No time to waste: third-generation trains in the spotlight

It has been argued that while the UK rail industry is now introducing rolling stock that is more advanced than ever, the time has come to focus on pushing the envelope even further with pioneering designs. But what defines third-generation railway cars?

Class 700 Desiro City

If a passenger happens to board a new Desiro City train on Thameslink, or, for example, the Class 345 stock which in June made its first appearance on the Elizabeth Line, they are stepping on to what can be classed as second-generation trains.

These are a considerable step up from some of the older rolling stock that still weaves its way through the UK’s rail network. They of course have that ‘freshness’ of anything that is new, with more space to accommodate rising passenger numbers, air conditioning as standard, better access for wheelchair users and improved connectivity to the internet, not to mention the technology in the cab.

However, now is the time to imagine what will come after this, according to Philip Heathcote, sales director, Siemens Rail Systems, and Graeme Clark, head of business development (rolling stock), Siemens Rail Systems.

Here, they delve deeper into what the third generation of trains will include and how hydrogen power could be rail’s next groundbreaking innovation.

Gary Peters: Before we analyse the next wave of trains, could you tell me how advanced the current second-generation is?

Philip Heathcote: Second-generation saw a number of improvements [compared to what went before it]. Trains are lighter, around 20% lighter, and one of the consequences of that is they consume less energy. Fundamentally the technology is 'fly by wire', and therefore they have less moving mechanical parts.

There's also a step-change in reliability and they are more spacious. It makes the passenger space lighter, brighter and less claustrophobic. When you put them side by side [with first-generation], even the uninitiated could see the difference without knowing what was happening.

GP: On that note, what defines third-gen and how does it differ from the second?

PH: The trend of weight reduction will continue, as will reduced energy consumption. Also, I think we might see different materials being used; perhaps the application of composites to take weight out, which we have seen in the automotive and aerospace industries. I think that's a natural progression.

Moreover, it will be about 'under the skin' of the train, around how the train is maintained. We'll have more self-diagnostics; the train will know what is wrong with it and send messages back to the maintenance location, so the maintenance team know what works needs to be done before the train arrives. That can become a quick pit stop.

GP: So, it’s about a much more data-heavy train?

PH: [Yes] and because the train is much more data-rich, we'll be able to monitor trends and patterns and ultimately build that knowledge to repair the train before a problem occurs, as you can then see the indicators of what will happen next. Trains will be much more intelligent.

On the land side, the train will go through some kind of diagnostic 'loop', so that some tasks that are today done manually will be automated. The other area where we will go is different power sources for trains.

We need to think again – not dissimilar to automotive – about batteries, which perhaps might be ideally suited for shorter distances, between 75km and 100km. For longer distances, it will be perfectly viable to have hydrogen-powered rolling stock.

Graeme Clark: To add on that, if you came across a structure that was particularly difficult to electrify, you could use the battery to get the train through the tunnel, for example, without needing to electrify that section. 

If you look at the periodic table, the issue with hydrogen is that hydrogen and hydrocarbon fuels, which are made up from carbon and hydrogen, is at one end and carbon is at the other end. So, you'd have a situation where, if you compare it to diesel, you need about nine times the volume of hydrogen storage as you do with diesel. However, that will change in the future as you’ll be able to store liquid hydrogen on trains.

GP: What sort of timeframe are we looking at here?

GC: I think for battery and hydrogen you're talking about anytime now. Compressed hydrogen, with the longer range, is probably three or four years away.

PH: I think the early 2020s is certainly feasible to imagine hydrogen/battery-powered rolling stock being far more common. Also, you would like to think that existing diesel rolling stock will be phased out and replaced, because the carbon footprint is so much lower with alternative sources of energy.

GP: What about for passengers? How will it change for them?

PH: It will continuously evolve, but I'm not sure there will be any huge differences. Many of those differences we are seeing in the second gen, such as real-time passenger information, for example, and the ability for passengers to know what carriages are crowded before they get on. 

What will happen over time is the quality of things will get better. The WiFi, the connectivity, will get better.

GC: I think you'll be able to know exactly what your whole journey is, from the moment you get up to the time you get to work and then get home. That’s much more of a door-to-door experience.

PH: The third gen is more about the technology as opposed to the aesthetic of the environment. We need to think about flexibility in terms of the passenger environment, being able to reconfigure interiors; that may become more of a fixture.

GP: How important is it that next-gen trains are designed to operate on various parts of the rail infrastructure?

PH: It's a little bit of a catch 22. We have an infrastructure and therefore it defines what rolling stock can run on what routes. You could, theoretically, design a universal train that would go everywhere, but you’d have to compromise, making it narrower and shorter, so there would be capacity limitations on certain routes.

The design needs to be flexible enough to move without undue cost and time. The universal train would be great, but I think there might be too many compromises with that. As far as is possible we try to design our rolling stock to go on as many routes as possible, but it needs an intelligent discussion between all parties.

GC: I also see a downward trend in operating costs. High-tech signalling will allow us to run trains much closer together. There is a limit to how many trains you can run if you just lengthen platforms and put more vehicles on. The secret to getting to the next stage is running them closer together.

PH: Yes, the connection between rolling stock and signalling will be closer. Whereas signalling is currently thought of as line side, in the future much more of the signalling capability will be onboard the rolling stock. Therefore, the harmonisation between the two will be better.

GP: We have apps for passengers to see how busy trains are, but often they rely on crowd-sourced data. Could the next gen do that automatically and perhaps send the information to passengers?

PH: The new Thameslink rolling stock we are bringing in does that already. It detects how many passengers are in a carriage. There's an indicator on the outside that shows how busy it is and that is connected to an app.

The next step is to connect it to the signage at stations, so those who don't have the app can see it. That technology is starting to be introduced in the second gen. By the time we get to third-gen it will just be the accepted norm. We respond to what operators need, and they are under tremendous pressure, both from each other and from other forms of travel. 

I can only envisage it getting more competitive as cities become more crowded. People will be migrating to public transport in greater numbers. People also have an expectation of good public transport. We all get very frustrated if you board a train and the WiFi doesn't work. Passenger expectations are constantly rising. You can't jump onto a train and step back in time; the rolling stock has to be up with the times.