Transcript Testing and Stability of Rolling Stock

Testing and Stability of Rolling
Stock
Need for Testing New Stock
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Safety of new design
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Get natural frequency in various modes
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Level of comfort
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Performance of locos
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Statutory requirements as per Policy Circular
No 6 of Rly. Bd.
Policy Circular No 6
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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
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Determine & recommend max permissible speed
for new design rolling stock
Policy Circular No 6(contd.)
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Zonal Rlys to apply for sanction through CRS
to Rly Bd. for running new design stock on
specific track taking into account
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RDSO's recommendations of provisional/final
speed
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Condition and maintenance of
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Track structure
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Fixed structures , incl bridges & OHE
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Rolling stock
Maximum Moving Dimensions
Policy Circular No 6(contd.)
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Definition of new rolling stock
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Different principal dimensions
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Different bogie design
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New braking system
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Change in axle load, track loading density,
unsprung mass
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Minor changes in design,internal layout(with
sanction of CRS) only if leading to significant
change in
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C.G.,Weight distribution, ride behaviour
Policy Circular No 6(contd.)
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Movement of newly designed rolling stock
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From manufacturer/dock to destination/testing
point
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Not more than provisional speed
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Determined by
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RDSO's EDs(MP, Bridges & Structures, Track)
Approved by CE,CME and CEE( for elect stock &
OHE)
CRS approval required for
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Attachment to passenger carrying vehicle
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Condonation for exceeding axle load
Policy Circular No 6(contd.)
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Provisional Speed by EDs (MP),(Bridge
&Structures),(Track) of RDSO before
deciding final speed
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< 80 for BG & < 60kmph for MG passenger
stock , <65 for BG & < 45kmph for MG goods
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With CRS sanction
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< 105 for BG & < 75 kmph for MG passenger stock
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< 75 for BG & < 50kmph for MG goods
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Determined from design features and data or
similar stock already in service
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Valid for 5 years max
Policy Circular No 6(contd.)
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Final speed of new stock decided by EDs
(MP), (Track),(Bridge&Structures)of RDSO
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Based on experience with similar stock &
detailed oscillation trials
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Detailed oscillation trials to be carried out by
ED(Testing) after consulting EDs (MP), (Track),
(Bridge &Structure) & Design directorate RDSO
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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
Policy Circular No 6(contd.)
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Types of trials -new stock
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Detailed oscillation trials
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Rating & performance trials of locos
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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 105-110 Kmph by zonal
rly using portable accelerometers
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Accel <.3 g or <.25 peaks/km for .3g < accel < .35g
Track and Related Issues
Indian Railway Track
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Classified into two categories
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Main Line (speed <110)
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High Speed
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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
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Unevenness of left & right rail
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Twist over 3.6m
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Gauge & Alignment
Indian Railway Track (Contd.)
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Categorisation of track based on TRC data
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Peak based
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Recorded every
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3 months for Rajdhani routes
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4 months for A& B routes (1660 sleeper/km)
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6 months for C & D routes (1440 sleeper/km)
Separate category (i.e A,B,C,D) for each
parameter
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Twist – A < 1.39 < B < 2.08 < C < 2.78,D>2.78mm/m
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Alignment – A < 3 < B< 5,C >5mm versine /7.2m
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Unevenness - A < 6 < B <10 < C <15, D>15mm /3.6m
Indian Railway Track (Contd.)
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Categorisation of track based on TRC
data(contd)
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10 peaks/km > limits set for each category
allowed
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No of peaks > B category limits is subscript e.g.
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Ten peaks of 3mm/m of twist => A10
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Eleven peaks of 3mm/m of twist => D11
Track maintenance standards
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NOT SAFETY standards
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Peak based
Indian Railway Track (Contd.)
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Separate standards for
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New track/relaying
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Planned maintenance
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Urgent maintenance
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Max speed above and below 105 kmph
Derailment
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Wheel climbing rail
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Tight gauge
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Due to excessive angle of attack
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Sharp flange
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Excessive wheel gauge(loose disc)
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Sharp curve -too much versine
Excessive lateral force- Nadal's formula
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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
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Usually on level crossings
Derailment
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Wheel offloaded
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Inadequate transition
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Cant excessive
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Uneven loading/empty between loaded wagons
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Bumping on sudden acceleration / retardation
Excessive Twist -cause of derailments at
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Low speed
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Straight track
Derailment
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Wheel offloaded due to resonance
/excessive spring deflection
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Due to inadequate ballast
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Unevenness of track
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Poor quality ballast -caked up
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Poor damping
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On multi-span bridges (more likely on steel
girder type)
Resonance
Derailment
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Wheel dropping between rails if track
expands
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Due to defective or inadequate fittings
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Excessive track gauge
Track buckling due to
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Inadequate stress relieving
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Inadequate ballast
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Wrong shape of ballast packing
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Usually in hot summer during high temperatures
Derailment
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Rail fractures due to
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Inadequate stress relieving
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Improper UFD
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Inadequate ballast
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Wheel flats?
Shifting of sleepers
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Prude Homme's Limit (wooden sleeper)
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Wrong shape of ballast packing
Track Measurements After
Derailment
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Type of Soil & Ballast
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Drainage
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Sleeper & Rails
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Fastenings & Joints
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Location of Point of mount
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Measurements from -90m +45m from zero
station if cause of derailment is disputed else
from zero station
Track Measurements After
Derailment
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Under load & without load
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Gauge
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Cross Level
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Versine on 20m cord
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Transition
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Length
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Rate of change of superelevation
Unevenness in case of sags
Effect of Vibration on Human Body
Sperling's Ride Index
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Human sensation of comfort proportional to
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Displacement (sinusoidal)
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Acceleration
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Rate of change of acceleration
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RI=.896(g(f)*b3/f)0.1, b= acceleration amp
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Ride comfort correction factor g(f) =kf2
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k=.325 for vertical RI (0.5-5.4Hz)
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k= .8 for lateral RI (0.5-5.4 Hz)
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k=1 for goods stock
Oscillation trials of Rolling Stock
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Report of Standing Criteria
Committee dated January 2000
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To evolve criteria for assessment of stability
of rolling stock on IR,
Composition
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Ed Testing, Convener
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EDs (MP), (Carriage),(Wagon),(Research)
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EDs (Track Design), (Track Machines)
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ED Electric loco
Formulates oscillation trial procedure and
Evaluation criteria
rd
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Report of Standing Criteria
Committee dated January 2000
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Need for Oscillation trials
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Establish vehicle is safe at desired speed
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Stability of vehicle at that speed
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Check vehicle oscillation behaviour
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Check vehicle ride comfort
Test track should include
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Straight 1 Km X 2
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Station yard
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700-800 m Curve of about 2 degree
rd
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Report of Standing Criteria
Committee dated January 2000
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Test track
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Rundown track worse than 90% of IR track
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On main line track
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Track geometry peak based track category
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Include high speed (C&M I vol I) for speed >110kmph
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,
rd
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Report of Standing Criteria
Committee dated January 2000
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Test Speed (Loaded & Empty)
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Start with low speed (60kmph/80kmph)
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Increase speed in increments of 5/10Kmph
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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
rd
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Report of Standing Criteria
Committee dated January 2000
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Recording in both empty and loaded
conditions
Transducer
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Accelerometers kept at floor level above bogie
pivot
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Linear Variable Differential Transformer for
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Spring deflections
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Bogie rotation
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Bolster Swing
Load cell for lateral force measurement at axle
Data Acquisition System
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Transducers
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Signal Conditioners
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Excitation to transducer (2.5 Khz, ~5V AC)
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Amplification
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Frequency filtration (.5 to 15 Hz)
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5 Hz for coaches
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10 Hz for Wagons
Data recording
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Chart Recorders
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Computerised -using PCI/PXI DAQ card
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Report of Standing Criteria
Committee dated January 2000
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Criteria for locos
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Hy2m <.85(1+P/3), P= axle load (Prud Homme's
limit)
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Hy/Q (for >1/20 sec) <1
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<.3g accelerations in vertical & lateral directions
(isolated peak upto .35g if no resonance)
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Ride index < 4, preferred 3.75
Criteria for carriage
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Ride index <3.5,preferred 3.25 (upto 4 for
EMU/DMU)
rd
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Report of Standing Criteria
Committee dated January 2000
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Criteria for Wagons
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Hy2m<.85(1+P/3),P= axle load (Prude Homme's
limit)
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Hy/Q (for >1/20 sec) <1
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In case Hy cannot be measured,
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Ride index < 4.5, preferred 4.25
General stable running characteristics based on
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Accelerations
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Spring deflections
Thank You!!!