pantograph acceptance requirements and methodology in great britain

Pantograph acceptance requirements and

1

Pantograph acceptance requirements and methodology in Great Britain

byTerry Johnson

RSSB

Outline of Presentation

What is the role of RSSB in the GB rail industry? Background

Dewirement Gauge clearance

The current limits for pantograph acceptance Infrastructure design

2

Infrastructure design Rolling stock

The T942 RSSB research project Pantograph sway Assessment of infrastructure

Revision of standard Benefits of the research

Role of RSSB in the Rail Industry

3

Background

How is OLE vulnerable to sway? Dewirement risk

No hook-over => extra horn & wire wear => maintenance cost Hook-over => dewirement => delay, damage to train, safety

Gauge clearance Mechanical => damage to pantograph

4

Mechanical => damage to pantograph=> dewirement

Electrical => flashover => damage to pantograph /infrastructure => trippings (delays) => safety

Background

5

Background - dewirement

Dewirement Risk Maximum deviation relative to track centre caused by:

Stagger Mid-span offset + blow off due to wind Track and overhead line equipment (OLE) tolerances Structure deflection

6

Structure deflectionNB Span lengths are limited by maximum deviation rules

Deviation relative to pantograph centre caused by Vehicle sway to left or right Lateral component of pantograph uplift force on wire

Background gauge clearance

Gauge Clearance Mechanical clearance to electrically common live parts of

OLE Mechanical clearance under minimum stagger rules Electrical clearance to bridges, signal structures and

station awnings

7

station awnings

Background - OLE dewirement limits

. Midspan, mm Support, mmOscillatory sway 100 +15 100 +15Wind effect on pan 30 40

Track tols. - lateral 25 25 Track tols. - cross level 65 65

8

Total vehicle movement 175 245(relative to contact wire)Pantograph working width 650 650OLE movements 75 25

Design deviation/ stagger 400 380

Span length calculated depending on local wind conditions to get as close as possible to the 400 limit (using 1 in 50 year gust wind)


OLE MOVEMENT

75mm

OLE DEVIATION

VEHICLE

MOVEMENT

85 mm

TRACK

MOVEMENT

90 mm

CL

TRACK

(DESIGN)

MID-SPAN

WIND

DIRECTION

9

OLE DEVIATION

(BLOW OFF)

400mm

WORKING WIDTH

650 mm

CL

PANTOGRAPH

HEAD

DIRECTION


10

Background - Origin of current sway limits

In British Rail (BR) days pantograph sway limits were specified in a design guide, with the prescribed method of analysis.Preceded use of MBS modelling of vehicles and so used a quasi-static approach.

The limits in RGS GM/RT 2149 correspond to vehicle movements as determined by this process: 130 mm at maximum speed/cant deficiency in still air; 190 mm at maximum speed/cant deficiency with maximum cross wind

of 35 m/s.

11

of 35 m/s. Vehicles were produced to BR specifications and accepted by BR

project engineers for specific applications/routes.

If they were not wholly compliant with the design guide, vehicles could still be accepted if the project team considered them suitable for the application/route.

The nature of the process changed with privatisation and the introduction of third party certification through Vehicle Acceptance Bodies.

Background - Origin of current sway limits

The limitations associated with the use of the design guide became apparent with the early design calculations on the Class 357 Electrostars - i.e. around 1996.

Calculations showed the following pan sway movements at maximum speeds and cant deficiencies on the same track:

12

track: Simulation results are given for mean 2.12 standard

deviations and represents a 96.6% movement probability limit.

Train DG MBS DG MBSClass 319 - 150 196 235Class 365 128 148 187 247Class 357 125 142 202 230

No Wind 35 m/s Wind

Background - sway limits: key points

The design guide method does not calculate the true vehicle/ pantograph movements due to quasi-static assumption and does not even reflect the true relative movements between vehicle types.

No modern EMU type vehicles have conformed to the design guide and current limits when correctly assessed; comparative arguments were used for acceptance with a derogation against Standards.

Though the true vehicle pantograph movements have exceeded the

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Though the true vehicle pantograph movements have exceeded the specified limits by up to 60 mm, actual performance has not resulted in noticeable in-service problems.

MU suspensions are a compromise between flexibility to resist derailment/good ride and being stiff enough to constrain the pantograph movement limits.

The pressure to produce lighter, more efficient vehicles will aggravate these conflicting requirements.

The potential opportunities rolling stock and infrastructure Different acceptance methodology closer matches reality

Reduced costs for new rolling stock, better control of derailment risk cost savings

Background - Opportunities

14

Better understanding of pantograph sway OLE & infrastructure can be designed more intelligently potentially very large cost savings

T942 - Approach to the analysis

GM/RT2142 sets out limits for vehicle pantograph sway displacements at 4.3 m above rail for all train speeds up to maximum:

130 mm at maximum cant deficiency in still air 190 mm at maximum cant deficiency with a maximum wind speed of 35 m/s.

Many multiple units do not meet these requirements, yet do not cause dewirements or infringements of OLE mechanical and electrical clearances.

Note that there are no formal requirements for OLE infrastructure, although design rules have been derived.

15

design rules have been derived. Research Project T942 set out to understand the apparent anomaly by

looking at real train operations on real routes: Class 365 on Kings Cross to Cambridge and compared with Class 325 on Preston to Carlisle Class 91 running at cant excess, (low speed).

It was anticipated that a probabilistic approach would be a key. The vehicle pantograph/OLE interface is very complex

Train speedprofiles

Cant deficiencyprofiles

Network Rail structure database

OLE layout diagrams

Route structuredatabase

OS maps

Eurocode 1wind map

WCRM Class 390database

Site localfactors

Mean wind speed

Terrainroughness Train speed

Vehicledimensions

Turbulenceintensity

Windtime

histories

Aerodynamicadmittance

Aerodynamiccoefficients

Aerodynamicforce andmoment

time historiesVehicle model Track roughnessfiles

Simple sway

OLE structurecross-sections

OLE componentdatabase

Train speedprofiles



OLE layout diagrams


OS maps

Eurocode 1wind map


Site localfactors

Mean wind speed


Vehicledimensions

Turbulenceintensity

Windtime

histories





Simple sway


Train speedprofiles



OLE layout diagrams


OS maps

Eurocode 1wind map


Site localfactors

Mean wind speed


Vehicledimensions

Turbulenceintensity

Windtime

histories





Simple sway


Train speedprofiles



OLE layout diagrams


OS maps

Eurocode 1wind map


Site localfactors

Mean wind speed


Vehicledimensions

Turbulenceintensity

Windtime

histories





Simple sway


Train speedprofiles



OLE layout diagrams


OS maps

Eurocode 1wind map


Site localfactors

Mean wind speed


Vehicledimensions

Turbulenceintensity

Windtime

histories





Mean wind speed


Vehicledimensions

Turbulenceintensity

Windtime

histories





Mean wind speed


Vehicledimensions

Turbulenceintensity

Windtime

histories





Mean wind speed


Vehicledimensions

Turbulenceintensity

Windtime

histories





Simple sway




T942 - Overview of the calculation process

Vehicle sway analysis

Route databases

16

Cant deficiency/excess

Track linespeeds

Wheel railprofile


Track linespeeds

Wheel railprofile

Wind loading onOHLE CoP

Siteprobabilityanalysis

Windprobabilityanalysis

Wind directionprobabilities

dynamicsimulations

Peak value

analysis

Swayinterpolation

functionsPantograph sway

values

Dewirementprobabilities

Structureprobabilities

Simple swayexceedance

analysis

dynamic interfaceanalysis

PhXdynamic

Critical structures

Tracktolerance

probabilities

OLEtolerance

probabilities

Clearances toStructures andcomponents

Margin todewirementdistances

Contactwire blow-off

analysis

Check ofstandards

OLE uplifts

Network RailMaintenance

standards

Design gauges





dynamicsimulations

Peak value

analysis

Swayinterpolation


values




analysis


PhXdynamic

Critical structures

Tracktolerance

probabilities

OLEtolerance

probabilities




analysis

Check ofstandards





dynamicsimulations

Peak value

analysis

Swayinterpolation


values




analysis


PhXdynamic

Critical structures

Tracktolerance

probabilities

OLEtolerance

probabilities




analysis

Check ofstandards




dynamicsimulations

Peak value

analysis

Swayinterpolation


values




analysis


PhXdynamic

Critical structures

Tracktolerance

probabilities

OLEtolerance

probabilities




analysis




dynamicsimulations

Peak value

analysis

Swayinterpolation


values






dynamicsimulations

Peak value

analysis

Swayinterpolation


values

dynamicsimulations

dynamicsimulations

dynamicsimulations

Peak value

analysis

Swayinterpolation


values

Swayinterpolation


valuesPantograph sway

values




analysis


PhXdynamicdynamic interface

analysis

PhXdynamic

Critical structures

Tracktolerance

probabilities

OLEtolerance

probabilities




analysis

Check ofstandards

OLE uplifts


standards

Design gauges

OLE uplifts


standards

Design gauges

Infrastructure and dewirement analysisSway probability analysis

T942 - Key parameters

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Movements

Picture courtesy of www.milepost91.co.uk

Tolerances

T942 - Pantograph sway analysis

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T942 - Vehicle sway analysis

Generate wind time histories analytically mean wind speeds 0 m/s,10m/s, 15m/s and 22m/s

single terrain roughness and turbulence train speeds 100-160 km/h Cl 365, Cl325 and Cl 91 train dimensions.

Train speedprofilesMean wind

speedTerrain

roughness Train speedVehicle

dimensionsTurbulence

intensity

Windtime

histories




speedTerrain



intensity

Windtime

histories




speedTerrain



intensity

Windtime

histories




speedTerrain



intensity

Windtime

histories




speedTerrain



intensity

Windtime

histories



Mean wind speed


Vehicledimensions

Turbulenceintensity

Windtime

histories



Mean wind speed


Vehicledimensions

Turbulenceintensity

Windtime

histories



Mean wind speed


Vehicledimensions

Turbulenceintensity

Windtime

histories



Aerodynamic force and moment coefficient values from wind tunnel tests, (full scale for Cl 91, estimation for Cl 325).

Generate a series of aerodynamic force Aerodynamic admittance applied.

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Track linespeeds

Wheel railprofile


Track linespeeds

Wheel railprofile



dynamicsimulations

Pantograph swayvalues



dynamicsimulations




dynamicsimulations




dynamicsimulations




dynamicsimulations




dynamicsimulations






dynamicsimulations

dynamicsimulations

dynamicsimulations




Generate a series of aerodynamic force and moment time histories for the 3 trains.

T942 - Vehicle sway analysis


speedTerrain



intensity

Windtime

histories




speedTerrain



intensity

Windtime

histories




speedTerrain



intensity

Windtime

histories




speedTerrain



intensity

Windtime

histories




speedTerrain



intensity

Windtime

histories



Mean wind speed


Vehicledimensions

Turbulenceintensity

Windtime

histories



Mean wind speed


Vehicledimensions

Turbulenceintensity

Windtime

histories



Mean wind speed


Vehicledimensions

Turbulenceintensity

Windtime

histories



Five VAMPIRE models for Cl 365 and 325, tare and crush, and Cl 91.

Using as inputs: aerodynamic side and lift force time histories acting at cog for the 3 trains

track roughness files cant deficiency/excess train speeds, 100 160 (200) km/h wheel/rail profiles

Generate pansway time histories over

20

-250

-200

-150

-100

-50

00 4 8 12 16 20

Distance, km

S

w

a

y

a

t

4

.

3

m

,

m

m

Cl325, 110 km/h, 22 m/s mean w ind


Track linespeeds

Wheel railprofile


Track linespeeds

Wheel railprofile


time histories Vehicle modelTrack roughness

files

dynamicsimulations




files

dynamicsimulations




files

dynamicsimulations




files

dynamicsimulations




files

dynamicsimulations




files

dynamicsimulations




files



files

dynamicsimulations

dynamicsimulations

dynamicsimulations




Generate pansway time histories over about 20 km of track;

at 4.3 m and 5.3 m pan heights, in leading and trailing directions of travel for Cl 365 and Cl 325.

T942 - Generation of route databases

Train speedprofiles



OLE layout diagrams

OS maps

Eurocode 1wind map

Site localfactors


Train speedprofiles



OLE layout diagrams

OS maps

Eurocode 1wind map

Site localfactors


Train speedprofiles



OLE layout diagrams

OS maps

Eurocode 1wind map

Site localfactors


Train speedprofiles



OLE layout diagrams

OS maps

Eurocode 1wind map

Site localfactors


Train speedprofiles



OLE layout diagrams

OS maps

Eurocode 1wind map

Site localfactors


21

Aim was to produce structure databases with all information relevant to probability analysis for the two routes.

A wide variety of sources was required














Infrastructure heights ie embankments, viaducts included. Local sheltering effects determined from OS maps and Bing Maps. Extreme mean wind speeds from Cooks wind maps; Weibull distribution parameters.

T942 - Pansway probability analysis




Peak value

analysis

Swayinterpolation


values

probabilities




Peak value

analysis

Swayinterpolation


values

probabilities




Peak value

analysis

Swayinterpolation


values

probabilities




Peak value

analysis

Swayinterpolation


values

probabilities




Peak value

analysis

Swayinterpolation


values




Peak value

analysis

Swayinterpolation


values

Peak value

analysis

Swayinterpolation


values

Swayinterpolation


valuesPantograph sway

values

probabilities

Pansway ( + 2.12) values analysed to develop functions of sway for different trains, varying train speed, (combined) cant deficiency/excess and mean wind speed expressed as an additional cant deficiency equivalent cant deficiency.

Vtr = 100 mi/h

22













Vtr = 100 mi/h

0

25

50

75

100

125

150

175

200

225

250

0 50 100 150 200 250 300 350 400 450 500 550 600 650

Eq cant deficiency, mm

P

a

n

s

w

a

y

,

m

m

No windWind 0 mm cdWind 150 mm cdWind limitNo wind limit

T942 - Pansway probability analysis The basic pansway limit exceedance probability in a span is:

- (the probability that the pansway displacement exceeds a particular limit value for a wind of mean speed V coming from a direction q0) times (the probability of occurrence of a wind of speed V) times (the probability of the wind coming from direction q0)

Component probabilities:

This has to be summed over all wind directions for the range of mean winds speeds for the complete probability. For a zero mean wind speed:

- (the probability that the pansway displacement exceeds a particular limit value for a wind of mean speed V =0)

23

- Peak ( + 2.12) value analysis

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0 45 90 135 180 225 270 315 360Direction to North, deg

P

r

o

b

a

b

i

l

i

t

y

Prob/degProb/30 deg sector

0.0

0.2

0.4

0.6

0.8

1.0

0 5 10 15 20 25Mean wind speed, m/s

C

u

m

u

l

a

t

i

v

e

p

r

o

b

.

0.E+00

2.E-02

4.E-02

6.E-02

8.E-02

1.E-01

P

r

o

b

a

b

i

l

i

t

y

d

e

n

s

i

t

y

cdfpdf

- Wind probability analysis- Wind direction probability

Note: these probabilities are the probabilities that pansway values exceed still air or with wind sway limits in a given span.

T942 - Pansway probability analysis The pansway limit exceedance probabilities for each span were factored to obtain:

- Estimate of dewirement potential by factoring by the length of span within 5 mm of the maximum wind deflection distance (400 mm).

- Estimate of exceedance at structures by assuming a critical length of 2 m in each span.

Results: probabilities relative to Class 325 (crush) on Preston to Carlisle line (benchmark operation)

Case Mid-span Structure

Class 365, tare, KX-C 1.6E-05 5.2E-06

24

Class 365, tare, KX-C 1.6E-05 5.2E-06

Class 365, crush, KX-C 2.6E-04 8.4E-05

Class 325, tare, P-C 4.0E-02 2.1E-02

Class 325, crush, P-C 1.0 5.6E-01

T942 - Infrastructure analysis

25

T942 - OLE infrastructure/dewirement analysis

Swayinterpolation

functions


analysis

Critical structures

Track

OLE uplifts


standards

Design gauges

Swayinterpolation

functions


analysis

Critical structures

Track

Swayinterpolation

functions


analysis

Critical structures

Track

Swayinterpolation

functions


analysis

Critical structures

Track

Swayinterpolation

functions

Swayinterpolation

functions

Swayinterpolation

functions

Swayinterpolation

functions


analysis

Critical structures

Track

OLE uplifts


standards

Design gauges

OLE uplifts


standards

Design gauges

Route databases with sway interpolation functions allowed identification of critical spans on the two routes.

Analysis of wind loading on contact wire starting from OHLE design CoP.

Preliminary assessment

26




PhXdynamic

Tracktolerance

probabilities

OLEtolerance

probabilities




analysis

Check ofstandards




PhXdynamic

Tracktolerance

probabilities

OLEtolerance

probabilities




analysis

Check ofstandards




PhXdynamic

Tracktolerance

probabilities

OLEtolerance

probabilities




analysis

Check ofstandards



PhXdynamic

Tracktolerance

probabilities

OLEtolerance

probabilities




analysis





analysis

PhXdynamic

Tracktolerance

probabilities

OLEtolerance

probabilities




analysis

Check ofstandards

Preliminary assessment made of dewirement for Cl 91 and Cl 365 on:

Mk1, Mk 3A/3B and UK1 OLE equipment

tangent and curve for two span lengths 57 m

and 75 m. Identified cases to study in

more detail, in conjunction with route span length distribution characteristics.

T942 - OLE infrastructure/dewirement analysis

PhXdynamicTM software used

Initially used in quasi-static mode

Planned to use to calculate total probabilities

Swayinterpolation

functions


analysis

Critical structures

OLE uplifts


standards

Design gauges

Swayinterpolation

functions


analysis

Critical structures

Swayinterpolation

functions


analysis

Critical structures

Swayinterpolation

functions


analysis

Critical structures

Swayinterpolation

functions

Swayinterpolation

functions

Swayinterpolation

functions

Swayinterpolation

functions


analysis

Critical structures

OLE uplifts


standards

Design gauges

OLE uplifts


standards

Design gauges

Swayinterpolation

functions


analysis

Critical structures

OLE uplifts


standards

Design gauges

Swayinterpolation

functions


analysis

Critical structures

Swayinterpolation

functions


analysis

Critical structures

Swayinterpolation

functions


analysis

Critical structures

Swayinterpolation

functions

Swayinterpolation

functions

Swayinterpolation

functions

Swayinterpolation

functions


analysis

Critical structures

OLE uplifts


standards

Design gauges

OLE uplifts


standards

Design gauges

probabilitiesWind loading on

OHLE CoP



PhXdynamic

Tracktolerance

probabilities

OLEtolerance

probabilities




analysis

Check ofstandards




PhXdynamic

Tracktolerance

probabilities

OLEtolerance

probabilities




analysis

Check ofstandards




PhXdynamic

Tracktolerance

probabilities

OLEtolerance

probabilities




analysis

Check ofstandards



PhXdynamic

Tracktolerance

probabilities

OLEtolerance

probabilities




analysis





analysis

PhXdynamic

Tracktolerance

probabilities

OLEtolerance

probabilities




analysis

Check ofstandards




PhXdynamic

Tracktolerance

probabilities

OLEtolerance

probabilities




analysis

Check ofstandards




PhXdynamic

Tracktolerance

probabilities

OLEtolerance

probabilities




analysis

Check ofstandards




PhXdynamic

Tracktolerance

probabilities

OLEtolerance

probabilities




analysis

Check ofstandards



PhXdynamic

Tracktolerance

probabilities

OLEtolerance

probabilities




analysis





analysis

PhXdynamic

Tracktolerance

probabilities

OLEtolerance

probabilities




analysis

Check ofstandards

T942 - PhXdynamicTM

Software tool developed outside T942 project Uses outputs from MBS, such as VAMPIRE Engineering tool, not black box Incorporates models for:

Track Vehicle (bogie and body) Pantograph OLE system OLE components Gauges Gauges Infrastructure ..including all tolerances

Considers inputs of: Speed Curvature (horizontal and vertical) Installed cant and cant deficiency Wind forces

Can work quasi-statically or in Monte Carlo mode

Produces Clearances Locus of movements

T942 - PhXdynamicTM

Used for: OLE structure clearances Kings Cross Cambridge Dewirement assessment Clearances to OLE components Clearances to OLE design gauges

T942 Mechanical gauge clearance


OLE Representative cross sections were selected from

drawings

30


Gauge Clearance Relevant OLE Drawings were identified

31



OLE Using PhXdynamicTM , cross sections were drawn to assess

clearance

32


Gauge Clearance Mechanical clearance under minimum stagger

- As stagger reduces the heel of the arm steadily approaches the pantograph horn

33



we wanted to check established allocation limits are ok.

34



35


Gauge Clearance Electrical clearance to Bridges, Signal Structures and

Station Awnings

PhXdynamicTM clearance assessments developed according to gauge drawings.

36

according to gauge drawings.


37


Gauge Clearance Electrical clearance to Bridges, Signal Structures and

Station Awnings It was concluded pantograph movements will be within

the generic gauges used in WCRM clearance assessment.

38

assessment.

The T942 project and its predecessor have been aimed at providing a comprehensive understanding of: vehicle behaviour; infrastructure design policy; environmental and operational input conditions; relevant vehicle/infrastructure interfaces.

Revision of standard

39

relevant vehicle/infrastructure interfaces.

From the above it should be possible to determine a basis for a revised standard.

MBS show that cant deficiency and wind force have the greatest effect on maximum sway, but track quality is not insignificant.

So how do we use the results of the research?

Analysed worst-case vehicles high pantograph sway Class 365 & Class 325 low pantograph sway Class 91 locomotive

High sway - electrical and mechanical gauge infringement


40

High sway - electrical and mechanical gauge infringement Low sway - more susceptible to dewirement Real life studies - operational route - safe operating histories Generated movement envelope of pantograph sway in all

operational conditions Use envelopes to create a comparative test for new or

modified vehicles

How might the new requirements look? - Maximum


41

How might the new requirements look? - Minimum


42

Key Benefits Vehicle Manufacturers able to accurately specify their

vehicles pantograph sway More likely to comply with the revised requirements Avoid derogation or additional risk assessments Avoid costs of seeking a benchmark vehicle


43

Assessment method aligned with existing requirements in Railway Group Standards

No additional software or calculation techniques required

OLE designers equipped with a range of limits Not just a single figure, improved understanding of vehicle dynamics

Potential major cost savings for new electrification projects Not catering for 130 mm or 190 mm in all locations

Thank you for your attention.

Any questions or comments?

pantograph acceptance requirements and methodology in great britain

Documents

pantograph infrastructure

pantograph centre

vehicle sway

current sway limits

design deviation stagger

dewirement electrical

current limits

mmoscillatory sway