Testing and Stability of Rolling Stock

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.

3
(No Transcript)
4
(No Transcript)
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
• lt 80 for BG lt 60kmph for MG passenger stock ,
  lt65 for BG lt 45kmph for MG goods
• With CRS sanction
• lt 105 for BG lt 75 kmph for MG passenger stock
• lt 75 for BG lt 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),(BridgeStructures)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 gt110 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 105-110 Kmph by zonal
  rly using portable accelerometers
• Accel lt.3 g or lt.25 peaks/km for .3g lt accel lt
  .35g

12
Track and Related Issues
13
Indian Railway Track

• Classified into two categories
• Main Line (speed lt110)
• High Speed
• For speed upto 140 Kmph
• Based on Vol-I of Civil and Mechanical Engg
  Report No-I (CM-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 lt 1.39 lt B lt 2.08 lt C lt 2.78,Dgt2.78mm/m
• Alignment A lt 3 lt Blt 5,C gt5mm versine /7.2m
• Unevenness - A lt 6 lt B lt10 lt C lt15, Dgt15mm /3.6m
• Gauge -A lt 3 lt B lt 6, Cgt 6mm loose/tight

15
Indian Railway Track (Contd.)

• Categorisation of track based on TRC data(contd)
• 10 peaks/km gt limits set for each category
  allowed
• No of peaks gt B category limits is subscript
  e.g.
• Ten peaks of 3mm/m of twist gt A10
• Eleven peaks of 3mm/m of twist gt 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)/(1mu tanA) .997,
  where Aflange angle wrt to horizontal60degree
  s 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
• 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
26
(No Transcript)
27
(No Transcript)
28
(No Transcript)
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 (0.5-5.4Hz)
• k .8 for lateral RI (0.5-5.4 Hz)
• k1 for goods stock

30
Oscillation trials of Rolling Stock
31
(No Transcript)
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
• 700-800 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 (CM I vol I) for speed
  gt110kmph
• Track geometry peak based track category
• Main line B or C Unevenness Gauge, C or D
  Twist, C Alignment
• CM 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

35
(No Transcript)
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

37
(No Transcript)
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)

39
(No Transcript)
40
(No Transcript)
41
(No Transcript)
42
(No Transcript)
43
(No Transcript)
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

45
(No Transcript)
46
3rd Report of Standing Criteria Committee dated
January 2000

• Criteria for locos
• Hy2m lt.85(1P/3), P axle load (Prud Homme's
  limit)
• Hy/Q (for gt1/20 sec) lt1
• lt.3g accelerations in vertical lateral
  directions (isolated peak upto .35g if no
  resonance)
• Ride index lt 4, preferred 3.75
• Criteria for carriage
• Ride index lt3.5,preferred 3.25 (upto 4 for
  EMU/DMU)
• lt.3g accelerations in vertical lateral
  directions (isolated peak upto .35g if no
  resonance)

47
3rd Report of Standing Criteria Committee dated
January 2000

• Criteria for Wagons
• Hy2mlt.85(1P/3),P axle load (Prude Homme's
  limit)
• Hy/Q (for gt1/20 sec) lt1
• In case Hy cannot be measured,
• Ride index lt 4.5, preferred 4.25
• General stable running characteristics based on
• Accelerations
• Spring deflections

48
Thank You!!!