Chiltern Railways Electrification

[Palmerston]

The Chiltern proposal is for the bare minimum of electrification, mainly so that batteries can be recharged, and all in easy locations. If the government can't even afford that, then they'll have to order some new DMUs which would be humiliating for the government's green credentials.

I suspect the government is wary of electrifying the Chiltern line and attracting a "they always have money for London" headline, even if it would make sense to get it done.

 

[HSTEd]

Lets compare the UK with Denmark then who both use 25 kv AC

Danish railway electrification isn't really that extensive.

 

[Mgameing123]

Danish railway electrification isn't really that extensive.

No but the electrification program is. The Danish Government is currently rolling out electrification on ALL main lines including on a single track line with trains only running every hourly.

 

[The Mercian]

I suspect the government is wary of electrifying the Chiltern line and attracting a "they always have money for London" headline, even if it would make sense to get it done.

Start in Birmingham then and work south, with the added advantage you get the two urban/suburban lines (Stratford and Leamington) done which I’d imagine would have just as big a BCR and carbon reduction benefit as doing the bits that go into London.

 

[The Planner]

Start in Birmingham then and work south, with the added advantage you get the two urban/suburban lines (Stratford and Leamington) done which I’d imagine would have just as big a BCR and carbon reduction benefit as doing the bits that go into Lo

Why would you do Stratford if the output is for Chiltern? That would never wash its face unless you go out the other side towards Stourbridge as it doesnt release diesel stock from WMT.

 

[Zomboid]

I'd take a wider view. Electrify Didcot to Coventry and Bletchley as a start (yes it's a big project, but with big potential benefits) and you support GWR operation to Oxford, EWR Oxford to MK, Chiltern between Aynho (Banbury) and Leamington/ Oxford and Bicester and create an electrified Cross Country route all the way from Manchester to Reading. Plus it's a big freight route, so if bi-mode freight locomotives catch on there's a lot of benefits there too.

To go BEMU on the Chiltern network would then need Moor St, Marylebone and probably a section somewhere around Wycombe to be wired.

 

[ShadowKnight]

Start in Birmingham then and work south, with the added advantage you get the two urban/suburban lines (Stratford and Leamington) done which I’d imagine would have just as big a BCR and carbon reduction benefit as doing the bits that go into London.

As an aside, that is what should have happened with HS2 but London centric government thinking...

I think electrifying the south west Midlands branch lines would benefit all operators on those routes (Chiltern, crosscountry, wmt)

 

[Mikey C]

Start in Birmingham then and work south, with the added advantage you get the two urban/suburban lines (Stratford and Leamington) done which I’d imagine would have just as big a BCR and carbon reduction benefit as doing the bits that go into London.

The driver for this though is replacing the 165s, which operate the stopping services into London.

Which isn't to deny the importance of electrifying the Birmingham end as well.

 

[MarkyT]

I'd take a wider view. Electrify Didcot to Coventry and Bletchley as a start (yes it's a big project, but with big potential benefits) and you support GWR operation to Oxford, EWR Oxford to MK, Chiltern between Aynho (Banbury) and Leamington/ Oxford and Bicester and create an electrified Cross Country route all the way from Manchester to Reading. Plus it's a big freight route, so if bi-mode freight locomotives catch on there's a lot of benefits there too.

To go BEMU on the Chiltern network would then need Moor St, Marylebone and probably a section somewhere around Wycombe to be wired.

The Banbury - Leamington section seems especially important and could help contribute to a BEMU future for XC. It could also allow bi-mode freight locos to rest their engines while achieving maximum output over a fast and busy stretch. I can see wiring of the Oxford area becoming more attractive to allow Chiltern and EWR battery units to charge at and around their terminus.

 

[zwk500]

No but the electrification program is. The Danish Government is currently rolling out electrification on ALL main lines including on a single track line with trains only running every hourly.

From the Danish Railway's website:

In comparison, since 2014 the UK has electrified:
Manchester to Preston, Wigan, and Liverpool (via Chat Moss),
extended the GWML electrification from Heathrow Airport Jn to Cardiff, Chippenham and Newbury (don't talk about the fact it doesn't get to Bristol...),
Preston to Blackpool,
Walsall to Rugeley,
Gospel Oak to Barking/Barking Riverside,
Edinburgh to Glasgow via Shotts,
Bedford to (nearly) Leicester,
Crossrail (London)
Cardiff Valley Lines (discontinuous)
Barrhead/East Kilbride lines

Many other small corners and curves that I'm not going to list in full detail. And is in the process of electrifying Manchester-Huddersfield-Leeds-York as part of Transpennine Route Upgrade. I've probably missed some things as well.
Unfortunately I don't have the time in the near future to work this out on a track-km or route-km basis. But see: http://www.railwaycodes.org.uk/electrification/dates.shtm

 

[Trainbike46]

From the Danish Railway's website:
View attachment 191911
In comparison, since 2014 the UK has electrified:
Manchester to Preston, Wigan, and Liverpool (via Chat Moss),
extended the GWML electrification from Heathrow Airport Jn to Cardiff, Chippenham and Newbury (don't talk about the fact it doesn't get to Bristol...),
Preston to Blackpool,
Walsall to Rugeley,
Gospel Oak to Barking/Barking Riverside,
Edinburgh to Glasgow via Shotts,
Bedford to (nearly) Leicester,
Crossrail (London)
Cardiff Valley Lines (discontinuous)
Barrhead/East Kilbride lines

Many other small corners and curves that I'm not going to list in full detail. And is in the process of electrifying Manchester-Huddersfield-Leeds-York as part of Transpennine Route Upgrade. I've probably missed some things as well.
Unfortunately I don't have the time in the near future to work this out on a track-km or route-km basis. But see: http://www.railwaycodes.org.uk/electrification/dates.shtm

Of course, Denmark's population (6m) is comparable to that of Scotland (5.5m), so you'd expect a slower rate in Denmark than in the UK as a whole.

The more important question is of course, are there things we can learn from electrification in Scotland or Denmark, that could be applied in England?

 

[GraphitProjekt]

From the Danish Railway's website:
View attachment 191911
In comparison, since 2014 the UK has electrified:
Manchester to Preston, Wigan, and Liverpool (via Chat Moss),
extended the GWML electrification from Heathrow Airport Jn to Cardiff, Chippenham and Newbury (don't talk about the fact it doesn't get to Bristol...),
Preston to Blackpool,
Walsall to Rugeley,
Gospel Oak to Barking/Barking Riverside,
Edinburgh to Glasgow via Shotts,
Bedford to (nearly) Leicester,
Crossrail (London)
Cardiff Valley Lines (discontinuous)
Barrhead/East Kilbride lines

Many other small corners and curves that I'm not going to list in full detail. And is in the process of electrifying Manchester-Huddersfield-Leeds-York as part of Transpennine Route Upgrade. I've probably missed some things as well.
Unfortunately I don't have the time in the near future to work this out on a track-km or route-km basis. But see: http://www.railwaycodes.org.uk/electrification/dates.shtm

Adding up all those UK lines since 2014 I came to about 821km. With a cracking 122km of Transpennine Route Upgrade coming in the near future. As opposed to Denmark's 1756 previous kilometres and 1150 coming soon.
Perhaps taking back the threshold to include all the modern Scottish schemes would be slightly more fair.

== Doublepost prevention - post automatically merged: 7 Nov 2025 ==

Having another look at that, it's possible those Danish numbers are STKs rather than route miles. Wikipedia says Denmark has 474km of 25kV

== Doublepost prevention - post automatically merged: 7 Nov 2025 ==

The more important question is of course, are there things we can learn from electrification in Scotland or Denmark, that could be applied in England?

I found an article on that question https://mag.railtechnologymagazine....rn-from-denmark-s-affordable-electrification-
It seems that the way the Danish state railways did it was to draw up a huge contract for their whole electrification goal, and then award that to a consortium who had the full confidence of delivering that work consistently meaning they all invested in the programme themselves and all were incentivised to work efficiently. So basically, it's a rolling programme again.

 

[Mgameing123]

Adding up all those UK lines since 2014 I came to about 821km. With a cracking 122km of Transpennine Route Upgrade coming in the near future. As opposed to Denmark's 1756 previous kilometres and 1150 coming soon.
Perhaps taking back the threshold to include all the modern Scottish schemes would be slightly more fair.

== Doublepost prevention - post automatically merged: 7 Nov 2025 ==

Having another look at that, it's possible those Danish numbers are STKs rather than route miles. Wikipedia says Denmark has 474km of 25kV

== Doublepost prevention - post automatically merged: 7 Nov 2025 ==


I found an article on that question https://mag.railtechnologymagazine....rn-from-denmark-s-affordable-electrification-
It seems that the way the Danish state railways did it was to draw up a huge contract for their whole electrification goal, and then award that to a consortium who had the full confidence of delivering that work consistently meaning they all invested in the programme themselves and all were incentivised to work efficiently. So basically, it's a rolling programme again.

So exactly. The UK needs to make a master plan for electrification and prioritise the routes that need it the most.

 

[Kuyoyo]

deleted

 

[Sparks807Evo]

So exactly. The UK needs to make a master plan for electrification and prioritise the routes that need it the most.

Precisely - there is a complete lack of strategy currently. A classic example being the lack of wires extending to Bristol and Oxford.

 

[zwk500]

Precisely - there is a complete lack of strategy currently. A classic example being the lack of wires extending to Bristol and Oxford.

That's not due to a lack of strategy but to a project failing to keep its costs under control.

The lack of strategy is more evident in things like the MML, XC and suburban networks of Bristol, Birmingham and other major cities.

 

[Mgameing123]

That's not due to a lack of strategy but to a project failing to keep its costs under control.

The lack of strategy is more evident in things like the MML, XC and suburban networks of Bristol, Birmingham and other major cities.

No it’s a lack of strategy because you going to have to spend more to get the project up + we now run more technologically complex Bi-mode trains vs simple EMU’s. And knowing these projects very well, if Bristol and Oxford were part of the original contact then the government would have had to pay compensation to the company involved in the electrification so we have wasted a good chunk of money by NOT electrifying Oxford and Bristol.

 

[HSTEd]

Precisely - there is a complete lack of strategy currently. A classic example being the lack of wires extending to Bristol and Oxford.

Oxford and Bristol were axed to stem the flow of money haemorrhaging out of the Great Western modernisation scheme.

I'd argue there is a strategy, and that strategy is that electrification is largely complete.

You may need a bit more to support battery trains, but the era of large continuous electrification projects is over.

== Doublepost prevention - post automatically merged: 8 Nov 2025 ==

No it’s a lack of strategy because you going to have to spend more to get the project up + we now run more technologically complex Bi-mode trains vs simple EMU’s.

Future trains will likely be battery hybrids that will not be significantly more complicated than a pure electric train.

And knowing these projects very well, if Bristol and Oxford were part of the original contact then the government would have had to pay compensation to the company involved in the electrification so we have wasted a good chunk of money by NOT electrifying Oxford and Bristol.

Well a fixed termination compensation payment is one thing, continuing a project in the face of enormous and potentially unbounded cost growth is quite another.

I don't think it's reasonable to expect the government to continuing to pour money into these schemes in the face of runaway cost growth and failure to reach claimed targets.

 

[zwk500]

And knowing these projects very well, if Bristol and Oxford were part of the original contact then the government would have had to pay compensation to the company involved in the electrification

Well if Bristol wasnt part of the original contract perhaps you can explain why there are unused masts west of chippenham, a substation thats never been used at Bristol, and track lowering works through bath were completed?
I could also point to the electrification of Swansea Depot and masts north of Didcot.

so we have wasted a good chunk of money by NOT electrifying Oxford and Bristol.

We did.

 

[BrianW]

No it’s a lack of strategy because you going to have to spend more to get the project up + we now run more technologically complex Bi-mode trains vs simple EMU’s. And knowing these projects very well, if Bristol and Oxford were part of the original contact then the government would have had to pay compensation to the company involved in the electrification so we have wasted a good chunk of money by NOT electrifying Oxford and Bristol.

Governments change. Transport Ministers change. Minds change. Priorities change. This train (project, whatever) terminates here ...

Of coursec 'sunk costs' are a consideration; so is cash, and cash is king.

IIRC the current Chancellor of the Exchequer has said 'If we can't afford it, we can't do it'.

Didcot- Oxford and/or Chippenham- Bristol could still be done; so could all unelectrified lines.

Myself, I would seek to make all urban centres pollution free, thus Marylebone, Birmingham etc- kinder to passengers, neighbours and planet. Can that be done with battery charging at both ends of journey? I'm not in charge!!

 

[The exile]

No but the electrification program is. The Danish Government is currently rolling out electrification on ALL main lines including on a single track line with trains only running every hourly.

… which is therefore the equivalent in track-km terms of double track with a half-hourly service.
The significant factor is the number of restrictive structures /overbridges etc it involves. For most British lines the answer tends to be “a lot”.

 

[eldomtom2]

I'd argue there is a strategy, and that strategy is that electrification is largely complete.

You may need a bit more to support battery trains, but the era of large continuous electrification projects is over.

Well no, I don't think there is a strategy, because as far as I'm aware there's been no official examination of what electrification would be required to fully replace diesel trains with battery ones.

 

[stevieinselby]

… which is therefore the equivalent in track-km terms of double track with a half-hourly service.

I'm not sure that track-km is the relevant measurement.
Yes, electrifying 10km of double track will cost more than electrifying 10km of single track, but I'm sure it won't cost anything like twice as much.
The actual cost will be somewhere between route-km and track-km.

 

[The exile]

I'm not sure that track-km is the relevant measurement.
Yes, electrifying 10km of double track will cost more than electrifying 10km of single track, but I'm sure it won't cost anything like twice as much.
The actual cost will be somewhere between route-km and track-km.

Clearly there is not a 2:1 relationship in terms of costs, but in terms of intensity of usage there is. A single track with an hourly service (each way) is used as intensively as each of the double tracks of a line carrying a half-hourly service. If that single line is a) rural with few structures in need of rebuilding, b) in an area where all other lines are electrified and c) able to form part of the electrical feed to other lines - then the fact that it's service is not that intensive may be fairly irrelevant.

 

[anthony263]

Certainly i think they need to extend the wires to bristol Tm and perhaps theough to WSM. They could also wire all the platforms at swansea as well as the depot. The Class 756s should have plenty of range to reach swansea on battery power.


If swanline was put back to just being a shuttle then units wpuld stable at swansea for at least 25 minutes. The ovsrhead wires would also reduce noise polution arpund the station area and depot

Maybe even extend wires to oxford and Bedwyn

 

[The Pelican]

Britain has generally tended to string electrification out over an extreamly long time, despite always having a fairly high quality railway system in general. Even though Chiltern will be the last main line out of London to be electrified, XC through Banbury and through Cheltenham as well as the Berks and Hants mean that there is a lot more electrification to go- so battery based methods will allow a certain investment to be shared around more places.

 

[haydenwilliams]

Seems to me the easiest option would just be to run Aylesbury services into Baker Street, not Marylebone, no issue with mixing electrification costs.

You can also add 4th rail electrification at Aylesbury Vale Parkway only energised when the train is in the station.

If That involves the Met Line going to Aylesbury I would Love that to happen, it has always been a pipe dream of mine

 

[BrianW]

If That involves the Met Line going to Aylesbury I would Love that to happen, it has always been a pipe dream of mine

Welcome to the forum. Sorry you've had no response; pipe dream on. Maybe the days of drawing 'boundaries' of support at the 'Greater London' boundary, eg Bakerloo to Harrow and not Watford, are gone with Elizabeth Line to Reading rather than to West Drayton. Perhaps we shall see an even Greater London, extending toward MK and the Oxford- Cambridge Arc/ Belt/ Corridor/... Network South East?? Welcome.

 

[Farigiraf]

If That involves the Met Line going to Aylesbury I would Love that to happen, it has always been a pipe dream of mine

Other than the general benefits of having a TfL-run service (decent trains and simpler fares, which can be achieved with a new BEMU order and Project Oval instead) I don't see how that would bring significant improvements.

Frequency is unlikely to go above 2tph - the only minor improvement possible is extending both trains per hour to Vale Parkway instead of just one. The Met Line S-stock trains are also slightly slower than the class 165s, and have more longitudinal seating, which wouldn't be comfortable if coming all the way from Aylesbury.

Also, while you would get direct trains to Baker Street, King's Cross, Liverpool Street etc, this would be at the cost of gaining extra stops at Finchley Road, Wembley Park and Moor Park, assuming it uses the Met line 'fast' stopping pattern (which is not a guarantee). Marylebone isn't perfect but running fast after Rickmansworth/Harrow is 20 mins faster, making the walk to Baker Street (or changing to the Bakerloo line) quicker than a direct tube service.

If the transfer at Marylebone is improved, through easier access to the Bakerloo platforms, or an easier walking route to Baker Street (avoiding traffic lights etc) it would be faster and cheaper than extending the Met.

 

[MerlinRail 804]

If the transfer at Marylebone is improved, through easier access to the Bakerloo platforms, or an easier walking route to Baker Street (avoiding traffic lights etc) it would be faster and cheaper than extending the Met.

Circle line platforms at Marylebone would be useful, considering it passes fairly close. Of course I realise how impractical that is!