Chiltern Mainline Upgrades post TPE Mk5As

[Bletchleyite]

It was mainly in reference to the 5 car service would that be using 20 or 24m long coaches?

The 5 car services use 23m vehicles at present. But they can go places other than P4 - in the peaks, when these mostly run, the inner suburban local ties up 4 anyway.

 

[BerkshireRails]

I am thinking you could do something like this for the electrification of the Harrow to Amersham with both OLE for Chiltern and retaining the existing Fourth Rail for the Metropolitan Line.

The 5 car services use 23m vehicles at present. But they can go places other than P4 - in the peaks, when these mostly run, the inner suburban local ties up 4 anyway.

Fair enough, that would probably be the High Wycombe shuttles which will fill that then, as both West Ruislip & Gerrards Cross termators would be extended to High Wycombe for a simpler suburban pattern.

 

[HamworthyGoods]

The buildings mentioned would be demolished to create space for the tracks to be all at one level, then Oversite Development would take place at London Marylebone.

The original post just said on top of the buildings so had wondered were you proposing a bi-level station like Antwerpen Central.

 

[BerkshireRails]

The original post just said on top of the buildings so had wondered were you proposing a bi-level station like Antwerpen Central.

It seems like a misunderstanding as I was referring to on the site of and you thought i was referring to on top of the, with the word on.

 

[Railwaysceptic]

Yeah to the point that you can’t even get on an 8 coach 165 off Peak.View attachment 186067

How many of Chiltern trains are 8 coaches long off peak? In my experience, none. Only during the morning and evening peak periods are trains lengthened. Pre Covid, the off peak trains were mainly 2, 3. or 4 coaches long and many are still that today. There are a few 5 or 6 coach trains now because they stop at more stations and pick up more passengers.

 

[mr_jrt]

I suspect that were this a real plan, you would need a High Wycombe avoiding line for the fast services to achieve any semblance of decent speed. Which handily also saves you the cost of smashing through High Wycombe to make room for the additional tracks required.

 

[Farigiraf]

To be honest I see no reason why the Chiltern Met service should stop between Amersham and Harrow on the Hill at any time. Those stations are served perfectly well by the Metropolitan Line, and aside from HotH people don't often alight at these stations coming from the Aylesbury direction/join it towards Aylesbury. HotH is heavily used for interchange with the Tube so would benefit from more stops.

I would make it an hourly (half hourly on weekdays plus some peak extras as now) perfect clockface service calling at all stations between Vale Parkway/Aylesbury and Amersham inclusive, then all trains to call at HotH (pick up/set down only) and Marylebone. This might allow a reduction in stock used to allow strengthening/reduced overcrowding.

Would calling at Moor Park in place of R-C-C&L help? It might only save a net four minutes to Aylesbury compared to current times, but improve Watford to Aylesbury journeys without needing to introduce extra services (and when Arriva have shown such little interest in doing so).

Alternatively you could instate an all-day half-hourly Chesham-Watford via the North curve, and then only stop Chiltern trains at Amersham, Rickmansworth and HotH. Chorleywood could be dropped already as 4tph is fine for the least used Met line station, and the argument for keeping Chalfont & Latimer and/or adding a Moor Park stop would be for connections to/from Chesham and Watford. All-day Chesham-Watford in theory could solve this problem, though I don't know how easy it would actually be to run on the current infrastructure. As an added bonus, Rickmansworth is the largest settlement between Harrow and Amersham (besides Pinner but that's irrelevant) so it would benefit the most from keeping a fast train to central London.

 

[BerkshireRails]

How many of Chiltern trains are 8 coaches long off peak? In my experience, none. Only during the morning and evening peak periods are trains lengthened. Pre Covid, the off peak trains were mainly 2, 3. or 4 coaches long and many are still that today. There are a few 5 or 6 coach trains now because they stop at more stations and pick up more passengers.

Basically whenever an enhanced timetable is run.

 

[A S Leib]

As an added bonus, Rickmansworth is the largest settlement between Harrow and Amersham

And the largest settlement between Pinner and Aylesbury, although of course Amersham should keep Chiltern calls (end of the Met line and no Chesham services).

 

[BerkshireRails]

And the largest settlement between Pinner and Aylesbury, although of course Amersham should keep Chiltern calls (end of the Met line and no Chesham services).

I see limited point in running the Chiltern trains fast, I get pick up & set down in the peak might be handy for Harrow but apart from that I think it is best to keep the existing stopping pattern, maybe with the introduction of electric traction an additional call of Moor Park could be made as not to catch up the Metropolitan Line services.

 

[Bletchleyite]

I see limited point in running the Chiltern trains fast

The point is that it would reduce the rolling stock requirement/reduce overcrowding.

 

[BerkshireRails]

The point is that it would reduce the rolling stock requirement/reduce overcrowding.

However, if you're electrifying the line, you'll get longer trains anyway, which will be at least a 4-car unit, if not a 5-car unit, with a minimum length of around 100, compared to the 45m of a 165 or 168. This will significantly reduce overcrowding as there is more capacity, along with the increased frequency, to help spread demand.

 

[cle]

Fast Oxford services aren't only to compete with GWR. They are predominantly (since 80x came in) - for fast London service to Parkway and to Bicester Village. So that becomes the purpose.

Chiltern are quite fortunate by having good sized commuter markets as their 'country' termini. So you have people at High Wycombe or Banbury boarding trains in both directions at 7am, heading to London, Birmingham and indeed, Oxford. And 'counter-peak' services have uptake at the other end (someone in Dorridge or Warwick probably thinks of Chiltern has their main rail provider, vs a Marylebone/Bucks-focused provider)

As such, I think having 3tph one day to Oxford would comfortably be sustainable:
A fast (High Wycombe / Bicester / Parkway only)
Two semi-fast (different hourly patterns but some places get 2tph, eg Princes Ris, Beaconsfield/GC) as well as the above. An Islip call. Even journey times to keep to a takt

Those two tph would probably be the contenders for Cowley, vs a fast. More regional connectivity.

 

[Bletchleyite]

Those two tph would probably be the contenders for Cowley, vs a fast. More regional connectivity.

It's looking likely if I recall that East West Rail will be what serves Cowley with its two trains per hour and not Chiltern to Marylebone; most people would probably change at Oxford for fast London services anyway as the Chiltern service is extremely slow.

 

[BerkshireRails]

Fast Oxford services aren't only to compete with GWR. They are predominantly (since 80x came in) - for fast London service to Parkway and to Bicester Village. So that becomes the purpose.

Chiltern are quite fortunate by having good sized commuter markets as their 'country' termini. So you have people at High Wycombe or Banbury boarding trains in both directions at 7am, heading to London, Birmingham and indeed, Oxford. And 'counter-peak' services have uptake at the other end (someone in Dorridge or Warwick probably thinks of Chiltern has their main rail provider, vs a Marylebone/Bucks-focused provider)

As such, I think having 3tph one day to Oxford would comfortably be sustainable:
A fast (High Wycombe / Bicester / Parkway only)
Two semi-fast (different hourly patterns but some places get 2tph, eg Princes Ris, Beaconsfield/GC) as well as the above. An Islip call. Even journey times to keep to a takt

Those two tph would probably be the contenders for Cowley, vs a fast. More regional connectivity.

Suppose there is a 4tph local metro-style service from High Wycombe to London. In that case, you can have the Oxford Semi-Fasts run non-stop from High Wycombe to London Marylebone, enabling a more consistent service pattern on the Southern part of the route.

It's looking likely if I recall that East West Rail will be what serves Cowley with its two trains per hour and not Chiltern to Marylebone; most people would probably change at Oxford for fast London services anyway as the Chiltern service is extremely slow.

Double-track the Cowley Branch and run 2tph Chiltern East West Rail and 2tph Chiltern London Marylebone, providing a well-timed turn-up-and-go style service between Bicester Village and Cowley.

 

[Bletchleyite]

Suppose there is a 4tph local metro-style service from High Wycombe to London. In that case, you can have the Oxford Semi-Fasts run non-stop from High Wycombe to London Marylebone, enabling a more consistent service pattern on the Southern part of the route.

And reducing their appeal. They are about connectivity, and would thus be better connected to all stations stoppers than fasts or semi fasts!

It is not competition. Those days are over.

 

[BerkshireRails]

And reducing their appeal. They are about connectivity, and would thus be better connected to all stations stoppers than fasts or semi fasts!

It is not competition. Those days are over.

It is still about competition with road and air, so having a Metro-style service and an express service would make it so that there is a better service for both local and longer-distance passengers. High Wycombe to London would be a perfect corridor for significant developments, supported by a 4-8tph Metro service alongside 8-10tph of Express and Semi-Fast services. It would make it more attractive as there would be shorter journey times for both Express and Metro passengers from the greater frequency and increased amount of four-tracking, enabling the Express to overtake a moving Metro train rather than having the Metro train wait for it to pass like now.

 

[Bletchleyite]

It is still about competition with road and air, so having a Metro-style service and an express service would make it so that there is a better service for both local and longer-distance passengers.

Again, there is one - from Paddington.

 

[BerkshireRails]

Again, there is one - from Paddington.

That is rather busy, plus Paddington trains don't go to most Chiltern stations. In addition, Chiltern is cheaper than GWR and Oxford. Plus, also the majority of people who benefit don't get a GWR service from their station, so using GWR as a reason not to upgrade the route is a poor excuse, as the rest of Chiltern don't get any benefits from the project you have cancelled because a few people don't have to use Chiltern.

 

[Bletchleyite]

That is rather busy

Then it needs to run longer trains (9 or 10 car).

plus Paddington trains don't go to most Chiltern stations.

Nor does a fast Oxford service. The whole point is connectivity!

In addition, Chiltern is cheaper than GWR and Oxford.

If you want it cheaper, you can cope with it being slower. That allows a segmentation of the market. The days of actual competition (two different fast services) are over and will not return.

Plus, also the majority of people who benefit don't get a GWR service from their station, so using GWR as a reason not to upgrade the route is a poor excuse, as the rest of Chiltern don't get any benefits from the project you have cancelled because a few people don't have to use Chiltern.

Not sure I understand that point.

 

[BerkshireRails]

Then it needs to run longer trains (9 or 10 car).

It is already often 9 or 10 cars with 2tph formed from one north Cotswolds and one Oxford Fast, calling at Reading and Didcot in the Down and only Reading in the Up direction.

Nor does a fast Oxford service. The whole point is connectivity!

Hence running an Oxford Fast from London Marylebone also improves connectivity.

If you want it cheaper, you can cope with it being slower. That allows a segmentation of the market. The days of actual competition (two different fast services) are over and will not return.

GWR is more expensive in Advance fares and the Afternoon Peak.

 

[SynthD]

It would take time to electrify the line. In the meantime, non-stop from Harrow to Amersham can be done sooner, even if it’s peak only or linked to fast Met line trains in off peak?

supported by a 4-8tph Metro service alongside 8-10tph of Express and Semi-Fast services.

I wonder what steps towards that is possible with the current track and trains, as there are time delays in using loops. What little they achieve now involves skipping many stops (links to MYB-HWY and MYB-WRU about now).

Realtime Trains | 2W50 1719 London Marylebone to High Wycombe | 11/08/2025

Real-time train running information for 2W50 1719 departure from London Marylebone to High Wycombe on 11/08/2025. From Realtime Trains, an independent source of train running info for Great Britain.

www.realtimetrains.co.uk

Realtime Trains | 2R51 1723 London Marylebone to West Ruislip | 11/08/2025

Real-time train running information for 2R51 1723 departure from London Marylebone to West Ruislip on 11/08/2025. From Realtime Trains, an independent source of train running info for Great Britain.

www.realtimetrains.co.uk

Hence running an Oxford Fast from London Marylebone also improves connectivity.

The connectivity needs to be with Islip, Bicester, Haddenham, not Marylebone.

 

[Bletchleyite]

Hence running an Oxford Fast from London Marylebone also improves connectivity.

The more places it stops, the better the connectivity.

GWR is more expensive in Advance fares and the Afternoon Peak.

Then accept a slower service for a cheaper fare.

== Doublepost prevention - post automatically merged: 11 Aug 2025 ==

The connectivity needs to be with Islip, Bicester, Haddenham, not Marylebone.

This.

 

[BerkshireRails]

It would take time to electrify the line. In the meantime, non-stop from Harrow to Amersham can be done sooner, even if it’s peak only or linked to fast Met line trains in off peak?

I wonder what steps towards that is possible with the current track and trains, as there are time delays in using loops. What little they achieve now involves skipping many stops (links to MYB-HWY and MYB-WRU about now).

Realtime Trains | 2W50 1719 London Marylebone to High Wycombe | 11/08/2025

Real-time train running information for 2W50 1719 departure from London Marylebone to High Wycombe on 11/08/2025. From Realtime Trains, an independent source of train running info for Great Britain.

www.realtimetrains.co.uk

Realtime Trains | 2R51 1723 London Marylebone to West Ruislip | 11/08/2025

Real-time train running information for 2R51 1723 departure from London Marylebone to West Ruislip on 11/08/2025. From Realtime Trains, an independent source of train running info for Great Britain.

www.realtimetrains.co.uk

The connectivity needs to be with Islip, Bicester, Haddenham, not Marylebone.

The 2tph Oxford Semi-Fasts would still call at Oxford Parkway, Islip, Bicester Village, Haddenham & Thame Parkway, Princess Risborough & High Wycombe, with electrifaction I can see an average journey time of 60 minutes from the current 88 minutes. The removal of calls at Beaconsfield, Gerrards Cross & Wembley Stadium should save in-between 2-4 minutes per stop based on Network Rail Kent saying a stop adds 2 minutes and Network Rail Wessex saying a stop adds 4 minutes.

To do the all stopper Metro services will require infrastructure upgrades there might be justification in closing Sudbury & Harrow Road to save the cost of Rebuilding it for the sake of 4 trains per weekday per direction. With ticket acceptance on Piccadilly line.

 

[A S Leib]

With ticket acceptance on Piccadilly line.

Given that the most common flow outside Oyster acceptance is to High Wycombe with 33 passengers per year, I doubt many people would be inconvenienced without any changes to ticketing.

 

[BerkshireRails]

Given that the most common flow outside Oyster acceptance is to High Wycombe with 33 passengers per year, I doubt many people would be inconvenienced without any changes to ticketing.

Might as well tell passengers just to use Sudbury Hill Harrow instead for connections with the Piccadilly Line.

 

[Farigiraf]

Considering that the tube takes three quarters of an hour from Sudbury to central London (maybe slightly less with an OSI at Park Royal / Hanger Lane) compared to 16min from Sudbury Hill Harrow / Harrow Road to Marylebone, a frequent and reliable Chiltern stopper would certainly convert a considerable amount of tube passengers over to NR. 4tph is about the minimum needed to make it somewhat turn-up-and-go as Piccadilly line frequency (6tph at the moment IIRC) would still remain a factor in which route people take.

 

[A S Leib]

Sudbury and Harrow Road is also only a twenty minute walk from Wembley Central, but that doesn't help people to the west of Sudbury, and Wembley lost its London Northwestern service at some point since Covid so there to central London is 25+ minutes.

 

[cle]

Sudbury is not a highly populated area, with much growth. It's very suburban and low density, and doesn't have huge Central London commuting. I suspect if both stations closed, it wouldn't be a huge loss. But - for the actual users, it's a quick link to town, definitely.

Wembley on the other hand, has had a ton of development and has changed a lot, and demand has followed.

For the Oxford piece - I think we have to define or not get hung up on what is fast and what is semi-fast.

Oxford will always be at least the third stop, but I think you would have something like:
Marylebone - High Wycombe - Princes or Haddenham - Bicester - Oxford Parkway - Oxford as one pattern.

And a slower pattern could include both Beaconsfield and Gerrards Cross - or you alternate them in the above, like PR/Haddenham.

 

[NCT]

The existing timetable has diesel accelerations and long dwell times, so stopping services take up disproportionate capacity. With (battery) electric traction and 30-second dwells the capacity impact of those stopping services then can be reduced to a point where you can run a half-hourly service with an overtake at West or South Ruislip.

There is merit in having fast Oxford services on Chiltern (calling at principal stations only) with comparable journey times to GWR. It's unhelpful to think of it in terms of competition as an irrational pushback against the franchise days. I simply see it as spreading the load just like South Central places have fast services to both Victoria and London Bridge. Beaconsfield and Gerrard Cross ought to be hived off to a semi-fast service to/from Aylesbury (a service that ran pre-Covid which ought to be restored at some point).