TfW class 398 Stadler Citylink tram trains

[VR494]

The problem with abandoning the 398s is that it's not just the 398s that would be abandoned.
Without the 398s, the Taffs Well depot would be mothballed, any aspirations for on-street running in Cardiff (which is a large part of Cardiff Crossrail) would be gone, 4tph to the Heads of the Valleys is gone, and EU funding would need to be returned if 4tph to is not achieved. There's too much at stake to just abandon the 398s now.

It’s a real mess that’s going to cost a lot of money to put right.

 

[BillStampy]

I’m sorry to be repeatedly negative, but I can’t see these things happening. They need to cut the loss and look at alternatives.

The May times they’ve promised are not going to happen, the mainline is going to short of units for the uplift they require.

They had planned to have them out for June, but this is not happening now.

Aren't Flirts meant to be moving soon anyway? I think regardless of whether these are ready or not units are going to start moving along. A Class 756 broke the Bargoed zone into Rhymney for the first time in passenger service yesterday and they're supposedly meant to be moving soon according to a friend of mine who has internal information. This, obviously, could now be different with another delay to the 398s.

IF the Flirts begin moving, we could see 150s return to the TAM lines, which I doubt would be met with any popular opinion from the public.

 

[bahnause]

Speaking to various sources in the know, what may have been the cause here is the excessive heat that has been generated from the electromagnetic braking system, which may have resulted in a serious episode of brake fade.

The 398’s primary braking system is an electronic, regenerative braking system, combining a hydraulic disc system for lower speeds. The heat from the system dissipates, but in this case, the wheel set has overheated, excessive running at high speeds and stop start work maybe? Trams don’t usually travel around all day at these speeds.

The only backup is a magnetic system which applies to the rails, and that also supposedly didn’t work either when it was demanded by the crew. There is also a lack of fire detection on the units and crews would be unaware of a fire on the unit.

The idea that a wheelset would overheat due to regenerative braking or a hydraulic disc brake is beyond me. Both systems don't even touch the wheels. The Citylink has been used for years on many networks at speeds of up to 100 km/h. Chemnitz, Karlsruhe, Szeged, Alicante, Saarbrücken... It seems to work everywhere but in Wales. It must surely be the train at fault...

The magnetic brake is not a backup system, but an additional one that is only used for emergency stops. It is neither used nor designed for normal operations. Depending on the speed and mode (tram or train), it may or may not activate.

 

[Daniel Boone]

Do we know how much (if any) support Stadler is providing at this stage?

 

[VR494]

The idea that a wheelset would overheat due to regenerative braking or a hydraulic disc brake is beyond me. Both systems don't even touch the wheels. The Citylink has been used for years on many networks at speeds of up to 100 km/h. Chemnitz, Karlsruhe, Szeged, Alicante, Saarbrücken... It seems to work everywhere but in Wales. It must surely be the train at fault...

The magnetic brake is not a backup system, but an additional one that is only used for emergency stops. It is neither used nor designed for normal operations. Depending on the speed and mode (tram or train), it may or may not activate.

It’s only what I’ve been told, something has overheated the braking system. They are trying to use these intensively as trains, which they are really not designed for really, and James Price said himself on Green signals during the interview they are having problems, and they don’t seem to work like in europe.

I’m sure Stadler will be providing full support and whether it’ll be a simple fix, only time is going to tell.

== Doublepost prevention - post automatically merged: 10 May 2026 ==

Aren't Flirts meant to be moving soon anyway? I think regardless of whether these are ready or not units are going to start moving along. A Class 756 broke the Bargoed zone into Rhymney for the first time in passenger service yesterday and they're supposedly meant to be moving soon according to a friend of mine who has internal information. This, obviously, could now be different with another delay to the 398s.

IF the Flirts begin moving, we could see 150s return to the TAM lines, which I doubt would be met with any popular opinion from the public.

The plan is to deploy the 150’s, or what is left of them until things are sorted out.

 

[Chris125]

It’s only what I’ve been told, something has overheated the braking system.

Has it occurred to you that your source might not be 100% accurate and objective?

 

[bahnause]

It’s only what I’ve been told, something has overheated the braking system. They are trying to use these intensively as trains, which they are really not designed for really, and James Price said himself on Green signals during the interview they are having problems, and they don’t seem to work like in europe.

Running as trains and trams is exactly what they are designed for...

 

[chargesmith]

Has it occurred to you that your source might not be 100% accurate and objective?

Whilst I doubt most of the speculation posted on this forum (something I didn't think was encouraged by the forum owner I would add), this does appear to be plausible as no test runs have run since the 6th May (I believe) so something has stopped the runs - even if it isn't this exact reason.

 

[Chris125]

Whilst I doubt most of the speculation posted on this forum (something I didn't think was encouraged by the forum owner I would add), this does appear to be plausible as no test runs have run since the 6th May (I believe) so something has stopped the runs - even if it isn't this exact reason.

I've never suggested the issues aren't real, what's questionable is how they're being described and their seriousness. Talk of this fleet being abandoned is fantasy, and they'd only be replaced by more tram trains anyway.

 

[chargesmith]

I've never suggested the issues aren't real, what's questionable is how they're being described and their seriousness. Talk of this fleet being abandoned is utter fantasy.

Agreed. Testing failures do not mean the units aren't any good, it means the testing team are doing their job properly.

In any industry, testing is as just as much about finding faults as much as it is proving the product works as described - in a safety critical industry like rail this is even more important.

We'll have to see what happens next but speculation from second hand sources is pointless and I wish people would just stick to facts.

 

[CapitalStar378]

The fact that the 398s have been sat round in Taff's Well for several years is a serious indicator that there are some major issues. The OHLE has been in place and working for quite a while and, apart from the Bay line, seems to be fine.

Unfortunately, TfW's policy of silence does not help the speculation on what's actually going on. Let's hope that the new government are a lot more open to discussing the reality on the ground.

 

[VR494]

Running as trains and trams is exactly what they are designed for...

I don’t think they are primarily meant to be used as a replacement for heavy rail trains though. These are more tram than a train. I’ve looked at the German versions operated by DB etc and they look a lot more robust, even if they are an older design. Not to mention the infrastructure is far more superior.

 

[Chris125]

The fact that the 398s have been sat round in Taff's Well for several years is a serious indicator that there are some major issues.

That can't be assumed, it could just indicate that 398s were a lower priority than other fleets like the 756s and had to wait their turn.

The OHLE has been in place and working for quite a while and, apart from the Bay line, seems to be fine.

Exactly, the key section of electrification for the 398s is only being finished now and then there's the toilet installation programme. Needless to say TfW's resources have been stretched thin in recent years, they can't do everything at once.

 

[Envoy]

I just went to the Stadler website and clicked on Stadler Cardiff - locate on map - and was taken to a place in Liverpool. https://www.stadlerrail.com/en/company/locations

"As an international company, Stadler is represented in 25 countries with 16 production and component plants, eight engineering locations and more than 95 service locations. Along with that, our solutions are in action in 49 countries worldwide. Our workforce comprises employees from over 75 different nations."

 

[D365]

I just went to the Stadler website and clicked on Stadler Cardiff - locate on map - and was taken to a place in Liverpool. https://www.stadlerrail.com/en/company/locations

Stadler Rail Service UK Limited is based in Liverpool, yes.

 

[AdamWW]

I don’t this they are primarily meant to be used as a replacement for heavy rail trains though. These are more tram than a train. I’ve looked at the German versions operated by DB etc and they look a lot more robust, even if they are an older design. Not to mention the infrastructure is far more superior.

I can't see how it matters what they happen to be replacing.
They are running on lines with relatively low speeds and frequent stops, aren't they?
Seems not an unreasonable use for something more at the tram end of things.

Manchester bought trams and successfully ran them on formerly heavy rail lines using the same stations. They didn't even call them "tram-trains".

 

[John R]

And Altrincham to Bury is a similar distance too, at around 18.5 miles.

 

[chargesmith]

Manchester bought trams and successfully ran them on formerly heavy rail lines using the same stations. They didn't even call them "tram-trains".

What exactly makes the difference between a tram and a tram-train? Is it interoperability with heavy rail? Or something else?

An independent network with street running and low platforms is clearly trams, but Manchester and South Wales both use heavy rail infrastructure to different ends so is it just a case of different naming choices?

 

[pokemonsuper9]

Is it interoperability with heavy rail?

I think that's the defining factor.

Trams to Altrincham do need additional systems that only about half the fleet have to communicate with the Network Rail signalling and systems (particularly for the level crossings), but they never actually share track with any heavy rail services.

Meanwhile in Sheffield and to be Wales, the tram-trains go from being trams, running on tram rules, to running on the same tracks as heavy rail trains.

 

[Caaardiff]

I'm unsure how well the 158 competency in South Wales is holding up considering the units avoid the area like the plague as they're needed on the Cambrian until the 197s are in.
The issues with the 398s are raising concerns. For my personally, I'm particularly concerned about how much the fleet is being stretched, particularly as Canton now have a backlog of units on depot waiting for availability at one of the north wheel lathes whilst Canton's is out of action, passing on the mainline there's a line-up of FLIRTs, 150s and 153s.

It's not good!

Cardiff crews that work north still sign them and use them frequently.
Other links based in the South either never had or are losing competency.
It would be a case of retraining or finding a way to put them on routes in the north and finding a Depot to maintain them.
Without the 398s the entire fleet cascaded goes out of the window so they'd need to do something.

 

[norbitonflyer]

I think that's the defining factor.

Trams to Altrincham do need additional systems that only about half the fleet have to communicate with the Network Rail signalling and systems (particularly for the level crossings), but they never actually share track with any heavy rail services.

I seem to recall BR (as it then was) insisted on some special precautions for the Manchester system because the trams run alongside main line tracks between Altrincham and navigatuion Road, and in the Victoria area, and a derailed tram - or I suppose a passenger evacuation) could foul one of the running lines, but i don't recall the details.

 

[H&I]

I read early on that they were meant to enter service in the May timetable change. However, looking at recent posts in this thread, it looks like there have been some issues with the testing of these units. Is there an updated entry date into service?

 

[Elecman]

Stadler Rail Service UK Limited is based in Liverpool, yes.

At Kirkdale depot

 

[VR494]

I read early on that they were meant to enter service in the May timetable change. However, looking at recent posts in this thread, it looks like there have been some issues with the testing of these units. Is there an updated entry date into service?

The plan was for early June on the Pontypridd to Cardiff Bay diagrams, there would have been three units in total. Then during the switch on of the Bay branch it was discovered there was not sufficient earthing on the installation.

They then proceeded to advise union officials the plan was to place them on the Treherbert line instead, but I don’t think this going to happen now initially. Concerns were raised about replacing a 4 car 756 with a single 398 and overcrowding.

There’s been more than few issues, the latest one being with the braking system, which resulted in operational activities being suspended. They could possibly be coming back out again soon, and Stadler has been working on a fix I’ve been told. Perhaps tomorrow or Friday you may see one.

The units are unfortunately not performing properly in multiple, even after a software upgrade, and it’s looking very likely they will be running solo for the foreseeable. This may have contributed to the brake control unit issues apparently. The ASDO works on the front but not the back unit. The DOO cameras are insufficient, especially in rain and they need some modifications to the interior saloon. Interoperability issues are also in play around the train’s lights, and that’s why they have yellow stickers on the lower coupler housing. These may have to stay.

The wiring in the couplers is the main issue and is not compatible with other units. They are all individually done by hand I’ve been told, and there is no continuity between units. Again this is not a sole 398 issue and affects other stock on the market.

It’s not been a good time for the DI’s trying to learn the coupling process!

== Doublepost prevention - post automatically merged: 14 May 2026 ==

It’s also worth mentioning that they have been running units in multiple on fault free accumulation runs to maximise the efficiency of the time. If they are unable to run in multiple this will also have an impact on the 1,500hrs and entry into service of other units, with the paths available.

398034 has recently been delivered from the the factory. I think they should focus on this unit, and if the same problems arise on a brand new unit that has not been sat around for years. Then maybe we can see who’s really at fault here.

 

[positron]

I seem to recall that some of them still have the white fronts, does someone have a recent photo to show if they've all been painted?

== Doublepost prevention - post automatically merged: 14 May 2026 ==

I wonder if they might be better off doing a line blockade each weekend for a different branch of the TAM and do an exhaustive back and forth run of units for training or mileage runs? It would obviously be annoying for customers but I think if they explained it was necessary to get this project and the disruption over sooner it might be okay?

 

[H&I]

The plan was for early June on the Pontypridd to Cardiff Bay diagrams, there would have been three units in total. Then during the switch on of the Bay branch it was discovered there was not sufficient earthing on the installation.

They then proceeded to advise union officials the plan was to place them on the Treherbert line instead, but I don’t think this going to happen now initially. Concerns were raised about replacing a 4 car 756 with a single 398 and overcrowding.

There’s been more than few issues, the latest one being with the braking system, which resulted in operational activities being suspended. They could possibly be coming back out again soon, and Stadler has been working on a fix I’ve been told. Perhaps tomorrow or Friday you may see one.

The units are unfortunately not performing properly in multiple, even after a software upgrade, and it’s looking very likely they will be running solo for the foreseeable. This may have contributed to the brake control unit issues apparently. The ASDO works on the front but not the back unit. The DOO cameras are insufficient, especially in rain and they need some modifications to the interior saloon. Interoperability issues are also in play around the train’s lights, and that’s why they have yellow stickers on the lower coupler housing. These may have to stay.

The wiring in the couplers is the main issue and is not compatible with other units. They are all individually done by hand I’ve been told, and there is no continuity between units. Again this is not a sole 398 issue and affects other stock on the market.

It’s not been a good time for the DI’s trying to learn the coupling process!

== Doublepost prevention - post automatically merged: 14 May 2026 ==

It’s also worth mentioning that they have been running units in multiple on fault free accumulation runs to maximise the efficiency of the time. If they are unable to run in multiple this will also have an impact on the 1,500hrs and entry into service of other units, with the paths available.

398034 has recently been delivered from the the factory. I think they should focus on this unit, and if the same problems arise on a brand new unit that has not been sat around for years. Then maybe we can see who’s really at fault here.

Thanks! As they're only coming out to test again on Friday, I take it that there still isn't an introduction date into service.

 

[Peter Sarf]

I seem to recall that some of them still have the white fronts, does someone have a recent photo to show if they've all been painted?

== Doublepost prevention - post automatically merged: 14 May 2026 ==

I wonder if they might be better off doing a line blockade each weekend for a different branch of the TAM and do an exhaustive back and forth run of units for training or mileage runs? It would obviously be annoying for customers but I think if they explained it was necessary to get this project and the disruption over sooner it might be okay?

I get the impression the problem is the 398s are really just not ready yet ?.

 

[XFeed]

The wiring in the couplers is the main issue and is not compatible with other units. They are all individually done by hand I’ve been told, and there is no continuity between units.

I have not followed this thread from the beginning and know nothing about 398s apart for what I have read on here.
My question is regarding the coupling issues. Is it that its only the wiring within the coupler electrical head that is incorrect or is other wiring inside the unit from the coupler incorrect also ?

If its only the wiring within the electrical head that`s the issue why can`t the electrical heads be replaced with electrical heads with the correct wiring versions installed or is it not as simple as that if the couplers are hard wired to the train or does the coupler electrical head wiring connect to the train using connection plugs which if so is a pretty easy change out ?

 

[VR494]

Test runs are currently ongoing between Taffs Well and Treherbert, if things are okay then hopefully runs can recommence next week.

 

[tfw756rider]

I just went to the Stadler website and clicked on Stadler Cardiff - locate on map - and was taken to a place in Liverpool. https://www.stadlerrail.com/en/company/locations

Stadler Rail Service UK Limited is based in Liverpool, yes.

The Cardiff and Liverpool links (the Cardiff link is right below the Liverpool one) both go to Liverpool.

== Doublepost prevention - post automatically merged: 16 May 2026 ==

What exactly makes the difference between a tram and a tram-train? Is it interoperability with heavy rail? Or something else?

Meanwhile in Sheffield and to be Wales, the tram-trains go from being trams, running on tram rules, to running on the same tracks as heavy rail trains.

Though there is the difference that the Sheffield 399s run mostly as trams and do a little bit of train running, whereas the Transport for Wales 398s will be the opposite, mostly being used as trains with a little bit of tram running.

== Doublepost prevention - post automatically merged: 16 May 2026 ==

I seem to recall that some of them still have the white fronts, does someone have a recent photo to show if they've all been painted?

Technically none of them have been painted, as it's a yellow vinyl that doesn't line up perfectly at the sides, fades, crinkles and has leftover traces of the holes being cut for the lights.