TRACK SYSTEMS FOR HIGH SPEED RAILWAYS: GETTING IT RIGHT

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

Abstract

Train speeds have steadily increased over time through advances in technology and the proposed second UK high speed railway line (HS2) will likely be designed with "passive provision" for future running at 400 km/hour. This is faster than on any ballasted track railway in the world. It is currently simply not known whether railway track for speeds of potentially 400 km/hour would be better constructed using a traditional ballast bed, a more highly engineered trackform such as a slabtrack or a hybrid between the two. Although slabtrack may have the advantage of greater permanence, ballasted track costs less to construct and if the need for ongoing maintenance can be overcome or reduced, may offer whole-life cost and carbon benefits. Certain knowledge gaps relating to ballasted track have become apparent from operational experience with HS1 and in the outline design of HS2. These concern
1. Track Geometry: experience on HS1 (London to the Channel Tunnel) is that certain sections of track, such as transition zones (between ballasted track and a more highly engineered trackform as used in tunnels and on bridges) and some curves require excessive tamping. This results in accelerated ballast degradation and increased ground vibration; both have an adverse effect on the environmental performance of the railway in terms of material use and impact on the surroundings. Thus the suitability of current design rules in terms of allowable combinations of speed, vertical and horizontal curve radius, and how these affect the need for ongoing maintenance to retain ride quality and passenger comfort is uncertain.
2. Critical velocity: on soft ground, train speeds can approach or exceed the speed of waves in the ground giving rise to resonance type effects and increased deformations. Instances of this phenomenon have been overcome using a number of mitigation measures such as the rebuilding of the embankment using compacted fill and geogrids, installation of a piled raft and ground treatment using either deep dry soil mixing or controlled modulus columns. The cost of such remedial measures can be very high, especially if they are taken primarily on a precautionary basis. However, many methods of analysis are unrefined (for example, linear elastic behaviour is often assumed or the heterogeneity of the ground, track support system and train dynamics are neglected), and conventional empirical methods may significantly overestimate dynamic amplification effects. Thus there is scope for achieving considerable economic benefits through the specification of more cost effective solutions, if the fundamental science can be better understood.
3. Ballast flight, ie the potential for ballast particles to become airborne during the passage of a very high speed train. This can cause extensive damage to the undersides of trains, and to the rails themselves if a small particle of ballast comes to rest on the rail and is then crushed. Investigations have shown that ballast flight depends on a combination of both mechanical and aerodynamic forces, and is therefore related to both train operating conditions and track layouts, but the exact conditions that give rise to it are not fully understood.
The research idea is that, by understanding the underlying science associated with high speed railways and implementing it through appropriate, reasoned advances in engineering design, we can vastly improve on the effectiveness and reduce maintenance needs of ballasted railway track for line speeds up to at least 400 km/h.

Planned Impact

The primary output of the research will be a detailed understanding of the performance of high speed ballasted track technologies. This will have substantial benefits for a wide range of stakeholders in the railway industry, including the infrastructure managers for HS1, engineers associated with the design and build of HS2 and the potential upgrade of parts of the existing UK rail network to a speed of 225 km/hour, and other practising railway engineers and consultants involved in the design, maintenance and renewal of high speed railway track. The research will also benefit other industry bodies including, but not limited to, train vehicle manufacturers, train operating companies, and those defining policy frameworks governing railway operations, standards and research. It will also benefit the users of rail transport, government and ultimately the whole of society.

Publications

10 25 50
 
Description 1 The measurements of track displacement and ballast acceleration coupled with full scale measurements by University of Birmingham of flow velocity and pressure beneath trains, have revealed the complex nature of the forces on ballast particles during the passage of trains. In particular initial analysis of the results suggests that accelerations due to the passage of trains are much larger than those induced by aerodynamic effects.
2 The use of moving model tests and CFD analysis to measure the flow velocities and pressures beneath trains shows a high level of agreement with the full scale data and offers possible way forward for train homologation.
3 The role of poor track support conditions in component defects has been studied and new monitoring systems using low-cost MEMS accelerometers have been developed. This has included novel methods of signal processing to automatically interpret data, and to assess the track support stiffness without needing to know the train weight / axle load. Track defects on HS1 have been analysed and improved maintenance techniques have been trialled and proved.
4 A multi-body vehicle model has been developed to predict the effect of changed in track geometries and speed on ride comfort.
5 New insights into the management of ballast flight on high speed railways have been obtained
Exploitation Route Results have been used to improve maintenance practices on HS1 and to inform design details (track form, location and type of under track crossings) on HS2; and have the potential to be used on other high speed railways .
Sectors Construction,Transport

 
Description Findings from this award have been and are being used by track engineers from HS1 to inform their maintenance decisions; and have been used by HS2 to inform decisions on, for example, the nature and depth of under track crossings (UTX) and the track form adopted for Phases 1 and 2. Field data have informed and been used a case studies in the cross industry "Guide to Track Siffness", published in August 2016 (c 1000 copies sold or distributed to Network Rail, LUL and elsewhere worldwide)
First Year Of Impact 2015
Sector Construction,Transport
Impact Types Economic

 
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 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 UKRRIN Centre of Excellence in Infrastructure 
Organisation AECOM Technology Corporation
Department AECOM, Nottingham, UK
PI Contribution Expertise and intellectual input to underpin innovation in railways, either by developing novel discoveries arising from UKRI-funded research or applying these new insights to address industry challenges. This may include access to data, equipment or facilities either in our laboratories or to enable field monitoring.
Collaborator Contribution Cash funding to support laboratory tests and field measurements. Access to sites; provision of materials. Membership of industry steering groups. Pathways to impact. IN addition, we have received via the University of Birmingham a contribution of £910,000 for equipment (partner not listed above). This is part of the £28.1M reported by UoB as HEFCE (now UKRI) funding for UKRRIN and is not included here to avoid double counting. It is the amount passported by UoB to the University of Southampton.
Impact This partnership underpins collaborations listed separately in this section; the first, and to date the only, project with an output is the laboratory testing of asphalt track for AECOM.
Start Year 2018
 
Description UKRRIN Centre of Excellence in Infrastructure 
Organisation Heriot-Watt University
Country United Kingdom 
Sector Academic/University 
PI Contribution Expertise and intellectual input to underpin innovation in railways, either by developing novel discoveries arising from UKRI-funded research or applying these new insights to address industry challenges. This may include access to data, equipment or facilities either in our laboratories or to enable field monitoring.
Collaborator Contribution Cash funding to support laboratory tests and field measurements. Access to sites; provision of materials. Membership of industry steering groups. Pathways to impact. IN addition, we have received via the University of Birmingham a contribution of £910,000 for equipment (partner not listed above). This is part of the £28.1M reported by UoB as HEFCE (now UKRI) funding for UKRRIN and is not included here to avoid double counting. It is the amount passported by UoB to the University of Southampton.
Impact This partnership underpins collaborations listed separately in this section; the first, and to date the only, project with an output is the laboratory testing of asphalt track for AECOM.
Start Year 2018
 
Description UKRRIN Centre of Excellence in Infrastructure 
Organisation Loughborough University
Country United Kingdom 
Sector Academic/University 
PI Contribution Expertise and intellectual input to underpin innovation in railways, either by developing novel discoveries arising from UKRI-funded research or applying these new insights to address industry challenges. This may include access to data, equipment or facilities either in our laboratories or to enable field monitoring.
Collaborator Contribution Cash funding to support laboratory tests and field measurements. Access to sites; provision of materials. Membership of industry steering groups. Pathways to impact. IN addition, we have received via the University of Birmingham a contribution of £910,000 for equipment (partner not listed above). This is part of the £28.1M reported by UoB as HEFCE (now UKRI) funding for UKRRIN and is not included here to avoid double counting. It is the amount passported by UoB to the University of Southampton.
Impact This partnership underpins collaborations listed separately in this section; the first, and to date the only, project with an output is the laboratory testing of asphalt track for AECOM.
Start Year 2018
 
Description UKRRIN Centre of Excellence in Infrastructure 
Organisation Pandrol UK
Country United Kingdom 
Sector Private 
PI Contribution Expertise and intellectual input to underpin innovation in railways, either by developing novel discoveries arising from UKRI-funded research or applying these new insights to address industry challenges. This may include access to data, equipment or facilities either in our laboratories or to enable field monitoring.
Collaborator Contribution Cash funding to support laboratory tests and field measurements. Access to sites; provision of materials. Membership of industry steering groups. Pathways to impact. IN addition, we have received via the University of Birmingham a contribution of £910,000 for equipment (partner not listed above). This is part of the £28.1M reported by UoB as HEFCE (now UKRI) funding for UKRRIN and is not included here to avoid double counting. It is the amount passported by UoB to the University of Southampton.
Impact This partnership underpins collaborations listed separately in this section; the first, and to date the only, project with an output is the laboratory testing of asphalt track for AECOM.
Start Year 2018
 
Description UKRRIN Centre of Excellence in Infrastructure 
Organisation Progress Rail Services UK Ltd
Country Unknown 
Sector Private 
PI Contribution Expertise and intellectual input to underpin innovation in railways, either by developing novel discoveries arising from UKRI-funded research or applying these new insights to address industry challenges. This may include access to data, equipment or facilities either in our laboratories or to enable field monitoring.
Collaborator Contribution Cash funding to support laboratory tests and field measurements. Access to sites; provision of materials. Membership of industry steering groups. Pathways to impact. IN addition, we have received via the University of Birmingham a contribution of £910,000 for equipment (partner not listed above). This is part of the £28.1M reported by UoB as HEFCE (now UKRI) funding for UKRRIN and is not included here to avoid double counting. It is the amount passported by UoB to the University of Southampton.
Impact This partnership underpins collaborations listed separately in this section; the first, and to date the only, project with an output is the laboratory testing of asphalt track for AECOM.
Start Year 2018
 
Description UKRRIN Centre of Excellence in Infrastructure 
Organisation University of Nottingham
Country United Kingdom 
Sector Academic/University 
PI Contribution Expertise and intellectual input to underpin innovation in railways, either by developing novel discoveries arising from UKRI-funded research or applying these new insights to address industry challenges. This may include access to data, equipment or facilities either in our laboratories or to enable field monitoring.
Collaborator Contribution Cash funding to support laboratory tests and field measurements. Access to sites; provision of materials. Membership of industry steering groups. Pathways to impact. IN addition, we have received via the University of Birmingham a contribution of £910,000 for equipment (partner not listed above). This is part of the £28.1M reported by UoB as HEFCE (now UKRI) funding for UKRRIN and is not included here to avoid double counting. It is the amount passported by UoB to the University of Southampton.
Impact This partnership underpins collaborations listed separately in this section; the first, and to date the only, project with an output is the laboratory testing of asphalt track for AECOM.
Start Year 2018
 
Description UKRRIN Centre of Excellence in Infrastructure 
Organisation University of Sheffield
Country United Kingdom 
Sector Academic/University 
PI Contribution Expertise and intellectual input to underpin innovation in railways, either by developing novel discoveries arising from UKRI-funded research or applying these new insights to address industry challenges. This may include access to data, equipment or facilities either in our laboratories or to enable field monitoring.
Collaborator Contribution Cash funding to support laboratory tests and field measurements. Access to sites; provision of materials. Membership of industry steering groups. Pathways to impact. IN addition, we have received via the University of Birmingham a contribution of £910,000 for equipment (partner not listed above). This is part of the £28.1M reported by UoB as HEFCE (now UKRI) funding for UKRRIN and is not included here to avoid double counting. It is the amount passported by UoB to the University of Southampton.
Impact This partnership underpins collaborations listed separately in this section; the first, and to date the only, project with an output is the laboratory testing of asphalt track for AECOM.
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 Countryfile Live 2016 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Participation in the high profile inaugural BBC Countryfile Live event 4-7 August 2016 at Blenheim Palace. As part of the science exhibit run by the University of Southampton, we took an exhibit concerning airflow around ballast particles and issues of ballast flight associated with ballasted track for high speed rail. Number of visitors is not know to us but it was substantial (in the thousands) and we benefited from association with a very well known brand.
Year(s) Of Engagement Activity 2016
 
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 HS1 presentation - T400 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact Presentation to Network Rail High Speed staff on the findings to date in the areas of
• Mitigation measures used to control, manage and predict deterioration rate of repeat geometry defects
• Dynamic structure response and its effect on track stability and maintenance
• Ballast flight beneath trains - aerodynamic and geotechnical measurements
Year(s) Of Engagement Activity 2015
 
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 MAFEX Spanish railways visit 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact Fact finding visit by Spanish railway industry delegates to find how the UK industry and academia engage. They were given presentations on engineering research and education at Southampton, and on the UK Rail Research and Innovation Network, and a tour of facilities.
Year(s) Of Engagement Activity 2018
 
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 
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 2017,2018
 
Description RTRI Japan track engineers' workshop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Hosted a workshop on railway track maintenance, with 5 papers by University of Southampton, 3 by other UK universities and 8 by Japanese delegates. The purpose was to advance knowledge and improve practice in the engineering of ballasted railway track. The papers were subsequently circulated to all delegates and more widely shared in the Rail Technical Research Institute, Japan.
Year(s) Of Engagement Activity 2018
 
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