TfW class 398 Stadler Citylink tram trains

[Akela]

There were plans for some street running from Cathays previously but I think that got canned when the new SU facade was built because there's no room now even for the 398s with tight curves.

The 398s do unlock other potential services though like perhaps a ponty northern chord etc. But for phase 1 the timetable matters south to abercynon/pontypridd beyond that it's not super important.

Obviously coryton and city line and much of rhymney it's all still very important. It's why I think the metro branding that's used everywhere is unfortunate.

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

Speaking of integration of buses I wonder when the 398s run to central will they finally abandon the 6 bay bus.

They could branch off to Dumbfries Pl south of Cathays, though they’ll likely have to demolish part of the office building on the corner tracks to make space. Either that or branch off before Cathays down North Rd, using the space that used to be where the Glamorganshire Canal was located which is now a car park. Could have new tram stops to serve the Royal Welsh College and Law Courts. Then it would be a case of threading the needle through the city centre which might require splitting the tracks down two streets (sort of like what Dublin and Croydon’s systems do I think) then re-merging them at the end of St Mary’s Street. Would be more expensive than the current on-street running planned but not massively more destructive then the sorts of on-street extensions we’ve seen in Manchester or Sheffield.

 

[tfw756rider]

030 is in public service today. This is the 5th 398 to enter public service.

Thanks for letting us know

The entry-to-service of 398030 'today' (Tue 14/7/26) now means that 5 (of 36) 398s have been in service:

398022/024/028/030/031

The number of 398s still to enter service is down to 31:

398001-021, 398023, 398025-027, 398029, 398032-036

=============================

The overall number of new Transport for Wales (TfW) trains that have been in service is now up to 116 (of 148):

76 (of 77) 197s
All 11 231s
5 (of 36) 398s
All 24 756s

This leaves 32 new TfW trains still to enter service:

1 197
31 398s

 

[56xx]

According to RTT it was cancelled due to a person being hit by a train, but I would expect a lot more disruption for that so unsure if it's a misreport.

According to RTT the 1124 from Pontypridd to Cardiff Bay (398 030) was terminated at Taffs Well due to a problem with the train and the 1254 from Pontypridd to Cardiff Bay (398 031) was terminated at Taffs Well due to a person being hit by a train.

 

[chargesmith]

According to RTT the 1124 from Pontypridd to Cardiff Bay (398 030) was terminated at Taffs Well due to a problem with the train and the 1254 from Pontypridd to Cardiff Bay (398 031) was terminated at Taffs Well due to a person being hit by a train.

Ah apologies, I've mixed up the services.

 

[CapitalStar378]

They can certainly recharge on the wired bits, but it's not necessarily the case that they spend enough time under the wires to replace the charge lost while on the unwired sections each time round. Especially as unlike in Caerphilly I think they can't charge in the bay platform at Pontypridd.

The 398s are using regenerative braking to top up the batteries while away from the wires. I spoke to an TfW engineer on the train at Cardiff Bay last week after my first ride from Queen Street. He said they only use 2 miles of battery power off the wires due to this.

 

[AdamWW]

The 398s are using regenerative braking to top up the batteries while away from the wires. I spoke to an TfW engineer on the train at Cardiff Bay last week after my first ride from Queen Street. He said they only use 2 miles of battery power off the wires due to this.

That makes perfect sense.

But my point still stands, even with dynamic braking.

 

[Last Hurrah]

They could branch off to Dumbfries Pl south of Cathays, though they’ll likely have to demolish part of the office building on the corner tracks to make space.
Either that, or branch off before Cathays down North Rd, using the space that used to be where the Glamorganshire Canal was located which is now a car park. Could have new tram stops to serve the Royal Welsh College and Law Courts.
Then it would be a case of threading the needle through the city centre which might require splitting the tracks down two streets (sort of like what Dublin and Croydon’s systems do I think) then re-merging them at the end of St Mary’s Street.
Would be more expensive than the current on-street running planned but not massively more destructive then the sorts of on-street extensions we’ve seen in Manchester or Sheffield.

The close proximity of the University’s Brain Research Centre (next to Cathays Station) would likely prevent overhead wires on North Road & the City Centre such is the sensitivity of their computers

Overhead wires would otherwise run through to Queen St

 

[AdamWW]

The entry-to-service of 398030 'today' (Tue 14/7/26) now means that 5 (of 36) 398s have been in service:

Though as it turned out, quite briefly! (Thanks for the statistics though).

Earlier today it had an extended call at Taffs Well then partly made up for lost time by skipping Radyr (and I think Llandaf but not Cathays).
So instead of travelling on it I got to watch it briefly as it passed through Radyr.

The close proximity of the University’s Brain Research Centre (next to Cathays Station) would likely prevent overhead wires on North Road & the City Centre such is the sensitivity of their computers

I cannot see any reasonable prospect of street running through the centre of Cardiff but I find it somewhat hard to believe that it would interfere with scientific equipment near Cathays or that the University could exert the power to prevent such a scheme if it did.

(I presume it is scanning equipment that is supposedly affected by overhead wires, not computers).

 

[chrisjo]

(I presume it is scanning equipment that is supposedly affected by overhead wires, not computers).

As first suggested by ...

Cardiff Queen street and Cathays area is also unable to have OLE due to sensitive brain scanning technology located in the area at a research facility.

 

[positron]

Probably best for further speculation on street running or discussion of the electrification to go in the other threads.

Re-398s does anyone know more about why the first unit today didn't run for very long?

 

[chargesmith]

Probably best for further speculation on street running or discussion of the electrification to go in the other threads.

Re-398s does anyone know more about why the first unit today didn't run for very long?

All we know is what it says in RTT which is that the service was cancelled "due to a problem with the train" but this could mean anything, especially if TFW are being cautious with the soft launch.

On the brain scanner thing, I've heard that rumour from another place and it does make sense as CUBRIC where the scanners presumably are is right next to the railway line. But the 398s are in service and are not having issues passing through that section, and Queen Street is OLE free anyway so it would add maybe half a mile of wires?

 

[positron]

All we know is what it says in RTT which is that the service was cancelled "due to a problem with the train" but this could mean anything, especially if TFW are being cautious with the soft launch.

On the brain scanner thing, I've heard that rumour from another place and it does make sense as CUBRIC where the scanners presumably are is right next to the railway line. But the 398s are in service and are not having issues passing through that section, and Queen Street is OLE free anyway so it would add maybe half a mile of wires?

There's also some bridges that might be pushing it for wires underneath so might need to be PES anyway at which point it's extra questionable on whether it's worth it. Fwiw I'm pretty sure that the CUBRIC stuff is real and not just rumours, I seem to recall a video that mentioned that being a problem but that they could work around it at design stage due to their advanced digital twin set-up.

 

[SWML9102]

There's also some bridges that might be pushing it for wires underneath so might need to be PES anyway at which point it's extra questionable on whether it's worth it. Fwiw I'm pretty sure that the CUBRIC stuff is real and not just rumours, I seem to recall a video that mentioned that being a problem but that they could work around it at design stage due to their advanced digital twin set-up.

Yes, interference caused by 25 kV overhead powered trains is a real thing. "Stray currents" as part of earth return path can affect sensitive equipment. Not something that couldn't be overcome, but if you are installing a discontinuous system anyway, it's an obvious section to avoid wiring.

 

[norbitonflyer]

Yes, interference caused by 25 kV overhead powered trains is a real thing. "Stray currents" as part of earth return path can affect sensitive equipment. Not something that couldn't be overcome, but if you are installing a discontinuous system anyway, it's an obvious section to avoid wiring.

This is not a new thing. The Royal Observatory objectted to the extension of the London & Greenwich Railway through Greenwich Park in the 1840s because of the potential for the trains to interfgere with its sensitive instruments.

 

[The exile]

The close proximity of the University’s Brain Research Centre (next to Cathays Station) would likely prevent overhead wires on North Road & the City Centre such is the sensitivity of their computers

Overhead wires would otherwise run through to Queen St

The Centre was only opened in 2016 by which time the railway had been required to build all new structures to accommodate OHLE for years. Seems like gross negligence on several people’s parts to plan and /or permit development of something that would be affected by electric current so close to a busy suburban railway line and the correct response to the University should be “you’ve got until (insert date) to move it. On that date Wires will go live and it’ll be your problem.

 

[Peter Sarf]

The close proximity of the University’s Brain Research Centre (next to Cathays Station) would likely prevent overhead wires on North Road & the City Centre such is the sensitivity of their computers

Overhead wires would otherwise run through to Queen St

Well I thought there were no wires on the railway past the "University’s Brain Research Centre" anyway. So no wires on an alternative road past the front of the university would be no big deal.

In fact I get the impression that the parts of the network that 398s will use on roads around the bay and central station area might not have overhead wires anyway. Granted it (road running) is less opportunity to top up the batteries.

As to whether interference with the brain scanner is true or not. I am inclined to believe it is true. In about 1985 I worked for a firm that had its computer centre near the line at Lewisham - in the end they worked out the occasional computer crash was down to the DC 750V third rail !. I think they were looking at isolating the building with all earthing for the building moved to a long way away via a dedicated cable.

 

[positron]

398031 back out again today.

 

[CapitalStar378]

Well I thought there were no wires on the railway past the "University’s Brain Research Centre" anyway. So no wires on an alternative road past the front of the university would be no big deal.

In fact I get the impression that the parts of the network that 398s will use on roads around the bay and central station area might not have overhead wires anyway. Granted it (road running) is less opportunity to top up the batteries.

As to whether interference with the brain scanner is true or not. I am inclined to believe it is true. In about 1985 I worked for a firm that had its computer centre near the line at Lewisham - in the end they worked out the occasional computer crash was down to the DC 750V third rail !. I think they were looking at isolating the building with all earthing for the building moved to a long way away via a dedicated cable.

The Central to Bay tram line section will not have OLE so will be battery powered only. I'm not sure if there's going to be a charging option at Central or if the Bay OLE will be sufficient along with regenerative braking.

 

[positron]

The only OLE will be on the bay line between Bute Town and Cardiff bay, there's not really a charging option that works at central other than I guess a fixed conductor bar but that would require trunking to get from the main stations OLE setup (which doesn't even cover 6, 7 and 8). So I highly doubt it'll happen.

The 398s have pretty capable batteries it seems and a third of the journey (assuming a central to bay platform 1 shuttle) will be covered with OLE.

 

[AdamWW]

The only OLE will be on the bay line between Bute Town and Cardiff bay, there's not really a charging option that works at central other than I guess a fixed conductor bar but that would require trunking to get from the main stations OLE setup (which doesn't even cover 6, 7 and 8). So I highly doubt it'll happen.

Or a setup with a big battery that uses a relatively low current power supply to charge itself up between uses and can then briefly provide a much higher current, as I believe is used with the GWR fast charge trial.

 

[norbitonflyer]

I recasll fifty years ago at Imperial College's field station at Silwood Park, some sensitive equipment could detect the passage of trains through Sunningdale station, about a mile away. These would be DC of course, and mainly 4CIGs.

 

[chargesmith]

Looks like 031 ran all the planned services today.

The service I was on (0824 to Cardiff Bay) ran fast to Queen Street from Radyr and passed through Llandaf and Cathays but that was because the train in front of it was running late.

 

[tfw756rider]

Looks like the passenger 398 is scheduled for Fri 17/7/26 but not Thu 16/7/26. Does anyone know why this is? Have I missed something?

 

[AdamWW]

Looks like 031 ran all the planned services today.

The service I was on (0824 to Cardiff Bay) ran fast to Queen Street from Radyr and passed through Llandaf and Cathays but that was because the train in front of it was running late.

And with the external speakers used to good effect to warn people of that as the train pulled in.

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

There doesn't seem to be a 398 diagram today. Currently realtimetrains is showing one for tomorrow but that could presumably change.

 

[chargesmith]

And with the external speakers used to good effect to warn people of that as the train pulled in.

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

There doesn't seem to be a 398 diagram today. Currently realtimetrains is showing one for tomorrow but that could presumably change.

Looks like all the testing runs have been cancelled so far today as well.

 

[positron]

Looks like all the testing runs have been cancelled so far today as well.

Maybe they've stopped them all to install the bucket and curtains

I thought maybe they weren't running because they wanted more test paths but if they're not running either that is a bit odd. Perhaps the people with the knowledge aren't available today? Hard to know, I guess if they're back out tomorrow it's probably not a major concern.

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

https://www.realtimetrains.co.uk/service/gb-nr:G39705/2026-07-17/detailed

Cancelled from WTT today
17th July 2026 only

Does this mean the path is cancelled tomorrow too?

 

[Benjwri]

Does this mean the path is cancelled tomorrow too?

Appears to be cancelled tomorrow yes.

 

[AdamWW]

Appears to be cancelled tomorrow yes.

I'm seeing the usual path from the depot to Pontypridd and a return at at 16:10 tomorrow on Realtimetrains.

 

[Benjwri]

I'm seeing the usual path from the depot to Pontypridd and a return at at 16:10 tomorrow on Realtimetrains.

If you look on the left hand side they are listed as 'Cancelled from WTT today'. The runs have just been cancelled in Darwin as well.

 

[chargesmith]

Maybe they've stopped them all to install the bucket and curtains

I thought maybe they weren't running because they wanted more test paths but if they're not running either that is a bit odd. Perhaps the people with the knowledge aren't available today? Hard to know, I guess if they're back out tomorrow it's probably not a major concern.

Lack of trained staff would be my guess - summer holidays are coming up!