Long distances under wires should not be covered by diesel trains

[hwl]

231s* are likely to be the only pure diesels left in say 25 years,

* If not fitted with a pantograph, which I believe TfW is looking at.

I think TfW may have quietly signed up for conversion later last year.

 

[43096]

But in late 1970s BR had about 250 electric locos (including the electro diesels), the idea before HSTs that you ran long distance on electrified lines with diesels was unimaginable. To some extent HSTs set up the bad trend.

Not sure I follow your logic given HSTs were ordered for the unelectrified Great Western, unelectrified East Coast and unelectrified Cross-Country routes.

 

[Bikeman78]

I'd go with C. The WCML falls over so often that some spare paths are a good thing, and I remain unconvinced of the benefits of open access anyway.

Especially if it shafts the MML in the process.

 

[The Ham]

Private EVs are also generally more environmentally friendly than rail. Unless there's a dramatic up-scaling of electrification in the UK, together with corresponding progress with the introduction of more energy efficient trains, rail is in danger of becoming the 'dirty option.'

Whilst we should be doing more electrification as a network the per passenger km rate is 31g of CO2, because a lot of passengers are using electric trains (chiefly DMU's are rarely over 4 coaches long when in service, when that's almost the minimum for EMU's).

A car with emissions of 100g/km would need 4 people to match that, however cars average 1.5 (although the average is 167g/km)

An EV has emissions of 46g per km (2025), so only just edge rail if they maintain an average of 1.5 people per km traveled.

Emissions per km for cars from here:

https://www.faraday.ac.uk/wp-content/uploads/2021/11/Faraday_Insights_12_FINAL.pdf#:~:text=On%20average%2C%20EVs%20in%20the%20UK%20in,distance%20travelled%20for%20both%20types%20of%20vehicle.

The other factor is, whilst people do use diesel only trains is also not uncommon for rail passengers to also use electric trains (as well as walk/cycle) so as an individual rail users are more likely to have a lower carbon footprint than those who own a car.

Especially given it's not uncommon to see people driving distances where the time saving is very limited (if not actually slower on a door to door basis, rather than engine on to engine off basis).

There are still some fairly easy wins for rail to deliver. For example XC could stay the transition to a bimodal fleet (I've previously suggested 12 nine coach 80x's whilst converting their current 22x fleet to being 43 six coaches, as that would get a big uplift in capacity without scraping too many 22x coaches or increasing the number of units on lease by very much), even if the 22x's are used as longer trains the emissions per passenger (assuming passenger growth, which was 15% last year and 18% the year before) is likely to reduce, as the emissions to run a service as 4+4 is less than two separate 4 coach units.

It's also worth noting that a 6 coach 22x units would have something like 332 seats vs 400 seats for a 4+4 train, even though there's 2 coaches fewer.

By having 6 coaches you could even reduce the fuel burn by (if suitable) removing the engines from one of the 6 coaches (a more expensive option would be to replace with batteries, however that would reduce fuel burn further), although at the very least it would allow engines to run a bit less hard.

However, that gives XC their first bimodal units (even if it's a fairly small percentage of their fleet), which could then allow then to be scaled up as time moves forwards. The cost of reforming the 22x's would be fairly limited and so wouldn't be too wasteful if they were then started to be withdrawn from service in (say) 8 years time to allow more bimodal trains to enter service.

8 years would be 2033 and so people can still buy plug in hybrids but not pure petrol/diesel cars and whilst new cars maybe mostly electric, there's still going to be a lot of petrol/diesel burn as part of the car fleet.

Whilst XC is only a small amount of the DMU fleet, as they are high speed and often with low numbers of seats per train (and certainly a low number of seats per coach) any reduction from them maybe enough to have an impact on the per passenger emissions at a national level.

 

[Sonik]

Private EVs are also generally more environmentally friendly than rail. Unless there's a dramatic up-scaling of electrification in the UK, together with corresponding progress with the introduction of more energy efficient trains, rail is in danger of becoming the 'dirty option.'

The spoiler here is long-distance freight, which is both:

1) A significant portion of road transport emissions
2) Essentially impossible to economically electrify using batteries, due to weight and drivers hours.

It's likely that long haul road freight sector will push for exemptions and continue with diesel for while yet, simply because it's very difficult to decarbonise.

 

[mike57]

I had a dig around on the .gov.uk website and found some interesting data which supports my arguement that rail is a small contributer to UK CO2 emmissions.

The following snip shows that rail is only responsible for 2% of emissions:


Here is a link to the data, which is freely available for anyone who wants to dig deeper- https://www.gov.uk/government/stati...d-environment-data-tables-env#:~:text=ENV0201

This supports my thinking that 'de-carbonising' the railway just for its own sake is not a good use of scarce resources. To put these numbers in perspective, I found in some related data that transport in turn contributes ~28% of total UK emisions.

This means that a 2% saving in the road contribution would be almost the same as the total contribution from rail.

By all means try and make best use of what we have, but not doing something rail related just because its 'diesel' makes no sense. If you could do something which would reduce road emissions by 10% but the penalty is a 50% increase in rail emissions, then in the overall view of things that would be good.

By all means set policy to drive things in the right direction, but we also need to do better at identifying quick wins and going for them rather than getting hung up on the 'gold plated' solution, which then takes longer.

My own thoughts:

Bi-mode still feels like the best solution for most routes that are not fully electified, its proven, and requires very little or no additional infrastructure, which 20 years down the road means that cascade onto other routes is easy. Battery may have a place but personally I would get on with electrifying most routes and accept that some lightly used rural routes will remain diesel, because it really is the best option. As more routes become 100% electric then either remove the engines or buy new electric only stock. Maybe with existing bi-modes there is a case for retaining one engine to provide onboard services in emergency and a limp mode to traverse a dead or short non electified section.

But as those figures show it is road transport where even small savings will make a big impact.

 

[The exile]

Not sure I follow your logic given HSTs were ordered for the unelectrified Great Western, unelectrified East Coast and unelectrified Cross-Country routes.

They were the first IC type train (other than the Blue Pullmans) which had the power source effectively built in. Made little difference initially, but once they started to spread their wings (or indeed as electrification started to spread) their mikes under the wires increased.
Before someone mentions the Brighton Belle sets, yes, OK, but they were electric and could (I suppose) have been diesel or steam hauled off route. HSTs that was definitely emergencies only (was an HST ever rescued by an AC electric?)

 

[AndrewE]

By all means set policy to drive things in the right direction, but we also need to do better at identifying quick wins and going for them rather than getting hung up on the 'gold plated' solution, which then takes longer.

My own thoughts:

Bi-mode still feels like the best solution for most routes that are not fully electified, its proven, and requires very little or no additional infrastructure, which 20 years down the road means that cascade onto other routes is easy. Battery may have a place but personally I would get on with electrifying most routes and accept that some lightly used rural routes will remain diesel, because it really is the best option. As more routes become 100% electric then either remove the engines or buy new electric only stock. Maybe with existing bi-modes there is a case for retaining one engine to provide onboard services in emergency and a limp mode to traverse a dead or short non electified section.

But as those figures show it is road transport where even small savings will make a big impact.

That is all true, and I am with you, but unfortunately that desn't take into account the health effects of diesel traction, and it seems wrong for us to support a major increase in ULEZ in persuit of cleaner air while saying rail isn't really a part of the problem. There are far too many diesel-hauled/powered trains in big cities (outside London) still and work is needed to get them out of city centres faster than full electrification will.
In the shortest term Voyagers ought to be re-formed to make them more suited to IC's needs (which could be done tomorrow!) and bimodes are also needed urgently but we know how long procurement takes...

There have been other suggestions like using the spare 350s to run Birmingham to Manchester, that would take out some of the diesel from 2 big cities, and lengthened Voyagers could operate maybe hourly from Manchester to the South in the same way as the Avanti and LNR trains interwork between Liverpool and Crewe to preserve the N-S connectivity.

Looking at Cardiff-Nottingham and the TfW services, if only there was a workable bimode solution for our existing DMU fleets which could be put into series production! Even class 93s vice 67s and Mk4s could play a part...

 

[The Ham]

I had a dig around on the .gov.uk website and found some interesting data which supports my arguement that rail is a small contributer to UK CO2 emmissions.

The following snip shows that rail is only responsible for 2% of emissions:
View attachment 182921

Here is a link to the data, which is freely available for anyone who wants to dig deeper- https://www.gov.uk/government/stati...d-environment-data-tables-env#:~:text=ENV0201

This supports my thinking that 'de-carbonising' the railway just for its own sake is not a good use of scarce resources. To put these numbers in perspective, I found in some related data that transport in turn contributes ~28% of total UK emisions.

This means that a 2% saving in the road contribution would be almost the same as the total contribution from rail.

By all means try and make best use of what we have, but not doing something rail related just because its 'diesel' makes no sense. If you could do something which would reduce road emissions by 10% but the penalty is a 50% increase in rail emissions, then in the overall view of things that would be good.

By all means set policy to drive things in the right direction, but we also need to do better at identifying quick wins and going for them rather than getting hung up on the 'gold plated' solution, which then takes longer.

My own thoughts:

Bi-mode still feels like the best solution for most routes that are not fully electified, its proven, and requires very little or no additional infrastructure, which 20 years down the road means that cascade onto other routes is easy. Battery may have a place but personally I would get on with electrifying most routes and accept that some lightly used rural routes will remain diesel, because it really is the best option. As more routes become 100% electric then either remove the engines or buy new electric only stock. Maybe with existing bi-modes there is a case for retaining one engine to provide onboard services in emergency and a limp mode to traverse a dead or short non electified section.

But as those figures show it is road transport where even small savings will make a big impact.

Also, I assume that 2% includes freight.

It's also worth noting that whilst rail accounts for 2% of trips, it accounts for 10% of miles travelled.

 

[dosxuk]

In the shortest term Voyagers ought to be re-formed to make them more suited to IC's needs (which could be done tomorrow!)

What voyager reform could you do tomorrow that a) reduces emissions and b) maintains capacity?

 

[AndrewE]

What voyager reform could you do tomorrow that a) reduces emissions and b) maintains capacity?

here and on the "How to make XC back into an InterCity railway" thread we are saying that re-forming increases the capacity by reducing the numbers of driving vehicles in use - and also stops the nonsense of 2-set trains running with one locked out of use.
see (e.g.) post 252 on https://www.railforums.co.uk/threads/can-gbr-bring-xc-back-up-to-intercity-standard.287481/page-9

 

[mike57]

Also, I assume that 2% includes freight.

Yes it did.

 

[dosxuk]

here and on the "How to make XC back into an InterCity railway" thread we are saying that re-forming increases the capacity by reducing the numbers of driving vehicles in use - and also stops the nonsense of 2-set trains running with one locked out of use.
see (e.g.) post 252 on https://www.railforums.co.uk/threads/can-gbr-bring-xc-back-up-to-intercity-standard.287481/page-9

But removing driving vehicles will remove capacity? According to that thread there are currently 140 driving vehicles in use, this reform idea would have 54 of them put out to pasture, along with all the seats and standing room they currently convey - that is absolutely a reduction in capacity whatever way you look at it.

The locked trains issue could equally be solved with additional staffing.

 

[Brubulus]

But removing driving vehicles will remove capacity? According to that thread there are currently 140 driving vehicles in use, this reform idea would have 54 of them put out to pasture, along with all the seats and standing room they currently convey - that is absolutely a reduction in capacity whatever way you look at it.

The locked trains issue could equally be solved with additional staffing.

There would be more trains too - 43 trains isn't enough to run XC, at least 10 more would be needed, which could be higher capacity than 6 cars for particularly busy diagrams.

 

[dosxuk]

There would be more trains too - 43 trains isn't enough to run XC, at least 10 more would be needed, which could be higher capacity than 6 cars for particularly busy diagrams.

But that isn't something that could be done tomorrow as suggested.

 

[43096]

The locked trains issue could equally be solved with additional staffing.

Or by removing the ridiculous need for a guard in both sets. It is a costly, unnecessary requirement.

 

[The Ham]

There would be more trains too - 43 trains isn't enough to run XC, at least 10 more would be needed, which could be higher capacity than 6 cars for particularly busy diagrams.

You could get the extra 10 trains fairly quickly (at least in terms of new orders).

If you lengthened the GWR 802/0's to be 9 coaches you could lengthen 2, then transfer the next unit to be lengthened to XC, repeat and then after that then every other unit goes to XC (the rest stay with GWR).

GWR would end up with 12 full length trains (rather than the equivalent of 11 of them).

XC would get a new unit after the production of just 12 coaches, the next after another 12 and then one for every 8 coaches. Whilst that would start off slowly, by the time you got to the 7th train it would be faster.

You'd probably want to build a couple of extra 9 coach units to boost capacity a bit further (and make the order over 100 coaches, as less than that and prices tend to be higher).

 

[sad1e]

On the WCML it'd be a much bigger benefit to have all freight electrically hauled: pathing would be easier and reliability improved.

Hopefully the new class 99's are the beginning of this trend and help electrically hauled freight become more popular around the uk considering their tractive effort to weight ratio is unlike any other loco seen in the UK before.

 

[Tazi Hupefi]

The WCML is essentially not electrified north of Crewe as far as additional trains go, or converting from diesel hauled to electric. The presence of wires doesn't mean they're actually available.

Existing services can use the electric wires.

No new services, especially not heavy freight electric locomotives with their loads can use the electric.

All well and good wanting to electrify other parts of the network, but I don't think people realise how limited the existing electric infrastructure actually is. It is for the most part either extremely dated and in need of total replacement or does not have enough electrical power available in the local supply area to support more trains or more powerful trains.

We need to re-electrify existing electric routes first, and find new ways to feed them from the grid.

Same for things like the route from London to Cambridge/Ely - electrified all the way, can't support LNER diversions.

 

[Mike Machin]

I had a dig around on the .gov.uk website and found some interesting data which supports my arguement that rail is a small contributer to UK CO2 emmissions.

The following snip shows that rail is only responsible for 2% of emissions:
View attachment 182921

Here is a link to the data, which is freely available for anyone who wants to dig deeper- https://www.gov.uk/government/stati...d-environment-data-tables-env#:~:text=ENV0201

This supports my thinking that 'de-carbonising' the railway just for its own sake is not a good use of scarce resources. To put these numbers in perspective, I found in some related data that transport in turn contributes ~28% of total UK emisions.

This means that a 2% saving in the road contribution would be almost the same as the total contribution from rail.

By all means try and make best use of what we have, but not doing something rail related just because its 'diesel' makes no sense. If you could do something which would reduce road emissions by 10% but the penalty is a 50% increase in rail emissions, then in the overall view of things that would be good.

By all means set policy to drive things in the right direction, but we also need to do better at identifying quick wins and going for them rather than getting hung up on the 'gold plated' solution, which then takes longer.

My own thoughts:

Bi-mode still feels like the best solution for most routes that are not fully electified, its proven, and requires very little or no additional infrastructure, which 20 years down the road means that cascade onto other routes is easy. Battery may have a place but personally I would get on with electrifying most routes and accept that some lightly used rural routes will remain diesel, because it really is the best option. As more routes become 100% electric then either remove the engines or buy new electric only stock. Maybe with existing bi-modes there is a case for retaining one engine to provide onboard services in emergency and a limp mode to traverse a dead or short non electified section.

But as those figures show it is road transport where even small savings will make a big impact.

But around 90% of distance travelled by land in the UK is by road, with about 85% by car.
Ten years from now a significant proportion of cars in use will be either fully electric or hybrid. Rail is in a relatively good position at the moment, but as a nation we need a continuous rolling programme of electrification.

 

[Trainbike46]

The WCML is essentially not electrified north of Crewe as far as additional trains go, or converting from diesel hauled to electric.

While that is true for now, how long will that last? There are plans to upgrade electrical supply to enable the extra Liverpool services. If the people in charge are remotely sensible (that may be asking too much, I know) it will be upgraded by more than needed just for the Liverpool services, and will allow the Lumo service as well as more freight to go electric

Existing services can use the electric wires.

No new services, especially not heavy freight electric locomotives with their loads can use the electric.

Existing services, including those freight services that already have rights to use electric, whether they currently use them or not.

All well and good wanting to electrify other parts of the network, but I don't think people realise how limited the existing electric infrastructure actually is. It is for the most part either extremely dated and in need of total replacement or does not have enough electrical power available in the local supply area.

We need to re-electrify existing electric routes first, and find new ways to feed them from the grid.

There are many places where the electrical supply needs to be upgraded - whether to enable longer trains (e.g. 10 car lumos on London-Edinburgh), more services, or switching from diesel to electric traction (e.g. TPE north of Newcastle).

However, I don't see why that should prevent further electrification on routes not currently electrified.

 

[Starmill]

Six trains a day with minimal seating capacity can be pretty much ignored as far as mode shift goes.

 

[Tazi Hupefi]

While that is true for now, how long will that last? There are plans to upgrade electrical supply to enable the extra Liverpool services. If the people in charge are remotely sensible (that may be asking too much, I know) it will be upgraded by more than needed just for the Liverpool services, and will allow the Lumo service as well as more freight to go electric

Existing services, including those freight services that already have rights to use electric, whether they currently use them or not.

There are many places where the electrical supply needs to be upgraded - whether to enable longer trains (e.g. 10 car lumos on London-Edinburgh), more services, or switching from diesel to electric traction (e.g. TPE north of Newcastle).

However, I don't see why that should prevent further electrification on routes not currently electrified.

Who's going to put the wires up/replace them/maintain them as well as the local power supply feeders?

Industry is already stretched as it is and struggles to find resources for existing projects, which is why there should have been a rolling electrification programme, moving the resources and assets from one location to the next.

This isn't just for railway infrastructure, the power firms can't get enough either, especially with huge changes to the grid with wind and other projects. It can take years to get a new major feed.

The other problem on the horizon is HS2 - at some point, and probably sooner than people realise, despite all the delays, there is going to be track being laid down, and wires strung up. Where are the skilled electrification staff going to come from to do that? It will be at the expense of other railway electrification work.

 

[The Ham]

But around 90% of distance travelled by land in the UK is by road, with about 85% by car.
Ten years from now a significant proportion of cars in use will be either fully electric or hybrid. Rail is in a relatively good position at the moment, but as a nation we need a continuous rolling programme of electrification.

The carbon emissions for rail is low enough that an EV has to always have an average of 1.5 people using it per km to match the passenger emissions per km of rail (which is for the network as a while includes diesel and is 31g/km).

Yes there's some TOC's which need to do better, those who exceed the rate for one passenger in an EV (43g/km, 2025 data) are:
TfW rail 85g/km
ScotRail 60g/km
XC 59g/km
EMR 54g/km
Northern 54g/km
TPE 47g/km
Grand Central 43g/km

Chiltern and GWR (both 40g/km) as does Caledonian Sleeper (37g/km) need to improve a bit to stay ahead of EV's.

Otherwise the rest (all 33g/km or lower) do need to make some improvements to aid the reduction, but are less critical.

TfW Rail is the biggest issue, mostly rural lines with limited scope for growth and a lot of fairly lightly used lines which makes more electrification less likely.

ScotRail could see further improvements if Scotland carries on with more electrification.

XC we've covered, needs longer trains and a couple of bimodal trains as a start for the longer distance services, and something done with their non 22x fleet.

EMR is due to get bimodals, so that will help, but probably need something for their local fleet too.

Northern needs more electrification and battery trains.

TPE is getting more electrification which will help, could also do with getting replacements for their 185's.

Grand Central are due to get bimodals which will help.

Chiltern and GWR could do with some batteries in their trains (like a Hybrid) to improve things, even if they aren't bimodal in the short term.

Caledonian Sleeper is more tricky until there's bimodal locos for the Northern legs (or electrification allows a change to where the locos can swap over).

 

[mike57]

but as a nation we need a continuous rolling programme of electrification.

I agree, because electrification also delivers other benefits. As for other complex schemes proposed to try and 'decarbonise' remote rural routes, my view is that money and effort would be better spent on electifying routes that see more use, and infill that allows end to end electric operation.

I would set the bar at 1tph, any route that sees more than 1tph is added to the 'get it electrified list' together with any short infills to allow end to end electic operation. Network rail or their successor then need to then build in house capability to deliver electrification in much the same way as BR did. This team and its learning can then be kept together and deployed on a rolling basis, with design, procurement, build, and commissioning all kept in house. This avoids the issues of scope change management that occur when you sub contract. With the in house team approach minor changes during the design and build phase are signed off by the engineers and implimented. No claim and counter claim with the contractor, with all the bureaucracy that comes with it. You give the team an annual budget which is fixed for long enough to actually make progress.

Electrification is currently a farce, look at the glacial pace of TPE electrification, which is a busy inter regional route.

Anyrthng less than 1tph remains simple diesel for the time being (as in until every busier route is electrified), I wouldn't even bother thinking about batteries or other solutions for these routes, because the contribution to emissions is miniscule, and the time, effort and money would be better spent on busier routes.

 

[The exile]

TfW Rail is the biggest issue, mostly rural lines with limited scope for growth and a lot of fairly lightly used lines which makes more electrification less likely.

Except that quite a bit of what is happening now is still to come fully on stream. I would also imagine/ hope that the 197s guzzle less fuel than the 158s, so the Cambrian switchover (whenever that happens) will help. After that, it’s going to be a challenge, I accept.

 

[AndrewE]

I agree, because electrification also delivers other benefits. As for other complex schemes proposed to try and 'decarbonise' remote rural routes, my view is that money and effort would be better spent on electifying routes that see more use, and infill that allows end to end electric operation.

certainly that is a good way to prioritise them

I would set the bar at 1tph, any route that sees more than 1tph is added to the 'get it electrified list' together with any short infills to allow end to end electic operation. Network rail or their successor then need to then build in house capability to deliver electrification in much the same way as BR did. This team and its learning can then be kept together and deployed on a rolling basis, with design, procurement, build, and commissioning all kept in house. This avoids the issues of scope change management that occur when you sub contract. With the in house team approach minor changes during the design and build phase are signed off by the engineers and implimented. No claim and counter claim with the contractor, with all the bureaucracy that comes with it. You give the team an annual budget which is fixed for long enough to actually make progress.

Electrification is currently a farce, look at the glacial pace of TPE electrification, which is a busy inter regional route.

It has been said upthread that a big block/cause of delay on electrification is getting grid connections. When the transformer fires were in the news (https://www.bbc.co.uk/news/articles/cx2wvz4pjryo) there was a follow-up (https://www.linkedin.com/posts/simo.../?rcm=ACoAAAVGXo8BYLo90i9aJ4YSnIuaoGZ9qXY4PUc) which said that they are not getting any more frequent, but had the interesting snippet, maybe in the comments, that the UK now has only a single manufacturer and there is a 20-month lead time if you want to order one in the USA.

This is why I think an OLE/rapid charge groundstation as at Greenford would be a good idea. At Tweedbank (e.g.) a capacitor bank could be charged up gradually from the local network without adding a massive load and the units could take enough charge to get them as far as the wires on the approach to Edinburgh - which could probably be extended a bit if needed, like the design idea for the Windermere branch...

Anything less than 1tph remains simple diesel for the time being (as in until every busier route is electrified), I wouldn't even bother thinking about batteries or other solutions for these routes, because the contribution to emissions is miniscule, and the time, effort and money would be better spent on busier routes.

but if they penetrate a city we I think we are duty-bound to eliminate the diesel exhaust (eventually.)

 

[mike57]

but if they penetrate a city we I think we are duty-bound to eliminate the diesel exhaust (eventually.)

I even wonder about that, routes like Heart of Wales, Far North, Whitby, a few trains per day, any contribution from diesel exhaust will be minimal even at terminals. Maybe just have a shore supply at terminal stations so that engines can be shutdown during layovers. That will be a few 100's of kW at most so will not stress the local grid and should be fairly simple to do.

The trouble with trying to eliminate all diesel is that we will spend time and money on designing and building alternatives. The money spent on these lighly used lines which would be better diverted to say power supply upgrades to existing electrified routes, to allow more services to run , which in turn will hopefully get people to mode switch. In other words more 'bang for your buck'

I will not say 'never' but I feel that there will always be a place for diesel on a few remote rural routes as the most logical choice of motive power.

 

[Bletchleyite]

I even wonder about that, routes like Heart of Wales, Far North, Whitby, a few trains per day, any contribution from diesel exhaust will be minimal even at terminals. Maybe just have a shore supply at terminal stations so that engines can be shutdown during layovers. That will be a few 100's of kW at most so will not stress the local grid and should be fairly simple to do.

Apart from in the middle of August you can just stop the engines. It's just not UK railway culture to do so. In Germany it's been practice for years.

I will not say 'never' but I feel that there will always be a place for diesel on a few remote rural routes as the most logical choice of motive power.

That's probably where the present CAF fleet will end up for the next 20-30 years or so. I seem to recall that was Northern's argument for ordering 2-car units despite the initial deployment plan not including very many 2-car workings. (Later they realised that the high acceleration of these units makes them very suitable for stuff like east Manchester locals, and 2-car has been quite useful for things like Rose Hill Marple).

 

[Zomboid]

Apart from in the middle of August you can just stop the engines. It's just not UK railway culture to do so. In Germany it's been practice for years

Probably a hangover from the first gen DMUs where you wouldn't dare turn them off because the batteries were so bad you'd never get them going again.

You do see it happening more now though. They usually shut down the diesels at Waterloo and I've seen Voyagers turned off at Basingstoke when they have a long dwell (a result of the Andover diversion) and when terminating at Didcot.