Class 197 Civity DMUs for TfW - alternatives and speculation

[popeter45]

I wonder if there will have to be more compromises with bi-modes.

yea if i was a betting man i would say GWR will prob either order FLIRTS with larger fuel tanks than the 755's or either a Bi mode Aventra or hitatchi AT200 if either are on offer

 

[Bletchleyite]

yea if i was a betting man i would say GWR will prob either order FLIRTS with larger fuel tanks than the 755's or either a Bi mode Aventra or hitatchi AT200 if either are on offer

I think there's a reasonable chance of a cascade - the 196s for instance wouldn't have to stay with whatever WMT is in 20 years' time if they wire the Snow Hill lines, for example (and the Snow Hill lines really do need wiring, they are a city commuter service). I can't imagine the Cornish branches having 25kV any time soon, but biodiesel DMUs would probably tick most of the environmental box.

 

[greatvoyager]

Exactly. Probably some sort of plant based biodiesel by then, I'd imagine.

Forgive me if this has already been asked, but do CAF produce a bi-mode of the Civity?
If so, is there a reason why this wasn’t looked into by TfW?

 

[craigybagel]

Forgive me if this has already been asked, but do CAF produce a bi-mode of the Civity?
If so, is there a reason why this wasn’t looked into by TfW?

CAF produce bi-modes, but it is unknown as to whether or not they can be made to fit the UK gauge, or whether the question was ever asked.

However, we can assume that they would have been a more expensive option - both to initially procure and the ongoing costs of carrying all that electrical equipment - and we're already talking about a very generously large order for a heavily subsidised franchise. And on the routes the 197s have been ordered for, it's really hard to see how you'd justify that extra expense when only small parts of it are electrified, a fact that isn't likely to change any time soon.

 

[anthony263]

I do wonder of more class 197s should be ordered to cover the heart of wales line, Shrewsbury to crewe locals as well as the west wales branches instead of the class 170s which could be cascaded elsewhere. Gives tfw a uniform dmu fleet

 

[Rhydgaled]

I'd figure that electrification programmes and bi-modes (battery, hydrogen and diesel) will mean classes 195, 196 and 197 are plenty to replace the Sprinter fleets when it comes to time for that.

That was my thinking, those will probably be the last DMUs in service.

Indeed; as the youngest DMUs the Civity fleets will presumably be the last DMUs in service.

I'd figure that electrification programmes and bi-modes (battery, hydrogen and diesel) will mean classes 195, 196 and 197 are plenty to replace the Sprinter fleets when it comes to time for that. Indeed, that's said to be the reason for Northern having ordered 2-car units - you're never going to need a longer set on Ormskirk-Preston, Kirkby/Skem-Wigan, the Bentham Line etc.

The trouble is that the 150s are all over 30 years old already and some of the earlier ones are over 35. The time to replace them is upon us and still the DfT/treasury is resisting electrification (or so it appears). On the plus side TPE wires would fit nicely with the 'leveling up' agenda and if the whole core route from Manchester to York was wired I think the Nova 1 and Nova 3 fleets would be sufficient to work TPE's remaining diesel routes meaning ALL the 185s would be available for cascade to Northern. That's the 150/1s gone at a stroke if you can find enough suitable Northern routes for the 185s.

I think there's a reasonable chance of a cascade - the 196s for instance wouldn't have to stay with whatever WMT is in 20 years' time if they wire the Snow Hill lines, for example (and the Snow Hill lines really do need wiring, they are a city commuter service). I can't imagine the Cornish branches having 25kV any time soon, but biodiesel DMUs would probably tick most of the environmental box.

Most of the Cornish branches are down for battery operation in the TDNS (Newquay being the exception). With no OHLE to charge the batteries from, this would probably be the last bastion of DMUs. With help from others on here, I estimated how many diagrams each battery/hydrogen route in the TDNS could need a while ago. Assuming we got that right, the four branches remaining unwired would need 5 diagrams, so presumably 6 or 7 196s or 197s could go down there (or possibly a few more if you want to use a pair of 2-car units on some of the routes at times instead of a 4-car 196). Even If you allow for all five diagrams to be doubled up that's a fleet of around 12x 2-car units. To where do you cascade the other 91 gangway-fitted Civity DMUs. And where do you cascade the 195s?

A first step for the 196s could be electrifying Wolverhampton-Shrewsbury and having WMR use the released 196s to take over the stoppers to Nottingham and Leicester from XC (with XC taking on 222s for Cardiff-Nottingham at around the same time) allowing most of XC's 170s to move elsewhere to help with Sprinter replacement (XC would then only need 170s for Birmingham-Stansted). The Snow Hill lines need to be wired yes, but with only hourly services on some sections, two TOCs (WMR and Chiltern) and WMR having two diesel fleets (172s and 196s) do you do it all in one big bang or can it be phased to release either the 172s or the 196s first and leave the hourly bits until busier routes in other regions have been wired?

on the routes the 197s have been ordered for, it's really hard to see how you'd justify that extra expense when only small parts of it are electrified, a fact that isn't likely to change any time soon.

I agree that bi-modes probably wouldn't be justified with the current extent of electrification - but with the fleet having a 30-35 year life 'any time soon' is hard to define. We agreed in the other topic that the British government's failure to invest in electrification is idiocy so I hope you'll agree that suituation should be different. A large fleet of relatively new pure DMUs would be a serious impediment to extending electrification - a small number less so as there's a possibility it could be cascaded to somewhere like Cornwall or even staying in Wales and moving to replace the 170s on the Heart Of Wales Line.

Bi-modes would be a statement of intent to do something about the lack of electrification, pure DMUs are the opposite.

 

[craigybagel]

I agree that bi-modes probably wouldn't be justified with the current extent of electrification - but with the fleet having a 30-35 year life 'any time soon' is hard to define. We agreed in the other topic that the British government's failure to invest in electrification is idiocy so I hope you'll agree that suituation should be different. A large fleet of relatively new pure DMUs would be a serious impediment to extending electrification - a small number less so as there's a possibility it could be cascaded to somewhere like Cornwall or even staying in Wales and moving to replace the 170s on the Heart Of Wales Line.

Bi-modes would be a statement of intent to do something about the lack of electrification, pure DMUs are the opposite.

I agree that it SHOULD be different, I just feel it's almost certain it won't be - and that there are far bigger impediments to electrification then a modern fleet. Electrification and other railway improvement schemes have been cut back all over the country of late - and that was before Covid put a massive hole in the countries finances. We all know it should happen, and that the there are implications for the environment if it doesn't - but that isn't going to persuade a government that isn't prepared to look further then the next election.

In any case, you only have to look at how long it's taken us to get to the current amount of electrification, and how many more worthy projects there are ahead of the network in Wales, to see that it's believable it won't be happening within 30 years.

And at least with buying now, in bulk, it's affordable to replace almost the entire fleet with much more modern, efficient and cleaner to the environment units - rather then being stuck with older more inefficient units for many more years, and then an uncertain future afterwards.

 

[greatvoyager]

And at least with buying now, in bulk, it's affordable to replace almost the entire fleet with much more modern, efficient and cleaner to the environment units - rather then being stuck with older more inefficient units for many more years, and then an uncertain future afterwards.

That’s a fair point. Have the 197s got any future proofing features?

 

[Rhydgaled]

I agree that it SHOULD be different, I just feel it's almost certain it won't be - and that there are far bigger impediments to electrification then a modern fleet. Electrification and other railway improvement schemes have been cut back all over the country of late - and that was before Covid put a massive hole in the countries finances. We all know it should happen, and that the there are implications for the environment if it doesn't - but that isn't going to persuade a government that isn't prepared to look further then the next election.

In any case, you only have to look at how long it's taken us to get to the current amount of electrification, and how many more worthy projects there are ahead of the network in Wales, to see that it's believable it won't be happening within 30 years.

I agree that it is believable that electrification on the proposed 197 routes won't be happening within 30 years. If there is no serious effort put in to decarbonising rail then you will probably be proved right and there won't be any expansion of electrification and, alarmingly, I think there is a very real prospect of no serious effort being put into decarbonising rail. However, in the event that serious effort is put into electrifying rail I think Wolverhampton-Shrewsbury could be quite near the top of the list if all 3tph were able to benefit, which they won't be if TfW has 197s on the route and intends to keep them there (the 196s could be cascaded as suggested above).

Have the 197s got any future proofing features?

Not as far as we know; aren't they basically a 195 with the cabs from a 196 and nobody has ever suggested any future-proofing on those fleets? I expect TfW would also have drawn attention to any future proofing on the 197s and they haven't. The nearest I've seen from TfW is a suggestion that they will consider implementing hydrogen fuel cells "on the new DMU’s later in the contract" - full quote below:

The new traction motors, driven from the power generated from the hydrogen fuel cells, are not bogie mounted, but drive the existing transmission in place of the original internal combustion engine. Therefore, as traction technology and the supply chain for hydrogen fuel becomes more available and cost effective, we will consider implementing them on the new DMU’s later in the contract.

No mention of drawing power from OHLE so presumably the idea is each coach is self-contained with its own fuel cells and fuel tanks, similar to a DMU, unlike an EMU which has current collection on one vehicle but traction motors on multiple vehicles. I suppose conversion to EMUs is possible but horrendously difficult and expensive.

 

[Domh245]

Not as far as we know; aren't they basically a 195 with the cabs from a 196 and nobody has ever suggested any future-proofing on those fleets? I expect TfW would also have drawn attention to any future proofing on the 197s and they haven't. The nearest I've seen from TfW is a suggestion that they will consider implementing hydrogen fuel cells "on the new DMU’s later in the contract" - full quote below:
No mention of drawing power from OHLE so presumably the idea is each coach is self-contained with its own fuel cells and fuel tanks, similar to a DMU, unlike an EMU which has current collection on one vehicle but traction motors on multiple vehicles. I suppose conversion to EMUs is possible but horrendously difficult and expensive.

The mention of traction motors makes me think it's a reference to the FLIRTs - the 197s have no traction motors, just the engine/gearbox. The hybrid MTU rafts are a possibility for the 197s though, and frankly it's a poor show that no civities have been delivered with these.

 

[greatvoyager]

The mention of traction motors makes me think it's a reference to the FLIRTs - the 197s have no traction motors, just the engine/gearbox. The hybrid MTU rafts are a possibility for the 197s though, and frankly it's a poor show that no civities have been delivered with these.

Probably all down to keeping costs acceptable.

 

[craigybagel]

I agree that it is believable that electrification on the proposed 197 routes won't be happening within 30 years. If there is no serious effort put in to decarbonising rail then you will probably be proved right and there won't be any expansion of electrification and, alarmingly, I think there is a very real prospect of no serious effort being put into decarbonising rail. However, in the event that serious effort is put into electrifying rail I think Wolverhampton-Shrewsbury could be quite near the top of the list if all 3tph were able to benefit, which they won't be if TfW has 197s on the route and intends to keep them there (the 196s could be cascaded as suggested above.

If there was any hope of Shrewsbury - Wolverhampton getting electrified any time soon it would seem rather odd that WMR have just bought a brand new fleet of diesels for it. I'm also confused as to how WMR buying these diesels is somehow ok but TFW buying almost identical ones for the same route isn't.....

In any case - holding off buying new trains in the hope the route does get electrified means holding the rest of the network to ransom - the Cambrian tail wagging the dog again. And even if that bit of line did get electrified, it still means that less then half of the Birmingham International - Aberystwyth route would be under the wires (and an even small portion for Pwllheli). Are you really achieving much there over brand new diesel vehicles that don't spend most of their time lugging an unused transformer and other electrical gubbins around?

 

[Bletchleyite]

And at least with buying now, in bulk, it's affordable to replace almost the entire fleet with much more modern, efficient and cleaner to the environment units - rather then being stuck with older more inefficient units for many more years, and then an uncertain future afterwards.

I'd not buy specific 150 replacements now while alternative technologies are in their infancy. 5-10 more years (and some more wiring and cascading) should make it clearer as to the right way to go for those routes that will never justify the wires.

Other option I suppose is to buy DEMUs and then you can just swap whatever generates the electricity for something else. The FLIRT platform would probably make that easier with the mini-locomotive than underfloor.

 

[craigybagel]

I'd not buy specific 150 replacements now while alternative technologies are in their infancy. 5-10 more years (and some more wiring and cascading) should make it clearer as to the right way to go for those routes that will never justify the wires.

Other option I suppose is to buy DEMUs and then you can just swap whatever generates the electricity for something else. The FLIRT platform would probably make that easier with the mini-locomotive than underfloor.

The Wales and Borders network has been desperately short of stock for years and you want to wait even longer for it?

 

[Bletchleyite]

The Wales and Borders network has been desperately short of stock for years and you want to wait even longer for it?

I was more talking about future 150 replacements than this order.

 

[craigybagel]

I was more talking about future 150 replacements than this order.

I'm a little confused then - do you mean 150s across the network as a whole or just within TfW? Most of the TfW 150s are being replaced with either hybrid or pure electric vehicles already.... The only routes that have been 150 operated that are getting 197s are Crewe - Chester and the Blaneau branch (with both being temporarily worked by 153s at present anyway).

 

[Philip]

Are 175s scheduled to be the first to leave the franchise once 197s start entering service; before the 158s?

 

[craigybagel]

Are 175s scheduled to be the first to leave the franchise once 197s start entering service; before the 158s?

That was certainly the plan. The last 197s to be introduced are meant to be the ERTMS fitted units

 

[Bletchleyite]

I'm a little confused then - do you mean 150s across the network as a whole or just within TfW? Most of the TfW 150s are being replaced with either hybrid or pure electric vehicles already.... The only routes that have been 150 operated that are getting 197s are Crewe - Chester and the Blaneau branch (with both being temporarily worked by 153s at present anyway).

150s on the network more widely. It was associated to my point that classes 195/6/7 will be a cascade not necessarily where they are currently based.

 

[craigybagel]

150s on the network more widely. It was associated to my point that classes 195/6/7 will be a cascade not necessarily where they are currently based.

Ah ok I'm with you now. And on that I agree with you that in 10 years time we will indeed know better what to do with replacing those units.

 

[greatvoyager]

Ah ok I'm with you now. And on that I agree with you that in 10 years time we will indeed know better what to do with replacing those units.

I’m hoping that there will be a clear plan.

 

[Rhydgaled]

The mention of traction motors makes me think it's a reference to the FLIRTs - the 197s have no traction motors, just the engine/gearbox. The hybrid MTU rafts are a possibility for the 197s though, and frankly it's a poor show that no civities have been delivered with these.

It says new traction motors, which would "drive the existing transmission in place of the original internal combustion engine". The traction motors on the FLRTs are on the passenger vehicles I assume? As for the hybrid engine rafts, I was expecting TfW to say they would be fitted and was really surprised to find out that they are not.

If there was any hope of Shrewsbury - Wolverhampton getting electrified any time soon it would seem rather odd that WMR have just bought a brand new fleet of diesels for it. I'm also confused as to how WMR buying these diesels is somehow ok but TFW buying almost identical ones for the same route isn't.....

It's on the radar on Midlands Connect, as part of the Midlands Engine Rail programme. While it does only say 'possible electrification', the proposed fourth hourly passenger service would make it even more important to electrify the route. As for your other question, there are a number of reasons why I see the 196s differently to the 197s:

• Only 26 of them were ordered, meaning they are less of a barrier to electrification than the massive 77-unit TfW order (there will of course always be a few routes, like the afforementioned Cornish branches, that are not electrified)
• They were ordered first, meaning GB didn't have quite as many new DMUs about, plus I didn't have the TDNS to tell me what a decarbonised railway would look like - before that I think I expected more battery and hydrogen operation and therefore more work for DMUs (I think I shifted the focus of my campaigning on the 197s when the TDNS was published)
• WMR retained the class 172s, meaning they could electrify part of their network and cascade one of the fleets rather than having a uniform fleet which would need to be broken up in the event of electrification. In other words - less risk that partial electrification would create micro-fleets.
• Although it is the same route, the 196s will be working local stoppers and not a regional express - you say yourself that the 196s and 197s are almost identical and I don't think local stoppers and regional expresses should have near-identical stock (this one is of course to do with the quality spec and not (directly at least) decarbonisation)

In any case - holding off buying new trains in the hope the route does get electrified means holding the rest of the network to ransom - the Cambrian tail wagging the dog again. And even if that bit of line did get electrified, it still means that less then half of the Birmingham International - Aberystwyth route would be under the wires (and an even small portion for Pwllheli). Are you really achieving much there over brand new diesel vehicles that don't spend most of their time lugging an unused transformer and other electrical gubbins around?

For Birmingham-Aberystwyth I think wires to Shrewsbury would be about a third of the route wired, it's sort of a grey area as to when it becomes more efficient to have a bi-mode rather than a DMU. The Pwllheli portion looks bad, but if it continues to interwork with the Birmingham-Holyheads (also down for wires in the TDNS) a large part of the diagram would ultimately be under the wires and if it doesn't interwork it will need to be capable of working in multiple with an EMU on the Holyhead service unless TfW grabs Midlands Connect's fourth path.

Your 'holding the rest of the network to ransom' statement works both ways. If, as seems likely, we do indeed end up with 161 Civity DMUs then the fate of electrification will be sealed. That's the problem with the 197s being DMUs rather than DEMUs designed to make addition of a transformer, pantograph etc. easy - by planning for the very likely (but very unsatisfactory) outcome of no further electrification TfW essentially ensures that outcome rather than keeping alive the possibility of a better future.

In short, we are in a suituation where we cannot hope for the best while planning for the worst. By planning for the worst, we kill off the hope.

I'd not buy specific 150 replacements now while alternative technologies are in their infancy. 5-10 more years (and some more wiring and cascading) should make it clearer as to the right way to go for those routes that will never justify the wires.

Other option I suppose is to buy DEMUs and then you can just swap whatever generates the electricity for something else. The FLIRT platform would probably make that easier with the mini-locomotive than underfloor.

I think you put that much better than I have tended to do, but I would extend that to all DMU replacement and not just the 150s. The mini 'locomotive' (it's not really a locomotive either) could in theory be applied to other platforms too - on a non-articulated design presumably you could just have a short vehicle with a single bogie - proably heavier than a FLIRT but without the awkward changes in floor height.

 

[greatvoyager]

Your 'holding the rest of the network to ransom' statement works both ways. If, as seems likely, we do indeed end up with 161 Civity DMUs then the fate of electrification will be sealed. That's the problem with the 197s being DMUs rather than DEMUs designed to make addition of a transformer, pantograph etc. easy - by planning for the very likely (but very unsatisfactory) outcome of no further electrification TfW essentially ensures that outcome rather than keeping alive the possibility of a better future.

In Devon and Cornwall we have little hope of electrification and all of our DMUs are still former BR stock with no replacement yet planned. I don’t believe we have any post privatisation units in service, except for IETs and 22x, although they are express rather than regional trains.

 

[XAM2175]

The mention of traction motors makes me think it's a reference to the FLIRTs - the 197s have no traction motors, just the engine/gearbox. The hybrid MTU rafts are a possibility for the 197s though, and frankly it's a poor show that no civities have been delivered with these.

It says new traction motors, which would "drive the existing transmission in place of the original internal combustion engine". The traction motors on the FLRTs are on the passenger vehicles I assume?

The current arrangement for short FLIRTs is two powered bogies - the outermost at each end. Traction current is distributed to them from the power pack.

Reading the exact phrasing again, it strikes me as relating to vehicles with mechanical transmissions, not electric:

The new traction motors, driven from the power generated from the hydrogen fuel cells, are not bogie mounted, but drive the existing transmission in place of the original internal combustion engine. Therefore, as traction technology and the supply chain for hydrogen fuel becomes more available and cost effective, we will consider implementing them on the new DMU’s later in the contract.

So effectively they envision removing the current diesel engine, then fitting a fuel cell that drives a traction motor that can then drive the original transmission. I can't really see how this would be practical, though, given the space required to store the hydrogen that's to be used in the cell.

(In the interests of completeness: the two centremost bogies on Class 745 units are also powered)

 

[greatvoyager]

Aside from the cost, would it have been any different if TfW had ordered more class 231s and forgotten about the 197s?

 

[Rhydgaled]

The current arrangement for short FLIRTs is two powered bogies - the outermost at each end. Traction current is distributed to them from the power pack.

Reading the exact phrasing again, it strikes me as relating to vehicles with mechanical transmissions, not electric:

So effectively they envision removing the current diesel engine, then fitting a fuel cell that drives a traction motor that can then drive the original transmission. I can't really see how this would be practical, though, given the space required to store the hydrogen that's to be used in the cell.

Thanks for the info on the FLIRTs. I agree, I don't see it being acheivable but as far as I know that's the best TfW have been able to come up with regarding the 'future proofing' of the 197s. Thus I consider the 197s to be 'not future proof at all really' but I thought I would put TfW's case up to avoid accusations of concealing information that doesn't help my case.

Unfortunately the problem with that is Northern simply doesn't make enough money to procure enough dual-mode units to replace all of the 150s, of which there will soon be 72 two-car and six three-car units. A better alternative, in my opinion, would be a modular 75mph commuter diesel unit designed with the capability of being converted to electric as and when OHLE infrastructure allows.

For the 150s, I would focus on cascading newer DMUs rather than new-builds. For example, if the government can be convinced to expand the TransPennine Route Upgrade to include full electrification between Manchester and York (which would fit with their leveling up agenda) TPE is unlikely to require any 185s which is 51 units for cascade - enough to get rid of the 150/1s if Northern can find enough suitable routes for the 185s. It is the 156s and 158s that I worry about most of all - a DEMU designed for easy convertion to bi-mode would seem a good solution but wouldn't be all that much cheaper than a bi-mode - essentially that would be a bi-mode with the pantograph and transformer left off initially.

Aside from the cost, would it have been any different if TfW had ordered more class 231s and forgotten about the 197s?

Would what be any different? The level of future-proofing would probably be different as I'm assuming the 231s will have space for a pantograph on the roof and all the wiring etc. to make use of it but I don't know that for sure.

 

[greatvoyager]

Would what be any different? The level of future-proofing would probably be different as I'm assuming the 231s will have space for a pantograph on the roof and all the wiring etc. to make use of it but I don't know that for sure.

Depends on build quality or seat layout.

 

[craigybagel]

It's on the radar on Midlands Connect, as part of the Midlands Engine Rail programme. While it does only say 'possible electrification', the proposed fourth hourly passenger service would make it even more important to electrify the route.

Good for them. As far as I can see however they're just a lobbying group, who are free to make any requests they want. They have as much power to make something happen as I do! And even they don't expect 4 tph to happen until after HS2 opens, so clearly not short term.

As for your other question, there are a number of reasons why I see the 196s differently to the 197s:

• Only 26 of them were ordered, meaning they are less of a barrier to electrification than the massive 77-unit TfW order (there will of course always be a few routes, like the afforementioned Cornish branches, that are not electrified)

They ordered fewer because they only need them for 2 routes. As has been pointed out to you many times before, there were very important reasons why TfW needed a larger order, but I'm not going into them yet again.

• They were ordered first, meaning GB didn't have quite as many new DMUs about, plus I didn't have the TDNS to tell me what a decarbonised railway would look like - before that I think I expected more battery and hydrogen operation and therefore more work for DMUs (I think I shifted the focus of my campaigning on the 197s when the TDNS was published)

There was only a few months between the orders.

• WMR retained the class 172s, meaning they could electrify part of their network and cascade one of the fleets rather than having a uniform fleet which would need to be broken up in the event of electrification. In other words - less risk that partial electrification would create micro-fleets.

True, but sadly TfW weren't blessed with such a modern fleet already on hand.

• Although it is the same route, the 196s will be working local stoppers and not a regional express - you say yourself that the 196s and 197s are almost identical and I don't think local stoppers and regional expresses should have near-identical stock (this one is of course to do with the quality spec and not (directly at least) decarbonisation)

But the majority of the passengers in both cases will be the same. The trains will be dealing with large amounts of people commuting to the a West Midlands. And the 197s are perfectly adequate for the smaller amount of people making the longer journeys into Wales.

For Birmingham-Aberystwyth I think wires to Shrewsbury would be about a third of the route wired, it's sort of a grey area as to when it becomes more efficient to have a bi-mode rather than a DMU. The Pwllheli portion looks bad, but if it continues to interwork with the Birmingham-Holyheads (also down for wires in the TDNS) a large part of the diagram would ultimately be under the wires and if it doesn't interwork it will need to be capable of working in multiple with an EMU on the Holyhead service unless TfW grabs Midlands Connect's fourth path.

North Wales isn't likely any time soon either

Your 'holding the rest of the network to ransom' statement works both ways. If, as seems likely, we do indeed end up with 161 Civity DMUs then the fate of electrification will be sealed. That's the problem with the 197s being DMUs rather than DEMUs designed to make addition of a transformer, pantograph etc. easy - by planning for the very likely (but very unsatisfactory) outcome of no further electrification TfW essentially ensures that outcome rather than keeping alive the possibility of a better future.

In short, we are in a suituation where we cannot hope for the best while planning for the worst. By planning for the worst, we kill off the hope.

But at least we're being realistic and making the best of it

Aside from the cost, would it have been any different if TfW had ordered more class 231s and forgotten about the 197s?

Unfortunately, cost really is the most important issue here that can't be discounted. Though there's also the question of whether or not 231s can be given gangways, and the political benefits of building the fleet in Newport rather then Switzerland.

 

[Bletchleyite]

I think you put that much better than I have tended to do, but I would extend that to all DMU replacement and not just the 150s. The mini 'locomotive' (it's not really a locomotive either) could in theory be applied to other platforms too - on a non-articulated design presumably you could just have a short vehicle with a single bogie - proably heavier than a FLIRT but without the awkward changes in floor height.

Remember that those "awkward changes in floor height" exist because of level boarding. That is certainly something I think should be a requirement.

As for "mini locomotives", I think that sort of works for the FLIRT because of its short vehicles and articulated design. In a conventional DMU, if it's low floor so it can't go underneath, it might as well go in the end vehicle behind one of the cabs like the Class 210.

 

[507021]

For the 150s, I would focus on cascading newer DMUs rather than new-builds. For example, if the government can be convinced to expand the TransPennine Route Upgrade to include full electrification between Manchester and York (which would fit with their leveling up agenda) TPE is unlikely to require any 185s which is 51 units for cascade - enough to get rid of the 150/1s if Northern can find enough suitable routes for the 185s. It is the 156s and 158s that I worry about most of all - a DEMU designed for easy convertion to bi-mode would seem a good solution but wouldn't be all that much cheaper than a bi-mode - essentially that would be a bi-mode with the pantograph and transformer left off initially.

I personally don't think it's fair to expect Northern (and GWR) to keep having to accept cascades and/or "make do and mend" solutions while everyone else gets new trains. The 150s (and possibly 155s) need to go before the end of the decade, and there's no way electrification will progress quickly enough for those replacements to be EMUs or dual modes which can actually make decent use of their capabilities. I would really like to be proven wrong on this next point, but at the moment I don't see HMUs becoming a realistic option for larger scale deployment until 2030 at least.

As for the 185s, they'd be totally unsuitable for directly replacing the 150s. One is a 75mph commuter unit, the other is a 100mph regional unit. Northern have already tried something similar on the Harrogate Line, however it didn't work because it highlighted that 100mph regional diesel trains with tall gearing aren't designed for stop-start services. I do however think using 185s to free up the 156s and 158s to replace 150s could theoretically work.

There's also the matter of what's going to be used on East-West Rail, considering it's bizarrely being built as a non-electrified route.