Transport for Wales Class 231 / 756 FLIRTs

[Spirit555]

No, you’ll often find classes where /0 indicates the 3 car variant and /1 indicates the 4 car variant, like 380, 385 - 756 is the same.

Thanks for update

 

[56xx]

231003/5/9/11 yet to work in passenger service.

 

[6Gtraincrew]

231003/5/9/11 yet to work in passenger service.

231005 has just come out to play. Due to work:

2P77 17:02 Cardiff C to Penarth
2R22 17:18 Penarth to Rhymney

 

[Peter Sarf]

231005 has just come out to play. Due to work:

2P77 17:02 Cardiff C to Penarth
2R22 17:18 Penarth to Rhymney

Then I think that makes four 231s in passenger service today ?.

Passenger 231002, 231004, 231005 & 231008.
With 231010 on test/training.

I wonder how long the 769s have left ?.

 

[william.martin]

I wonder how long the 769s have left ?.

The answer is Here

 

[krus_aragon]

To add nnn/0 does not always mean the same number of cars across different classes. Most common is four car takes the nnn/0 slot as that is (has been) the most common length around London and the home counties. Easier to assume /0 means the shortest and /1 the next length but its not hard and fast.

A good example relevant to Wales would be the Class 175: 175/0 are 2-car DMUs, 175/1 are 3-car.

 

[AdamWW]

According to realtimetrains, 2R04 (operated by 231 002) was terminated at Heath Junction this morning "due to a problem with the traction equipment"

And 2R06 (231 008) left Penarth 18 minutes late despite arriving only 2 minutes late.

 

[56xx]

2P39 1027 Rhymney - Penarth cancelled today. Due to be 231 005 which went back into Canton from Central earlier with a problem.

 

[AdamWW]

2P39 1027 Rhymney - Penarth cancelled today. Due to be 231 005 which went back into Canton from Central earlier with a problem.

It does look as if a decrease in reliability has coincided with having more of them in passenger service at a time.

 

[Peter Sarf]

It does look as if a decrease in reliability has coincided with having more of them in passenger service at a time.

Bear in mind an increase in use will be more likely to find staff who are not totally familiar with the new trains. Plus, I imagine, any support available would be more stretched. I noticed on my run last week that the PIS (Passenger Information System) was doing nothing for quite a while after the unit turned round and came back from Rhymney - this might explain some delays changing ends on other days. Two days before I had noticed a 231 stuck at Cardiff Central for about 10 minutes. It then moved off to Canton instead of Penarth - possibly an untrained driver had dropped onto it ?.

 

[AdamWW]

Bear in mind an increase in use will be more likely to find staff who are not totally familiar with the new trains. I noticed on my run last week that the PIS (Passenger Information System) was doing nothing for quite a while after the unit turned round and came back from Rhymney - this might explain some delays changing ends. Two days before I had noticed a 231 stuck at Cardiff Central for about 10 minutes. It then moved off to Canton instead of Penarth - possibly an untrained driver had dropped onto it ?.

Or possibly it had developed a similar fault to the one I was on recently that didn't seem keen to leave Queen Street for more than 10 minutes but was then fixed.

If it's 10 minutes late and the trains aren't busy then I can see good grounds for turning it round in Cardiff rather than continuing to Penarth given that the next train should only be 5 minutes behind it (which is what seemed to happen to the one I was on).

I do appreciate that the problem might be staff not having the familiarity to sort out problems quickly rather than an increase in faults occurring, but whatever the cause from a passenger's point of view I'd argue that reliability is based on whether the train runs to time, not what it might have done had a different crew been on board.

 

[56xx]

It might only mean 5 mins for Penarth but its 1 hour for Rhymney when a full line train is cancelled.

 

[AdamWW]

It might only mean 5 mins for Penarth but its 2 hours for Rhymney when a full line train is cancelled.

I was talking about turning it round at Cardiff rather then Penarth. And if you see a train heading off to Canton instead of Penarth it could be just doing that to turn round, rather than go out of service.

Though if it then formed a service all the way to Rhymney it would be inconvenient for someone who intended to travel there from points south of Cardiff and would miss it by catching the next train.

 

[ac6000cw]

231s are 90mph diesel only units, 756s are 75mph tri-mode (diesel, electric, battery). Also the 756s have an extra door on each side of the unit.

Just out of interest, does anyone know why the 756s are 75mph max (rather than 90 or 100mph like the other UK Flirts)?

The 100mph GA 755s accelerate so fast on OHLE power (2600kW power/200kN starting TE for 4 cars) that it doesn't feel like it's because of needing lower gearing for faster acceleration...

 

[AdamWW]

Just out of interest, does anyone know why the 756s are 75mph max (rather than 90 or 100mph like the other UK Flirts)?

The 100mph GA 755s accelerate so fast on OHLE power (2600kW power/200kN starting TE for 4 cars) that it doesn't feel like it's because of needing lower gearing for faster acceleration...

Maybe just because they're not expected to go anywhere that has a higher line limit?

 

[Peter Sarf]

Just out of interest, does anyone know why the 756s are 75mph max (rather than 90 or 100mph like the other UK Flirts)?

The 100mph GA 755s accelerate so fast on OHLE power (2600kW power/200kN starting TE for 4 cars) that it doesn't feel like it's because of needing lower gearing for faster acceleration...

My only guess is the 756s gearing is optimised for the hard climbs and frequent stops up the valleys which is where they will work when the knitting is done. The 231s however will end up on the South Wales main line so need to be faster to keep out of the way of IETs and less frequent stops. But, as you say, the 755s on 25KV AC do seem to have plenty of acceleration despite their higher top speed. Are the relevant valley lines going to be 100% electrified or are they relying on the diesel engine plus batteries in places ?.

 

[AdamWW]

My only guess is the 756s gearing is optimised for the hard climbs and frequent stops up the valleys which is where they will work when the knitting is done. The 231s however will end up on the South Wales main line so need to be faster to keep out of the way of IETs and less frequent stops. But, as you say, the 755s on 25KV AC do seem to have plenty of acceleration despite their higher top speed. Are the relevant valley lines going to be 100% electrified or are they relying on the diesel engine plus batteries in places ?.

As I understand it the electrification will be intermittent to avoid difficult areas (like bridges, Caerphilly tunnel and I believe Queen Street station) not to mention the bits of track that they will run on that TfW doesn't own.

I don't think the diesel engines are supposed to be required north of Cardiff in normal operation.

 

[Peter Sarf]

As I understand it the electrification will be intermittent to avoid difficult areas (like bridges, Caerphilly tunnel and I believe Queen Street station) not to mention the bits of track that they will run on that TfW doesn't own.

I don't think the diesel engines are supposed to be required north of Cardiff in normal operation.

Thanks for that. So batteries will have more than a minimal/backup use. The gearing on the 756s therefore might be quite important if the 25kV AC, and so the power available, is not 100% on the routes.

 

[AdamWW]

Thanks for that. So batteries will have more than a minimal/backup use.

That's my understanding.

Aslo the fact that the power pack is mostly battery (three battery sets and one diesel generator) presumably shows that the batteries are fairly fundamental to operation.

 

[Rhydgaled]

Remember that when the Welsh Government / TfW re-let the franchise they specified that bidders needed to have an infrustructure development partner to upgrade the Core Valley Lines (the only bit of track that has been devolved to Welsh Government). It wasn't just a Train Operator they were looking to apoint and I think the idea was that the bidders would be submit their own proposals for how much of the Core Valley Lines they could electrify within the available budget.

I seem to recall reading somewhere that one of the critera for bid evaluation was percentage of electric operation on the Core Valley Lines. The winning bid from KeolisAmey offered 100% electric operation on the Core Valley Lines without full electrification by using batteries under bridges etc. as AdamWW said above - the diesel engines on the 756s were only for use south of Cardiff (on Network Rail owned track).

 

[AlexNL]

Why would 756s not use their pantograph when running under Network Rail wires?

 

[Peter Sarf]

Why would 756s not use their pantograph when running under Network Rail wires?

I don't think there are wires to Penarth ?.

 

[AdamWW]

Why would 756s not use their pantograph when running under Network Rail wires?

So far as I know there won't be any wires on the Network Rail parts of the routes they are intended for. (Except I suppose for the odd occasion they may end up in platforms 1-4 in Central)

 

[Rhydgaled]

I don't think there are wires to Penarth ?.

I agree - don't think there are any OHLE wires between Cardiff Central and Penarth. Also no OHLE that I'm aware of to Barry Island and round the Vale Of Glamorgan line through Rhoose to Bridgend (which are pretty much the only other bits of Network Rail infrustructure currently planned to be served by 756s I think).

 

[AdamWW]

I agree - don't think there are any OHLE wires between Cardiff Central and Penarth. Also no OHLE that I'm aware of to Barry Island and round the Vale Of Glamorgan line through Rhoose to Bridgend (which are pretty much the only other bits of Network Rail infrustructure currently planned to be served by 756s I think).

Quite.

Apart from the odd train that might end up in platforms 1-4 in Cardiff during disruption.

 

[ac6000cw]

My only guess is the 756s gearing is optimised for the hard climbs and frequent stops up the valleys which is where they will work when the knitting is done. The 231s however will end up on the South Wales main line so need to be faster to keep out of the way of IETs and less frequent stops.

That was my thought too, plus maybe there are higher maintenance requirements for greater than 75mph operation. I was partly thinking about when a 756 gets borrowed to substitute for a 90/100mph DMU on a 'mainline' service (like a 75mph 150/153/156/142 etc. standing in for a 158/175).

 

[Meerkat]

That was my thought too, plus maybe there are higher maintenance requirements for greater than 75mph operation. I was partly thinking about when a 756 gets borrowed to substitute for a 90/100mph DMU on a 'mainline' service (like a 75mph 150/153/156/142 etc. standing in for a 158/175).

Maybe it’s so they don’t get borrowed!

 

[Peter Sarf]

That was my thought too, plus maybe there are higher maintenance requirements for greater than 75mph operation. I was partly thinking about when a 756 gets borrowed to substitute for a 90/100mph DMU on a 'mainline' service (like a 75mph 150/153/156/142 etc. standing in for a 158/175).

Yes indeed. Another thought - would track access charges reduce with a lower maximum speed ?. What are the maximum line speeds for the valleys etc anyway.

If there is no practical reason for the 756s being 75mph then it means perhaps there is a practical reason for them being not 90-100mph.

Maybe it’s so they don’t get borrowed!

There's an answer (maybe).

 

[ac6000cw]

Maybe it’s so they don’t get borrowed!

That thought crossed my mind too...

 

[supervc-10]

I wonder if it means they can eliminate a yaw damper somewhere? Like with the 458s, which had the yaw damper removed when they were re-geared to 75?