Porterbrook Cl.769 'Flex' trains from 319s, initially for Northern

[Emblematic]

A cheaper option might allow a longer average train length.

The SWT and LM franchises may possibly be the first franchises ever where they've had a choice of taking on various different types of existing EMUs, opposed to the class of train DfT have dumped on them or new build if DfT haven't dumped a class on them.

For SWT, a large part of the fleet will be the Desiros which are under a section 54 agreement until 2025 - so we can safely assume they are going nowhere. The new franchise is also bound to introduce any remaining 707s to service and retain them until 2019, so it's really in the BR-era part of the fleet, and possibly the 458s, that we may see some interesting options.
The LM 350/1s are similarly on a guaranteed lease until 2025.

 

[Bletchleyite]

The LM 350/1s are similarly on a guaranteed lease until 2025.

It has been suggested that a future LM bidder might replace the 350/2s with something else (because the lease is expensive, and because they are 3+2 seated which nobody likes, a decision the present LM has in the past said it regrets, and indeed no further LM stock was procured with that layout) but retain the /1s, /3s and take the TPE /4s. Will be interesting to see what is proposed as a replacement. Renatus 321s might be a reasonable option if East Anglia no longer need them.

Another option would be to lose the /2s but introduce something new and more InterCity-like on the Crewes, Liverpools and perhaps Birmingham fasts, and cascade down. Desiro Verve could be an option if they want to stay a Siemens shop, otherwise all the manufacturers offer suitable EMUs so there would be plenty of competition for the bid and so the price could be very good indeed.

 

[hwl]

It has been suggested that a future LM bidder might replace the 350/2s with something else (because the lease is expensive, and because they are 3+2 seated which nobody likes, a decision the present LM has in the past said it regrets, and indeed no further LM stock was procured with that layout) but retain the /1s, /3s and take the TPE /4s. Will be interesting to see what is proposed as a replacement. Renatus 321s might be a reasonable option if East Anglia no longer need them.

Another option would be to lose the /2s but introduce something new and more InterCity-like on the Crewes, Liverpools and perhaps Birmingham fasts, and cascade down. Desiro Verve could be an option if they want to stay a Siemens shop, otherwise all the manufacturers offer suitable EMUs so there would be plenty of competition for the bid and so the price could be very good indeed.

The treat of replacing the 350/2s with something else from a different ROSCO (either old or new) might be enough to bring a reduction in future leasing costs on /2s. The is the current case study of the expensive 379s not currently having a home post 2020 to help focus minds.

The /4s ex TPE make the most sense and there are also the 360s ex Anglia and additional 323 ex Northern in addition to help focus minds.

 

[northwichcat]

For SWT, a large part of the fleet will be the Desiros which are under a section 54 agreement until 2025 - so we can safely assume they are going nowhere. The new franchise is also bound to introduce any remaining 707s to service and retain them until 2019, so it's really in the BR-era part of the fleet, and possibly the 458s, that we may see some interesting options.
The LM 350/1s are similarly on a guaranteed lease until 2025.

I meant if the franchises want additional EMUs to what has already been secured.

 

[Emblematic]

I meant if the franchises want additional EMUs to what has already been secured.

You are quite right, these are really the first franchises being let where there will be a choice of surplus, cascaded stock available and we should get some proper competition in the marketplace - they way the system was intended to operate and never has. However, at least for the SWT franchise, my impression is that the need to provide a bid scoring high in the quality elements, and particularly the requirement for reduced dwell time, means that an element of new build is still likely, be that a continuation of the 707s or something else. What we won't see is a wholescale fleet replacement, that can't happen.

It will be interesting to see what happens on the DMU front, although the 185s are hinted at in the SW franchise ITT, there just aren't enough available to avoid a mixed fleet, and I just can't see an operator putting that forward as a proposal.

 

[Mordac]

It has been suggested that a future LM bidder might replace the 350/2s with something else (because the lease is expensive, and because they are 3+2 seated which nobody likes, a decision the present LM has in the past said it regrets, and indeed no further LM stock was procured with that layout) but retain the /1s, /3s and take the TPE /4s. Will be interesting to see what is proposed as a replacement. Renatus 321s might be a reasonable option if East Anglia no longer need them.

The 321s also have 3+2 seating, and are older than the 350s.

 

[Bletchleyite]

The 321s also have 3+2 seating.

Renatus 321s have whatever seating layout the purchaser of the conversion wants.

 

[Islineclear3_1]

I'm sorry, but what does any of this discussion of TPE services have anything to do with the 319 flex project?

Glad you got there before me...this thread is really going OT

 

[IanXC]

It does as deployment of TPEs stock will have an effect on northern, bearing in mind the 6TPH plan, the introduction of Northern Connect services along the calder and the fact there are 22 185s currently deployed on Northern operated MIA-BPN/WDM services becoming homeless (SWT has been suggested internally)

22?! 4 daily hire ins, and not all of those diagrams stay on Northern work all day either. Somehow think the rest of TPE would be hard to operate on 29 sets, and neither would Northern have to have resorted to locohauled or all the other mitigating actions that have been required.

 

[northwichcat]

22?! 4 daily hire ins, and not all of those diagrams stay on Northern work all day either. Somehow think the rest of TPE would be hard to operate on 29 sets, and neither would Northern have to have resorted to locohauled or all the other mitigating actions that have been required.

The 22 and 29 figures represent the number of 185s TPE will free up and the number they still require once all the new TPE Hitachi and CAF stock is in service.

 

[IanXC]

The 22 and 29 figures represent the number of 185s TPE will free up and the number they still require once all the new TPE Hitachi and CAF stock is in service.

Absolutely

 

[The Ham]

I could see the 319 flexes being used by SWT to run the Salisbury 6 services (Salisbury, Southampton, Eastleigh, Romsey) and to a lesser extent the Lymington services to free up 158's to run longer WofE line services. It would also remove a chunk of over third rail diesel running. Those services only really involve short journeys and so the quality wouldn't be such an issue, likewise given the dramatic uplift in capacity 3+2 seating wouldn't be a problem either.

The only problem would be the franchise having to make a decision on it before it has been tested.

Although having said that I could also see the 185's doing the same. However the advantage of that would be being able to run a few extra diagrams into London as 9 coach 185's rather than 6 coach 159's. That could significantly improve capacity by supplementing the existing fleet.

 

[swt_passenger]

...and to a lesser extent the Lymington services to free up 158's to run longer WofE line services.

That'll be a 450. It's an electrified line, why would anyone consider a bi-mode for it?

 

[notlob.divad]

The problem with considering flex 319s in 3rd rail land is that we don't know if they will be able to work 3rd rail and diesel. The press releases imply that the 3rd rail shoes will be gone and the 3rd rail bus used for the diesel generator connections. To parallel this with the shoes both the DC generated would have to match the 3rd rail with identical reference voltages all the times or some more DC switch gear included.

It would be a lot easier to just put it in place of the shoes and not use 3rd rail.

 

[Bletchleyite]

I suspect this is probably true unless a third-rail TOC expresses an interest - but 750VDC switchgear is hardly like to put fifty grand on the price.

 

[a_c_skinner]

I had rather gained the impression that 3rd rail would be possible after conversion, though I cannot recall where. Rail perhaps.

 

[ainsworth74]

Yes I had the same impression. I believe there was a lengthy article in the last issue or so of Rail on the topic.

 

[Chris125]

The problem with considering flex 319s in 3rd rail land is that we don't know if they will be able to work 3rd rail and diesel.

The RAIL interview with Porterbrook's Helen Simpson suggests 3rd rail operation can be retained:

"we are effectively tricking the traction system into thinking it is still a DC unit. It is effectively replacing the DC operation with diesel, but we could still retain the shoegear and have a tri-mode '319' if it was needed"

 

[Starmill]

I've certainly heard it described as 'not a true bi-mode' because it will only have the one 'mode' just that instead of overhead wire a diesel engine will feed the DC bus... although if that is another 'mode' or not is probably a pointless case of semantics.

 

[Bletchleyite]

I've certainly heard it described as 'not a true bi-mode' because it will only have the one 'mode' just that instead of overhead wire a diesel engine will feed the DC bus... although if that is another 'mode' or not is probably a pointless case of semantics.

It is bi-mode/EDMU - diesel or OHLE.

 

[furnessvale]

I've certainly heard it described as 'not a true bi-mode' because it will only have the one 'mode' just that instead of overhead wire a diesel engine will feed the DC bus... although if that is another 'mode' or not is probably a pointless case of semantics.

Isn't that more or less what any other bi-mode does?

 

[WatcherZero]

True bi-mode is able to vary its engine output to meet its needs, this form its more of a diesel backup generator providing a constant fixed electrical output.

 

[Bletchleyite]

True bi-mode is able to vary its engine output to meet its needs, this form its more of a diesel backup generator providing a constant fixed electrical output.

I very much doubt that, it will vary engine output (current) to meet demand. Otherwise you'd waste a lot of fuel.

 

[AM9]

I very much doubt that, it will vary engine output (current) to meet demand. Otherwise you'd waste a lot of fuel.

My thoughts as well. Just imagine it pulling into the station with the diesel engine going full pelt to keep the hotel supply there!

 

[edwin_m]

True bi-mode is able to vary its engine output to meet its needs, this form its more of a diesel backup generator providing a constant fixed electrical output.

Most likely it will provide a fixed voltage output but not a fixed current or power - otherwise where would all the surplus go when the traction package doesn't need it? Pretty straightforward to have a regulation circuit that adjusts the throttle to keep the voltage on the DC bus constant, so when the traction package demands more power the circuit senses the voltage starting to drop and ramps the diesels up accordingly. It's made a bit more complicated because there are gensets both ends of the train feeding the same DC bus, so there is some risk of voltage oscillation if the voltage set points or the response times are different. It may be possible to deal with this by adding diodes so one genset doesn't feed into the other's voltage regulation circuit.

You would probably also need to limit the maximum current demanded by the traction package when on diesel power, so as not to exceed what the diesels can supply. Otherwise if the driver selected maximum power when on diesel, the DC bus voltage would just drop until something shut down or tripped out. Also necessary to consider what happens if one of the two diesel gensets is offline.

 

[Bletchleyite]

Most likely it will provide a fixed voltage output but not a fixed current or power - otherwise where would all the surplus go when the traction package doesn't need it? Pretty straightforward to have a regulation circuit that adjusts the throttle to keep the voltage on the DC bus constant, so when the traction package demands more power the circuit senses the voltage starting to drop and ramps the diesels up accordingly.

Indeed, just about every cheapo plug-in petrol generator has this facility - it'll basically give you 230VAC until you stall it or pop the breaker.

 

[keith1879]

True bi-mode is able to vary its engine output to meet its needs, this form its more of a diesel backup generator providing a constant fixed electrical output.

I'm puzzled by this. Surely any train that can maintain a satisfactory performance using either diesel or electric power is a bi-mode.
I can see the argument that electric traction with a "last mile" diesel capability is not a true bi-mode but that is not the case here.

 

[Starmill]

As I have already pointed out, it depends on your definition of 'mode'. The train is not changing the way it operates just because there is a different supply. People don't call units that can accept power from overhead wires or third rail 'bi-mode'.

 

[Jonny]

The RAIL interview with Porterbrook's Helen Simpson suggests 3rd rail operation can be retained:

"we are effectively tricking the traction system into thinking it is still a DC unit. It is effectively replacing the DC operation with diesel, but we could still retain the shoegear and have a tri-mode '319' if it was needed"

The only potential issue was that in a 3rd rail area, would there need to be some system to prevent back-flow from a "flex" with the generator(s) running onto the 3rd rail itself?

 

[D365]

The only potential issue was that in a 3rd rail area, would there need to be some system to prevent back-flow from a "flex" with the generator(s) running onto the 3rd rail itself?

Turn off the engine?