Centre of Excellence in Rail Decarbonisation

We are delving deeper to understand the factors which affect exactly how much energy trains use and need.

Our group of researchers are experts in all aspects of railway traction and propulsion systems, and we do this through our research and application focussed projects. Our most notable recent success is the partnership with Porterbrook, together with other specialist companies, to develop and deliver the HydroFLEX train. This is the UK’s first Hydrogen-powered train, where we use electricity produced by a Hydrogen fuel cells instead of overhead wires or a diesel engine.

Much of the focus of this theme uses basic physics and the principles behind low-cost energy. We make use of the fact that energy is only ever transferred, not created, to see how we exploit this for the benefit of moving trains. It is easy to get a train moving due to its low rolling resistance, meaning energy put into the train by the traction system gets very efficiently transferred into kinetic energy. When the train needs to brake we can collect this using regenerative braking to return it to the electricity supply network or to store it in batteries on the train, to use again when the train needs it to accelerate.

The railway uses both electricity and diesel as sources of energy for traction. In the future, however, diesel will become less and less popular as governments around the world work on meeting their climate change commitments. Sustainable Traction Systems research investigates how we can provide sufficient low-carbon energy to run the world’s railways. Hydrogen is an alternative energy carrier which can be used to provide energy. When produced through electrolysis using renewable electricity, a hydrogen fuel cell can be zero-carbon and thereby contribute to meeting global decarbonisation objectives.

The lead academic for Sustainable Traction Systems is Dr Stuart Hillmansen:

Research areas include:

• Novel Traction Systems for Sustainable Railway Futures in low-income countries (LICs)
• FOAK 3 HydroFLEX Mainline Testing and Approvals
• FOAK 4 HydroFLEX Development of a raft production design
• Optimisation of train traction energy reduction (OTTER) in partnership with Ricardo Rail to deliver energy savings in Light Rail applications
• Network Rail Remote Earth Monitoring for 25 kV and 750 DC systems
• Network Rail Signalling Power Supply Monitoring – developing techniques for fault identification and location in signalling power supply cables
• Research and Demonstration on metro energy saving key technology based on multiple objectives in Singapore SMRT
• Powertrain: Fuel Cell Electric Multiple Unit (FCEMU) concept design work for RSSB
• Optimisation of energy consumption of train traction for Guangzhou Metro Line 7
• Partnering with G-Volution on the application of dual fuelling locomotives for carbon and emissions reduction

Work with us

If you would like to get in touch, please email: railway@contacts.bham.ac.uk.

Rail decarbonisation requires primarily the introduction of electric trains and electrical power infrastructure with improved energy efficiency.

The rail industry’s carbon footprint derives from energy used for traction i.e., running trains and non-traction equipment such as stations, operations, signalling systems, and using electricity generated mostly from burning fossil fuels. The energy consumption from fossil fuels can be reduced by controlling with power converters the power flows between networks for traction and those for non-traction use. The control of the converters exploit synergies between the two networks, utilising the regenerative braking of trains for the local public grid and supporting of the traction network with renewable energy sources. Our researchers are experts in all aspects of power electronics for railway systems, and we are involved in a large number of UK and international projects. One of our recent successes in this area is developing and delivering a new smart soft open point in collaboration with Metro de Madrid and other European academic and industrial partners.

We are also investigating the use of high voltage DC for rail electrification systems, exploring solutions to embed electric railways in micro grids fed by renewable power sources. Railways will be able to play an even more important role in future transport systems if they can be more integrated with road transport. There is an evident opportunity to integrate electric railways with electric mobility to achieve 100% clean journeys. This would be facilitated by adding a sufficient number of charging points at railway station car parks and by using clean electricity sources such as solar photovoltaics to generate electricity.

The lead academic for Power electronics and energy is Dr Pietro Tricoli.

Research areas

• Boost-inverters for fuel cell trains
• Hybrid power trains with fuel cells and batteries using dual three-phase machines
• Power converters for battery trains with integrated battery management systems
• Traction substations with static frequency converters
• Medium voltage DC railways
• Inverting substations for DC railways
• Smart Soft Open Points for electric railways and power distribution grids
• Rail-to-grid energy management systems
• Vehicle-to-grid to feed station and signalling loads
• Fast charging of electric vehicles from traction power supply

Work with us

If you would like to get in touch, please email: railway@contacts.bham.ac.uk.

The railway infrastructure is a significant proportion of rail’s carbon footprint and provides us with ample opportunity to consider:

• Lower-carbon materials and designs
• Managing assets more effectively
• Using AI and data science to underpin decision-making
• Applying whole-systems-thinking to the railway

The following research themes have been identified to support the movement of decarbonising the railway:

Sustainable smart materials

Development of eco-friendly construction and railway materials that enhance cleaner and lower-carbon infrastructures. Enabling low-carbon materials such as high-damping and self-healing concrete, 3D printing composites, self-sensing materials that can monitor cracks and damage, and using advanced simulations, AI and data science, to understand problems that vibration cause.

Lifecycle performance and forensics

We have embarked on a sustainability-based management of infrastructures throughout the whole asset life. Forensic investigations in each phase of the lifecycle – through design, construction, operation, maintenance and disposal of infrastructure assets. This research will enable the decarbonisation of infrastructures and assets that strike the economic, social and ecological balances. This research has been instrumental in establishing a new ISO Standard for the recycling of rolling stock.

Infrastructure engineering, resilience, reliability and risk

Analysing and quantifying design reliability, taking into account safety, risk and uncertainty, allows engineers to design, construct and maintain infrastructure for operational readiness and resilience in uncertain settings. Innovative solutions to extreme events and uncertain demands, combines theory with practice: structural mechanics and principles of dynamics with field measurements and laboratory experiments, in order to determine robustness, vulnerability and resilience of materials, components and structures.

Research areas include:

• Sustainable and smart materials
• Infrastructure engineering and resilience
• Reliability, risk and uncertainties
• AI and data sciences
• Net zero buildings
• Noise and vibration mitigation
• Systems thinking for greener infrastructures

If you would like to get in touch, please email: railway@contacts.bham.ac.uk.

Extreme weather events of many types regularly affect railway infrastructure and the provision of train services across the UK.

If the UK is due to have hotter, drier summers and warmer, wetter winters in the future, how will this affect the railway network and how can we adapt to these changes?

These are the two key questions that lead our research.

Resilience is the ability of a system, the railway network, to reliably resist and recover from the effects of external disrupting factors such as weather and climate change. This includes having sufficient redundancy to absorb the impact and recover quickly, resuming normal operations; or being able to reroute and redeploy workers and equipment to make repairs wherever required.

The physical resilience of rail infrastructure is a topic that has been investigated here at BCRRE for over ten years. By improving our understanding of the effects of extreme weather on rail infrastructure we can begin to develop ways of redesigning and adapting the railways to resist the impact of weather, creating reliable railway infrastructure for the future. The operational resilience of train services in the UK focuses particularly on investigating delay propagations. If one train is affected by one incident and is delayed, this can affect the whole network.

Research areas include:

• TRaCCA – investigating the risks associated with extreme weather events and climate change and the impact these will have on our railway networks in the future.
• Rail Adapt project – developed a comprehensive adaptation framework, to support the rail industry in improving their processes for adapting its infrastructure.
• SIRMA – to develop risk models, mitigation, and resilience-based decision support tools utilising a systems of systems approach. This ensures that transport infrastructure along Atlantic coastlines is resilient under future climates to a variety of fast-acting (e.g., storm) and slow-acting (e.g., corrosion) hazards.

If you would like to get in touch, please email: railway@contacts.bham.ac.uk.

Improvement in aerodynamic efficiency of a train can lead to significant reductions in the amount of fuel required, helping to meet decarbonisation targets.

These effects are not only apparent for high-speed passenger trains but also slower moving freight trains, which are traditionally highly bluff-shaped vehicles with little aerodynamic consideration. Better understanding of these key aerodynamic parameters can improve train modelling simulations, leading to better train pathing diagrams and timetables. This will undoubtedly improve train management leading to less fuel consumption and greater efficiency.

Unlike other vehicles, it is not only the aerodynamic drag that is important for trains, however. The highly turbulent aerodynamic flows created with large velocity and pressure magnitudes can create safety issues when interacting with passengers waiting on platforms or trackside workers, railway infrastructure when passed by the train (such as noise barriers and hoardings), or through interactions with local wind conditions which may result in train instabilities, which in the worst case scenario can lead to overturning. There are also issues related to pressure waves created as a train enters into a tunnel, which can cause effects ranging from aural discomfort for passengers to micro-pressure waves exiting the tunnel as sonic booms.

Related to the theme of decarbonisation is that of pollution dispersion.

Exhaust emissions from diesel rolling stock will be directly influenced by the aerodynamic flow surrounding moving vehicles, potentially leading to the intake of pollutants back into the train through the air conditioning intakes.

The lead academic for Areodynamics is Dr David Soper.

Research areas include:

• Aerodynamic drag and slipstream velocity measurements
• Static pressure pulse measurements and sonic boom
• Pressures acting on the train
• The effects of crosswinds at various yaw angles, train effects and local wind environment analysis
• Aerodynamic pressures acting on trackside structures, effects of a train passing through a tunnel and effects due to train design and size
• Design optimisation
• Aerodynamic loads affecting ballast flight and slab track running
• Pollutant dispersion

If you would like to get in touch, please email: railway@contacts.bham.ac.uk.

Our railway geotechnical engineering and asset management research involves:

• The whole life cycle assessment under uncertainty of railway track designs, maintenance schemes and strategies
• Novel approaches for building new railway track and maintaining existing track
• Providing tools to facilitate railway asset management decision-making

Through our life cycle analysis under uncertainty research we have developed an approach to appraise railway track investment that considers life cycle costs and benefits to infrastructure owners, train operators, users and the environment.

Our research into innovative solutions for track design and maintenance is founded on understanding the effects of stochastic dynamic train loads on railway track and soil behaviour via numerical modelling and laboratory experimentation and, thereby developing solutions using micro-piling, sandgrips, under-sleeper pads and geotextiles.

Good track drainage is fundamental to the proper functioning of the railway track. However, railway drainage asset management is challenging because it involves the consideration of large interconnected assets, limited maintenance budgets, and unknown failure probabilities.

To address this, we are developing new low-carbon drainage products and risk analysis decision support systems to enable effective drainage asset management at the strategic, tactical and operations levels.

Fundamental research into the above aspects is carried out by our cohort of PhD students. Their work feeds into the products of our research that are used by the industry worldwide.

Research projects include:

• A Risk-Informed Whole Life Cost Tool for Railway Design and
• Maintenance Appraisal (RiTRACKTM)
• Risk-based models for maintenance and renewal of drainage
• Use of innovative low-maintenance materials for drainage componentsInvestigation into the effectiveness of geotextiles in railway track foundations
• Improving the stiffness of railway track using micro-piles and under-sleeper pads
• Improving the Stiffness of Existing Railway Track (ISERT)

If you would like to get in touch, please email: railway@contacts.bham.ac.uk.