VERSE

AT LAST -

cost effective and practical

checking of temperature stress

in rail

A giant leap

for track safety

management,

risk reduction

and new track

quality acceptance

Non-Destructive Stress Free Temperature Measurement

R

Approved by DB Netz AG

a joint development with© 2007 Vortok International Issue number 03.08

VORTOK International is the trading name of the Multiclip Company Ltd

Innovation House - 3 Western Wood Way - Langage Science Park - Plymouth PL7 5BGDevon - uk

Tel +44 (0)1752 349200Fax +44 (0)1752 338855

VORTOK and VERSE are registered trade marks

The Multiclip Company Ltd is a member of the PANDROL Group of Companies Link-up ®Certificate Number: 15513

e-mail sales@vortok.co.ukwebsite www.vortok.co.uk

English - UK

BS EN ISO9001 Certificate Number: 6901

AcceptED BYNetwork Rail

PADS NO: PA05/901

Some current ® VERSE users:

VERSE - Non Destructive Stress Free Temperature Measurement System

Proven and Accepted Worldwide with over150, 000 accurate readings

*

*

FRANCESNCF x 1

FINLANDOy VR-Rata Ab x 3

ITALYRFI x 5

BRAZIL 4CVRD x 1MRS X 3

CANADA 5Canadian National x 3Canadian Pacific x 2

AUSTRALIA 5Pandrol x 1ARTC x 2FMG x 2

*

USA 15Dallas Area Rapid Transit x 1

Union Pacific x 6BNSF x 2CNIC x 1

MARTA Metroplex x 1Long Island Railway x 1

Amtrak x 2St Louis Metro x 1

BOSNIABIH x 1

*

UNITED KINGDOM 60Carillion Rail x 1

First Engineering x 5Jarvis Rail x 9AMEC Rail x 1

Balfour Beatty Rail x 2Amey Rail x 2

Electro-Thermit UK x 3Serco Rail x 1

Network Rail x 34Metronet x 1

Eurotunnel x 1

EIRE x 1Iarnrod Eireann

IRELANDTranslink x 1

09/01/07

*

*

MEXICOSTC x 1

GERMANYDB Netz AG x 1

SWEDENBanverket x 2

Carillion UK x 3NORWAY

Baneservice x 1

CHINAMinistry of Railways x 1

*

***

****

***

*

*

*

**

***

* *

KOREAKorail x 1

IRANIIER x 1

*

10ºC rise in rail temperature creates a compressive force of 18 tons Every railway engineer knows that rail should be at

the correct Stress Free Temperature (SFT) (also referred to as Neutral Temperature). Whilst care is normally taken to ensure that new track is laid in this condition, there are many factors which can cause local changes over time.

Rail outside of its SFT limits is at risk of:

In addition it is possible for the left and right rails to develop a different SFT which can produce uneven loads with unpredictable results, as has been

Most railways endure both rail buckles and

breaks. The statistics for the UK reveal a typical experience.

Until now the only choice has been to cut the rail, measure the gap, manually calculate the SFT and finally re-weld the rail. This traditional method is high cost, labour intensive, frequently inaccurate, and introduces an additional and unnecessary weld. Not surprisingly most railways have tended to limit such measurements of SFT.

A non-destructive, cost effective and practical method for checking SFT will provide today's railway engineer with the means to measure the network, determine the change and rate of change of SFT and its causes, identify high risk sites and plan pre-emptive measurement and re-stressing programmes.

Although it is well understood that SFT in rails can, and does, change over time it has not previously been economical to study the cause and effect relationship for specific sites in a way that will aid predictive maintenance.

®The VERSE method now provides that option.

Accuracy means risk reduction

Since the prevention of rail buckling is often the prime consideration (the greatest safety hazard) many railway engineers have preferred to err on the side of caution and have set the SFT above the average. This then risks a higher number of

®rail breaks. Now that VERSE has made SFT measurement so much easier and more accurate, the SFT can be set much more sensitively to mitigate against both rail breaks and rail buckles. A step forward in track safety management and risk reduction.

Much new track is now laid by contractors on behalf of the infrastructure authority who are increasingly seeking assurances related to track quality at the time of hand over. SFT can now effectively be added to a number of track parameters that constitute quality assurance which in turn improves track safety.

New track quality acceptance

Most railway engineers are able to predict which parts of their network are likely to be vulnerable to SFT change. SFT measurement can therefore be well targeted in the first instance to bring maximum benefits. It is now possible to plan cost effective re-stressing programmes which will help to bring significant improvements in confidence and safety across the rail network.

Predictive maintenance

Buckling in hot weather

Fracturing in cold conditions

Pull-in on curves when cold

Anyone of these track failures will, at best, cause considerable disruption to the network and, in the worst case, cause catastrophic de-railment of a high speed passenger train.

The fact that buckles and breaks are prevalent, is in many respects due to the absence o f a cos t effective and practical method of checking SFT.

Through such management, the modern railway can demonstrate a determined approach to risk reduction, and add another level of safety to the rail transport network.

found in recent measurements.

Track Buckles UK

0

20

40

60

80

100

120

140

160

2004 2003 2002 2001 2000 1999

Non-Destructive Neutral Temperature Measurement

Proven with many thousands of measurements

taken in service conditions by different railways

across the world.

non-destructive

quick & easy

accurate

instant result

portable

low cost

no need to cut the railunless SFT check proves re-stressing necessary.

only 20 to 30 minutes per measurement depending on type of rail clip.

less than 5% of the cost of performing the traditional cut, measure, and re-weld method.

database

excellent reproducibility with a mean error of 0.2 and standard deviation of 1.3 so you can be confident in the result.

ºCºC

follow on-screen instructions on hand held computerfor easy measurement and instant result.

files from the hand-held can be downloaded into a PC database to produce a record of your whole rail network.

supplied in a convenient carry casewhich will fit into small van or estate car.

VERSE delivers a direct SFT result without needing to know any residual stress history of the rail.

VERSE measurement is made whilst the rail is in tension, at an ambient temperature lower than the existing SFT of the rail.

Only one measurement at one ambient rail temperature is required.

Bibliography of Tests and Demonstrations

Non-Destructive Neutral Temperature MeasurementVERSE

VERSE

versatile suitable for all rail profiles.

Graphic Comparison of NeutralTemperatures

Canada April 1999 USA July 1999

Finland September 2000 Denmark April 2001

Italy August 2001 France January 2000

Czech Republic March 2000 Germany April 2002

China October 2002

A selection of some of the many tests carried out:

5

10

15

20

25

30

00 5 10 15 20 25 30

Development and ValidationValidation of the technique was carried out by AEA Technology-Rail during the research phase of perfecting the methodology. These tests showed an accuracy of 0.2 C and a standard deviation of 1.3 C. Tensors were used to pull the rail to known tensions, as read by strain gauges, and the rail measured using .

VERSE

ºº

VERSE

In addition, tests were conducted under service conditions during which the rail was first checked with , and then cut and the SFT measured using strain gauges.

VERSE

Validation has since been carried out by other technical rail organisations. The Transportation Technology Centre Inc. (TTCI), Peublo, Colorado, conducted tests on large section American rails. Results indicated a mean error of 2.50ºF and a standard deviation of 1.170ºF.

The Railway Research Institute in Prague, Czech Republic, conducted validation of using similar techniques to TTCI and produced the results shown in the graph.

VERSE

A full Technical Pack including testimonials, approvals and test reports is available on our web page:

www.vortok.co.ukSelect the ‘Download Brochures’ option and follow the instructions

2005.02

FRAME

ADJUSTABLEJACK STRUT

JACK

PLUM BOB

LIFTHOOK

LOADTRANSDUCER

DISPLACEMENTTRANSDUCER

RAILCLAMP

unclipped

10m 10m 5m5m

VERSEsupportsupport

rail

Non-Destructive Neutral Temperature Measurement

Making a Measurement

The Equipment

VERSE

At points 10 metres each side of the centre point, the rail is lifted onto a rail support spacer. This leaves a 20 metre length of freely suspended rail.

The equipment is positioned over the central point, and the rail is jacked steadily to a load of 10 KN and monitored by a load transducer. D i s p l a c e m e n t i s s i m u l t a n e o u s l y monitored for each increment of load by another transducer attached to the rail.

VERSE

The software menu prompts the user to enter certain site specific data such as ambient railtemperature, rail profile and actual rail height.

The software then calculates the SFT directly. equipment is self calibrating for each lift

and the software is able to check the validity of each measurement. Time on site is between 20 and 30 minutes per rail depending on the type of rail fastening.

VERSE

The Software

The hand-held computer software guides the user through the measurement procedure, logs certain site specific data and produces a track side SFT result. The rail profile is easily selected from a drop down menu.

Data sets for each measurement can subsequently be uploaded to the PC software and stored in a database as a permanent record of ra i l network measurements and can be interrogated at any time.

VERSE

The comes ready assembled for positioning over the rail.Once the electrical connections have been made between the transducers, signal processor, battery pack and hand-held computer, measurement can commence.

VERSE equipment

Data can also be exported and analysed with other databases such as MS Excel or MS Access types where it can be integrated w i th o the r t rack da ta fo r m a i n t e n a n c e m a n a g e m e n t decision making.

Utilising nightpossession tomake VERSE measurements

PC Software

Measurement entails unclipping approximately 30 metres of rail.

The output from both transducers is sent to a hand-held computer.