High-speed rail technologies

7th November 2016

The Institution of Mechanical Engineers frequently organises topical seminars with excellent speakers. This one was no exception with speakers such as Jim Steer and Andrew McNaughton. The timing of the event was to celebrate the success of the UK’s High Speed Train (HST), which has been responsible for transforming the image of inter-city rail travel since it entered service on 4 October 1976. It was the 08:05 London Paddington to Bristol Temple Meads, although one member of the audience was on what he was told was the first train which departed from Weston Super Mare. Perhaps there was a first “up” and a first “down” train?

As Andrew Mellors, deputy managing director and engineering director of GWR said, as he introduced the event, the purpose was not to rake over the history of the HST, more to nod to its history whilst looking forward at the technologies that are required for today’s and tomorrow’s high speed lines.

Yesterday

The first presentation was by another Andrew – Andrew McLean, the head curator at the National Rail Museum in York. His title of “The Most Successful Train in the World?” referred to the impact of the HST. His assertion was that the UK has always been in the forefront of high-speed railways ever since Stephenson’s Rocket travelled at the unheard of speed of 30mph, and that the times when the UK appeared to be in the speed wilderness were mere blips of history.

Andrew treated the audience to a gallop through railway development in the nineteenth century before going on to the era between the two World Wars, immediately following the formation of the “big four” railway companies. He focussed particularly on the London and North Eastern Railway and its chief mechanical engineer (later Sir) Nigel Gresley, who pushed the envelope to and beyond 100mph.

Gresley was a man who travelled widely and had befriended Ettore Bugatti, from whom he learned the importance of streamlining. He applied these ideas to the A4 pacific locomotives, but also to the rest of the train with articulated coaches where the gaps between coaches with ‘India-rubber fairings’, and a streamlined observation car minimised turbulence following the train.

Andrew also emphasised the importance of LNER’s publicity and service that accompanied the streamlined trains, with the train as the very visible and marketable ‘face’ for the offering.

The second World War and nationalisation almost certainly extended the life of steam in the UK by about 20 years, and the story moves to the 1960s where there was both an urgent need to do something about the competitiveness of long distance rail and to solve some fundamental problems of keeping trains on the track at higher speed. Andrew mentioned three people who were transformational in UK railways and had influence worldwide.

Dr Alan Wickens led the research work to understand why high speed trains were prone to derail and to provide solutions, leading directly to the work on the Advanced Passenger Train.

Terry Miller, then chief mechanical engineer of British Railways, led the development of the HST and the strong, light and spacious Mark 3 carriage; and Kenneth Grange designed the iconic and timeless “face” of the HST. Andrew argued that these three men had a transformational impact on the UK’s long distance passenger services. Together with the Deltics on the East Coast, and the ‘sparks effect’ on the West Coast main lines, BR had products that could be marketed well, and developed the ‘Inter-City’ brand, with the HST and Mark 3 coach featuring strongly in advertising. The HST still holds the world speed record for a diesel train of 148mph, recorded in 1987.

Andrew concluded that the HST has had a transformational impact on the UK economy (for example, people now commute to London from York) and is going to continue in front line inter-city service in Scotland until the end of the 2020s, still retaining the timeless good looks designed by Kenneth Grange all those years ago.

Today and tomorrow

The keynote address was given by Karen Boswell OBE, managing director of Hitachi Rail Europe. Her message was that high speed has been good for Britain. Moving on from the success of the HST, she talked about the contribution of the class 395 trains to the economy of Kent, how these trains have halved the journey time to Ashford and that the domestic high speed service carries half the passengers that use the High Speed 1 route.

The success of this fleet has established Hitachi’s reputation in the UK and has led to the orders for high- speed trains for East Coast, Great Western Railway and Trans Pennine Express as well as inter-regional trains for the Edinburgh-Glasgow route.

Karen’s message emphasised connectivity, creativity, collaboration, and engagement with people at all levels, whether customers or employees. Moreover, she highlighted that high-speed lines are successful the world over. Don’t let critics talk HS2 down, she said.

Practical lessons of high speed

Jim Steer, who set up Steer Davies and Gleave in 1978 and has been a champion of high speed rail for over three decades, talked about what can be learned from 125mph operation in the UK, from High Speed 1 and from the experience of France.

Jim highlighted that, as 125mph operation spread through the UK, journey times fell, stimulating more journeys and land development. Many of these improvements took place at roughly the same time as other developments including motorways, housing and retail. As such, it was not easy to attribute which activity contributed most to the economy. Complicating the picture is the green belt land around most of the UK’s major cities, which means that development might not necessarily be allowed to happen. He cited examples of Doncaster and Newport, which received high speed trains but did not receive significant economic development.

Photo: shutterstock.com — Photo: Paul J Martin/shutterstock.com

For his section on HS1, and with reference to the fears of many of HS2’s neighbours, Jim recalled that the Eurostar train is comparatively noisy and that it was the subject of many complaints when running over the old boat train route on the Southern electric network. These complaints ceased when HS1 opened. His point is that a well-designed high-speed railway is generally not intrusive on neighbours’ lives. The key points included:

HS1 has stimulated development around Kings Cross/ St Pancras whilst Ebbsfleet has yet to catch up;
HS1 was justified on forecast Eurostar numbers that have never been forthcoming although the introduction of the domestic high-speed service has delivered, overall, passenger numbers in line with forecasts;
Reliability of the HS1 infrastructure is very high;
Infrastructure needs to be flexible and this flexibility has value for uses not envisaged when the line was built, such as the HS1 domestic service.

France

With its main cities tending to be separated by significant distances, France was an ideal location to grow high-speed rail. For example, the first high-speed line, from Paris to Lyon, currently runs trains in just two hours. By comparison, a car journey takes four hours and, unless you are close to either airport, flying is slower than the train.

The success of the high-speed lines is well known; France is currently constructing four more lines, and the risks and rewards have become well enough understood to make a Public Private Partnership viable. Jim also highlighted that countries which have commenced building high speed lines have always built more of them.

He added though, that a number of lessons have been learned. France expanded TGV services but has recognised that secondary routes have been neglected. Furthermore. the president of SNCF has declared that railways are guilty of underestimating long term growth, that more cross-Paris travel routes should have been provided and that strategic thinking should be applied to linking every major town and city, and not just be Paris- centric.

In closing, Jim Steer made several points. Mixed traffic railways are not efficient users of capacity, and taking long-distance fast journeys off existing lines provides the opportunity to improve the offering on those existing lines.

The HS2 business case assumes best-case growth of about 2.8 per cent, although current actual growth is significantly greater than the HS2 best case.

And the key to the success of high-speed lines is improved connectivity, both for customers and for regional economies.

What Can the UK learn from Japan?

Felix Schmid, director of education at the Centre for Railway Research and Education at Birmingham University, compared the European and Japanese approaches to high-speed rail or, as he asked, “Is it all about speed?”

Starting with a little self-deprecation, Felix told his audience: “I visited Japan thanks to Central Japan Railways’ exchange programme. I had read lots about Japan, about its railways and the Shinkansen and I was convinced that I would learn nothing new! And then I understood…”

Felix highlighted the essential truisms of high-speed rail everywhere – bringing communities closer together – and contrasted some of the engineering approaches in Britain and in Europe with those adopted in Japan. He illustrated how the Shinkasen developed on Honshu island, which is slightly smaller than Britain but has nearly twice the population.

More significantly, the Tokyo – Osaka corridor (about 500km apart) represents less than 25 per cent of Japan’s land mass, but has nearly 60 per cent of the population and more than 60 per cent of Japan’s economic activity. It was between these two cities that the Tokaido Shinkasen opened in 1964, partly to reduce journey times and partly to improve capacity.

The opportunity to increase services on Japan’s conventional 1067mm gauge mixed traffic lines was small. The Japanese decided to create the new line using standard gauge, dedicated solely to the high-speed service, thus not importing any of the issues that might affect the narrow-gauge lines. From opening, the reliability of the service has been legendary, with average delays of less than six seconds per train.

In covering the expansion of the network, Felix superimposed the network onto a light pollution map showing the distribution of Japan’s urban population, and how, in the interests of connectivity, both dense and lightly populated areas are served.

Felix moved onto railway system design, where there are some differences in approach between Europe and Japan. As the Shinkansen has always been a dedicated system, Japan has developed its infrastructure based on the needs of the train. For example, the Japanese engineers determined that a width of almost 3.4 metres was required to accommodate rows of 3+2 seats in standard class. This determined the structure gauge and track spacing.

However, in the desire to build stations in densely populated areas, where people want to go, land take had to be kept to a minimum. It became usual, therefore, to specify quite short turnouts with an operating speed of 75km/h. For these not to be a constraint, trains with high acceleration and braking rates were specified.

Conversely, in Europe, it is quite common for high-speed trains to have their own infrastructure and also to use the existing infrastructure at ends of the line, sometimes for a considerable distance. Thus, the vehicle gauge has to be compatible with the existing lines, which is almost always smaller than in Japan.

In Europe, space is often made available for longer, 230km/h turnouts from the main line to a deceleration track and then 95km/h into platforms, with the reverse for acceleration. These turnouts are rated at more or less the correct speeds for the deceleration (and acceleration) curve of the trains, and thus a stopping train will get out of the way of a following train with minimal impediment. The higher the throughput required, the more important this becomes, particularly if the stopping pattern is irregular.

However, 230km/h turnouts are very long and require considerable track equipment to make them work, resulting in issues for maintenance and reliability.

Felix’s point was that the high-power train and simpler infrastructure provided a number of benefits such as:

High ratio of motored axles increases acceleration andbraking rates – the latest Japanese trains have all axlesmotored;
All axles motored opens the way for purely electro-dynamic braking (270km/h to 30km/h);
Low speed (75km/h) turnouts have multiple benefits:» No need for swing nose crossings / moving frogs;
Low complexity and cheaper to buy and renew;
Reduced land take and lower track forces;
Replacement in one five-hour maintenance window.
Low technology maintenance is flexible.

Felix also stated that all aspects of a journey need to be considered in the planning of high-speed lines. His example was a three-hour journey where only 90 minutes are on the train. If a high-speed line allows the on-train time to be reduced to 60 minutes, the saving in on-train time is one-third but the saving on the overall journey is only one-sixth.All phases of a journey, both value-adding and non- value-adding, need to be considered. Non-value-adding elements include having to wait 10 minutes to buy a ticket or walking up and down the train to find a seat.

He also illustrated the sort of analysis that can be undertaken to minimise the activities necessary at terminus stations (other than disembarking and embarking passengers). He compared this with what the low cost airlines have done to minimise time on stand at airports.

Developments in high-speed rail

Andrew McNaughton, technical director HS2, has over 40 years in the industry or, as he put it “40 years of mistakes and they call it wisdom”. Andrew’s approach was to emphasise similarities, not differences, because, he said in his understated way, “the laws of physics are pretty much the same worldwide”.

High-speed rail is over 50 years old, has been adopted across the world and has all been built to similar technical standards. Andrew illustrated the point with a photograph taken in Korea of a train to largely French standards on track to largely German standards.

Highlighting some different approaches to optimising requirements that can possibly be conflicting, such as connectivity, capacity, reliability and availability, Andrew described how there are broadly three categories of high- speed lines in different countries/continents.

In Asia, closed systems are preferred, with high-speed trains running solely on dedicated infrastructure. This tends to produce the highest capacity and reliability.

France, Italy, and the UK have generally adopted high- speed infrastructure where only high-speed trains run, but some of those continue on existing ‘classic’ lines to destinations beyond the high-speed network. There is generally high capacity on the high-speed line.

Germany, Austria and Switzerland have built new high- speed lines that allow mixed high speed, conventional and even freight trains to operate to destination on existing lines. These tend to have lower capacity reflecting limited demand.

Andrew talked about the discipline and opportunities offered by closed systems which are similar to those of a metro – managing all aspects of the operation to maximise capacity. The issue of demand is critical, there’s no point building the railway if the demand isn’t there. Moreover, if there is demand for a new railway, then it might as well be build it as a high-speed one – the additional cost is comparatively small and the benefits are significant.

Moving onto HS2, Andrew reiterated that HS2 is all about capacity. Britain is growing. In 2008 the population of England was about 52 million, by 2033 it’s estimated to rise to 60 million and to 70 million by 2050. He illustrated the UK with a light-pollution map and superimposed the path of the Y-shaped HS2 line to illustrate that it is planned for HS2 to go where the people are located.

Andrew outlined the operational specification for the core section:

Capacity: up to 18 services per hour each way of up to1,100 people per train, which represents roughly the capacity of three 3-lane motorways;
Availability: operational hours 05:00 to 24:00 (0:800 onSundays);
Reliability: average delay less than 30 seconds per service;
Journey times will be based on up to 360km/h maximum speed balanced with environmental impact;
Reduction of whole journey time – station design,service frequency will both be part of the mix.

He then moved on to infrastructure maintenance specification. Bluntly, he said infrastructure maintenance is still in the dark ages. Anyone running trains at speeds of 100m/s or more (360km/h) really ought to know on a continuous basis that it’s safe to do so and it should rarely, if ever, cause service-affecting delays. His outline maintenance specification is thus:

Automation of examination/condition monitoring;
Preventive servicing;
Mechanisation of maintenance (replace not repair);
Largely rail-based;
Standardised elements;
‘Factory’ approach throughout.

Building on his comments about the whole journey, Andrew showed a number of cartoons that had been produced when interviewing potential customers on their wants and needs from the stations. The challenge for the designers is to provide for many thousands of individual journeys and all sorts of individual needs, but common factors emerge such as ‘no barriers’ and ‘no steps’.

Andrew foresaw that customers should be able to navigate the station to their train using satnav style spoken instructions though their smart phone, based solely on knowledge of their current location and their train time/seat number. Clearly there are a number of developments required to make all this happen, not least the ticketing system to enable ‘barrierless’ travel.

His team is already modelling the performance of the line as it is being designed using BIM (Building Information Modelling), which allows all elements to be integrated in a virtual world to ensure they all work together before anyone starts building anything.

Metro – a digital incubator for high-speed rail

Andrew Love and Doug Blanc of SNC-Lavalin argued the proposition that the integrated approach of modern metros provides a working model for closed system high- speed systems.

For example, metro CBTC systems do today what it is hoped the ETCS level 3 might do at some point in the future. However each supplier’s CBTC system is proprietary and the trains and infrastructure both have to have the same system.

It is also fair to say that few, if any, metro CBTC systems cope well with freight (engineers’ trains in metro-speak). Metros usually have the advantage of integrated management, ability to specify the whole system and have relatively small fleets/infrastructure compares with most main line railways. However, taking the system design principles and applying them to the HS situation is a valid proposition.

All in all, it was interesting to hear of the various developments, both in the UK and overseas. Whilst there were some differences of opinion, speakers generally agreed on the way forward. The only significant divergence of view was about the proposed station track layout and length of points, with Felix Schmid advocating the Japanese short points whereas HS2 is proposing something that takes up more space but is likely to have headway benefits.

Andrew McNaughton summed it up pretty well when he said, in response to a question, “Well, decisions have to be made”.

Written by Malcolm Dobell

Collaborating on the Red Arrow

4th November 2016

The term “Jack of all trades, master of none” dates back to Elizabethan times, with one William Shakespeare being on the receiving end of an early version. Today’s railway industry is very complex technically. The supply chain is made up of many small companies, each with its own specialisation, and several giants who provide a broad range of services and products. To prevent them being “masters of none”, they employ a host of specialist engineers and technicians, masters in their own fields, and combine that knowledge and experience to provide a complete offering.

Even so, every company will still have its strengths and weaknesses. The latter may not necessarily be technical, but could be geographical or political.

On many occasions, the company’s strengths allow it to win supply contracts from its customers. However, there are occasions when the weaknesses might prevent that, or at least throw the result into doubt.

Pragmatic managers are therefore quite prepared to collaborate with other concerns whose own strengths and weaknesses counteract theirs. Joined in a collaboration or joint venture, the result should be almost only strengths, and very few weaknesses.

Planning for speed

This was the case when Italian state railways (Ferrovie dello Stato – FS) first started to consider a new very-high-speed train for its Eurostar Alta Velocità Frecciarossa (Eurostar high speed Red Arrow) services operating Turin-Milan-Florence- Rome-Naples. New lines from Milan to Bologna (opened 2008) and Bologna to Florence (2009) would then combine with the older Direttissima line (1977-1986), resulting in a high-speed corridor between Milan and Rome. Another new line (completed 2009) would take trains on to Naples.

To have a train design ready for the new route, Bombardier and AnsaldoBreda (now Hitachi Rail Italy) started working together in 2008. A design office was established by the joint venture at Bombardier’s Hennigsdorf plant, pulling together experts from various locations around Europe.

“It was not just Germans and Italians,” remembers Marco Sacchi, Hitachi Rail Italy’s head of engineering. “There were Spanish engineers from Trápaga, bogie designers from Derby and an electrical power team from Västerås in Sweden.”

Bombardier personnel were responsible for the concept and detailed design of the trains, the provision of propulsion equipment and bogies, as well as project management, engineering, testing, homologation and commissioning of the first five trains. AnsaldoBreda personnel were looking after the industrial design, carbody, interior, interior systems, doors and signalling, together with final assembly and commissioning of the series production trains. Both parties were involved in detail design and engineering activity.

“But everybody worked in one office,” adds Marco. “It was a strong team to develop the train. It was a very challenging time, the customer had big demands for both technical solutions and aesthetics.”

In terms of performance, the team was working to produce a train capable of 350km/h (217mph), even though the high-speed lines had not yet been upgraded to allow for running at that speed.

As for the aesthetics, Italy has more than its fair share of design houses that have, over the years, produced some stunning cars. It was to one of these, Bertone, that the joint venture turned to design the shape of the new train. The design brief was complex. Bertone was asked to come up with a style that represented “elegance and speed”, but it would have to include crash protection, meet driver visibility standards and also take account of the functionality of the headlights in terms of international railway standards.

The result was an elegant cab with an elongated nose that incorporated the crash protection structures. The joint venture team checked the submitted design, both theoretically and in the wind tunnel where drag coefficients and crosswind stability were assessed, and found that it didn’t need any changes. The Bertone design had ticked all the boxes.

Changed requirements

After two years of hard work, the design was ready. The team only had to wait for the official invitation to tender and then submit its proposal.

But…

When the documents were opened, all was not as expected. FS, and operator Trenitalia, was now looking for a train with a maximum operating speed of 360km/h, not 350. In addition, the train would have to be able to operate in seven countries across Europe and there was a requirement for condition-based maintenance.

With six months to revise the design, the team was re-established at Pistoia in Tuscany, home of AnsaldoBreda. Almost everything had to be checked and revised.

The new top speed had implications for the design of the bogies, power and control systems and pantograph. The aerodynamics and crosswind stability had to be rechecked. Room had to be found for a number of new signalling systems, although this would be passive provision with the trains to be delivered only with ERTMS level 2 and the legacy Italian system. Power supply and cubicles for other systems would be in place, in case other signalling was to be installed later.

Of course the joint venture’s competitor, Alstom, had the same challenges, but in the end it was Bombardier/AnsaldoBreda that won out.

“I believe we won as we had some special solutions that were appreciated by the customer,” Marco explained. One example of these was the provision made for customers in wheelchairs. As well as having space to park them, and access to the disabled toilet, the walkways are wide enough that a wheelchair can move about the train and visit the Bistro.

Production

An order for 50 eight-car trainsets, worth around €1.54 billion, was signed in September 2010. Detailed design commenced immediately and the first mock-up was shown to the world at Rimini on 19 August 2012. Now called the Frecciarossa 1000, it was also shown at InnoTrans that year where, being a mock-up rather than a finished train, it was parked on a pavement not the railway tracks. Still, the striking looks attracted a lot of attention.

Incidentally, also in 2012, FS retired the Eurostar name and the new trains were to be destined for the Frecciarossa (Red Arrow) service, representing the fastest trains. Other services are categorised as Frecciargento (Silver Arrow) and Frecciabianca (White Arrow).

The first actual train was unveiled at the Pistoria factory on 26 March 2013. In a short ceremony attended by representatives of both companies, as well as FS Group chief executive Mauro Moretti and Mrs Lilli Bertone, the new train was named ‘Pietro Mennea’ after the Italian sprinter and European 200 metres record holder who had died only five days earlier.

Testing commenced in August 2013 on the Genoa-Savona line and then moved to night time running between Milan and Bologna. To save time, five trainsets were involved in the testing programme, which included 10 per cent overspeed tests on a specially prepared length of line. During these, the train recorded an actual speed of 399 km/h.

Testing was complete by 25 April 2015, when the president of Italy, Sergio Mattarella, boarded the train in Milan for an inaugural run to Rome, where it arrived just three hours 39 minutes later.

Commercial services commenced in June 2015, with 36 trains in revenue service as of September 2016. Today, the final cars are in production and trains are leaving the factory at the rate of two every week. The last train will enter service next year.

Legacy and the future

So the joint venture between Bombardier and, now, Hitachi Rail Italy can be judged a success. A 10-year service contract for the trains has been awarded to the consortium by Trenitalia, worth €250 million. Work on the high-speed lines should shortly result in line speed being increased from 300km/h to the full potential of the train – 360km/h (224mph).

There seems to have been true cooperation and collaboration between the two parties. Marco Saachi has stated that there were very few ‘black boxes’, in which one of the two companies hid their proprietary technology. The team used English as a common language although, by the end, the Bombardier engineers were quite fluent in Italian.

He then looked back at the whole experience of designing and producing the new train.

“It was a fantastic experience for all the people who worked on this project. It was a very important experience, unique really, to develop a train on this level. The customer has declared that, after three months of revenue service, it was the easiest introduction of a new train into service in their history. That is fantastic to hear.”

Also after three months, the train has hit all of its reliability targets. So would the two companies work together on another project?

“We already are,” Marco replied. “Having developed a good way of working on the Frecciarossa 1000, we (Bombardier Transportation and Hitachi Rail Europe) have jointly designed and bid for a new tube train for London. The success of our first project has shown that, by combining our strengths, we can have the best of both worlds and create a really compelling offer. Also, there are a lot of things we’ve learnt so, if the bid is successful, it will be easier the second time around.”

What is Marco’s abiding memory of the project? “To improve the functionality of the team, we had a meeting for three days in the Tuscan countryside, with support psychologists and everything. It was a great thing to do and, over some nice dinners, the team really came together well…”

There are some advantages in building a train in Italy!

Thanks to James Rollin (Bombardier), Adam Love (Hitachi Rail Europe) and Alessio De Sio (Hitachi Rail Italy) for providing the background material for this article.

Written by Nigel Wordsworth

And now Hydrogen Power – Alstom’s new fuel cell powered train

4th November 2016

I first saw a hydrogen fuel cell locomotive four years ago, at the Stapleford Miniature Railway near Melton Mowbray in Leicestershire. A team from Birmingham University had entered a fuel cell powered one-fifth scale locomotive in the Institution of Mechanical Engineers’ Railway challenge. If someone had told me then that a full-sized fuel cell train would be launched just four years later, and that I would be writing about it, you could have “knocked me down with a feather” (on both counts).

It was therefore quite a surprise to be invited by Alstom to visit InnoTrans in September 2016 to witness a product launch that was widely speculated to be a fuel cell powered passenger train. This visit also included a tour of Alstom’s Salzgitter plant where these trains are being manufactured.

iLint launch

The world is committing itself to targets to reduce CO2 emissions, some of which are tough and with no obvious means of delivery.

It is frequently held that railways are inherently environmentally friendly due to the extensive use of electric trains. However, as the UK has learned, electrification can be very expensive and, increasingly, there are views that electrification might not be viable for any lines other than those attracting significant volumes of traffic. The challenge of significantly reduced or zero-carbon trains on non-electrified lines is therefore likely to remain.

In general, these un-electrified lines are operated by diesel multiple units. Just four countries, Germany, UK, Italy and France (in descending order), operate two-thirds of Europe’s DMU cars, and it is suggested that the annual market value of Europe’s DMU market is some €650 million.

The potential market is significant and Nick Crossfield, Alstom’s managing director for the UK and Ireland, explained that there is a very compelling argument for an electric train that doesn’t require overhead catenary. He added that Alstom has extensive experience with tram vehicles that do not require catenary, and he could foresee a time when catenary electrification would be confined solely to high density or, perhaps, heavy haul routes.

A fuel cell system adds another option to operators to provide high quality transport without the cost or visual intrusion of catenary systems. This, and the political context in Germany (below), led to the development of the Coradia iLint.

Up to now, hydrogen fuel cell proposals have suffered from the lack of ready sources of hydrogen and concerns about performance and range. Is this about to change? We will get to the iLint launch, but, as with most railway issues, the train in isolation doesn’t provide the answer. A carbon-free train requires a system solution, so we’ll start with the infrastructure.

System context

As Alstom’s launch was in Germany with a train for the German market, the German context is as good a place to start as any.

Clearly, any mass exploitation of hydrogen technology will require some sort of infrastructure to provide the fuel to enable relatively unrestricted operation of vehicles. This is usually more than any one organisation can manage. It needs political will to provide the environment and the infrastructure.

Germany has committed to reducing its CO2 emissions by 40 per cent by 2020 (compared to 1990) and to using 80 per cent renewable energy in its power supply mix by 2050. Given that about 50 per cent of German railways are not electrified, the need to reduce diesel operation is crucial if German railways are to play their part in delivering the target reduction in emissions. As hydrogen is a source that allows 100 per cent CO2-free traffic, Alstom signed a Letter of Intent (LOI) in 2014 with four German States (Lower Saxony, North Rhine-Westphalia, Hesse, Baden-Württemberg), and another LOI with one additional region (Calw) in 2015, for the development of a fuel cell train.

But where will the hydrogen come from and how will it be distributed? As part of its commitment, Germany has started to invest in a hydrogen generation plant and hydrogen distribution networks. Whilst these facilities may not yet be developed to permit extensive use, a train refuelling depot located next to a compressed hydrogen pipeline, servicing a captive fleet, is the ideal starting point for trials of hydrogen technology.

Manufacture of compressed hydrogen requires a great deal of energy, which could make hydrogen uneconomic, but Germany has invested heavily in wind turbine technology. As part of its energy mix, Germany is using the energy generated by the wind turbines to make hydrogen when electricity demand is low. This energy might otherwise have gone to waste, so can be regarded as almost free.

As this shows, the infrastructure is gradually becoming available and, because German regional transport authorities are pushing for the implementation of emission-free transport technologies, the scene is set for a truly zero- emissions train.

Andreas Knitter, Alstom’s senior vice-president for Europe, confirmed that Germany, with its Hydrogen Association and some support for development costs, was a good place to explore the benefits in practice.

Alstom Coradia iLint

Henri Poupart-Lafarge, Astom’s chairman and chief executive officer unveiled its zero emission train at InnoTrans on 20 September 2016. This is the Coradia iLint, a hydrogen fuel cell version of the Coradia Lint regional diesel mechanical unit which is available in a variety of configurations from single cars though to three car units.

On the Lint, each car generally has an underfloor diesel engine driving through a cardan shaft onto the adjacent bogie. The fuel tank is provided at the other end of the vehicle and, in between, there is a low floor section for reasonably level access at typical regional stations.

The iLint retains the same mechanical configuration to allow the homologation work to be restricted solely to the changes necessary to gain acceptance of the revised drive train.

The prototype trains will be two-car sets, approximately 54 metres long. On each of the two cars, the propulsion system will comprise:

Compressed hydrogen tanks on the mid-section roof of each car;
Hydrogen fuel cell on the trailing end roof of each car;
A body-mounted AC traction motor and converter;
A static auxiliary converter to provide power for the train’s systems and a lithium-ion battery pack to store energy recovered during braking, located in the trailing end underfloor space.

Alstom has partnered with experts in fuel cell and battery technology. The fuel cell (from Hydrogenics) takes hydrogen from the high- pressure fuel tanks (Xperion) and combines it with oxygen from the air to produce electricity with steam and water as a by-product. The fuel cell supplies the auxiliary converter, the lithium ion battery pack (Akasol) and the traction converter.

The efficiency of the system relies on the storage of energy in the lithium-ion batteries. Fuel cells tend to work at their best if they are run continuously at reasonably constant performance. The battery stores energy from the fuel cell when not needed for traction and from regenerative braking when the train’s motors turn kinetic energy into electrical energy. In short, the batteries store the energy not immediately required, in order to supply it later, as needed.

During acceleration, the power of the fuel cell will be used mainly to supply traction power demanded by the traction inverter and to supply the on-board systems (via the auxiliary converter), supplemented by power from the battery. The level of fuel cell power depends on the rate and duration of acceleration – short acceleration phases with limited power demand will mainly be supplied by the battery. Only during longer phases of high power demand will the fuel cell operate at full power.

During phases of lower acceleration, constant speed running or coasting, part of the fuel cell power will be used to recharge the battery and to supply the on-board systems. When the battery is fully charged, the fuel cell output will be reduced so that it only supplies the auxiliary converter/on-board systems. This will reduce hydrogen consumption.

During braking, the fuel cells are almost completely powered down. The traction inverter supplies the DC-link with electrical power generated by the motor from the kinetic energy of the vehicle. This power is used to supply the on-board systems and surplus power is used to recharge the battery, a feature that also saves hydrogen.

In service

The specification included a requirement for minimum change from the established Coradia Lint product and that the standard product’s top speed of 140km/h and range (on a single tank of fuel) of at least 600km be retained.

To successfully introduce a new energy source into routine service, a number of changes will be necessary, not least to depot infrastructure and maintenance arrangements. To make the deployment of the fuel cell system as easy as possible for operators, Alstom will be offering a complete package consisting of the train itself, its maintenance and the whole hydrogen infrastructure. This will allow the operator to focus on its core competence while Alstom and its partners take care of all rolling stock and hydrogen-related matters.

During the launch, Alstom officials were confident that, following homologation in 2017, and pre-service trials in 2018, the trains would be in passenger service by 2019. Moreover, they were also confident of receiving a fleet order by the end of 2016.

Testing and homologation will have to demonstrate that all the changes, both to infrastructure and to the trains themselves, meet the requirements that have been set and are safe. Alstom’s engineers will no doubt be considering the risks arising from the introduction of hydrogen (such as sparks during refuelling, or implications for crashworthiness) and lithium ion batteries (possible runaway failures – the launch coincided with the battery problems reported on a well- know brand of mobile phones).

Returning to the conversation with Messrs Knitter and Crossfield, and the cost of hydrogen fuel, readers may be surprised to learn that it is competitive with diesel – at least in Germany. Andreas Knitter added that Germany has an advanced strategy for rolling out the distribution network necessary for its successful introduction.

As for the opportunities for hydrogen in the UK, this was seen as more challenging than in Germany, partly, because the UK is less well advanced in developing hydrogen infrastructure, and partly because the train would have to be a new design, given the need to design for the UK loading gauge. That said, Nick Crossfield confirmed that Alstom is looking for a suitable UK opportunity.

Alstom Salzgitter

Alstom’s largest rail vehicle plant is in Salzgitter, some 68km south east of Hanover. It occupies a site of area 1.2 million square metres, of which 200,000 are occupied by workshops. Approximately 2,500 people work there.

The Salzgitter plant carries out train and bogie manufacture and wagon repair. Alstom’s activity in this part of Germany started in nearby Breslau when Gotfried Linke began manufacturing rail wagons in 1839. The Linke organisation eventually became Linke Hofmann Busch, before partial takeover by GEC Alsthom in the mid-1990s. It was finally wholly absorbed into Alstom Transport Deutschland in 2009.

Production at Salzgitter restarted in 1949 after a period making what were described as “other things”! In 2015, some 150 trains of various lengths were delivered, over 1,000 bogies manufactured and over 3,500 wagons overhauled.

Burkhard Reuter, operations director of the plant, and Christian Wiegand, global planning director for Germany/Austria, showed Rail Engineer around the facility.

The plant currently specialises in regional trains – particularly the Coradia range – Continental, Nordic and Lint. It is also manufacturing the DT5 U-Bahn cars for Hamburger Hochbahn.

Outline descriptions of the products in approximate order of vehicle size are:

Hamburg DT5 – This is an electric third-rail three-car set. The centre vehicle has two bogies and the end vehicles are suspended off the centre vehicle and mounted on one bogie each. They are constructed from stainless steel, partly unpainted and have open wide gangways through the set. Over 80 of these have been produced in a consortium with Bombardier.
Coradia Lint – A diesel-mechanical rail car design available as a single car, articulated two- car, bogie two-car or bogie three-car sets. They are steel construction, with an entrance height of approximately 630mm or 810mm above rail. Each car’s power pack is rated at 335 kW or 390kW and they have a top speed of 140km/h. Over 900 trains have been built or are on order. The Coradia iLint is based on this series.
Coradia Continental – An electric rail car design available as three, four, five or six-car articulated sets. They are steel construction, with an entrance height of approximately 600mm or 800mm and suitable for 25kV, 50Hz or 15kV 16.23⁄ rd Hz electrical supply. Top speed is160km/h. Over 200 trains are in service with nearly another 200 trains on order or in production.
Coradia Nordic – Based on the Coradia Continental but with a wider carbody to take advantage of the Scandinavian gauge and additional winterisation features for extreme cold weather. They are steel construction, entrance heights are 610mm or 760mm and the top speed is 180km/h. It is currently produced in four and six car articulated sets and for 15kV 16.23⁄ rd Hz electrical supply. Over 300 trains have been built with another 70 trains on order/in production.

The scale of manufacturing plant necessary to build modern steel rail vehicles is impressive. It all starts with steel sheet (bodies) and plate (underframes), cut and shaped precisely and then welded in extensive jigs. Roof sheets are welded flat and then bent and welded to the curved roof frames. Jigs are arranged such that they can be rotated where necessary to allow access for welding to be carried out in the most advantageous way, and some of the welding is carried out in automated plant.

Seeing them side-by-side, it was noticeable that the only significant structural difference between the Continental and the Nordic versions of the Coradia is the flat sides of the former and the curved sides of the latter.

Underframes are necessarily formed of heavier sections than body sides and roofs and the structure on the front end of the end vehicles is even more massive so as to comply with the crashworthiness requirements specified in EN15227.

Once the individual elements have been completed, they are all welded together in a jig and then sent to what was described as the straightening shop which was not visited as it was described as “rather noisy”. This was probably an understatement! In this shop, the vehicles
are adjusted (cue heat and hammers) to correct inevitable distortion during welding. Following this process, the cars shells are sandblasted, inspected and then painted.

The next stage is fit out, using kilometres of cable, great lengths of pneumatic pipes, windows, insulation, doors, traction equipment, compressors, brake equipment, toilets, cladding, pantographs, gangways, floors, seats and luminaires, before the cars are ‘married’ to their bogies. Following that is a static test, and then a dynamic test on the plant’s own electrified test track. The final stage is cleaning and preparation, and then customer inspection.

At the end of the process, a shiny new train, off to carry passengers somewhere in Europe.

Written by Malcolm Dobell

Thanks to Will Roberts, communications director of Alstom UK, for organising the visit to InnoTrans and the factory and to the many Alstom employees who gave their time to support this article.

Photos courtesy of Alstom.