Railway Track for the 21st Century

Lead Research Organisation: University of Southampton
Department Name: Faculty of Engineering & the Environment

Abstract

The majority of the world's railways - including all main lines in the UK - are currently on ballasted track. Although there have been developments in component specifications and materials, the principles of the system have changed little over the past 150 years. Ballasted track has generally been considered to offer the optimum solution in terms of construction cost, stiffness and drainage properties, and ease of modification: thus although more highly engineered track forms have been used (e.g. in Japan, Germany and China), ballasted track has been employed both for upgrades such as the UK West Coast Main Line and for new high speed lines including HS1 (UK), TGV (France) and AVE (Spain). However, the limitations of ballasted track as currently constructed are becoming more apparent and more significant as the demands placed upon it have increased. This has led to higher than expected maintenance requirements and costs, and demonstrates that a transformation in track performance - by retro-fit measures for existing ballasted track, or by an informed decision in favour of an alternative track system in the case of large-scale renewals - is essential if the Government's aspirations of reduced cost and increased capacity for rail transport are to be realised. This Programme Grant will bring about a step-change improvement in the engineering, economic and environmental performance of railway track making it fit for a 21st century railway, by developing new techniques for its design, construction and maintenance. By obtaining a better understanding of the behaviour of track components, the interactions between them and their response to external loading and environmental conditions, the performance of railway track can be significantly enhanced. Improved understanding will allow the development of more effective and efficient maintenance and renewal strategies, leading in turn to reduced costs, increased capacity and improved reliability. The Programme Grant will also enable a radical overhaul of current railway track design appropriate for both new build (e.g. HS2) and upgrades to meet current and future train loading requirements more efficiently than is at present possible. Meeting these challenges will require a coordinated programme of research to investigate how the various components of the track system relate to each other and to external factors. This will involve a series of inter-related experiments together with supporting mathematical and numerical modelling, field monitoring and observation. The outputs of these studies will feed into economic modelling work, leading to the production of a decision-support tool, for use by industry, to appraise the cost implications of using different track technologies in combination with specific external factors. The aims of this Programme Grant can only be achieved by combining a variety of skills and techniques. The research team therefore comprises world-leading engineers and scientists from different disciplines and universities, working together to apply their collective expertise. A well-defined organisational structure and adaptable methods of operation will together provide a high level of integration and synergy between the various research areas and activities; excellent communications between the researchers, institutions and industry partners; flexibility in the allocation and use of resources; agility and responsiveness in research direction; proactive management of risk; and ownership and early uptake of research results by industry.

Planned Impact

The results of the Programme Grant will directly benefit railway infrastructure owners and operators, and will have an immediate impact on practising railway engineers involved in the design, maintenance and renewal of railway track. A radical improvement in the understanding and performance of contemporary track technologies will also have substantial benefits for a wide range of stakeholders in the railway industry (including, but not limited to, builders and maintainers of vehicles, train operating companies, consultants, and those defining policy frameworks governing railway operations, standards and research), for users of rail transport, for government and ultimately for the whole of society. Benefits to academia are described in the main Case for Support. Infrastructure owners and operators and practising railway engineers involved in the design, maintenance and renewal of railway track will benefit from advances in the fundamental understanding of the railway track system and track technologies that will inform strategies for optimising engineering (reduced deterioration rates and maintenance frequency), environmental (lower noise and vibration, more efficient use of resources) and economic (lower maintenance and whole-life costs) performance. The Programme will make a contribution to the reduction of the whole-life costs and environmental impacts of new railways in time to ensure maximum value from the substantial investment being proposed in new and refurbished rail infrastructure (e.g. HS2). Industry stakeholders will benefit through improved business efficiency, increased volume of business (less maintenance will contribute to an increase in capacity) and reduced costs. Government will benefit from the Programme's contribution to meeting the DfT's Rail Industry Research Strategy targets on Cost, Capacity, Carbon and Customers, contributing to the modal shift to rail needed to achieve the UK's commitment to reduced CO2 emissions from transport. Customers - the travelling public and freight users - will ultimately benefit from improved levels of service, reduced delays and reduced costs. The whole of society will gain from the environmental (carbon) benefits of the modal shift from road to rail that increased capacity and attractiveness of rail transport will bring, and from an improved understanding of whole life environmental costs. Results and details of research in progress will be widely disseminated and engagement with industry stakeholders will be ensured so that research results are implemented. The plans for this are described in the Impact Plan.

Publications

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Abadi T (2016) Improving the performance of railway tracks through ballast interventions in Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit

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Abadi T (2019) Effect of Sleeper Interventions on Railway Track Performance in Journal of Geotechnical and Geoenvironmental Engineering

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Ahmed S (2016) Numerical modelling of railway ballast at the particle scale in International Journal for Numerical and Analytical Methods in Geomechanics

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Ajayi O (2017) A behavioural framework for fibre-reinforced gravel in Géotechnique

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Ajayi O (2017) Scaling relationships for strip fibre-reinforced aggregates in Canadian Geotechnical Journal

 
Description Our work on foundations has applied principal stress rotation (PSR), which represents the actual stress experienced by the soil during train passage more closely than the current industry standard test, and we have quantified the susceptibility of different soil types to failure in cyclic loading with PSR. We have shown that increasing train axle loads may cause old embankments to fail, and have developed quantitative design tools.

We are studying ballast and sleepers. A large number of complementary rig tests have been carried out at both Southampton (SSTF below) and Nottingham (RTF and box tests below) to investigate the effect of different ballast gradations and configurations, sleeper types, under-sleeper pads (USPs) and geogrid and fibre reinforcement:
• Box tests to determine effect of sleeper type, geogrid reinforcement and USP.
• RTF tests to determine effect of sleeper type.
• SSTF tests to determine effect of gradation, sleeper type, USP and ballast shoulder geometry.
• Triaxial tests to determine the effect of fibre reinforcement in scaled ballast; development of scaling laws to full size ballast.
In parallel, and partly to better understand and support the rig test results, DEM analyses using both the Southampton (potential particles) and Nottingham (PFC using clumps of spheres) approaches have been carried out:
• DEM analyses of triaxial tests of scaled ballast, to determine optimal simulation parameters and explore the effect of confinement.
• DEM analyses to understand the boundary effects involved in box tests vs RTF tests.
• DEM analyses of ballast settlement under cyclic loading.

In our work on noise and vibration, we have
• shown that dynamic stiffness of ballast depends strongly on preload whilst the effects of frequency and ballast depth are comparatively weak.
•shown variations in the dynamic stiffness of different sleeper types whilst under preload.
• shown that, in terms of noise, the absorption of the ballast appears to be of greater importance than its stiffness.
• measured ground vibration at five sites in the UK with differing track constructions to validate and improve prediction models. Shown that the soil types and layering tends to have a greater effect on the transmitted vibration than the ballast stiffness.
• shown that generally UK rail and wheel roughness is low compared with historic and standardized values.
• shown that track is noisier at higher temperatures due to lower pad stiffness, and found that renewed track was significantly noisier than unrenewed track due to softer pads. Under sleeper pads have a small but measureable effect on ground-borne vibration.
•shown clear differences in the propagation of vibration at critical velocity and subcritical velocity sites. A newly developed model has been optimised in terms of computation cost and performance with respect to model size, elements size and type.

Through integration of field studies, we have
•understood the extent and likely causes of problems at critical zones
•assessed the possible (and, potentially, the actual) effectiveness of interventions and component improvements in reducing maintenance requirements at critical zones
•improved numerical modelling techniques for transition and other critical zones
•improved approaches for vehicle and track instrumentation for monitoring transition zone and point performance

In our lab integration work area, we have brought together complementary experimental and numerical results generated by other parts of the programme, to determine
• the effect of sleeper type, geogrid or fibre reinforcement, and USP on ballast settlement and resilient behaviour.
• the stress state within the ballast due to typical traffic loads.
Exploitation Route We expect our findings to underpin a radical overhaul in techniques for railway track design, construction and maintenance.

This will be taken forward by the prime beneficiaries: the owners and managers of infrastructure - in the UK, Network Rail, London Underground Limited and HS1. Our findings will be incorporated into new guidance notes and manuals: in the case of Network Rail we hold strategic partnerships and are a member of a working group preparing maintenance guidance, and we have representatives of these and other potential users on our Industry Steering Group (ISG).

In addition to these users, HS2 is a significant potential beneficiary for new design and they too are closely engaged with the ISG. They and government will benefit from the new analytical techniques we have developed to inform decision-making.

Another key pathway to impact is that our results will be embedded in updates of industry standard software used for asset management decisions, such as VTISM (which models vehicle track interaction for whole life cost optimisation) and TWINS (which models rolling noise generation), and will thus be brought quickly into widespread use.

The new techniques and insights are available to the wider rail industry, such as component designers, who are already taking advantage of this (eg sleeper performance assessment for Progress Rail, a Caterpillar company).

Finally, our close engagement with the European Shift2Rail joint undertaking will continue to create consortia for taking this new knowledge forward into development and deployment across Europe and beyond.
Sectors Construction,Environment,Transport

URL http://www.track21.org.uk/
 
Description Track 21 has already influenced UK national rail policy. Early findings were used to inform the DfT's Rail Technical Strategy (RTS), which sets out a vision and strategy for rail to 2040. The RTS's vision is based on that articulated for Track 21, which it cites as an example of best practice for research and development. The RTS says, "Track 21 improves understanding of the complex mechanisms of railway track behaviour governing stiffness, robustness, longevity, noise and vibration performance to allow us to optimise the track system. These projects are undertaken in partnership with government, academic and industrial organisations to bring about improvements in capacity, infrastructure performance and sustainability by developing new design, construction, monitoring and maintenance techniques." Similarly, Network Rail's (NR's) Technical Strategy cites Track 21 as an enabler of its vision for infrastructure. We are represented on NR's Track Stiffness group and have prepared and published a Guide to Track Stiffness (ISBN 9780854329946). This Guide has been widely distributed in the industry (Network Rail alone have bought 650 copies) and is becoming de facto standard guidance in the UK. We are working with an industry partner to develop new track monitoring equipment for the Wessex rail alliance and have recently been contracted by Progress Rail UK to apply techniques developed in Track 21 to analyse the performance of their product. We are providing advice to London Underground Ltd on novel track forms. The three partner institutions have been made Strategic University Partners of NR, undertaking further work for application in the areas of infrastructure, data integration and asset management. Results from Track 21 are being used by HS2 to inform their decisions about trackform, particularly a decision yet to be made between ballast and rigid construction. Our techniques are being used in additional research on the HS1 track. Ideas generated by Track 21 have been adopted by the EU Horizon 2020 Shift2Rail call and we have established new overseas links and partnerships, for example with the Railway Technical Research Institutes in Japan (RTRI) and Korea (KRRI), Deutsche Bahn and SNCF.
First Year Of Impact 2012
Sector Construction,Environment,Transport
Impact Types Societal,Economic

 
Description Track Stiffness working group
Geographic Reach National 
Policy Influence Type Membership of a guideline committee
Impact Publication of Guide to Track Stiffness, a guide to good practice, co-authored by Prof William Powrie and Dr Louis Le Pen of University of Southampton. 650 copies of the guide have been purchased by Network Rail and distributed at a workshop, and it has therefore become de facto guidance to engineers maintaining the majority of the UK rail network. Copies have also been taken in small numbers by London Underground and consulting engineers in the rail industry.
 
Description In2Rail
Amount € 17,998,546 (EUR)
Funding ID 635900 
Organisation European Commission H2020 
Sector Public
Country Belgium
Start 05/2015 
End 04/2018
 
Description In2Track
Amount € 2,799,993 (EUR)
Funding ID 730841 
Organisation Network Rail Ltd 
Sector Private
Country United Kingdom
Start 09/2016 
End 02/2019
 
Description Roll2Rail
Amount € 16,000,000 (EUR)
Funding ID 636032 
Organisation European Commission H2020 
Sector Public
Country Belgium
Start 05/2015 
End 10/2017
 
Description Run2Rail
Amount € 2,732,464 (EUR)
Funding ID 777564 
Organisation European Commission H2020 
Sector Public
Country Belgium
Start 09/2017 
End 08/2019
 
Description Strategic University Partnership in Future Infrastructure Systems
Amount £567,000 (GBP)
Funding ID PO1496855 
Organisation Network Rail Ltd 
Sector Private
Country United Kingdom
Start 10/2013 
End 05/2015
 
Description UK Research Partnership Investment Fund (UKRPIF)
Amount £28,086,000 (GBP)
Organisation Higher Education Funding Council for England 
Sector Public
Country United Kingdom
Start 04/2018 
End 03/2020
 
Description UKCRIC Pump Priming Panel July 2017
Amount £1,013,092 (GBP)
Funding ID EP/R013535/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Academic/University
Country United Kingdom
Start 01/2018 
End 12/2019
 
Description Asphalt Track (field monitoring) 
Organisation Network Rail Ltd
Country United Kingdom 
Sector Private 
PI Contribution Design, develop and implement field monitoring and analysis techniques for existing areas of asphalt/ballast trackbed.
Collaborator Contribution Experience and access to field trials; some existing equipment being assessed for suitability.
Impact Improved understanding of the behaviour of asphalt trackbed under real life train loads.
Start Year 2018
 
Description Ballast or Slab? - Rail Technology Magazine 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact Editorial article for industry magazine on the arguments for and against using ballasted or slab track in high-speed rail. A summary of current thinking and research intended as a contribution to an ongoing debate in the industry, of contemporary relevance in the light of HS2. Aimed at the wider rail industry rather than research community.
Year(s) Of Engagement Activity 2017
URL http://t2f.org.uk/wp-content/blogs.dir/sites/5/2018/01/Ballast-or-slab-RTM-AUG-SEP-17-1.pdf
 
Description Ballasted railway track: reducing maintenance needs - Rail Technology Magazine 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact Authors of an op-ed piece in a widely read industry magazine considering the ways through which the economic and operational performance of ballasted track could be improved. Reporting on advances made through research led by Prof Powrie/Southampton over the last ten years, and looking forward. Aimed at practitioners and interested lay people.
Year(s) Of Engagement Activity 2017
URL http://t2f.org.uk/wp-content/blogs.dir/sites/5/2018/01/Ballasted-track-reducing-maintenance-needs-RT...
 
Description Distinguished Lecture by Andrew Wolstenholme, Crossrail 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Undergraduate students
Results and Impact The University hosted a Distinguished Lecture by alumnus Andrew Wolstenholme, OBE, the Chief Executive of Crossrail, on the project and generated a discussion about the better management of major engineering projects.
Year(s) Of Engagement Activity 2015
 
Description Dragonfly 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact This series of activities aims to attract and support women in a traditionally male-dominated discipline, including making engineering an attractive study path. Since the start of Track to the Future the Dragonfly outreach programme for young women at major education path decision points has reached 360 pupils and 29 teachers at 20 schools, and has been used to launch other events reaching a further ~150 pupils. These events frequently involve a laboratory tour and an introduction to testing ballast track systems.
Year(s) Of Engagement Activity 2015,2016,2017
URL https://www.southampton.ac.uk/engineering/outreach/dragonfly-day.page
 
Description IMechE Stephenson Conference 2015 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Three papers were presented at a major three day international conference in London organised by IMechE. One was a case study of the Track21 research programme and the other two on train-induced ground-borne vibration.
Year(s) Of Engagement Activity 2015
URL http://events.imeche.org/ViewEvent?code=C1408
 
Description Interview with Paul Clifton for Rail magazine 2013 (climate change) 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact Prof Powrie was interviewed and extensively quoted in an article by the BBC's transport correspondent, Paul Clifton, in the large circulation railway general interest magazine "RAIL". Reference was made to TRACK21, work on vegetation and embankment stability, and also on long term data.
Year(s) Of Engagement Activity 2013
 
Description Letter to Modern Railways Oct 2015 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Prof Powrie had a letter published in Modern Railways arguing the case for railway research in the UK, in response to a critical article in the Sept 2015 edition.
Year(s) Of Engagement Activity 2015
 
Description NR SUP group presentation week 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Participated in a five day event hosted by Network Rail at their Milton Keynes HQ. We presented practical outcomes and ongoing research with an emphasis on monitoring railway linear infrastructure. We participated in an exhibition during the week and made some contacts for further discussion and support for site monitoring.
Year(s) Of Engagement Activity 2015
 
Description RIA innovation conference 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact We participated in the Rail Research UK Association activity at the two-day Rail Industry Association Innovation conference. We provided and manned an exhibition stand and had a number of useful conversations with delegates, one of which led to a very positive comment on our work from the platform by the Chair of the Office of Rail Regulation. Others led to new contacts.
Year(s) Of Engagement Activity 2015
 
Description RIA innovation conference 2017 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact RIA, a rail industry body with a high membership rate among SMEs, held a two day innovation conference 15-16 March 2017. Three universities were invited, all partners in T2F, to exhibit and lead breakout sessions on how industry can engage with universities to drive innovation.
Year(s) Of Engagement Activity 2017
 
Description RRUKA annual conference 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Presented two papers and participated in an exhibition to showcase the work of the Rail Research UK Association. The exhibition stands were particularly successful and generated a lot of interest, particularly in work on cleaning leaf debris from the wheel/rail interface, and good engagement with the specialist media.
Year(s) Of Engagement Activity 2014,2015
URL http://www.rruka.org.uk/wp-content/uploads/2015/05/Annual-Conference-2015-Programme-FINAL.pdf
 
Description Rail Review: Paul Clifton on transport policy 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact Prof Powrie was interviewed by the respected journalist Paul Clifton, the only academic among other senior figures in transport, for a substantial article in Rail Review on how the UK's infrastructure will be affected by a rapidly evolving society.
Year(s) Of Engagement Activity 2017
URL http://t2f.org.uk/wp-content/blogs.dir/sites/5/2018/01/Q2-2017-Clifton-A-Vision-for-Transport-1.pdf
 
Description SOTSEF 2017 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact The annual Southampton Science and Engineering Day attracted 7,000 visitors in 2017. Some 140 interactive exhibits and activities, run by hundreds of staff and student volunteers, make this an important outreach targeting primarily school age children to interest them in a future in science and engineering. Several exhibits have a railway or geotechnical theme, including custard rolling, experiments on railway noise and vibration using lego, tribology, railway networks and engineering using railway models and Minecraft, wind tunnels, anechoic and reverberant chambers, and many more.
Year(s) Of Engagement Activity 2017
URL https://www.southampton.ac.uk/per/university/festival/index.page
 
Description Science and Engineering Day 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact This is a major "open day" event aimed attracting some 4,000 people to the main campus. Most are children of primary or secondary school age. A wide range of interactive, "hands-on" engineering and science activities is presented over six hours by undergrad and postgrad volunteers. In 2014, we won a National Science and Engineering Week award for Best STEM institution event.
Year(s) Of Engagement Activity 2014,2015
URL http://www.southampton.ac.uk/per/university/festival/index.page
 
Description Slope Engineering and Geotech Asset Management Conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact Speaking at a two-day conference bringing together asset owners, engineers and contractors to share best practice in solving recent failures and discuss solutions for futureproofing assets. The subject was "the role of technology in managing geotechnical assets and mitigating risks on the UK rail network."
Year(s) Of Engagement Activity 2015
 
Description T21 key findings to RIA 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact The PI made a presentation on the key findings of the TRACK21 programme (first 4.5 years) to the Rail Industry Association infrastructure technical meeting. The audience comprised mainly track and infrastructure engineers from the rail supplier and contractor community, with customers throughout the UK and overseas. This gave rise to an invitation to participate in future events.
Year(s) Of Engagement Activity 2015
 
Description T21/T2F article in Railway Gazette International 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact 5 page article in Railway Gazette International by Prof Powrie, describing the findings of Track21 and setting out the plans for Track to the Future and other associated work.
Year(s) Of Engagement Activity 2015
 
Description TRACK21 dissemination event at Network Rail, Milton Keynes 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact The key dissemination event for the outputs from TRACK21 to Network Rail technical staff at their headquarters. The PI and many of the Co-investigators presented new discoveries and case studies and led a discussion of real problems and practical applications. An exhibition was held in the communal area of this large facility where Network Rail staff were able to obtain more detailed information and discuss the findings with the researchers. A number of NR staff remarked on the value of these new insights.
Year(s) Of Engagement Activity 2015
URL http://track21.org.uk/wp-content/blogs.dir/sites/4/2015/08/150722-NR-The-Quadrant-22-July-2015-final...
 
Description VT/SIC presentation of TRACK21 outputs 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Presentation of Track21 outputs to the annual seminar of the Rail Safety and Strategy Board's Vehicle/Track Systems Interface Committee.
Year(s) Of Engagement Activity 2015
 
Description WP TV interview - Paul Clifton 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact (Feb 2014) BBC transport journalist Paul Clifton interviewed Prof Powrie about risks to and maintenance of rail infrastructure. This was picked up and led to a further interview for BBC breakfast.
Year(s) Of Engagement Activity 2014