Transport for Wales Class 231 / 756 Stadler FLIRTs

[Tram Inn SB]

If these are having pantographs added, I wonder whether they'll be upgraded to 100mph maximum speed at the same time? Seeing as I believe they are currently limited at 90?

I really can’t see any point to be honest, there isn’t and won’t be any 100mph certificated track on their operational network.

 

[BillStampy]

Having a quick peek at the December Timetable, most if not all Cheltenhams, Ebbw Vales and Maestegs are pathed as Class 231 DMUs.

The Newport to Ebbw Vales are still classed as 75mph Sprinters, so possibly 153s.

 

[positron]

Having a quick peek at the December Timetable, most if not all Cheltenhams, Ebbw Vales and Maestegs are pathed as Class 231 DMUs.

The Newport to Ebbw Vales are still classed as 75mph Sprinters, so possibly 153s.

I wonder if they plan to order more 231s for the Newport to Ebbw vale routes? It's odd if they're kept as a 197 or 153 longer term

 

[Anonymous10]

I wonder if they plan to order more 231s for the Newport to Ebbw vale routes? It's odd if they're kept as a 197 or 153 longer term

Unless its being used as a way to keep cardiff mainline drivers qualified on them to get them onto canton from swansea and central - as i believe they will be maintained there after the rest of the 15x fleet leaves.

 

[tfw756rider]

I wonder if they plan to order more 231s for the Newport to Ebbw vale routes? It's odd if they're kept as a 197 or 153 longer term

But then we'd have a microfleet of diesel-only 231s after the original 231s are converted to bi-mode over the next 4 years.

 

[Jez]

Are there not enough 231's to cover the Ebbw Vale to Newports as well as the other routes they are going to. 9 diagrams out of a fleet of 11?

If TFW were to keep any of the Sprinters longer it would make sense to keep the 153s as they already need them for the Heart of Wales.

 

[Harpo]

Are there not enough 231's to cover the Ebbw Vale to Newports as well as the other routes they are going to.

Given that Ebbw Vale services seem to be TfW’s first choice for outright cancellation whenever there are ‘more trains than usual needing repair’, would they diagram types that have limited utility elsewhere?

 

[positron]

Given that Ebbw Vale services seem to be TfW’s first choice for outright cancellation whenever there are ‘more trains than usual needing repair’, would they diagram types that have limited utility elsewhere?

Well surely yes? Because then they'd have the more useful types for elsewhere?

 

[Harpo]

Well surely yes? Because then they'd have the more useful types for elsewhere?

My point is that when the Ebbws are (inevitably) cancelled outright again, the units released need to be able to prop up the 197 fleet shortages directly or indirectly. 231s won’t be able to do that given their limitations of use.

 

[trainspotter4]

Quick question on the 231s moving to mainline, for the Cheltenham diagrams, one unit is stabled in Gloucester overnight weekdays - does a 231 unit fit into Platform 3 at Gloucester as it's used regularly to turn back if late.

 

[Cardiff123]

Having a quick peek at the December Timetable, most if not all Cheltenhams, Ebbw Vales and Maestegs are pathed as Class 231 DMUs.

The Newport to Ebbw Vales are still classed as 75mph Sprinters, so possibly 153s.

I'm assuming you can tell this by the paths on RTT going from a 100mph DMU to 90mph DMU? Or do you have access to internal TfW diagram info?

 

[BillStampy]

I'm assuming you can tell this by the paths on RTT going from a 100mph DMU to 90mph DMU? Or do you have access to internal TfW diagram info?

Both that and also on Live Rail Record where it is internally diagrammed as a Class 231.

 

[Richard Scott]

Quick question on the 231s moving to mainline, for the Cheltenham diagrams, one unit is stabled in Gloucester overnight weekdays - does a 231 unit fit into Platform 3 at Gloucester as it's used regularly to turn back if late.

I would think they would fit, sure there was plenty of room spare when 3 coach DMUs went in.

 

[Tram Inn SB]

Given that Ebbw Vale services seem to be TfW’s first choice for outright cancellation whenever there are ‘more trains than usual needing repair’, would they diagram types that have limited utility elsewhere?

The Newport shuttles are the mainline cut first service group, with turn it all at Caerphilly or Bargoed on the Rhymney line.

Unfortunately if your short of units something has to give.

There are at the last time of looking a 158, 3 153s, and at least 4 flerts on Canton Pullman OOS.

 

[SWML9102]

756002 was running around today with a non-multi sign in the cab window. I believe there are planned moves on and off depot in multiple, nothing in service.

 

[positron]

But then we'd have a microfleet of diesel-only 231s after the original 231s are converted to bi-mode over the next 4 years.

When did I say they'd be diesel only?

 

[trainspotter4]

756002 was running around today with a non-multi sign in the cab window. I believe there are planned moves on and off depot in multiple, nothing in service.

There is a lot of units generally with non-multi being displayed, I've seen it across multiple 197 and 150s in the last week or so, wonder what's the reason for it.

 

[tfw756rider]

When did I say they'd be diesel only?

Class 231s are diesel multiple units (with electric transmission). When they're converted to bi-mode units (overhead AC electric mode and diesel mode), they'll be reclassifed in the 7xx range (as explained in post #3,320).

 

[AdamWW]

Class 231s are diesel multiple units (with electric transmission). When they're converted to bi-mode units (overhead AC electric mode and diesel mode), they'll be reclassifed in the 7xx range (as explained in post #3,320).

You have more faith in the consistency of TOPS class numbers than I do.

 

[TT-ONR-NRN]

Class 231s are diesel multiple units (with electric transmission). When they're converted to bi-mode units (overhead AC electric mode and diesel mode), they'll be reclassifed in the 7xx range (as explained in post #3,320).

Post 3,320 -- that you refer people to -- is speculation on your part. There's nothing to confirm for sure that they'll be re-classified, and I'd avoid making sweeping assertions and presenting them as confirmed facts.

 

[tfw756rider]

You have more faith in the consistency of TOPS class numbers than I do.

Individual TOPS class numbers within a number range (1xx, 2xx, 3xx, 7xx etc.) can not make sense, but the number range used for a class of unit must be the right one to tell Network Rail what it is and what it can do.

You can't have a "231" or any other 2xx-numbered unit drawing massive amounts of power from the electrification (while falsely telling Network Rail that it can't do that, because a 2xx-numbered unit by definition is a "unit with electric traction motors, but which cannot connect to electrification infrastructure while on the move").

 

[tfw756rider]

Post 3,320 -- that you refer people to -- is speculation on your part. There's nothing to confirm for sure that they'll be re-classified, and I'd avoid making sweeping assertions and presenting them as confirmed facts.

Though there's no source or confirmation, the way things work (with additional explanation in my reply to @AdamWW) mean that reclassification to a 7xx number will have to be what happens.

 

[ABB125]

Individual TOPS class numbers within a number range (1xx, 2xx, 3xx, 7xx etc.) can not make sense, but the number range used for a class of unit must be the right one to tell Network Rail what it is and what it can do.

You can't have a "231" or any other 2xx-numbered unit drawing massive amounts of power from the electrification (while falsely telling Network Rail that it can't do that, because a 2xx-numbered unit by definition is a "unit with electric traction motors, but which cannot connect to electrification infrastructure while on the move").

Somehow I doubt that the first digit of a class number is the only mechanism by which Network Rail is aware of power draw (or lack thereof)... Not least because class 802s regularly run on diesel under the wires (how do NR know about this*? Clearly must be something other than the 8 at the start). I can just imagine the conversation in the traction power allocation office: "someone wants to run a service with a class 231. The application says electric power" "well that can't possibly be right, the class number begins with a 2 which means it's impossible for the train to use electricity. They must be imagining pantographs that don't actually exist". Doesn't sound very believable does it...

That said, renumbering would be sensible. I'd go for another class 755 subclass (and personally I'd have numbered the class 756s as 755 too...)


*Yes, I know it's a NR-imposed requirement due to lack of available power

 

[tfw756rider]

Somehow I doubt that the first digit of a class number is the only mechanism by which Network Rail is aware of power draw (or lack thereof)... Not least because class 802s regularly run on diesel under the wires (how do NR know about this*? Clearly must be something other than the 8 at the start). I can just imagine the conversation in the traction power allocation office: "someone wants to run a service with a class 231. The application says electric power" "well that can't possibly be right, the class number begins with a 2 which means it's impossible for the train to use electricity. They must be imagining pantographs that don't actually exist". Doesn't sound very believable does it...

That said, renumbering would be sensible. I'd go for another class 755 subclass (and personally I'd have numbered the class 756s as 755 too...)


*Yes, I know it's a NR-imposed requirement due to lack of available power

I hear you, but 8xx is just the higher-speed version of 7xx. A unit numbered in either of those two ranges either [does] or [can, but might not] draw power from the electrification on the move, whereas 3xx always does and 2xx never can. Yes, there's already some inconsistency there, but because the 231s are 2xx (and therefore can never draw power from the electrification on the move while numbered in that range), they'll have to change to 7xx when they're bi-mode (as you acknowledge).

I think they will be something like 757 though. I think they'll be too different to the 755/4s to be another 755 subclass - even if the weight is different enough from the different interior, they also have a different exhaust system (I've compared them by looking down to the roofs from overbridges). I also, therefore, think that the 756s are even more sufficiently different enough to the 755s to not be 755s (tri-mode rather than bi-mode). [Yes, Great Western Railway were going to have 769s that were going to be tri-mode rather than bi-mode, but with the third mode being DC electric pick-up shoes rather than battery power.]

 

[MidlandRailfan]

Hi - just wondering where 231005 is presently, and if there is any understanding of why it has been out of service for some weeks now.
Any information gratefully appreciated.

 

[BillStampy]

Hi - just wondering where 231005 is presently, and if there is any understanding of why it has been out of service for some weeks now.
Any information gratefully appreciated.

I saw it two days ago on Canton depot, it's currently in the pile up of units waiting tyre turning in the Pullman part of the depot, viewable by any train on the mainline from Cardiff to Bridgend. Hope this helps.

 

[positron]

Class 231s are diesel multiple units (with electric transmission). When they're converted to bi-mode units (overhead AC electric mode and diesel mode), they'll be reclassifed in the 7xx range (as explained in post #3,320).

Still a completely pointless statement to pretend like someone saying 231 obviously means they will be the diesel only version and not the TBD new classification?? How am I meant to refer to them other than as 231s if they don't even have the new class yet.

 

[MidlandRailfan]

I saw it two days ago on Canton depot, it's currently in the pile up of units waiting tyre turning in the Pullman part of the depot, viewable by any train on the mainline from Cardiff to Bridgend. Hope this helps.

Thanks Bill - appreciate your reply…many thanks.

 

[BillStampy]

Thanks Bill - appreciate your reply…many thanks.

Now on it's way to Holyhead for tyre turning hauled by ROG Class 37, 37884. (https://www.realtimetrains.co.uk/service/gb-nr:K00142/2026-06-24/detailed)

 

[MidlandRailfan]

Now on it's way to Holyhead for tyre turning hauled by ROG Class 37, 37884. (https://www.realtimetrains.co.uk/service/gb-nr:K00142/2026-06-24/detailed)

…many thanks - appreciate the update ✔️