The illuminated pantograph on the ICE-S test train in Germany.
Delivery of energy to rolling stock through high-voltage overhead lines is the predominant distribution method used on many of the world’s railways. Indeed, this has become the primary choice, particularly on high-speed, high-profile routes. Ensuring consistent contact at the interface between the pantograph on the train and the overhead line is of fundamental importance to almost every aspect of operation. If this contact is broken, so is the energy supply.
Deutsche Bahn’s ICE-S test train is fitted with a system for contact wire inspection very similar to that which will be used by Network Rail (DB/Hannes Frank)
To ensure a reliable energy supply, where the carbon strips are in constant contact with the overhead wire, it is important that the pantograph and overhead line specifications are appropriately matched. Furthermore, ensuring that the equipment performs as specified, day in – day out, is of fundamental importance in ensuring smooth and safe running, minimising the costly delays of overhead line (OHL) failures.
Simulation and monitoring
Determining conformance with the design requirements is the first stage of ensuring continuing correct system performance.
The initial stage is to perform a simulation of the whole system – train and infrastructure. European standard EN50318 covers simulations of the dynamic interaction between pantograph and overhead line and such a simulation will provide confidence that the current collection system will perform as designed.
At this stage, it is also possible to determine the worst-case vehicle configuration. Normally, for multiple units, this usually happens to be when units have been coupled together, resulting in two pantographs being in close proximity. It is possible to define a homologation test strategy for the system and the expected vehicle configuration.
Firstly, the test pantograph needs to be suitably instrumented and its ‘measurement system’ calibrated according to European standard EN50317. In Germany, DB Systemtechnik (DBST) does this in its laboratory in Munich, which houses its calibrated test rig.
The test rig in DB’s Munich laboratory (DB)
During homologation testing, according to the requirements of various TSIs (technical specifications for interoperabity), including ENE (energy), LOCPAS (locomotive and passenger) and European standard EN50367, on-board engineers monitor the interaction of the pantograph with the overhead line. This testing normally starts with test engineers being located at a test track in mainland Europe, followed by specific route testing in the country concerned. So for the UK, for example, DBST and ESG Rail have been supporting Hitachi Rail Europe with the testing and commission of its new trains for the Intercity Express programme, and this has involved pantograph and OHL testing.
Contact forces, accelerations, height and stagger are all monitored, and it is normal to include a speed and location system to ensure that the location of the captured data is accurately recorded.
Engineers monitor the interaction between the pantograph and overhead line. As part of the testing, they also determine the contact forces between the pantograph and overhead line, as well as the aerodynamic performance in each direction of travel and the directional flow.
A test pantograph similar to the one which will be used on the MENTOR test coach (DB)
In-service trains
The same technologies can be deployed, in a very similar manner, on passenger trains in service, albeit the equipment is capable of unattended operation without the requirement for operator intervention.
This provides a wealth of monitoring data, on a daily basis, simply as a consequence of passenger operations. Collected data is transmitted off-board for data interrogation and analysis purposes.
Occasionally, the system’s video image capture and analytics capability is also required. This involves the addition of high-resolution cameras and lighting to enable the system to operate in poor light conditions and at night. The additional benefit here is that the operator gets to make use of analytics software that provides additional data and analysis and is capable of identifying infrastructure anomalies.
The illuminated pantograph on the ICE-S test train in Germany (DB/Matthias Vogt)
The true benefits of this monitoring lie in the early detection of vulnerabilities in the catenary system, providing warnings of impending infrastructure failures. This leads to:
Fewer incidents, leading to improved safety;
Avoidance of costly and time-consuming repairs to infrastructure and trains;
Improved passenger services and confidence.
One of the most important benefits, and one that is often overlooked, is the ability to ‘learn’ from such events by understanding the root causes of any incidents. Knowing this is essential to the elimination of future and repeat failures of the same type.
New contract
At the beginning of November, ESG Rail announced that it has received a new contract from Network Rail for overhead line monitoring. DBST will provide the overhead line monitoring equipment, which has the capability to measure a number of interface attributes, most notably contact force, as well as contact wire height and stagger (lateral alignment). There are also a number of other supporting data channels that will be collected during operation.
Initially, the focus will be to deploy two monitoring systems onto Network Rail’s Mobile Electrical Network Testing, Observation and Recording (Mentor) test coach.
Network Rail’s asset information services team is responsible for monitoring the condition of the UK’s railway infrastructure and reporting condition exceedances to the route asset managers and maintenance teams. This delivers compliance with standards and supports maintenance planning for safe network operation. Network Rail has a number of dedicated vehicles deployed across the network on a periodic basis, with Mentor dedicated to overhead line monitoring.
Following the fitment on Mentor, ESG Rail will then install a single system onto a Class 390 Pendolino unit to cover a specific area of the network. This system will provide data on a daily basis, via normal passenger train service operation. The regular collection and assessment of asset condition data will support Network Rail’s ambition to move towards a ‘predict and prevent’ maintenance approach.
Kevin Hope, principal engineer – mobile monitoring, explained: “As well as enabling a transition to more predictive maintenance regimes, this contract is the starting point for Network Rail’s strategy to use in-service passenger vehicles to make dynamic measurements of the overhead line at 125mph – something that isn’t possible using just Mentor, which is limited to 100mph. In addition, the use of EN compliant systems will also enable commissioning of new OLE infrastructure in accordance with the TSI.”
The monitoring system will measure the force between the contact wire and pantograph carbon strips, via high fidelity sensors mounted directly to the pantograph head. All sensors will be subject to a thorough calibration process at DBST’s laboratory in Munich, Germany, before they are deployed in the UK.
The programme will see the Mentor systems operational towards the end of 2019, with the Class 390 deployment scheduled for a few months later. While all three systems will be fundamentally the same, additional equipment will be fitted onto the Class 390 unit to allow for the tilting capabilities of this fleet.
Commenting on the importance of this new arrangement, Nick Goodhand, managing director of ESG Rail, said: “One of the key infrastructure to vehicle interfaces is the contact between the overhead line and the train’s pantograph. Because traction energy is supplied via this interface, on-going, correct operation is essential for maintaining service performance. Failures at this interface can be catastrophic, with extensive service disruption and significant financial consequences.”
“So this is a landmark project, and we recognise the important role that ESG Rail and DB Systemtechnik will play in supporting Network Rail’s asset management team.”
Written by Martin Loibl and Kevin Dilks of DB Systemtechnik/ESG
Virgin Trains Pendolino running through Bolton station.
One of Virgin’s Class 390 Pendolinos has become the first electric train to run between Manchester and Preston via Bolton.
On the night of 13 December 2018, the train was used to test the new infrastructure along the 25-mile route via Salford, Bolton and Chorley, closely monitored by Network Rail engineers checking the new overhead power lines.
Virgin Trains Pendolino running through Bolton station.
The test runs are taking place in two phases. These first runs will be used to check that the new electrical infrastructure works correctly, while a second set of tests in early January will check that the infrastructure can handle trains running at full linespeed.
As part of the Great North Rail Project, the rail industry’s joint programme to transform train travel for customers through track and train upgrades, the Manchester-Preston upgrade will give Northern and TransPennine Express customers faster and more comfortable journeys using a new fleet of electric trains which will replace the old diesel-powered Pacers.
Commenting on this latest development, Network Rail route managing director Martin Frobisher said: “This challenging upgrade has been really disruptive for passengers and our train operating partners who use this route. We’re sorry for this.
“I would like to thank local people for their patience, and I hope this milestone reassures them the end is in sight.”
The latest extension to Bangkok’s rapid transit Skytrain, the 13km Bearing-Samut Prakam section of the Sukhumvit line, opened recently using a turnkey wayside rail system supplied by a consortium led by Bombardier Transportation.
Bombardier itself was responsible for system integration, delivery of its Cityflo 450 rail control solution and the main power supply works. Partner ST Electronics (Thailand) provided the telecommunications, automatic fare collection and platform screen door systems while AMR Asia Company provided the depot workshop facilities, supervisory control and data acquisition, building management, back-up power supply and fire-fighting systems as well as installation.
The new line opened on 6 December and is expected to carry up to 100,000 more journeys on the Skytrain, which now regularly carries over 750,000 passengers per day. It was inaugurated by Thailand’s Prime Minister, Prayut Chan-o-cha, at a special event attended by many senior officials and dignitaries.
Gregory Enjalbert, Bombardier’s managing director in Thailand, commented: “It is exciting to witness the opening of a new rail link that is extending connectivity to new parts of the Thai capital and will significantly improve the travel experience for commuters. As a long-term partner to Bangkok Mass Transit System Public Company Limited (BTSC), we continue to positively impact the life of Bangkokians and are proud that our project was delivered by our large local team in Bangkok.”
Network Rail and the Royal Institute of British Architects (RIBA) have announced the winner of a design competition for the possible railway footbridge of the future.
As announced by Rail Engineer on 13 August 2018, Network Rail and RIBA Competitions set the challenge to design fully accessible footbridges that could be used across Britain’s rail network. The competition was looking for ideas that were innovative, challenged presumptions and raised expectations for the quality of future design.
In all, over 120 entries were received from 19 countries. The evaluation panel was very impressed by the high quality of the submitted entries, the breadth of the approaches and interesting ideas developed in response to the challenge.
Footbridge competition winning design (Gottlieb Paludan Architects and Strasky, Husty and Partners)
Although the competition was open to amateurs and professionals alike, it was the pros that won the day. Danish architectural practice Gottlieb Paludan Architects, working with Czech engineering and bridge specialist Strasky, Husty and Partners, put forward a bridge which most convincingly addressed the wide range of practical challenges whilst proposing a bold, elegant and uncluttered response that would create an uplifting experience to suit many contexts.
Due to the high quality of the entry, the judges also decided to highly commended the entry by Hawkins\Brown with WSP. They commented that this design presented a strong strategic approach, proposing a modular ‘kit of parts’ that would enable a standardised bridge system to be adapted via the use of simple pre-fabricated, clip-on modular elements to different contexts and settings, with the footbridge being conceived as a social engine focussed on people and place.
The entry by Hawkins\Brown with WSP was Highly Commended for its modular design and its focus on people and place.
Anthony Dewar, head of buildings and architecture at Network Rail, said: “Footbridges can have a significant positive impact on their local environment and offer wider social and economic benefits.
“As part of Network Rail’s commitment to make the railway more inclusive and fit for today’s needs through good design, the competition winner will be added to our new catalogue of improved station footbridge designs, and we are in discussions to agree how this idea can be fully realised.
“We have been overwhelmed by the response to this competition and would sincerely like to thank all the organisations, design professionals and students who entered.”
An exhibition of a selection of the entries submitted to the competition including the winning and highly commended designs will be held at the RIBA in February 2019.
Swiss train operator Schweizerische Südostbahn (SOB) has signed a contract with Stadler for 12 additional ‘Traverso’ FLIRT trains that will be used on the Chur-Zurich-Berne line from 12 December 2021, when SOB will begin operating an hourly service under an SBB long-distance licence.
The order covers seven eight-car, copper-coloured FLIRT multiple units, called ‘Traverso’, and five four-car, silver-coloured FLIRT trains.
The Traverso trains have 359 seats, 68 of which are in first class with 2+1 seating. All seats are equipped with power outlets and each train has two bistro areas and a designated family area.
SOB will operate the long-distance Traverso trains on the Voralpen-Express route between St. Gallen and Lucerne from 15 December 2019, on the Gotthard mountain route from 13 December 2020, and between Chur and Berne from mid-December 2021.
SOB had already ordered six eight-car and five four-car electric low-floor multiple units from Stadler at the end of June 2016 in order to replace older stock, some of which had been in operation for 40 years, ready for the timetable changes for 2019. The four-car multiple units can carry 197 passengers, including 22 in first class, reinforcing the existing FLIRT fleet used in regional transport.
In December 2017, SOB exercised an option to order eleven additional eight-car Traverso long-distance trains for the long-distance line from Basel or Zurich over the Gotthard mountain route to Locarno.
The latest order is a result of SOB exercising a second option, bringing the total number up to 24 of the eight-car Traversos and 10 of the four-car FLIRTs.
Alstom Citadis X05 tram for the agglomeration community of Grand Avignon. (Alstom / Yves Ronzier)
The first of 14 Citadis X05 trams that Alstom is building for the agglomeration community of Grand Avignon (communauté d’agglomération du Grand Avignon), which is centred on the city of Avignon in southern France, has now been delivered.
Each tram is 24 metres long, equipped with four double doors on each side and able to carry more than 140 passengers. It is based on the Citadis platform which has already been sold to more than 50 cities around the world, including 23 in France. The new Citadis X05 model has already been ordered by Nice (France), Sydney (Australia), Lusail (Qatar) and Caen (France).
Alstom Citadis X05 tram for the agglomeration community of Grand Avignon. (Alstom / Yves Ronzier)
With glass covering 40 per cent of the tram’s surface, passengers will have a good view from the new vehicles, which are assembled at Alstom’s La Rochelle plant and will be in service in summer 2019.
Jean-Baptiste Eyméoud, president of Alstom France, said: “Alstom and its teams are proud to present this first tram which addresses the major transport issues of the Agglomeration Community of Grand Avignon. We always take great pleasure in showcasing the knowhow and technologies deployed by Alstom’s men and women, for our customers in France and around the world.”
A group of Network Rail graduates had the opportunity to try out Transport for Wales’ train simulator this week.
The graduates, who work in a range of functions for Network Rail, were given the chance to drive both the Class 175 and Class 150 simulators under the watchful eyes of operations training manager Adam Bagwell and seasonal delivery manager Neil Driscoll.
The simulators are normally used for a 36-week driver training programme. On this occasion, they were set up to give the graduates specific practice on low adhesion tracks. giving them a greater understanding of the challenges drivers go through during the autumn period.
To help explain the difficulties, the group was accompanied by two members of the Network Rail autumn control and Daniel Booth, Network Rail’s seasonal delivery specialist for the Wales route.
After the driving experience, Adam Bagwell commented: “It was great to get the guys along and to share some of the skills that go into driving our trains during very difficult and challenging weather conditions.”
Neil Driscoll added: “I was really pleased with how the day went and it is fantastic to be working closely with Network Rail to help the development of graduates. This typifies the joint working between ourselves and Network Rail on helping to build a better service for our customers.”
Electrification of the Great Western main line (GWML) reached a new milestone at the end of October when, following the installation of overhead electrical equipment from Didcot Parkway, the first revenue service operating under electric power pulled into Swindon station.
Once timetable changes are implemented in 2019, passengers will enjoy more frequent, faster services from Swindon into London Paddington thanks to Great Western Railway’s state-of-the-art Class 800s now running under wires. By Christmas, Network Rail has said that the line will be electrified all the way to Bristol Parkway and, by November 2019, it is aiming to electrify the GWML to Cardiff.
Route managing director Mark Langman said that electrification to Swindon represented a “significant milestone” that will provide a major boost to the historic railway town and its economy – a win for passengers and a win for locals.
Changing times
Electrification forms a key part of the biggest upgrade to the GWML since it was built by Isambard Kingdom Brunel in the 1840s, when steam locomotives ran through the great towns of the South West. Times have changed, and more than the means of traction.
Following the recent departure and subsequent replacement of the notified body (NoBo) lead, all four key safety assurance positions in the £2.8 billion Wales and Western electrification project are filled by women – an entirely different cause for celebration.
Like many safety critical sectors, railways have stakeholders – governments, regulators and passengers – who all expect a degree of third party assurance on issues related to safety and quality. Therefore, authorisation of the project’s infrastructure for use by passenger trains is not possible without Network Rail’s Jane Austin, the region’s head of engineering, and Jo Griffiths, principal system safety engineer, as well as representatives Carolyn Salmon, assessment body (AsBo) lead, and Daniela Phillips, NoBo lead, both from independent body Ricardo Certification, giving the green light.
More than 175 years ago, none of the project job roles would be filled by women, never mind four of the most important.
Overseeing the approval of complex systems in a safety critical environment means the four are understandably very busy, but, for one hour in October, the quartet sat down for an (almost) uninterrupted discussion with Rail Engineer to talk about the project’s progress, their careers and what it’s like working in a traditionally male-dominated world.
L-R: Jane Austin, Daniela Phillips, Carolyn Salmon and Joanna Griffiths.
Invisible barriers
From engineers to train drivers and project managers, across the industry more and more women are entering the rail sector, but the numbers are still low. Figures from Women in Rail reveal that women make up around 16 per cent of the sector’s workforce, with an even smaller number in senior positions. For example, of Network Rail’s 431 employees in its highest salary tier Band 1 (£78,624-£186,486, according to data from 2017) only 66, or 15 per cent, are women, including Jane Austin.
Nevertheless, Jane, Jo, Carolyn and Daniela are adamant that there are no obstacles to women entering and finding success in the rail industry.
“The only time I’ve been prevented from going on site was when I was pregnant‚” explained Jo, who has worked abroad, started a family with two children and has become a chartered engineer and a fellow of the Institution of Civil Engineers (ICE) since the turn of the century. “If you know what you want to do, and you know where you want to go, you will find a way and make the rest of your life happen with it.”
Jo, who admits she has taken “the most vanilla” route of the four, graduated as a civil engineer 18 years ago and hasn’t looked back since. After building waste-water treatment works for construction firm the Miller Group, she joined Atkins Rail as a graduate designer and then left for Network Rail’s assessment management team in the Midlands route. Following the Great Heck rail crash of 2001 – the country’s worst rail disaster of the 21st century, when a land rover crashed down a motorway embankment onto the railway line, causing a high-speed train accident – Jo was tasked with risk assessing all of her region’s bridges. She then returned to Atkins before taking up the role she occupies today.
“When I started working in rail, I assumed it would be this male dominated world, and that they wouldn’t take me seriously,” added Daniela, who studied politics and wanted to work for the European Union before she fell in love with rail. “I’ve been so lucky; I’ve never once experienced that.
“If you know your stuff, then they respect you regardless of whether you are male or female.”
On her journey from university to Ricardo, Daniela has worked for the Office of Road and Rail, the European Railway Agency – looking after northern European, Scandinavian and Eastern European countries in the cross acceptance team – Lloyd’s Register (now a part of Ricardo) and Steer, where she recently re-wrote all of the technical standards for the Department for Transport in case of a no-deal Brexit situation. The only non-engineer of the group, Daniela then joined Ricardo.
Carolyn’s story is completely different once more. She started her career as a mathematics graduate, working as a safety engineer across rail, nuclear and avionics for the likes of Lloyd’s Register, ERA Technology (where she became the operations manager for the safety and EMC group), RINA Consulting and now Ricardo. A chartered engineer and mother of two, Carolyn said that her employer was flexible when she had two young children, allowing her to go down to a three-day working week for 12 years. She only returned to full-time work when she was offered a managerial position.
“It was a bit of a juggling act sometimes,” she said. “But it meant I never gave up my career.”
Perceptions and unnecessary pressures
None of the four women said they feel being a woman in the rail industry has held them back, although they all agreed there is a perception that they have to be better to succeed, aided by some unhelpful comments.
“You feel like you have to be better, you feel like you have to prove yourself,” explained Jane, a chartered engineer and fellow of the ICE. “I can remember being pulled into someone’s office and they sat me down and said: ‘Jane, you’re the first girl at this level [Band 1], please don’t let me down.’
“I think as women, potentially we feel a little bit more pressure than men – but I don’t know, because I’m not a man.”
Jane, the final ‘key player’ when it comes to assurance of the Wales and Western electrification project, left school aged 16 to become a draftswoman. She re-took her O Levels at night school and attained an Ordinary National Certificate and then a Higher National Certificate. At the time, she worked on non-rail structures until her boss advised her to pack it all in, to head to university and obtain a degree. Jane said she initially thought it was “a silly idea” but, aged 21, came around to it to study civil engineering for three years, finishing with first class honours despite leaving school with just one O Level.
Spells at Readymix Concrete followed before she joined British Rail’s management trainee apprenticeship scheme in 1992 as the only woman on the programme, the start of a long relationship with the infrastructure owner. Moves to Railtrack and Network Rail followed, working as an assistant resident engineer, resident engineer, assistant project manager, senior programme engineering manager, head of track for track renewals and switches and crossings and now head of engineering, a role she has held for the past six years.
Encouraging women to join rail
The issue of a lack of women in the sector isn’t the result of barriers and a lack of opportunities, the group said, but through not encouraging enough girls to take up science, technology, engineering and mathematics (STEM) subjects from an early age.
According to Women in Science and Engineering data from 2014, the overall proportion of girls doing STEM subjects drops off at A-level, with lower numbers of females compared to males being entered for all STEM subjects, except biology.
“You can’t attract more women if more women are not going in to do the subjects in the first place”, said Jo. “The math just doesn’t add up.”
A key element to encouraging a greater take up is through tackling the misconceptions people have of the industry and what an engineer looks like. Jane said she recently welcomed a secondary school teacher, who had been given the role of careers development for engineering, into her team for a week, to plug the huge knowledge gap they had of the profession.
“We need to somehow help the education department in the fact that not many teachers have ever been engineers, so, therefore, are they really promoting it?” she said. “The point is, I don’t think our younger generation really understand what these jobs are, and what’s available to them, because it seems we don’t get any of that when they’re going through school.
“They should realise that, actually, it’s not a dirty, horrible, wet, vile world out there, because you can do all different types of engineering. You can be on a building site, or you can be on a nice warm office.
“It’s not just girls, it is girls and boys because we need more engineers. So it’s about how we encourage both sexes, really, to become engineers, because it’s still not thought of as a great career opportunity – but it’s a fantastic one.”
Jo, who is a STEM ambassador at the Swindon City club of the ICE, summed up the challenge succinctly: “How do you know you want to be an engineer if you’ve never even heard of the word?”
Between the quartet, they have been involved in the rail industry for almost 80 years and, in their experience, there is nothing stopping women from succeeding.
Jo, who admits there are still challenges to overcome – she often answers the phone to someone assuming they’ve reached the wrong person, because of her unisex name – added: “Male-dominated does not equate to female-does-not-succeed.”
“If you’re good at what you do, people will see that,” concluded Jane.
As the hands on the clock face reached the hour mark, the four dashed off for an important decision-making meeting that would lead to Swindon welcoming the first electric, passenger train.
In Victorian Britain, Isambard Kingdom Brunel was one of many pioneers who led a wave of great change during the Industrial Revolution, forever altering the face of the country’s landscape.
Jane, Jo, Carolyn and Daniela, through their work on the biggest upgrade to the GMWL since Brunel, and as great role models for women in rail, are helping to do the same in modern day Britain.
Sustainable city concept including icons set. Nicely layered.
On 30 October, over 150 delegates from the industry and research institutions attended RSSB’s “Intelligent Power Networks to Decarbonise Rail” conference, held at the University of Warwick. This event considered how more energy-efficient, zero-carbon technologies could be developed in response to the former Transport Minister’s challenge to see all diesel only trains off the tracks by 2040.
The conference was a platform to launch two research competitions that offered significant funding for projects to decarbonise the rail industry.
It opened with an overview of the industry’s sustainability initiatives and the background to the competition. This was followed by presentations on innovative traction power projects and industry stakeholders describing their main priorities, to which sixteen companies gave one-minute pitches in response. Information was then provided about the competitions and other funding opportunities.
No diesels after 2040?
Transport accounts for 24 per cent of the UK’s total greenhouse gas emissions. Although UK Rail only accounts for two per cent, and is already a low carbon form of transport, there is significant scope for improvement, particularly in respect of local emissions. Traction alone consumes over 700 million litres of diesel and 3,500 GWh of electricity each year, at a cost of over £500 million. In addition, Network Rail spends £60 million each year on utilities for its non-operational estate.
In February, the then Transport Minister, Jo Johnson, called for diesel-only trains to be off the tracks by 2040. However, his reference to diesel-only trains shows that it is considered acceptable for diesel bi-mode trains to continue operating beyond this date.
Andrew Kluth, RSSB’s lead carbon specialist, explained that, in response to this call, an industry task force had been set up which will soon publish the industry’s response. He explained that the task force aimed to move UK rail to the lowest practicable carbon energy base by 2040, enabling the industry to be world leaders in developing and delivering low-carbon transport solutions for rail.
As part of its work, the task force considered journey types and performance requirements against various traction options as shown in the table.
It concluded that a whole system balance will be required between electrification, where it is cost effective, and new traction technologies such as hydrogen and batteries. Transitional arrangements for these new technologies have to be considered and, where no other options exist, significantly more efficient and cleaner diesel will be needed.
Low carbon trains
Mike Muldoon of Alstom, which already has the world’s first hydrogen train, the iLint, in passenger service, gave the first of three presentations on projects to modify existing rolling stock. The iLint is a hydrogen-hybrid train with a traction battery. As Mike described, “the clever bit was the energy power management system for which the development effort should not be underrated”.
To bring this technology to the UK, Alstom is planning to convert a Class 321 EMU to create a UK-gauge hydrogen train in a partnership with Eversholt Rail.
Mike emphasised that hydrogen trains are “no silver bullet”, but have a potentially useful role on lines for which electrification cannot be justified where they can exceed the performance, but not the range, of a DMU. Although hydrogen trains can easily be refuelled, to make the best use of the required hydrogen supply and production facilities, it is best to operate them as a small fleet.
A significant advantage of hydrogen trains is that they have no harmful emissions, as their only exhaust is water. However, their carbon credentials depended on how hydrogen is produced. Almost all hydrogen is produced by steam reforming, which offers a 45 percent reduction in CO2 compared with diesel. Hydrogen can only be a truly zero-carbon fuel if it is produced by the more expensive electrolysis process using ‘green electricity’, such as wind power.
Kevin Blacktop from the University of Birmingham described the Hydroflex train, which is another UK hydrogen train proposition currently under development. He explained that the University had undertaken much research into hydrogen propulsion and, in 2012, produced the UK’s first hydrogen train. This was a 10¼ inch gauge locomotive powered by a one-kilowatt fuel cell as the University’s entry in the IMechE’s Railway Challenge.
Hydroflex is the subject of an agreement, signed in September at Innotrans, between the University and Porterbrook which will supply a Class 319 for conversion. This will operate on 25kV overhead and 750V DC third-rail and, in self-powered mode, will use a hydrogen fuel cell. Demonstration runs are expected to commence in summer 2019.
Angel Trains is developing the Hydrive. This will be a new hybrid train that will have a diesel engine, traction battery and power management control system and which, as David Bridges explained, will offer significant environmental advantages. These include constantly running the engine at its “sweet spot” to maximise efficiency and reduce emissions, regenerative braking, and the elimination of diesel engine emissions at stations.
The first Hydrive unit will be a converted Chiltern Railways Class 165 unit that is expected to enter service in October 2019.
Challenges and opportunities
To set the scene, representatives from different parts of the industry outlined the challenges that needed to be addressed.
From Freightliner, Paul Smart stressed that rail freight faced keen competition from road haulage and so required any diesel-replacement technology to match diesel’s operational characteristics with no increase in size or weight or reduction in payload.
Network Rail’s Wendi Wheeler noted that there were limited decarbonisation options, as there is currently no viable alternative fuel source to diesel. She also highlighted the need for traction and non-traction energy storage, for which Network Rail could provide land. In addition, she mentioned the scope for savings at major stations, which are massive energy users, including the deployment of modern metering.
Graeme Clark from Siemens Mobility was concerned that rolling stock companies had to invest in the future of a frequently changing, delayed and unstable rail franchising system with no fixed, long term view of rail electrification.
Presentations from Porterbrook, First Group and Virgin Trains all stressed the need to reduce traction fuel consumption. Virgin’s Russell Preece noted how driving style affected fuel consumption, whilst Porterbrook’s Chandra Morbey emphasised the need to reduce embedded carbon by minimising the use of spare parts and materials. From First Group, Martin Ward highlighted the need for energy efficiency at depots and noted that the franchise business-case timeframe – seven years or less – made it difficult to justify the cost of decarbonisation measures.
Herb Castillo explained how HS2’s electricity consumption would eventually be 60 per cent of that required for all current UK rail traction. Hence the company’s aspiration is to have directly connected, renewable, low-carbon traction supplies and technologies to reduce non-traction energy consumption. HS2 is already in discussion with potential electricity suppliers so as to have time to invest in the required facilities before the high-speed line starts operation.
The two-mile high-speed rail tunnel in Antwerp has 16,000 solar panels on its roof which produce 3,300 MWh of electricity each year.
Cases and pitches
In four case studies and sixteen elevator pitches, solutions and expertise were promoted to respond to these challenges.
Riding sunbeams to power the 750V DC rail network was the first case study. Leo Murray of Climate Action, an organisation promoting community-level practical projects to tackle climate change, explained how this initiative builds on the success of the Blackfriars solar bridge and Antwerp’s solar rail tunnel.
He explained how local solar farms, such as a 4MW installation at Cuckmere, could be connected directly to DC rail network sub-stations via DC to DC converters. This was one of seven identified sites that were estimated as being able to supply fifteen percent of the southern DC network’s annual demand of 1.38 TWh.
Solar farms could also power other UK DC traction networks and, possibly the 25kV AC network, for which solar power connection options were being evaluated.
The benefits of an internal combustion engine without a crankshaft were explained by Professor Tony Roskilly from Newcastle University in his presentation on the free-piston engine, in which two connected pistons move in a cylinder with compression chambers at each end. Drive and control are by a linear induction motor at the centre of the cylinder.
This configuration gives an engine that is 60 per cent smaller and 25 per cent lighter than a conventional internal combustion engine with lower friction and heat transfer losses. It also has better thermal efficiency due to an ability to control the piston velocity profile as well as being easily modified to use alternative fuels as compression ratios and valve timing are software controlled.
This concept, which was first proposed in the 1940s, has now become potentially viable with the availability of modern, microprocessor control technology. The University of Newcastle has been working on it for some years and has a £200,000 research grant to use it as a 25kW range-extender for hybrid electric vehicles.
In another case study, Professor Philip Mawby of the University of Warwick explained how Power Electronics UK was using Silicon Carbide (SiC) for lower cost, higher efficiency power electrical applications. His presentation showed that the use of SiC devices is currently saving 10 million tonnes of CO2, the equivalent of eight coal-fired power stations or 1.7 million cars being taken off the road.
The advanced multi-fuel technology offered by G-volution enables diesel engines to use lower carbon alternative fuels. Shimon Shapiro explained how his company’s technology enables engines to use a diesel-LNG combination of fuels, giving a carbon reduction of 25-70% and a fuel cost saving of 33-44% (according to the G-volution feasibility study). Other fuel combinations, including diesel-bio-LPG, and diesel-bio-hydrogen, can offer carbon savings of 10-45% per cent, and fuel cost savings of 25-50%.
These case studies were followed by short, one-minute elevator pitches from the following organisations:
University of Nottingham – one of the world’s biggest power electronics research groups;
Loughborough University – rail vehicle modelling and simulation, control system development;
Manchester Metropolitan University – power systems, energy storage and forecasting;
Warwick Manufacturing Group – advanced propulsion and lightweighting, technology transfer from automotive to rail sectors;
University of Chester – carbon capture and utilisation, fuel cell technology, energy control systems;
University of Birmingham – power system modelling, including large scale power grid simulation;
University of Sheffield – mechanical expertise including overhead line dynamics, material fatigue and wear at train-infrastructure interface, optimisation of rail operation with energy supply and storage;
University of London, SellickRail, Dynamic Boosting Systems and Gyrotricity – patented electric flywheel;
Hasler Rail/Sario – accurate measurement of AC, DC or fossil fuel energy consumption;
Ultra Light Rail Partners – ultra light rail solutions including compressed air and cryogenic engines;
Unipart Rail – product development for global rail markets;
Perpetuum – expertise in wheelset life extension and maintenance optimisation;
FTI Communication Systems – telecommunications networks;
Clean Power Hydrogen – advanced electrolyser technology;
Global Gas Logistic Solutions – lightweight efficient fuel containers;
Ricardo – low carbon propulsion hybrids and storage.
Unlocking funding
The competitions announced at the conference will have several winners, as the intention is to make funding available to various projects that meet the competitions’ requirements.
The £1 million RSSB competition is for feasibility studies and demonstrator projects. These projects must address one of three key challenges:
High speed train power – carbon efficient traction energy, reduction of auxiliary energy consumption and energy harvesting;
Freight traction power – carbon efficient traction energy and improving diesel traction to reduce carbon;
Infrastructure to support operations – energy storage and distribution including studies on scaling up current technologies and cross modal integration.
The competition proposals need to be submitted by 9 January 2019. RSSB will announce the winning bids in February and produce an initial report on the findings of each successful project in March 2020.
RSSB is also co-funding a scheme for rail carbonisation and energy efficiency initiatives organised by Innovate UK’s Knowledge Transfer Partnership (KTP). KTPs match companies with an academic associate that has the required research expertise and facilities.
For the targeted rail decarbonisation KTPs, there are three funding rounds which close on 12 December 2018, 6 February and 20 March 2019.
Although the Innovate UK KTP call follows the same three challenges as the RSSB collaborative R&D competition, its scope also includes additional areas such as non-high-speed trains and more efficient electric trains, both of which are specifically excluded from the RSSB competition.
Finally, the conference heard how Innovate UK was running a “First of a Kind – round 2” competition on behalf of the Department for Transport. Entitled “Demonstrating tomorrow’s stations and a greener railway”, for which a total of £3.5 million is available, the closing date for this was 28 November. This competition will provide successful entrants with funding to deploy a well-developed technology in a rail environment.
The missing solution
It was good to see the many decarbonisation initiatives presented at this conference. Some of these are already delivering significant carbon savings, whilst others will be powering trains in a year or so. Of these, the Class 165 hybrid being produced by Angel Trains is a welcome development, as it shows the rail industry is starting to follow the automotive sector’s lead in hybrid technology.
RSSB’s competitions will no doubt accelerate such developments and it will be interesting to hear of the winners’ proposals early next year.
Because these competitions form part of the industry’s response to the government’s call for an end to diesel-only trains from 2040, they are bound by government requirements. Reports indicate that the government does not wish the industry’s response to include further electrification, despite this being the only alternative to diesel for high-power traction requirements.
Initiatives for more efficient electric traction are also excluded from the RSSB competition. This seems odd as the electric trains that comprise 72 percent of the UK passenger fleet offer significant potential for carbon savings. At the conference, it was explained that electrification was covered by Network Rail and Railway Industry Association initiatives. As an example, Network Rail’s Wendi Wheeler advised that the company is to specify the requirement to minimise CO2 in is contracts for electricity supply.
The exclusion of electrification from these competitions reflects the UK Government’s view which seems to be that electrification is just too expensive and the solution is better trains without appreciating the space constraints that limit the power of self-powered trains.
Furthermore, as Graeme Clark of Siemens Mobility pointed out, international rolling stock companies must invest in the future of UK rail despite frequently changing requirements with no stable, long term view of rail electrification. Indeed, the boom and bust nature of UK electrification is one reason why it has proved so expensive.
The UK government is right to require the rail industry to accelerate its rail decarbonisation initiatives. In this respect, the competitions launched at the RSSB’s decarbonisation conference have a valuable part to play. Yet the government also needs to understand just how its policy decisions affect the industry’s ability to decarbonise.
Railway electrification provides faster and reliable train journeys compared to those of diesel trains and a strong reduction of pollution in busy stations and the countryside. However, many national programmes for the electrification of new and existing railway lines have required a substantial investment for the railway infrastructure.
This is because railway electrification uses AC single-phase power that requires connection to high-voltage transmission lines, which are not always available in the intended places where the railway feeder stations should be located and usually require complicated and extremely expensive modifications of the existing layouts.
New AC electric railways are not seen favourably by the transmission operators as they introduce negative phase sequence current and intermittent load peaks that affect the stability of the system, especially for future scenarios where the inertia of the power system will be substantially reduced for the widespread adoption of renewable power sources.
There is currently a need to find suitable and cheaper alternatives to traditional electrification systems that do not rely on connection to the high-voltage transmission system and allow the integration of renewable power sources and energy storage.
The typical power level of heavy railways and even high-speed railways are in the range of 100-500MVA, with individual supply points designed for a peak-power of 50-100MVA, which is compatible with the typical capabilities of medium-voltage distribution systems. However, innovative railway feeder stations need to be based on technologies that do not introduce any phase imbalance to the distribution network.
Passive and active methods are available to reduce or eliminate the imbalance. Passive solutions alternate the phases that supply each section of the track. The major drawback of this solution is the requirement of neutral sections ensuring electrical isolation between consecutive sections of the track. V-V, Le-Blanc or Scott transformers can further reduce the imbalance, but they are effective only for specific loading conditions. As a result, they are not ideal solutions for the connection to power distribution grids.
Active solutions use power electronics converters operating together with, or in substitution of, the main power supply equipment in the feeder stations. Traditional methods use the power converters as power compensators – they inject a negative phase sequence current in phase opposition with the one drawn by the railway, so that the current supplied by the utility grid is balanced. More advanced solutions are instead based on replacing single-phase transformers with full-size power converters, operating at either the same or a different frequency of the power grid.
Active power compensators
An established technology is based on Static VAR (volt ampere reactive) compensators (SVCs), albeit they require large filters for the additional harmonics introduced by the thyristor switching. More recently, static synchronous compensators (STATCOMs) have been introduced. As they are switch-mode power converters operating with switching frequencies higher than those of thyristors, they require passive filters relatively smaller than those of SVCs. STATCOMs can be connected to the three-phase grid or the single‑phase overhead line and use a conventional two-level or three-level H-bridge topology. In East Asia, STATCOMs have been used in conjunction with V-V and Scott connected transformers to the phase imbalance of the railway.
Co-phase and advanced co-phase system
An alternative electrification system, called co-phase power supply, is a hybrid solution between a STATCOM and a full static converter. It uses a static single-phase to single-phase power converter and an impedance matching balance transformer, which acts as a three-phase to two-phase converter.
The aim of the control system is to inject the appropriate current to filter harmonics and eliminate the negative sequence on the three-phase supply. Unlike STATCOMS, the converter of the co-phase supply can also supply active power directly to the load. At present, a prototype feeder station has been built in China and the trials undertaken so far have shown improvement on the power quality of the supply.
The co-phase system has been further improved into the advanced co-phase power supply in which one three-phase transformer, connected to the railway line through the static converter, is added in parallel to the existing single-phase transformer and controlled to supply active power to the trains and to balance the three-phase current on the grid.
Full-size static converters
In this scheme, single-phase transformers are replaced by static converters that convert the three-phase power of the grid into the single-phase power for the railway. The power conversion can be either direct (AC/AC) or with an intermediate DC link (AC/DC and DC/AC).
Feeder stations with full-size static converters draw a nearly sinusoidal balanced current at nearly unity power factor. This is the technology widely used for all the countries operating with railway frequencies different from 50Hz. However, it is now becoming attractive also for 50Hz railways for the possibilities of longer feeding distances and better control capabilities compared to traditional feeding arrangements.
The static converter has an independent control of the input currents on the three-phase side and a regulated voltage on the single-phase side. Therefore, the utility grid can be fully isolated from nonlinear traction loads, like legacy locomotives that use diode or thyristor rectifiers.
The control of the voltage on the single-phase side also allows the synchronisation of the output voltages of multiple feeder stations, thus creating a continuous overhead line without neutral sections. Therefore, the electrified network would have a feeding arrangement similar to DC railways, where multiple feeder stations simultaneously supply the trains.
Static converters also allow active and reactive power sharing, thereby reducing the power ratings of the feeder stations. Additionally, as the output current is monitored, static converters can implement any desired short circuit management scheme, with much reduced short‑circuit current and, consequently, switchgear rating.
Medium-voltage DC electrification
At the present state of the art, DC electrified lines are already connected to medium voltage power distribution grids, as the DC voltage is generated by a three-phase diode rectifier that draws balanced current with high power factor. However, the level of the DC voltage is limited to around 3kV for the limitation on the maximum short-circuit breaking current of circuit breakers, which in turn limits the maximum capacity of the railway. A higher voltage of the power supply would also pose problems for traditional traction system of the trains, which operates at voltage levels of a few kV.
The recent introduction of new multilevel topologies now allows the design of reliable medium-voltage static converters that could be used for DC railway electrification. The advantages are being connected to a lower voltage drop for the DC operations of the line, enabling longer feeding distances, lower power losses for the lower resistance of the conductors and higher capacity for the lower currents on the line.
The main challenges are the need of suitable protection schemes to deal with short-circuit currents and the need of power electronics-based DC transformers on board of trains to replace traditional transformers. Both of these are under development, and valuable input can be taken from other research fields, mainly HVDC transmission and medium-voltage DC power distribution.
The new concept of medium voltage DC railways would fit very well with a future vision of electric railways better integrated with power distribution networks, especially for the possible interconnection with renewable power sources and energy storage, which typically operate with DC power.
Written by Pietro Tricoli, a senior lecturer in electrical power & control at the University of Birmingham and a member of the Birmingham Centre for Railway Research and Education.
