1. Testing and Stability of Rolling Stock

2. Need for Testing New Stock
Safety of new design
Get natural frequency in various modes
Level of comfort
Performance of locos
Statutory requirements as per Policy Circular No 6 of Rly. Bd.

5. Policy Circular No 6
No.92/CEDO/SR/4/0 dated 23/12/1999 issued by Member(Engg), Rly.Bd.
Contains rules for certification of maximum permissible speeds for rolling stock
Rly.Bd. is safety controlling authority for Indian Railways under Indian Railways Act
Responsibility delegated to RDSO
Determine & recommend max permissible speed for new design rolling stock

6. Policy Circular No 6(contd.)
Zonal Rlys to apply for sanction through CRS to Rly Bd. for running new design stock on specific track taking into account
RDSO's recommendations of provisional/final speed
Condition and maintenance of
Track structure
Fixed structures , incl bridges & OHE
Rolling stock
Maximum Moving Dimensions

7. Policy Circular No 6(contd.)
Definition of new rolling stock
Different principal dimensions
Different bogie design
New braking system
Change in axle load, track loading density, unsprung mass
Minor changes in design,internal layout(with sanction of CRS) only if leading to significant change in
C.G.,Weight distribution, ride behaviour

8. Policy Circular No 6(contd.)
Movement of newly designed rolling stock
From manufacturer/dock to destination/testing point
Not more than provisional speed
Determined by
RDSO's EDs(MP, Bridges & Structures, Track)
Approved by CE,CME and CEE( for elect stock & OHE)
CRS approval required for
Attachment to passenger carrying vehicle
Condonation for exceeding axle load
Condonation by Rly Bd for exceeding max moving dimensions

9. Policy Circular No 6(contd.)
Provisional Speed by EDs (MP),(Bridge &Structures),(Track) of RDSO before deciding final speed
< 80 for BG & < 60kmph for MG passenger stock , <65 for BG & < 45kmph for MG goods
With CRS sanction
< 105 for BG & < 75 kmph for MG passenger stock
< 75 for BG & < 50kmph for MG goods
Determined from design features and data or similar stock already in service
Valid for 5 years max

10. Policy Circular No 6(contd.)
Final speed of new stock decided by EDs (MP), (Track),(Bridge&Structures)of RDSO
Based on experience with similar stock & detailed oscillation trials
Detailed oscillation trials to be carried out by ED(Testing) after consulting EDs (MP), (Track), (Bridge &Structure) & Design directorate RDSO
After Jt safety certificate of zonal PHODs & CRS approval
Evaluation based on Standing Criteria Committee
Speed certificate includes max no of locos in multiple Unit

11. Policy Circular No 6(contd.)
Types of trials -new stock
Detailed oscillation trials
Rating & performance trials of locos
EBD(speed >110 for passenger & 75 for goods) & Coupler force trials of trains
Signal Interference trials for Elect locos
Confirmatory oscillgraph car run on tracks above 110Kmph
Route Proving run between Kmph by zonal rly using portable accelerometers
Accel <.3 g or <.25 peaks/km for .3g < accel < .35g

12. Track and Related Issues

13. Indian Railway Track Classified into two categories Track parameters
Main Line (speed <110)
High Speed
For speed upto 140 Kmph
Based on Vol-I of Civil and Mechanical Engg Report No-I (C&M-I) dated May 1969 for “Increase of Speed on DLI-HWH Route Feasibility Study”
Track parameters
Unevenness of left & right rail
Twist over 3.6m
Gauge & Alignment

14. Indian Railway Track (Contd.)
Categorisation of track based on TRC data
Peak based
Recorded every
3 months for Rajdhani routes
4 months for A& B routes (1660 sleeper/km)
6 months for C & D routes (1440 sleeper/km)
Separate category (i.e A,B,C,D) for each parameter
Twist – A < 1.39 < B < 2.08 < C < 2.78,D>2.78mm/m
Alignment – A < 3 < B< 5,C >5mm versine /7.2m
Unevenness - A < 6 < B <10 < C <15, D>15mm /3.6m
Gauge -A < 3 < B < 6, C> 6mm loose/tight

15. Indian Railway Track (Contd.)
Categorisation of track based on TRC data(contd)
10 peaks/km > limits set for each category allowed
No of peaks > B category limits is subscript e.g.
Ten peaks of 3mm/m of twist => A10
Eleven peaks of 3mm/m of twist => D11
Track maintenance standards
NOT SAFETY standards
Peak based
Standard deviation based

16. Indian Railway Track (Contd.)
Separate standards for
New track/relaying
Planned maintenance
Urgent maintenance
Max speed above and below 105 kmph

17. Derailment Wheel climbing rail Tight gauge
Due to excessive angle of attack
Sharp flange
Excessive wheel gauge(loose disc)
Sharp curve -too much versine
Excessive lateral force- Nadal's formula
Hy/Q =(tanA-mu)/(1+mu tanA)= .997, where A:flange angle wrt to horizontal=60degrees & mu=.27
Inadequate clearance between rail and check rail or space between them filled with grit
Usually on level crossings

18. Derailment Wheel offloaded Inadequate transition Cant excessive
Uneven loading/empty between loaded wagons
Bumping on sudden acceleration / retardation
Excessive Twist -cause of derailments at
Low speed
Straight track

19. Derailment
Wheel offloaded due to resonance /excessive spring deflection
Due to inadequate ballast
Unevenness of track
Poor quality ballast -caked up
Poor damping
On multi-span bridges (more likely on steel girder type)

20. Resonance

21. Derailment Wheel dropping between rails if track expands
Due to defective or inadequate fittings
Excessive track gauge
Track buckling due to
Inadequate stress relieving
Inadequate ballast
Wrong shape of ballast packing
Usually in hot summer during high temperatures

22. Derailment Rail fractures due to Shifting of sleepers
Inadequate stress relieving
Improper UFD
Inadequate ballast
Wheel flats?
Shifting of sleepers
Prude Homme's Limit (wooden sleeper)
Wrong shape of ballast packing

23. Track Measurements After Derailment
Type of Soil & Ballast
Drainage
Sleeper & Rails
Fastenings & Joints
Location of Point of mount
Measurements from -90m +45m from zero station if cause of derailment is disputed else from zero station

24. Track Measurements After Derailment
Under load & without load
Gauge
Cross Level
Versine on 20m cord
Transition
Length
Rate of change of superelevation
Unevenness in case of sags

25. Effect of Vibration on Human Body

29. Sperling's Ride Index Human sensation of comfort proportional to
Displacement (sinusoidal)
Acceleration
Rate of change of acceleration
RI=.896(g(f)*b3/f)0.1, b= acceleration amp
Ride comfort correction factor g(f) =kf2
k=.325 for vertical RI ( Hz)
k= .8 for lateral RI ( Hz)
k=1 for goods stock

30. Oscillation trials of Rolling Stock

32. 3rd Report of Standing Criteria Committee dated January 2000
To evolve criteria for assessment of stability of rolling stock on IR,
Composition
Ed Testing, Convener
EDs (MP), (Carriage),(Wagon),(Research)
EDs (Track Design), (Track Machines)
ED Electric loco
Formulates oscillation trial procedure and Evaluation criteria

33. 3rd Report of Standing Criteria Committee dated January 2000
Need for Oscillation trials
Establish vehicle is safe at desired speed
Stability of vehicle at that speed
Check vehicle oscillation behaviour
Check vehicle ride comfort
Test track should include
Straight 1 Km X 2
Station yard
m Curve of about 2 degree

34. 3rd Report of Standing Criteria Committee dated January 2000
Test track
Rundown track worse than 90% of IR track
On main line track
Include high speed (C&M I vol I) for speed >110kmph
Track geometry peak based track category
Main line “B or C” Unevenness & Gauge, “C or D” Twist, “C” Alignment
C&M Vol-I “A or B” Unevenness & Gauge, “B or C” Twist, “C” Alignment
Long confirmatory run for 10-50kms with resonance check hard spots like L-Xing, Culverts, Bridges

36. 3rd Report of Standing Criteria Committee dated January 2000
Test Speed (Loaded & Empty)
Start with low speed (60kmph/80kmph)
Increase speed in increments of 5/10Kmph
Stop if any limit is exceeded
Max speed 10% higher than the proposed speed
Test vehicle to be last vehicle (except loco)
Free end bogie (leading bogie for loco) usually instrumented
Data acquisition system usually in oscillograph car

38. 3rd Report of Standing Criteria Committee dated January 2000
Recording in both empty and loaded conditions
Transducer
Accelerometers kept at floor level above bogie pivot
Linear Variable Differential Transformer for
Spring deflections
Bogie rotation
Bolster Swing
Load cell for lateral force measurement at axle box level
(Pressure transducers for braking tests)

44. Data Acquisition System
Transducers
Signal Conditioners
Excitation to transducer (2.5 Khz, ~5V AC)
Amplification
Frequency filtration (.5 to 15 Hz)
5 Hz for coaches
10 Hz for Wagons
Data recording
Chart Recorders
Computerised -using PCI/PXI DAQ card

46. 3rd Report of Standing Criteria Committee dated January 2000
Criteria for locos
Hy2m <.85(1+P/3), P= axle load (Prud Homme's limit)
Hy/Q (for >1/20 sec) <1
<.3g accelerations in vertical & lateral directions (isolated peak upto .35g if no resonance)
Ride index < 4, preferred 3.75
Criteria for carriage
Ride index <3.5,preferred 3.25 (upto 4 for EMU/DMU)

47. 3rd Report of Standing Criteria Committee dated January 2000
Criteria for Wagons
Hy2m<.85(1+P/3),P= axle load (Prude Homme's limit)
Hy/Q (for >1/20 sec) <1
In case Hy cannot be measured,
Ride index < 4.5, preferred 4.25
General stable running characteristics based on
Accelerations
Spring deflections

48. Thank You!!!