Track Monitoring

An over View On Indian

Railway

1
 Track Performance
Track geometry deteriorates under
influence of dynamic track loads.
Track geometry deterioration -
complex issue - 3 main causes
Random settlement of ballast
Lack of straightness of rails
Variations in dynamic load along the
2 track caused by vehicles
Why measure track geometry?
To identify the deviations or the defects
To compare the track with other tracks and
with the benchmark
To monitor the rate of deterioration for
special attention and
To give timely input and prolong the life of
the asset
To assess the quality of track maintenance
How do we assess track geometry
manually?
Push Trolley Inspections
Foot Plate and Brake Van Inspections
Manual Measurements
Unevenness
Alignment
Gauge
Cross Level
Versines and Super elevation on Curves
Other track elements like LC, P&C, SEJ
 Manual Measurement - Limitations

 Subjective (human response dependent)

 Floating Condition
 No Systematic Recording
 Time Consuming; Slow and tiring
 Inappropriate for Modern Track Structure
and mechanized Maintenance
 No Continuous record of Track Geometry
5  Not amenable to detailed analysis
 MECHANISED
Objective assessment
In Loaded Condition
Systematic recording and analysis of
data
Fast and convenient
Continuous record of track parameters

6
 Track Performance
Final output from track - accelerations
various directions
It depends on
Track Geometry parameters
Vehicle Design parameters
Speed of Operation
What are we concerned with?
Track defects which are causing the
7 undesirable accelerations
 PARASITIC VEHICLE MOVEMENTS
Z Yaw (Nosing)

Y Bouncin
g
Uneveness Rolling
tt l ing X
Sh u

Twist
Al
ig
nm
X en
t&
Pitching
Ga
u ge Lu
rc
hi Y
ng
Z
 Track Monitoring
Mechanized Measurement – Systems
on IR

Track Recording Cars (TRC) – TMM

directorate of RDSO – Engineering
Department
Oscillograph Cars Mechanical
Directorate of RDSO
Oscillation Monitoring System
9
(OMS) – Divisions or Zonal
Basis of Track Geometry Monitoring
Peak Based
It helps in identifying isolated
localized defects
It helps in isolated attentions
SD Based
It helps in identifying bad stretch
It is useful in deciding machine
maintenance
10
 A A
B B
C C

D D

11
 A,B,C,D Limits (old TRC/IRPWM)

Parameter Chord LIMITS (mm)

A B C D
UN 3.6 6.0 10 15
9.6 5 10 15
Twist 3.6 5 7.5
4.8 5 10 15
Gauge 3 6
AL 7.2 3 5
9.6 5 10 15
Note- Not more than 10 peaks (exceedences) in a Km for a
particular parameter, otherwise track be down graded to
next category, suffix w r t no. of peaks exceeding B
12 category
 A,B,C,D Limits (New TRC)

Parameter Chord LIMITS (mm)

A B C D
UN 3.6 6.0 10 15 20
9.6 10 15 20 25
Twist 3.6 5 7.5 10 15
4.8 7 12 15 20
Gauge 3 6 9 15
AL 7.2 3 5 7 12
9.6 10 14 20 25
Note- Not more than 10 peaks (exceedences) in a Km for a
particular parameter, otherwise track be down graded to
next category, suffix w r t no. of peaks exceeding B
13 category
 Track Indices
PEAK BASED INDICES
A,B,C (A,B,C,D) categorisation of Track
CTR ( Rly. Bd. Letter 90/Track-III/TK/72
dt. 18.7.90)
CTR=100-(ULA+URA+TA+GA+ALB+ARB)
Rev. CTR (item 840 of 66th TSC)
RCTR=100-
(ULB+URB+TB+GB+0.5ALB+0.5ARB)-
0.25(ULA+URA+TA+GA)
14
 Track Indices
SD BASED INDICES
TQI; SD based ( RDSO Report no.
C-223)
TQI=8(U2+2T+G+A)
TGI; SD based ( Rly. Bd. Letter
94/Track-III/TK/23 dt. 25/31.08.95)

15
PEAK DISTRIBUTION (Short Chord) – A, B, C, D
Cat.
UNIT OF REPORTING – 1 Km
BAND UN1L UNIR TW1 G AL1L AL1R

>A 31 15 63 23 39 57

>B 4 2 34 5 10 17

>C 0 0 13 2 0 2

>D 0 0 0 1 0 1

B4 B2 D34 B5 B10 C17

 Locations in a Peak Value (mm)
KM A9 C15
• ABCD
Gauge :
categorizatio 1. 4 7
A limit
n ..Which 2. -7 -7
= 3 mm,
3. 18 7
track is better 4. -16 -7
A9 or C15? 5. 23 7 B limit
6. -20 -7 = 6 mm
7. 14 7
8. -23 -7
9. 17 7
10. -12 -7
11. 3 7
12. -2 -7

A9 13.
14.
0
-1
7
-7
C15
15. 2 7
Strength of A,B,C,D categorization

Easy and convenient to understand

A track may be good in other

parameters but bad in one parameter
 Limitations of A,B,C,D categorization
Only no. of peaks are counted in case of
exceedence and their magnitudes are not
considered
Comparison is not possible (no single result
value is available)
No correlation to the Riding Quality of the
track
Magnitudes of all samples of the various track
segments of a block (200m) are not considered
19


Service tolerances - CS No 45-Para 607 IRPWM
for speed 100 Kmph to 140 Kmph

Parameters Generally Permitted at

Permitted isolated Location
Unevenness 10mm (3.5m chord) 15mm (3.5m chord)

Twist
(a) Straight 2mm/m 3.5mm/m
(b) Transition 1mm/m 2.1mm/m

Alignment
(a) Straight 5mm (7.5m) 10mm (7.5m)
(b) Curve 5 mm(av. Ver) 7 mm(av. Ver)
Total change <10mm (stn.to stn.)
CTR Formula

CTR=100-
(ULA+URA+TA+GA+ALB+ARB)
No. of peaks exceeding “A” category
are taken for Unevenness, Twist and
Gauge and exceeding “B” category
taken for Alignment (all on short
chord).
 Limitations of CTR Formula
The formula based on ‘A’ peaks (B in
case of alignment) which are very tight &
prone to variations
Index not related to riding quality
The fluctuations are not much in good
track but they are more on poor track
CTR values are generally very low ,
causes feeling of despondency
Wide variation in CTR values (-500 to
+100)
All parameters given equal weightage .
 Standard Deviation
More value of SD for any parameter indicates
more variation and less uniform track profile.
Less value of SD for any parameter indicates
less variation and more uniform track profile.
Uniform track profile results in better riding
quality
SD based index takes into account magnitude
of each and every data of vehicle ride while
peak based index indicates no. of peaks
exceeding a limit without giving an idea of
magnitude of various peaks
Peak based index facilitates isolated attention
TGI Formulae (RDSO report TM-
11)
 REVISED SD BASED TRACK STANDARDS
Parameter Chor New Up to 110 KMPH > 110 <=130
d/ Track KMPH
Base Priority II Priority Priority Priority
(M) I II I

Unevenness 3.6 1.2 2.5 3.3 2.3 3.0

9.6 2.5 6.5 7.4 5.1 6.2
Twist 3.6 1.75 3.8 4.2 3.4 3.8
4.8 2.5 4.2 5.0 3.8 4.5
Alignment 7.2 1.5 2.7 3.8 2.3 3.0
9.6 2.5 5.0 6.3 3.3 4.0
Gauge - report 1.0
• Based on RDSO’s 2.5
No.TM-109 3.6
circulated vide 1.8 letter
Railway Boards 2.6
No.2007/Track-III/TK/7 dated 12-07-2007
• For spot exceedences based limits those given in lettr dated 30-12-96 to be
continued
• Priority I; Urgent maintenance and Priority II is planned maintenance
TGI values for typical cases

Case 1 Measured SD value = SD for New Track

X = 0 so Index Value = 100 x1 = 100
Case 2 Measured SD value = SD for Urgent Maintenance
X = -1 so Index Value = 100/e ≈ 36
Case 3 Measured SD value = 0
X = Index Value for different parameters ranging from 147
to 272 based the presently stipulated values of SD for new
track and that for urgent limits
(UI = 196.54, TI = 234.82, AI = 271.83 and GI = 196.90 TGI =
240.58
 TGI_Max
Urgent Urgent I>105 I<105
New Urgent Urgent Tol>105 Tol<105 Revis Revis
Para Tol Tol>105 Tol<105 I>105 I<105 Revised Revised ed ed
Un 2.5 6.2 7.2 197 170 6.2 7.4 197 167
Tw 1.8 3.8 4.2 235 204 3.8 4.2 235 204
G 1 3.6 3.6 147 147 2.6 3.6 187 147
Al 1.5 3 3 272 272 3 3.8 272 192
TGI 241 232 245 184

30
 TGI

TGI formula has good correlation with ride

index
SD values reflect general quality of track in
a block of 200m and is measure of variance
over mean profile for that parameter
SD values of individual parameters should
also be seen; It may happen that overall TGI
of a Km is 80, however TGI of a particular
parameter is 40 and need attention
Peak size of individual parameter should
also be seen for “spot attention”.
 TGI …. Contd..
TGI for individual parameters give quality
rating to the measured SD values w.r.t. the
SD values prescribed for newly laid track and
SD values for urgent maintenance
SD values of Unevenness, Alignment, Twist
and Gauge are given weightage of 2,6,1 and 1
Variation in the TGI value will be faster for
good track with changes in the SD value
more than for a run-down track.
Features of TGI
Tool for deciding maintenance
requirement; through as well as spot
Proper appreciation of maintenance effort
Good correlation with Ride Index Values
Proper range and reasonable variation in
values

33
Limitations of TGI
Combination of all parameters makes it
redundant for reflecting maintenance
requirement for a particular type of defect
For maintenance individual index should be
considered
Very high weightage to Alignment parameter
and Low weightage to TWIST which is
critical for safety particularly for goods stock
It gives Values over average profile (average
profile may change from a block to the other
block) and not over the ideally required
profile
Doesn’t indicate speed restriction 34
Short Chord and Long Chord

Parameters Short Chord Long Chord

Unevenness 3.6 m 9.6 m

Twist 3.6 m 4.8 m

Alignment 7.2 m 9.6 m

Short Chord and Long Chord (TM-11)

The short chord is pertinent for four

wheelers and bogie freight wagons

The long chord is important for passenger

coaches and locomotives
 Vehicle Response - Critical Wavelength

The wavelength of track irregularity at which resonance in

vehicle acceleration occurs is defined as critical wavelength

The critical wavelength of track irregularity for any vehicle

at various speeds depends on the natural frequency of
vehicle in vertical and lateral mode.
 Vehicle Response

Time Period T = /v f = Input Frequency in Hz

f = 1/T= v/  v = Speed (m/s)
 = Wave Length (m)
Response
 
 
Response For Unit Input
V (m/s)

 
 
 

fn
 
Input Frequency of Input excitation (Hz)
 
 
 Critical Wavelengths

The relationship is given as below :

f = V/
Where,
f is the frequency generated in Cycles/second
V is the speed of the vehicle in meter/sec.
 is the track defect wavelength in meters

Vehicle Resonance Speed Speed Critical

Frequency Km/h m/sec Wavelength
CRT Wagon 4.0 to 2.5 75 20.8 5.2 to 8.3
BoxN Wagon 3.5 75 20.8 5.95
WDM2 Loco 2.4 110 30.6 12.75
ICF Coach 1.2 130 36.10 30
Future coaches 1.0 160 44.4 44.4

39 Track Monitoring
 Vertical Mode Lateral Mode
Speed
S.N. Coach Type Natural Critical Natural Critical
(kmph)
frequency Wavelength frequency Wavelength

1 GS 1.61 22.43 1.68 21.49

2 AC-III TIER 130 1.33 27.15 1.39 25.98

3 Ist AC CC 1.29 27.99 1.27 28.43

4 GS 1.61 17.25 1.68 16.53

5 AC-III TIER 100 1.33 20.89 1.39 19.98

6 Ist AC CC 1.29 21.53 1.27 21.87

7 LHB AC 2 TIER 1.19 30.35 1.21 29.84

130
8 LHB AC-III TIER 1.32 27.36 1.47 24.57

9 LHB AC 2 TIER 1.19 23.34 1.21 22.96

100
10 LHB AC-III TIER 1.32 21.04 1.47 18.90
 Vertical Mode Lateral Mode

Speed
S.N. Loco Motive
(kmph)
Natural Critical Natural Critical
frequency Wavelength frequency Wavelength

1 WDM3A 3.45 10.47 3.03 11.92

2 WAP5 130 1.26 28.66 1.4 23.81

3 WAP7 1.35 26.75 1.3 25.64

4 WDM3A 3.45 8.05 3.03 9.17

5 WAP5 100 1.26 22.05 1.4 19.84

6 WAP7 1.35 20.58 1.3 21.37

 Critical
CriticalWavelength
Wavelength at
at different
different speed
speed

Critical Wavelength for diff. R/Stock at diff. Speed

50
45
Critical Wavelength -->

40
35 Coach
30
25
20 Loco
15 f =1 Hz
10 f =1.35 Hz
5 Wogon
f =2.4 Hz
0 f =3.5 Hz
50 60 70 80 90 100 110 120 130 140 150 160
Speed of operation -->
 Short Chord and Long Chord
(TM-11)
The short chord is pertinent for four
wheelers and bogie freight wagons
The long chord is important for passenger
coaches and locomotives
Longer chord for unevenness and short
chords for alignment and twist are taken as
the same have been selected for TMS also.
 Track Parameters
Unevenness
At Short Chord- 3.6m & At Long Chord-9.6m (For
Left Rail & Right Rail)

Twist - Lower base of 3.6m & Higher base of

4.8m

Gauge --- Variation over 1673 mm(BG)

Alignment
At Short Chord- 7.2m & At Long Chord-9.6m (For
45
Left Rail & Right Rail).
50
51
52
 Old TRC

1.8 m 1.8 m

* Vertical
*
* Displacement

3 Axle Bogie & Measuring Frame

For Unevenness Measurement
53
 INERTIAL PRINCIPLE OF
RECORDING

ACCELERATION
DISPLACEMENT TRANSDUCER
TRANSDUCER
ŋ=H=Z+W
Z
=∫∫
DAMPING

SPRING
TRACK IRREGULARITIES
MOUNTING POSITION OF
TRANSDUCERS
 INERTIAL PROFILE - VERTICAL

ò ò ÿ dt² = y ( Vert. Locus

of point ‘A’or ‘B’)
ÿ ÿ yA+ LVDT(L)= Vert. Profile
of left rail
A B
LVDT(L) LVDT(R) y + LVDT(R)= Vert. Profile
B
of right rail

56
APPLICATION OF INERTIAL PRINCIPLE
IN TRC

Generation of Vertical Profile

APPLICATION OF INERTIAL PRINCIPLE
IN TRC

Generation of Lateral Profile

 TRANSDUCERS

LIGHT PHOTO SENSING

SOURCE DIODE

FLEXIBLE CABLE
TO WHEEL
DISC WITH SLITS

TACHO
59
 Tachometer
60
 b1 b2

d
a2
a1

Gauge = a1 + d + a2

Sword Sensor.
Gauge Sensing with Contact Sensor
61
 Accelerometer

62
 Lateral acceleration

63
64
 CALIBERATION

66
67
68
 Calibrations

69
70
71
72
 OLD TRC

73
BASIC VALUES OF DIFFERENT PARAMETERS – One time Sheet
 Typical Kilometer wise Chart – Actual Result BCT-VR section
– Speed 100 kmph
D F
E B

A C

H
J K

L
 SIGN CONVENTION IN TGMS-10
POSITIVE NEGATIVE
ACCELERATION UPWARDS / TOWARDS DOWNWARDS / TOWARDS
VERTICAL/LAT. RIGHT LEFT
DISPLACEMENT LVDT COMPRESSION LVDT ELONGATION
ROLL ANTI-CLOCKWISE CLOCKWISE
YAW TOWARDS RIGHT TOWARDS LEFT (ANTI-
(CLOCKWISE LOOKING CLOCKWISE LOOKING
FROM ABOVE) FROM ABOVE)
UNEVENNESS UPWARDS DOWNWARDS
ALIGNMENT AWAY FROM THE CENTER TOWARDS THE CENTER OF
OF THE TRACK THE TRACK
CANT TILT TOWARDS LEFT TILT TOWARDS RIGHT
(RIGHT SIDE AT A HIGHER (RIGHT SIDE AT A LOWER
LEVEL THAN LEFT SIDE) LEVEL THAN THE LEFT
SIDE)
GAUGE WIDE NARROW
 USING TGI FOR MAINTENANCE
DECISIONS

77
Maintenance Guidance using TGI
Values (RDSO report - TM-11)
As per Rly. Bd.’s letter Dated 30.12.96

Band width of Maintenance

TGI Requirement
80 and above No maintenance
Required
50 to 80 Need based
maintenance
36 to 50 Planned maintenance
Below 36 Urgent maintenance
For spot attention and not for through tamping of section of PWI
78
 Extract from TM-11
TGI value - not a direct measure of the
maintenance requirement of track
Track needing urgent maintenance can have a high
TGI value up to 70 or more.
The maintenance requirement is governed by the
SD value of the individual parameters
The TGI value should be used for making
assessment of the overall quality of track geometry
rather than for assessing the maintenance needs,
for which SD values of individual parameter
TM-11 - Limitations
These guidelines were found to have some
limitation, as these were suitable for spot
attention and did not give a picture of the
complete section
Also emphasis was not given on improvement
of TGI value beyond 80, which is easily
achievable in field with modern machines
NO GUIDELINES WERE THERE FOR
THROUGH TAMPING OF TRACK BASED
ON CONDITION OF TRACK
Pre TM-115 - INSTRUCTIONS FOR THROUGH
ATTENTION TO TRACK

On PSC, frequency once in two years or

passage of 100 GMT whichever is earlier
(para 5.7.4 IRTMM)
On other than PSC, once in a year
Above provision by experience and there is
a tendency of more frequent tamping
TM-115 ( Oct 2007)
• To study pre and post tamping records vs TGI
• Monitoring of quality of tamping- to assess
the efficacy of tamping
• The above guidelines issued are for the
through attention
• For spot attention guidelines issued vide Rly.
Bd.’s letter Dated 30.12.96 will continue
• Prescribed TGI based criteria for through
attention to the track
• Stipulated the TGI values to be achieved as a
result of through attention
82
 TM-115 - Introduction
Tamping is essential for correcting track geometry and
providing resilient & firm support to track.

Unwarranted tamping is however not desirable due to:

Pulverization of ballast, which results in choking of
drainage,
Disturbance of consolidation of track,
Deterioration of track geometry,
Loss of resilience in long term,
Deployment of costly resources for unproductive use.
TM-115 – Reason for study
 Tamping was discussed in the 76th meeting of the TSC, on which
the Railway Board passed the following orders;

“Railways should prepare database regarding TGI, standard

deviation of unevenness, twist, gauge and alignment achieved
after tamping, for monitoring of quality of work done by track
machine and send the same to RDSO for further analysis”.
TM-115 – Data Collection
 A proforma was circulated to all zonal railways vide this office
letter number TM/GL/70 dated 22.9.06 asking for the
information about track parameters before tamping and after
tamping.
 The various track parameters asked were SD for UN1, UN2,
TW1, TW2, Gauge, AL1, AL2 and TGI values. This information
was required both before and after tamping. Also the track
structure, total ballast cushion and the clean cushion were asked
for.
CFD
 Statistical Glossary
Cumulative Frequency Distribution:
A cumulative frequency distribution is a summary of a
set of data showing the frequency (or number) of items
less than or equal to the upper class limit of each class.
 What is CFD60%

TGI values in increasing order for a SE(P. Way)’s section

56,58,58,59,63,64,64,65,66,68,69,71,73,73,75,
76,78,82,85,85,86,89,91,93,94,94,95,97,99,105
 CFD60%=
 CFD10%=
 Cumm Frequency Diagram... Plot of
CFD vs TGI
Frequen Cumm. % CUMM. Cumm. % CUMM.
TGI TGI Frequency
cy Frequency FREQUENCY Frequency FREQUENCY

56 1 1 76 1 16 53
3
78 1 17 57
58 2 3 10
82 1 18 60
59 1 4 13
85 2 20 67
63 1 5 17
86 1 21 70
64 2 7 23
89 1 22 73
65 1 8 27
91 1 23 77
66 1 9 30 93 1 24 80
68 1 10 33 94 2 26 87
69 1 11 37 95 1 27 90
71 1 12 40 97 1 28 93
73 2 14 47 99 1 29 97

75 1 15 50 105 1 30 100
 % CFD vs TGI

100

90

80

70
%
60
C
F 50

D 40

30

20 CFD60%= 82
10
CFD10%=58
0
50 60 70 80 90 100 110

TGI
 CFD
A PWI’s section, let us take 50 Km
TGI indices in increasing order
-45,47,48,49,52,52,55,56,56,58,61,62,
67,67,68,69,70,70,71,71,74,75,77,78,
80,80,83,83,84,85,86,87,88,88,88,89,
89,89,90,92,95,95,98,98,99,100,101,
102,105,106
CFD10=52 CFD60=84
S. Railway Route MSS TGI Values
No.
60% CFD 60% CFD after 10% CFD after
before tamping tamping tamping
1. SCR A 110,120 85 95 70
2. SCR B 100 90 90 65
3. WR A 120,130 75 100 75
4. WR A&B 100 82 113 80
5. NER D 110 77 90 50
6. NER D 100 77 90 50
7. SER A 105 84 102 76
8. SER B 105 84 90 65
9. SEC A 110 84 90 62
10. SEC A 105 78 93 70
11. ECR B 105 102 117 76
12. SR B 110 106 107 72
13. NCR A 110 103 111 70
14 NR B&D 50,110 81 88 54
ECoR – PSA-VSKP (Nov’06, Jan, Mar’07)
CFD

CFD for pre & post tamping readings of "B" route ECoR
(PSA-VSKP)MSS 105 kmph
110%
100%
90%
80%
70%
60%
50%
40%
30%
20%
Pre Tamping
10% Post Tamping
0%
20 40 60 80
TGI 100 120 140 160 180
 SR
CFD

CFD for pre & post tamping readings of route of SR, MSS 110 kmph

110%
100%
90%
80%
70%
60%
50%
40%
30%
20% Pre Tamping
10%
Post Tamping

0%
20 40 60 80 100 120 140 160
TGI
 SER – HWH-JSG(A) (Sep, Dec, Dec’06)
CFD

CFD for pre & post tamping readings of "A" route SER,
MSS 105 kmph
110%
100%
90%
80%
70%
60%
50%
40%
30%
Pre tamping
20%
Post tamping
10%
0%
50 60 70 80 90 TGI 100 110 120 130 140
 TM-115 - Recommendations
Board to discontinue system of awarding points to
Railways for overall improvement in TGI values.
Due to this system, frequent tamping is carried out
to maintain TGI, which is serving no purpose.
Weightage to be given to average improvement in
TGI after tamping which will ensure quality work
and prolonging the tamping cycle.
The following values are recommended for planning
through tamping i.e. tamping form one end of PWI’s
jurisdiction to the other end. The 60% and 10% CFD
values after tamping should be adopted as
benchmark for the results obtained after tamping.
Rationalization of tamping requirement on
IR (Rly bd.’s letter no. 2007/Track III/TK/7 Pt. dated
16.01.2008)
 For speeds greater than or equal to 110 Kmph

Sr INDICES TGI
No. values
1. 60% CFD before tamping ≤ 90
(60% of track length having TGI)
2. 60% CFD after tamping ≥ 115
(i.e. min 40% track length after
tamping should have TGI)
3. 10% CFD after tamping ≥ 75
(i.e. min 90% track length after
tamping should have TGI)
Rationalization of tamping requirement on
IR (Rly bd.’s letter no. 2007/Track III/TK/7 Pt. dated 16.01.2008)
For speeds less than 110 Kmph
Sr INDICES TGI
No. values
1. 60% CFD before tamping ≤ 80
(60% of track length having TGI)
2. 60% CFD after tamping ≥ 115
(i.e. min 40% track length after
tamping should have TGI)
3. 10% CFD after tamping ≥ 75
(i.e. min 90% track length after
tamping should have TGI)
Tamping Frequency (Latest Instructions)
Tamping Frequency (Latest Instructions)
ISSUES with TM 115 recommendations.
Should the stipulated TGI values be same for all
the sections irrespective of the…? Historical TGI
values of the section
Maximum permissible speeds on the section
Variation in formation condition
Variation in ballast cushion
Track Geometry – Ghat section with worn
rails on curves, fish plated joints
Heavy Haul
Track memory
Condition of Track Structure – Rails etc.
 ISSUES with TM 115
recommendations.

• What about the spot attention if parameters of

blocks/stretches with good TGI value as high as
>80 but bad TGI value for certain parameter
index…?
• Field reaction to this
It is simplistic, unachievable and creates more
issues than it attempts to solve

101
ISSUES with TM 115…
Is the improvement of TGI value of flat 25
TGI points from 90 to 115 on routes with
MSS>110 and
flat 35 TGI points on routes with MSS<110
Kmph feasible?
So should we revise the threshold values of
TGI for asking for machine
Should the Zonal Railways be ask to fix the
achievable TGI value based on Broad guidelines
by RDSO.
Variation of TGI without tamping and
OMS 2000
 WHAT FACTORS AFFECT VEHICLE
RESPONSE?

FREQUENCY OF TRACK

IRREGULARITY SPACING OF THE

TRACK DEFECTS

SPEED OF THE VEHICLE

DIRECTION OF MOVEMENT
104
RESONANCE-EFFECT OF CYCLIC TRACK
IRREGULARITY ON VEHICLE
 Oscillation mode of vehicle will be bouncing and pitching
For speed v = 13 m/s, excitation freq.=1 cps, t=13m
For speed v = 26 m/s’ excitation freq. = 2 cps, t=13m
This is “forcing” frequency, f = v/t

 “Natural” frequency of a vehicle in a particular mode of

oscillation : Frequency of osc. in that mode, when system
oscillates freely, after removal of external forcing frequency.
For simple spring of stiffness “k” & mass “m” natural freq.,
1 k
fn 
2  m
 OMS-2000
OMS-2000 is microprocessor based system

It records

Speed of the vehicle

Vertical and Lateral Acceleration on coach floor
Calculates the Sperling ride index
Under the control of zonal Hq or div.

 Generally kept on coach/loco of a through running

commercial train..
107
 ACCELEROMETER
Accelerometer is main component of
acceleration
measuring system.
It consists of a mass “m” attached to a thin
flexible plate whose other end is firmly
fixed in
casing of accelerometer.
Space within casing is filled with damping
fluid
which is normally sillicon liquid.
TRANSDUCERS

DAMPING FLUIDE

Strain gauges

MASS
x

ACCELEROMETER
 SALIENT FEATURES OF OMS-2000
Portable with only 18 Kg weight
Battery operated: 8 Hrs operation with fully charged
battery.
Possible to operate with 24V DC, coach battery, 110V/220V
AC supply.
Built in amplifier : No messy connections
Real Time digital out put
Operate in Tacho and Non Tacho Mode
Can store data during run in battery backed RAM
Rugged : Does not require air conditioning

110
 OPERATION MODES OF OMS 2000
 OMS 2000 can operate in three modes :
 Mode 1 : Monitors Ride Quality and prints ride index
for every 200 mt blocks.
 Mode 2 : Monitors speed, vert. and lat. acceleration and
prints exception reports
 Mode 3 : Combination of above two modes. Monitors
speed, vert. and lat. acceleration and prints exception
reports. Also prints ride indices for each Km.
Acceleration exceedences stored in memory for later
use.

Mode 3 is normally used for regular monitoring.

111
 LIMITS OF ACCELERATION PEAKS

Lateral and vertical acceleration peaks

exceeding the following values are considered
for track quality assessment
Broad Gauge
(i) High Speed routes above 110 kmph: > 0.15g
On A and B routes

(ii) Other route upto to 110 kmph : > 0.20g

Meter Gauge : > 0.20g

112
 TRACK QUALITY CLASSIFICATION
(Para 618 of IRPWM)

Track Categorization is based on total number of vert. and

lateral acceleration peaks/Km for a given stretch as under
No. of Peaks/Km
Very Good Good Average

High Speed < 1.0 1-2 >2

Others < 1.5 1.5-3.0 > 3
 All locations with acceleration peaks (lat/vert) exceeding
0.35 g needs to be attended urgently.
 If average numbers of peaks (lat. and vert acceleration)
exceeding 0.30g is more than 0.25/Km or more than one in
113
any particular Km, track will need attention.
 NON RECORDING SPEED FOR
OMS-2000

Recording by OMS done at the following speed shall be

treated as non recorded :
Broad Gauge
“A” Routes : Less than 75 Kmph
“B” Routes : Less than 65 Kmph
Other Routes : Less than 75% of maximum speed
or 60 Kmph whichever is less
Metre Gauge
“Q” Routes : Less than 60 Kmph
Other Routes : Less than 55 Kmph
114
 SPERLING RIDE INDEX
Sperling Ride Index (R.I.) is defined as :
R.I. = 0.896 x {b3x F(f)/f }1/10
b = Avg. of the cubes of acceleration peaks
(cm/sec2)
f = Frequency in Hz.
F(f) = Function of frequency that takes in to account
the human reaction to frequency of acceleration

Ride Index value depends on acceleration peaks and

their frequency of occurrence
115
 SPERLING RIDE INDEX …
contd..

For Vertical Mode F(f)= 0.325x f2 for 0.50 < f <= 5.9 Hz
400/ f2 for 5.90 < f < =20 Hz
1 for f > 20
For Lateral Mode F(f)= 0.80 x f2 for 0.50 < f <= 5.4 Hz
650/ f2 for 5.40 < f < =26 Hz

1 for f > 26

116
 SPERLING RIDE INDEX

Value of RI generally vary from 1 to 5.

Interpretation of RI for riding is as under :
R.I. Interpretation
1.0 Very good
1.5 Almost very good
2.0 Good
2.5 Almost good
3.0 Satisfactory
3.5 Just satisfactory
4.0 Tolerable
4.5 Not tolerable
117
5.0 Dangerous in service
SPERLING RIDE INDEX (TM-109)
Track Standards (3 criteria Committee; source TM-109)
rd

Criteria Committee has recommended Ride Index values for different rolling stocks
in use on IR which is as under :

Acceleration
Ride Index
Stock Lateral Vertical
Preferable Limiting Preferable Limiting Preferable Limiting
Coaches 3.25 3.50 0.30 g 0.35 g 0.30 g 0.35 g
EMU & DMU 3.25 4.00 0.30 g 0.35 g 0.30 g 0.35 g

Locomotives 3.75 4.00 0.35 g 0.35 g 0.30 g 0.35 g

Wagons 4.25 4.50 Not specified Not specified
Break down
4.25 4.50 - 0.5 g - 0.5 g
crane
Departmental
4.25 4.50 0.55 g 0.6 g 0.55 g 0.6 g
vehicles
 TYPICAL OUT PUT OF OMS IN MODE 3
04,11,88 Date (DD/MM/YR)
12.56.16 Time (Hr/Min/Sec) 24 hr format
 
1251 0000 K Starting location in KM
0100 0.15 0.15 G Max. speed, V accn. limit, L accn limit
2.50 2.50 R Max. V RI limit and L RI limit
 
1251 0092 K Location in KM, Distance from last KM
102 0.16 0.04 G Speed, Vert. accn., Lat. accn. in ’g’
1251 0320 K
089 0.19 0.07 G
1251 0917 K
095 0.06 0.17 G
1251 Km switch pressed
092 Average speed during last KM
01 2.93 2.33 R Block No., Vert. RI , Lat. RI
02 2.91 2.63 R
03 3.14 2.54 R
04 3.02 3.30 R
05 2.97 2.83 R
119
 IMPORTANT POINTS FOR USING OMS
In addition to track geometry, ride quality
depends
on
• Speed of the vehicle
• Vehicle Characteristics
To eliminate above effects, successive
recordings should be done preferably using
same coach with same train in same direction
(up or down) of movement.
 Trained operator should be used for recording
 OMS should be sent to RDSO once in eight
120
months or whenever in doubt for calibration
 ADVANTAGES OF OMS

 No need for special train running and separate

path for recording.
 Digital out put gives location of isolated
acceleration peak thus helps in easier
identification of track defect at site.
 Data stored in OMS : Can be integrated with
TMS.
 Gives RI which is indicator of combined effect of

track geometry and vehicle performance.

121 Not to be kept in Loco now due to induction effect
 OSCILLOGRAPH CAR
Run by research/Mechanical directorate of RDSO
Runs at max sectional speed of section with dedicated power as a
special train..
Main transducer is accelerometer
 For track monitoring runs, accelerations at loco cab floor near
bogie pivot are monitored.
 Parameters recorded in run are :
Vertical acceleration, Lateral acceleration,
Primary spring deflection (left and right),
Bogie rotation
 Accelerations are in the form of analog chart
called accelerogram.
122
 THRESHOLD VALUE OF
ACCELERATION
As per para 616(b) of IRPWM, values are
as under
Vertical Lateral
For all locos at loco floor 0.20 g -----
For diesel & electric Locos ,---- 0.20 g
with double stage suspension
For other locos with single ----- 0.30 g
stage suspension
On passenger coach floor 0.15 g 0.15 g

123
 STATEMENT ‘A’
OCILLOGRAPH RESULTS (Para 616)
Total length of Section: 232 Kms Section : BPQ-KZJ
Length recorded : 185 Kms Loco No……….
Date of recording : 22nd March 1982 Type of Loco………..
Station Yards (Peaks above Threshold values)
Sl. No. Name of Yard and Speed in Vertical Lateral Remarks
Location Kmph Acceleration Acceleration
1 SPUR 100 - 0.26
FP-2
2 MCI 100 0.22 -
TP-1 100 0.22
TP-2
3 PPZ 100 0.20 -
FP-1 105 0.20 -
FP-2
4 BGSF 110 - 0.22
324/10-11
5 OPL 100 0.26 -
343/5-6
6 HSP 100 0.20
TP-1
 STATEMENT ‘B’
Date of recording: 22nd March 1982 Section : BPQ-KZJ(Km 367-135)
Loco No………. Length recorded : 185 Kms
Type of Loco……….. Total Length: 232 Kms

Oscillograph Results in Places other than Station Yards

Isolated Locations (Peaks above Threshold value)
Sl. No. Location Speed in Vertical Lateral Remarks
Kmph Acceleration Acceleration
1 146/1-2 100 - 0.28 Curve
2 148/15-16 110 - 0.28 Br.
3 149/7-8 110 0.28 -
4 149/7-8 110 0.35 - Br.
5 151/8-9 110 - 0.24
6 151/8-9 110 - 0.22
7 151/11-12 105 - 0.24
8 160/7-8 110 - 0.22 Curve
9 164/9-10 110 0.24 -
10 168/1-2 100 And so on 0.30
 STATEMENT ‘C’
Date of recording: 22nd March 1982 Section : BPQ-KZJ(Km 367-Km135)
Loco No………. Length recorded : 185 Kms
Type of Loco……….. Total Length: 232 Kms

OSCILLOGRAPH RESULTS
Active Continuous Stretches
Sl. Kms Distance Speed Active Total Maximum No. of No. of Remarks
No. in Kms. in in Mode No. of Value peaks peaks
From To Kmph peaks between above
above 0.20g & 0.25 g
0.20 g 0.30g

Nil

Note- If there are on an average more than 10 peaks above the

threshold value per km, the length may be included in this
 Frequency of Track Recording Car Run

G
d

u
o
a

g
e
Br

a) Shatabdi Route (NDLS-BPL) Once in two months

b) Rajdhani Routes with speeds Once in 3 months
120-130 Kmph
c) Other ‘A’ and ‘B’ Group routes Once in 4 months
d) ‘C’ and ‘D’ Group routes Once in 6 months
e) ‘E’ routes Once in a year or at
the discretion of Rly

Ref:Para 606,IRPWM, CRS’s Letter No. 374 dated 20.5.1988

128
 Frequency of Oscillograph Car Run
[ Ref: IRPWM 615 (3) CS no. 107]

a) On Rajdhani routes
 Once in 6 months on Group A routes for
riding quality of track distinct from actual
track geometry at maximum sanctioned
speed

129
 Frequency of OMS - Para 618 of IRPWM
Broad Gauge
a) Routes having speed above Once in every month
100 Kmph
b) Other routes Once in 2 months
Metre Gauge
a) Routes having speed above Once in every month
75 Kmph
b) Other routes Once in 2 months

Ref : Railway Board’s Letter No. 91/Track-III/TM/26 dated 14.02.1992

130
 Recording Speed

a)Track Recording Car (RDSO Instructions)

i. Phase I Cars 50 Kmph-100 Kmph

(7973,7975 & 803)
ii. Phase II & III cars 35 Kmph to 110 Kmph
(225 & 2500)

b) Oscillograph Car : [IRPWM 615 (3)]

Recording is done at the maximum sectional speed.

131 Ref: Railway Board’s letter No. 91/Track-III/TM/26 dated 14/02/1992

 4. Recording Speed

c) OMS

B.G. – ‘A’ Route 75 Kmph & above

-- ‘ B’ routes 65 Kmph & above
-- Other routes 75% of max. perm. speed or
60 Kmph which ever is less
M.G.– ‘Q’ Route 60 Kmph & above
-- ‘Other MG routes 55 Kmph & above

132 Ref: Railway Board’s letter No. 91/Track-III/TM/26 dated 14/02/1992

 Railway Board’s instructions regarding running of
Track Monitoring Cars
Ref : 1. Para 609, 610 of IRPWM
2. Rly. Bd’s letter No. 90/Track-III/Tk/72 dated 09/07/1990
3. Rly. Bd’s letter No. 92/Chg-II/34/TRC dated 15.10.92
4. Rly. Bd’s letter No. 92/Chg-II/34/TRC dated 24.02.93

i) Programme of TRCs to reach RLys at least 2 weeks in

advance.
ii) Arrangement of suitable power/path from optg to be done
by the engg branch of the zonal railways.
iii) AEN & PWIs of the originating and halting stations are
responsible for proper placement, watering, charging and
other assistance to RDSO Special.
iv) H.S.D. Oil for the generators of the recording specials to
133 be arranged by Engineering Department of division as per
 Railway Board’s instructions regarding
running of Track Monitoring Cars
v) The monitoring special shall be accompanied by the following
officers from the Railway and Division –
a) Group ‘A’ route:
Railway – The territorial HOD or any other SAG/JAG
officer nominated by
CE/CTE
Division – Sectional Sr.DEN/DEN, AEN & PWI
b) Other than Group ‘A’ route:
Railway – A officer from track modernization cell not
below the rank
of SS/JA Grade
Division – Sectional Sr.DEN/DEN, AEN & PWI
vi) One nominated Sr. DEN/DEN at Divisional Headquarters shall
ensure that there is proper liaison in the control office to ensure
134 suitable path for the monitoring special
 Railway Board’s instructions regarding running of
Track Monitoring Cars… Contd..
vii) Any special requirement as indicated by RDSO should also be
taken care of by the railway / division.
viii) The operating staff at the starting/halting station shall ensure
the following:
a) The TRC is properly attached as the last vehicle with
window trailing.
b) The TRC is placed on level track adjacent to the platform
line at least one hour before the scheduled departure for
calibration of the TRC.
c) Rough shunting of TRC is not permitted. At the starting
and destination stations, the TRCs should only be placed
in the saloon sliding.
135
 Actions to be taken in event of non-running of
TRC/Oscillograph Car on Rajdhani Routee
1. CRS/Eastern Circle’s letter No. 549 dated 08/07/1980
2.CRS/Western Circle’s letter No. 30-5/20/886 dated 05/08/1980
3. CRS/Central Circle’s letter No. 374 dated 20/05/1988

A. Track Recording Car

i)fails to run the TRC with in 3 months of the date of the
last run. Locomotive inspection on Rajdhani Express by
J.A. Grade officer nominated by CE/CTE. A monitoring
report and a safety certificate to be issued. The CE/CTE
to issue an order permitting the continuation of speed of
136
Rajdhani Express for the 4th month. A copy of the same
 Actions to be taken in event of non-running of
TRC/Oscillograph Car on Rajdhani Route
A. Track Recording Car (contd..)
ii) fails for the 4th month, the above procedure to be followed
for the 5th month except that the monitoring on the foot-
plate of Rajdhani Express should be done by Addl. CE
instead of J.A. Grade Officer.
iii) fails for the 5th month, the above procedure to be followed
except that track monitoring on the locomotive, of the
Rajdhani Express should be done by the CTE.
iv) In the event of the TRC not being run with in 6 months of
the date of the last run, the speed on the Rajdhani Route
on expiry of 6 months, should be brought down to 110
137 kmph but the Rajdhani Express itself should be booked
Development Of Track Recording Cars

(VII) High Speed TRC (Under Commissioning)

 Wider Speed Band Of Recording - 20 To 200 Kmph
 Laser Based Contact-less Sensors for Measurement of
Lateral Track Geometry
 Simultaneous Storage Of Processed, Raw Data And
Profile / Chord Data
 Recording Of Curvature And Vehicle Ride Parameters
 Recording Of Rail Corrugation, Cupped And Misaligned
Welds
 Both Analogue And Digital Output
 Synchronization With Route Data Information

140
Revision of Chord for Measurement of
Track Geometry
Fixing Chord Length
 The vehicle accelerations mainly depends on
 Frequency response of the vehicle
 Speed of the Vehicle
 Wavelength of the Track Irregularity
 The above parameters are mathematically related with
following simple relationship
V = f x λ Where
V = Speed of vehicle in Meter/Second
λ = Wavelength of Track Irregularity in
Meters
f = Input frequency in Hz.
 Fixing New Chords
Transfer Function of Chord
 A Mid Chord measurement system vitiates the measurement of
actual track irregularity according to the transfer function of the
system.
 The transfer function depends on the chord length selected for
measurement and wavelength of irregularity.
 For pure sine wave irregularity the transfer function is calculated
by the following relationship.
H(λ) = 1-cos ((π x L)/ λ)
Where:
H(λ) = Transfer function
L = Chord Length selected for Measurement in meters
λ = Wavelength of irregularity in meters
 Fixing New Chords
 Present Chords/Bases

S.N. Parameter Short Chord Long Chord

1 Unevenness 3.6 m 9.6 m
2 Alignment 7.2 m 9.6 m
3 Twist 3.6 m 4.8 m

 Short Chord for unevenness was fixed in 1964 on the basis of c/c
distance of wheel base of TRC and for alignment in 1969.
 Long Chord for unevenness was fixed in 1978 at the time of
introduction of inertial principle of track recording and for
alignment in 1985 at he time introduction of microprocessor
based TRCs.
 Short base for Twist was fixed in 1978 and long Base in 1985
 Fixing New Chords
Need for Revision of Chords

 Improvement in suspension system of rolling stock
 Introduction of New rolling stock having better suspension
system
 Improvement in Track Structure
 Increase in speed potential of Track
 Change in measuring principle from Mid Chord offset
method to Inertial Principle
 Introduction of mechanized maintenance of track. Chord
used in track machines varies from 14.65 to 18.4 meter
 Fixing New Chords
•New Chords approved by Railway
Board
S.N. Parameter Short Chord Long Chord
1 Unevenness 9.0 m 18.0 m
2 Alignment 9.0 m 15.0 m
3 Twist 3.0 m 15.0 m
Criteria used in revision of chord
 Identification of critical wavelength at various speed on
the basis of natural frequency of different rolling stocks.
 Calculation of transfer function for critical wavelengths
on different chords at various speeds.
 Selection of relevant chord having transfer function in the
range of 0.8 to 1.2.
THANK
YOU