A railway running through the forests of west Germany is seeing a very unusual sight at the moment – as a Piccadilly line tube train is running through the area.

What is a Piccadilly line train doing in Germany?

It’s the first of 94 new Piccadilly line trains which will be carrying passengers in 2025, but before that, they need intensive testing before arriving in London, and Siemens Mobility owns one of the world’s largest train testing centres, built on a former RAF base in west Germany.

The new trains are very different to the ones they will replace, with a new lightweight design and plenty of internal improvements. The change that most people will be excited about though is that it will also be the first deep level trains to come with air conditioning.

To fit air conditioning into the trains has been a challenge, and one that’s far more visible than it might seem at first glance.

Officially known as the New Tube for London, the first trains have been ordered for the Piccadilly line, with the intention that, funding permitting, modified versions will also be used on the Bakerloo and Central lines in the future.

The reason London needs new trains is that while the average age of mainline trains in the UK is just 17 years, the Piccadilly line trains are 48 years old, and the Bakerloo line trains are even older, having hit their half-century last year. There’s a need to replace the trains as reliability declines and maintenance costs increase, so in 2018, Siemens Mobility won the contract to supply up to 250 new trains.

An initial 94 trains are on order, with options to buy more in the future. The first batches are being built by Siemens in their Austria factory, but production will soon switch to a new factory at Goole in Yorkshire, where the majority of the trains will be constructed.

There have been a lot of changes in mainline train technology over recent decades, but the challenge that was pointed out was how to fit as many of those improvements into a small tube train. What Siemens has developed is a fully walkthrough train that can carry about 10 percent more people than the current trains, with wider doors, improved information screens and most significantly, air conditioning.

To nip one argument in the bud, the trains will use vapour-compression refrigeration with temperature control but without the humidity control that is typically provided in buildings. Strictly speaking this is an “air cooling” system, however this type of system is widely referred to as an “air conditioning” system when referring to trains and other mobile applications such as cars. And lets be honest, everyone is going to call it air conditioning anyway, so lets not get hung up on technicalities.

The main problem with putting air conditioning in the deep tunnel trains is the lack of anywhere for the heat to go – as the tunnels themselves can’t absorb the heat expelled from the trains.

The solution has taken advantage of an innovative train design, reducing the heat they emit from the engines and brakes. Cooler running trains could help to cool the tunnels, but it would take decades to notice the difference, or they can use that temperature gap between the new and old trains to put air conditioning inside the carriages today.

In effect, the new trains, with air conditioning, will run at about the same temperature as the old trains — but will be considerably more comfortable for passengers.

If a future plan to run even more trains through the tunnels goes ahead, that will require increased cooling in the stations, which, funding permitting, is being developed at the moment.

To fit air conditioning into the trains has been rather an interesting challenge, as air conditioning units are large and tube trains are small, and Siemens Mobility has taken several ideas and put them together to create the space needed. One of the most noticeable, for train geeks at least, is the design of the bogies underneath the trains — the wheels, which have been reduced thanks to the use of walk-through articulated train carriages.

Tall people will also notice a difference, as they’ve managed to squeeze out a few more inches in height inside the carriages, which was noticeable even to this 6ft tall person.

Fewer bogies mean less weight and less energy needed to move the train and a bit more space underneath the train for extra equipment. The air conditioning units themselves slot in underneath the seats, where you might notice the air intake vents with a recessed tube roundel in the middle.

The most significant visual change though is in the windows, as Siemens needed more vertical space for cabling and ducts than could be squeezed in beside the door frames. That’s why instead of two large windows, there are three smaller windows — as the gaps between the windows carry cables and also the cooled air up to the ceiling.

The slightly smaller windows don’t make the trains darker though, as the trains are fitted with modern LED lights, including some very fetching art-deco inspired light rings above the gangway poles.

Another design change is the moquette.

A brand new moquette, called Holden, after the legendary architect Charles Holden, which includes several nods to Picadilly line heritage, most noticeably the design of Southgate station in north London.

You’ll be able to sit on the Holden moquette seat in an air conditioned train in 2025.

But before that, the trains need to be certified for use, which requires a lot of testing, and that’s why there’s a Piccadilly line train in Germany at the moment.

It’s at the former British military base, RAF Wildenrath, which closed at the end of the Cold War, and is now the Wegberg-Wildenrath Test and Validation Centre used by Siemens to put trains through their paces. After an hour’s drive from Dusseldorf and down an inconspicuous road, you can find yourself driving past rows upon rows of mainland Europe sized trains brought here for testing.

Thameslink trains were also tested here, along with several other liveries familiar to British eyes, and now, dwarfed by its bigger European brothers, is a Piccadilly line train.

To show off what the new train looks like, Siemens Mobility invited rail journalists to have a ride, so although mostly filled with test equipment, one carriage was fitted out for visitors to see what the new trains look and feel like to ride in.

The interior looks very much like the final trains, although there are still a few modest tweaks to the design expected as London Underground staff notice snagging issues or ask for changes based on experiences of how Londoners behave in trains. However, as most of those will be imperceptible to the average person, what we’re seeing today is 99.9% of what the travelling public will see in 2025.

The seats will probably get a lot of comments when the trains come into service as they are very different from the existing Piccadilly line trains. The new seats can be described as closer to the DLR in padding, while the existing seats are now so saggy after decades of use that they feel like they’re missing half their springs. So even though the new seat padding levels are in use on loads of other London trains, I’d expect a bit of a reaction when the trains come into service. Personally, I prefer the new seats.

Alongside the internal digital display screens, external displays between the doors will show the train destination and other helpful information.

While the visitors were in the front carriage getting cab rides through the German countryside, engineers were still at work in the rest of the train monitoring their test equipment and sensors. The tests aim to prove that the trains run as expected, prove reliability and iron out any bugs before they go into full production in Yorkshire.

Once the train has been certified, it then has to come to London, where it will be used for extensive tests on the live Picadilly line and build up the mileage to get UK authorisation to carry passengers. The train is expected to arrive next summer, when you will start to see it out and about on the Piccadilly line – initially overnight and during engineering closures, but later during the daytime.

Only then can it start to carry passengers – in early 2025.

As the trains have much wider doors than the current trains, they can spend less time in stations picking up and dropping off passengers, and with 94 new trains replacing 86 old trains, TfL expects that to enable them to increase peak capability on the Piccadilly line from 24 to 27 trains per hour from 2027.

However, that is only the beginning.

Along with the 10 per cent additional space inside the trains and more trains per hour, the net effect is a capacity increase of around a quarter on the Piccadilly line compared to today. There is also a — currently on hold — plan to upgrade the signalling system on the Piccadilly line, increasing capacity from 27 to 36 trains per hour.

While the Piccadilly line trains are heading to London, there’s an option to replace the trains on the Bakerloo and Central lines, but that option expires in late 2026, and TfL has to be in a position to place the order by then otherwise the option lapses and would need to be renegotiated, likely at a higher price.

Companies like options in contracts as they give both buyers and sellers assurance about their intentions and support investment by both parties.

Speaking at the trials last week, Stuart Harvey, TfL’s Chief Capital Officer, confirmed that discussions are still ongoing about long term investment to replace the Bakerloo line trains, which are now the oldest electric passenger trains in service in the UK.

Although the option to buy the trains could be taken in 2026, realistically, it needs to be sooner.

When buying new trains, you don’t just order trains, and that’s it — over the past 50 years since the Bakerloo lines were introduced, the technological improvements in rolling stock mean that 50 year old track equipment can’t offer the benefits needed. So that needs replacing, and they’re likely to need a new depot to store the extra trains, and all that takes years to arrange.

The key message from both TfL and Siemens is that a decision on the Bakerloo line is needed fairly soon. Even if taken immediately, it’s quite possible that people born when the Bakerloo line trains were introduced will have retired from work before the first of the new trains arrives. Which is an heck of a long time to keep trains in use.

In the meantime, as we headed home, the Siemens engineers continued their tests and a Piccadilly line train resumed its loops through the German forest.

Sambit Banerjee, Joint CEO for Siemens Mobility UKI and Stuart Harvey, TfL’s Chief Capital Officer

An unusual view from the front of a Piccadilly line train

Inside the new trains

Seating above air conditioning vents

The train in test mode in the German countryside.

Close up of the moquette

The drivers cab


Be the first to know what's on in London, and the latest news published on ianVisits.

You can unsubscribe at any time from my weekly emails.

Tagged with: , ,

This website has been running now for over a decade, and while advertising revenue contributes to funding the website, it doesn't cover the costs. That is why I have set up a facility with DonorBox where you can contribute to the costs of the website and time invested in writing and research for the news articles.

It's very similar to the way The Guardian and many smaller websites are now seeking to generate an income in the face of rising costs and declining advertising.

Whether it's a one-off donation or a regular giver, every additional support goes a long way to covering the running costs of this website, and keeping you regularly topped up doses of Londony news and facts.

If you like what you read on here, then please support the website here.

Thank you

  1. Andrew H says:

    Great article; very thorough.
    Awful moquette (but we’ll get used to it!).
    Thank you.

  2. NG says:

    All three of today’s “notes” seem to be good news – most welcome & most unusual

  3. Jonathan says:

    Not a fan of the white on the moquette. The Elizabeth line ones are already grey/brown in the middle area of the seats.

  4. Rod says:

    When you change from the Victoria Line at Finsbury Park to the Piccadilly Line there’s quite a temperature drop; it’s the VL that needs the air ‘conditioning’. We’ll probably have to wait 35 more years for it…

    • alistair says:

      The Victoria being entirely underground that makes it harder to cool. puting AC on the trains would just make them hotter in the long run. at least the Picaddilly can blast the AC when overground and slowly warm up underground.

  5. EC says:

    When will the Northern line trains get a much needed upgrade to also reduce painful screeching? Must we wait a further 20 years for the 1995 stock to be mature enough to retire?

    • ianVisits says:

      That’s nothing to do with the trains, and due to a lack of money to maintain the tracks.

    • GEFF says:

      Some tweaks to train speed (too consistant) and drive torque were being trialed but the main initiative is to adust the rails mountings – but this is labour intensive and hence expensive.

    • Dave says:

      Carriages are too long on that line -> longer wheelbase -> noise.
      These look like they have shorter carriages so something like this would be better.

    • EC says:

      I was under the impression that regardless how much maintenance was carried out on the track, it’s the angles that causes the screeching. Such an unenjoyable experience

  6. Dan says:

    It this air cooling the same type of air conditioning that they have on mainline trains and the sub service lines? Or is that full air conditioning?

    • alistair says:

      It’ll be cooling. (eg the same air in the carriage is circulated and cooled, not fresh air brought in, cooled and delivered) there will likely be a separate system to get fresh air in and out (or they might just rely on the doors)

  7. Stewart says:

    These trains go to LHR but I didn’t notice any expanded luggage storage spaces?

    • ianVisits says:

      There’s a lot of things you can’t see photos of – because we only had one carriage for the visitors.

  8. Johnny says:

    They have awfully narrow windows. I’m not talking about the width but the height. The gaps between the windows are perfectly acceptable, but why can’t the windows be higher, like the current trains? Look at the current 1973 trains for example, they have much higher windows. 1992 trains on the Central line have even higher windows. 2009 trains on the Victoria line also has small windows, but that’s perfectly acceptable since they only run underground. For the Piccadilly line with so much overground running, these small windows will be a huge downgrade.

    • alistair says:

      my guess is that is for structural reasons, there are no bogies on 4 of the 9 cars and they are supported off the next cars, it means they can get rid of 2 sets of bogies over the whole train. but these suspended cars will need to be stronger i assume.

      Most of the time there isn’t a lot to see unferground

  9. Johnny says:

    So the air cooling vents will be located under the seats? Then the air cooling will be pretty useless, just a shivering stream of cold air blowing at your feet. If you blow cold air at the floor it will not rise. Cold air sinks, that’s the law of physics. Air cooling intake MUST be at the roof to work properly.

    • ChrisC says:

      The INTAKE vents will be under the seats.

      The cooled air will be introduced into the carriage from the ceiling.

  10. maniacmartin says:

    I personally find the existing “saggy” Piccadilly line seats very comfy so I’ll be sad to see them go. Being a regular commuter on Thameslink Siemens Class 700s and hating their seats, I don’t have high hopes for this new stock’s comfort.

  11. Stewart Clark says:

    As a child, I remember seeing on army maps of Germany an odd road layout around a place called Wegberg.I was told that the layout was the pototype for the Autobahn, a circular road with flying junctions etc. Easy then for circular rails to follow.

  12. Chris Rogers says:

    Not mentioned is whether there are the same number of seats as now – I assume not since all new stock has fewer seats than the last. Yes I know the arguments, I’m just asking. Never found any tube seat ‘baggy’ – they are all fine. If these ones are harder, well, luckily I seldom have to go far on the Picc line…

  13. SteveP says:

    Good news! Yes – heat has to go somewhere. I occasionally use the NYC subway – which as we all know varies (even on the same line) from modern to decrepit between stations. One learns to avoid any carriage with few/no passengers – either the cooling is broken or someone has left a “deposit”. Exiting an overly-cooled NY Subway car onto one of the old station platforms can feel like stepping into an oven

    First rule of the Bakerloo Line is “bring earplugs”. Perhaps I will live to see new (quieter) cars in use there. Time will tell

  14. Ray White says:

    That test track in Germany is interesting, with every kind of electrification on offer. And the conductor rails have guards on them too…

Leave a Reply

Your email address will not be published. Required fields are marked *


Home >> News >> Transport News