutes with two motor system
– Braking distance required is 1280 m from a speed of
280 kmph and 2400 m from a speed of 480 kmph
IRPWM 2020

27
High Speed Tracks: Super High-Speed Concepts

• Magnetic Levitation (Maglev)

– The passing of the superconducting magnets by
figure eight levitation coils on the side of the tract
induces a current in the coils and creates a
magnetic field.
– This pushes the train upward so that it can
levitate 100 mm above the track
– The train does not levitate until it reaches 80
kmph, so it is equipped with retractable wheels
IRPWM 2020

28
High Speed Tracks: Super High-Speed Concepts

• Magnetic Levitation (Maglev)

– When one side of the train nears the side of the
guideway, the super conducting magnet on the
train induces a repulsive force from the levitation
coils on the side closer to the train and an
attractive force from the coils on the farther side.
This keeps the train in the center on the track
– An alternating current is run through
electromagnet coils on the guide walls of the
guideway
IRPWM 2020

29
High Speed Tracks: Super High-Speed Concepts

• Magnetic Levitation (Maglev)

– This creates a magnetic field that attracts and
repels the superconducting magnets on the train
and propels the train forward
– Braking is accomplished by sending an alternating
current in the reverse direction
– The vehicle uses superconducting electric
magnets, which are cooled by liquid helium or
liquid nitrogen. This means that once electrified
these magnets do not require additional energy
IRPWM 2020

30
High Speed Tracks – Safety on Track

• Safety Features for High-Speed Tracks:

– Crash Avoidance through DS-ATC

NHSRCL: Safety features of high speed rail corridor

31
High Speed Tracks

• Safety Features for High-Speed Tracks:

– Early Earthquake Detection System
• This system will enable automatic power shutdown
when primary waves emerging from an earthquake
epicenter is sensed
• Trains will have power failure detection device
which will evoke emergency brake when the power
shutdown is detected in such case
• Thus, the safety of the passengers and critical
infrastructure will be ensured
NHSRCL: Safety features of high speed rail corridor

32
High Speed Tracks

• Safety Features for High-Speed Tracks:

– Continuous monitoring of rail temperature and
wind
• High speed rails will be fitted with a network of
sensors monitoring rail track temperature, rain
monitoring (with special sensors in heavy rainfall
prone areas) and anemometers for wind
monitoring
• Crosswind speed above 30 m/s will send an alarm
signal to operational control center so that the
train can be stopped
NHSRCL: Safety features of high speed rail corridor

33
High Speed Tracks

• Safety Features for High-Speed Tracks:

– Advanced Loco-Pilot Support System
• Driving unit of bullet train is equipped with
number of display units, communication
equipment and other tools
• This will help the loco pilot in taking prompt
decisions based on sufficient information and in
coordination with operational control center

NHSRCL: Safety features of high speed rail corridor

34
Today we discussed the high-speed tracks. This included the
need for high-speed tracks, the effects of high speed and
the resulting restrictions on the permissible speeds,
modernization requirements, the concepts for super
high-speeds on tracks, and the safety features which can
be taken up on such tracks.
Thank You

35