TT-ONR-NRN
Veteran Member
Is 231002 undergoing maintenance? Doesn’t seem to be out in all the time I’ve been back in the UK.
-
Our new ticketing site is now live! Using either this or the original site (both powered by TrainSplit) helps support the running of the forum with every ticket purchase! Find out more and ask any questions/give us feedback in this thread!
Transport for Wales Class 231 / 756 Stadler FLIRTs
- Thread starter DaveHarries
- Start date
Sponsor Post - registered members do not see these adverts; click here to register, or click here to log in
R
RailUK Forums
Bob Price
Established Member
- Joined
- 8 Aug 2019
- Messages
- 1,245
Interesting development. 231009 went on a trip to Aberdare last night. Seen in this Tweet having platform gaps measured. Could this be a precursor to having 756's temporary used on these services making use of the powered overhead until the 398's are ready?
Or just 231s? Or is the entire fleet required to run Rhymney-Penarth services?
Anonymous10
Established Member
I believe nearly the entire fleet is in use on Rhymney line services so would make sense to get the 756s doing something in service ASAP and free up the 150s
I believe the Penarth-Rhymney line requires 9 diagrams. Most of which are 231s (with the odd Sprinter sometimes used) so with a couple of 231s for maintenance each day that is the entire fleet.
It would make sense to put any 756's that are ready for service on the Rhymney route and move the 231s to where they are meant to be going, Maesteg, Ebbw Vale and Cheltenham, once the remaining 170s have gone if they want to free up more Sprinters.
It would make sense to put any 756's that are ready for service on the Rhymney route and move the 231s to where they are meant to be going, Maesteg, Ebbw Vale and Cheltenham, once the remaining 170s have gone if they want to free up more Sprinters.
CapitalStar378
Member
- Joined
- 22 Jun 2013
- Messages
- 610
Except that the Rhymney line doesn't have any OHLE in place so would be tricky.
DanNCL
Established Member
756s are bi mode. No technical reason why they couldn't run entirely on diesel as an interim measure.
stevieinselby
Established Member
The diesel generators in the 756s produce more power than a 2-car Sprinter and about the same as a 3-car Pacer – sure, the train is probably a bit heavier, but with electric traction is that not enough to keep to time on those slow branch lines?
CapitalStar378
Member
- Joined
- 22 Jun 2013
- Messages
- 610
The diesel engine is for back up only, could not run the whole line on diesel/battery. These are the tech. details (from Wikipedia page);
- On AC power:
- 2,600 kW (3,500 hp)
- On battery power:
- 1,300 kW (1,700 hp)
- On diesel power:
- 480 kW (640 hp)
craigybagel
Established Member
- Joined
- 25 Oct 2012
- Messages
- 5,830
Do you know this as a fact or are you just making assumptions?
I don't recall seeing anything that the 756 diesels are explicitly for backup only, so in the absence of anything to contrary assuming that they could run indefinitely on diesel seems reasonable enough.
That said, even though the 756 diesel does generate 54 kW more power than both engines on a 150 combined, they may still struggle a bit given that a 756 will weigh a fair bit more, and not all of the engine output will make it to the traction system.
Fuel capacity will almost certainly also be a limiting factor to diagramming flexibility.
That said, even though the 756 diesel does generate 54 kW more power than both engines on a 150 combined, they may still struggle a bit given that a 756 will weigh a fair bit more, and not all of the engine output will make it to the traction system.
Fuel capacity will almost certainly also be a limiting factor to diagramming flexibility.
TT-ONR-NRN
Veteran Member
Pretty poor if a bi-mode can’t run a two hour round trip on diesel.
56xx
Member
And Merthyr Tydfil.
2 units was a guess based on how many are usually taken out for maintenance from a fleet of trains..
Perhaps just 1 is taken out daily.
Peter Sarf
Established Member
Not really enough diesel power.
I think it is the lack of overhead wires that will limit the 756s.
Not enough diesel power compared to a 231 - just 25% iirc.
The power car on a flirt has space for four power modules.
On a 231 all four modules are diesel engine modules.
On a 756 only ONE module is a diesel engine and three modules are batteries.
That is if I remember correctly but I am sure it was a lot less diesel power on a 756 than on a 231 because I remember being disappointed that 756s won't be as powerful on diesel as a 231. Blame the batteries !.
Last edited:
TT-ONR-NRN
Veteran Member
And it’s so ironic, serviceable 756s waiting for Caerphilly wires and Pontypridd wires waiting for serviceable 398s.
craigybagel
Established Member
- Joined
- 25 Oct 2012
- Messages
- 5,830
All day long, over and over again, when it's not been specifically designed to be able to do so?
Anonymous10
Established Member
So why not use the 756s on the lines through pontypridd?
stevieinselby
Established Member
Until the wires are switched on (which I don't think has happened yet) it's no better. Even when the wires are switched on, are the Rhondda lines cleared for 756s as there was never any plan to run them there? Is the power supply sufficient for them, when I would imagine they will draw more current than the 398s?
Indeed, the diesel engine is just a backup in case the batteries run out in a tunnel.
Envoy
Established Member
- Joined
- 29 Aug 2014
- Messages
- 3,159
Why don’t they just start the 756’s on the Radyr to Coryton service which already has live wires on the City Line in west Cardiff?
markymark2000
On Moderation
That would be a waste of a train. The city line doesn't carry enough passengers to 1/4 fill a 153, let alone a 4 carriage train. Complete waste.
Envoy
Established Member
- Joined
- 29 Aug 2014
- Messages
- 3,159
I was just thinking that it would be somewhere to use a modern train which was also partly wired and would help with crew familiarisation ready for the longer trips to the heads of the valleys. It would also get rid of smelly unreliable diesels in high population areas. Selective door opening would be used for the shorter platforms. It might also boost passenger numbers once people realise that they have modern trains. More members of the public would also see that an improvement has at long last happened. I thought that some of the 756’s had three cars rather than four?
Last edited:
SuperLuke2334
Established Member
Pretty sure the 3-car 756s were for Coryton. But yes I get your point. I imagine they want to try and induce growth with the South Wales Metro.
TT-ONR-NRN
Veteran Member
How is it a waste when the alternative is having them sat around doing jack? We’ve established they can’t run on Rhymney yet. Mind you, aren’t they intended for the unelectrified Vale of Glamorgan?
SuperLuke2334
Established Member
They are, as well as Barry Island and Penarth, however whether some parts of them are due to be electrified or not I don't know...
Anonymous10
Established Member
And mean more dmus available for other services or to be on standby on Bidston services up north
They do and I think these are the ones that have already been delivered.
Tri-mode. Not bi-mode - don't forget the batteries replacing some of the diesel generators in the middle power module/vehicle.
Or between Cardiff and Barry/Barry Island/Penarth/Bridgend which are currently not planned to be wired (because those lines still belong to Network Rail and are therefore the responsibility of the UK Government unlike the Core Valley Lines which have transfered to Welsh Government control).
It will be ironic once the Pontypridd wires are ready, but are they yet?
Yes, they are meant to be the main (only) stock for the Vale Of Glamorgan. From what I recall around the time of the franchise announcements, KeolisAmey's winning bid promised 100% electric operation on the Welsh Government's bit of track (Core Valley Lines) through the batteries and pantographs on the 756s and 398s. Use of the diesel engine on the 756s north of Cardiff was therefore not part of the plan, but no such commitments were made for the Vale Of Glamgorgan so at the time I assumed that that batteries on the 756s did not have sufficient range to do Cardiff to Bridgend (via Barry) and back so the diesel engine was required for that. I do however also recall reading later that the 756s may in fact be able to go the distance without firing up the diesel at all, but I don't think it was certain.