Reinstating passing loops on the Chiltern Sudbury stations

[London Trains]

There will no be Chiltern and Met line platforms.

The OSI is staying.

This is the speculative discussion part of the forum, that would be a valid response elsewhere on the forum but not here.

 

[Bald Rick]

There will no be Chiltern and Met line platforms.

The OSI is staying.

This is the speculative discussion part of the forum, that would be a valid response elsewhere on the forum but not here.

I’m going to speculate that there will be no Chiltern nor Met Line platforms at West Hampstead.

 

[150219]

How about some platforms at Finchley Road? Not quite as good as West Hampstead, a bit better than Neasden?

There's definitely no room for anything that would provide the up platform at Finchley Road. The main problem being the falling gradient away from West Hampstead to Marylebone. The LU Finchley Road is higher than the mainline and there is a retaining wall supporting the station on the Up cess.

== Doublepost prevention - post automatically merged: 9 Sep 2025 ==

This is the speculative discussion part of the forum, that would be a valid response elsewhere on the forum but not here.

There's room for interpretation there. It's possible to speculate that we could get rid of the railway entirely, which could be seen as the opposite of there not being any new platforms at Neasden, West Hampstead or Finchley Road.

I like to at least try and read and contribute to what I think is broadly realistic. It doesn't make anyone else's contributions less valid.

 

[BerkshireRails]

What improvements would it allow, and would the loops actually be in the right place? You have a loop on the up at West Ruislip and the old down line at South Ruislip. As @Zomboid notes, you would be sitting at a Sudbury station for a while as you now have approach control into the loop, as well as being 3 minutes minimum infront of the train behind you amd not being able to leave until at least 2 minutes after its passed you. You are looking at a minimum of 5 minutes penalty.

	Stopper (2W58 the 19:14 London Marylebone to High Wycombe)	Stopper (2R28 the 19:20 London Marylebone to West Ruislip)	Fast (1G59 the 19:36 London Marylebone to Birmingham Snow Hill)
London Marylebone	19:14 (d)	19:20 (d)	19:36 (d)
Neasden South Junction	19:21 (p)	19:27 (p)	19:43 (p)
Wembley Stadium	19:22 (a) / 19:23 (d)	19:28 (a) /19:29 (d)	19:44 (p)
Sudbury & Harrow Road	19:25 (p)	19:32 (a) /19:33 (d)	19:45 (p)
Sudbury Hill Harrow	19:26 (p)	19:35 (a) / 19:36 (d)	19:45 (p)
Northolt Park	19:27 (p)	19:38 (a) / 19:39 (d)	19:46 (p)
Northolt Park Junction	19:28 (p)	19:41 (p)	19:47 (p)
South Ruislip	19:30 (a) / 19:31 (d)	19:42 (p)	19:48 (p)
West Ruislip	19:33 (p)	19:45 (a)	19:49 (p)
Denham	19:36 (a) / 19:37 (d)		19:51 (p)
Denham Golf Course	19:39 (a) / 19:40 (d)		19:51 (p)
Gerrards Cross	19:43 (a) / 19:44 (d)		19:53 (p)
Seer Green	19:47 (p)		19:55 (p)
Beaconsfield	19:50 (a) / 19:51 (d)		19:56 (p)
High Wycombe	19:58 (a)		20:00 (p)

(p) = Pass
(d) = Departure
(a) = Arrival

Based on the timetable one of the better places for a new build dynamic loop looks to be between Wembley Stadium and Sudbury Hill Harrow inclusive based on a stopper takes 8 minutes to cover the distance from arriving into Wembley Stadium until departure and the Fast taking 1 minute to cover the same distance.

Another one seems to be South Ruislip to Denham Golf Course, as it is 11 minutes for a stopper and 3 minutes for a fast. This could also allow both 2R28 & 2W58 to stop at both South & West Ruislip, thereby improving connections between North West London and Buckinghamshire.

 

[Mgameing123]

There's definitely no room for anything that would provide the up platform at Finchley Road. The main problem being the falling gradient away from West Hampstead to Marylebone. The LU Finchley Road is higher than the mainline and there is a retaining wall supporting the station on the Up cess.

== Doublepost prevention - post automatically merged: 9 Sep 2025 ==


There's room for interpretation there. It's possible to speculate that we could get rid of the railway entirely, which could be seen as the opposite of there not being any new platforms at Neasden, West Hampstead or Finchley Road.

I like to at least try and read and contribute to what I think is broadly realistic. It doesn't make anyone else's contributions less valid.

But just saying “There won’t be Met or Chiltern platforms and OSI is staying” is a little cold. Like yeah in the real world money could maybe be better used elsewhere. But a West Hampstead Interchange definitely be looked at and be built at some point in the future. It’s an interchange that’s got potential.

 

[Bald Rick]

But a West Hampstead Interchange definitely be looked at and be built at some point in the future.

It’s been looked into at least twice to my knowledge. And found to be a) difficult, b) very disruptive to build (both to the railways and the local comminity) and c) therefore very expensive. Then there is d) it offers little in the way of additional benefit compared to what exists today.

One issue that no-one has covered up thread yet is… what Chiltern services would actually stop there?

When answering the question, consider minimum headways.

 

[Mgameing123]

It’s been looked into at least twice to my knowledge. And found to be a) difficult, b) very disruptive to build (both to the railways and the local comminity) and c) therefore very expensive. Then there is d) it offers little in the way of additional benefit compared to what exists today.

One issue that no-one has covered up thread yet is… what Chiltern services would actually stop there?

When answering the question, consider minimum headways.

I can say for certain that Chiltern Metro, Aylesbury via Amersham, High Wycombe and Aylesbury via High Wycombe trains should stop there. You can also look into stopping Oxford trains at West Hampstead with the argument that most people who need to go Oxford from London would take the faster GWR train anyways.

 

[zwk500]

I can say for certain that Chiltern Metro, Aylesbury via Amersham, High Wycombe and Aylesbury via High Wycombe trains should stop there. You can also look into stopping Oxford trains at West Hampstead with the argument that most people who need to go Oxford from London would take the faster GWR train anyways.

And what does that do to the total throughput of Neasden South Jn for Chiltern?

 

[Mgameing123]

And what does that do to the total throughput of Neasden South Jn for Chiltern?

I can’t know for certain. I’m not an expert on that topic.

 

[zwk500]

I can’t know for certain. I’m not an expert on that topic.

Having had experience of timetabling Marylebone for NR, my hunch is 'completely breaks it'.

 

[mr_jrt]

I would imagine that once OOC has NNML platforms, then the "mainline" Chiltern services will use those, leaving just the metro services using Marylebone, and the headways for those would be less of an issue. Of course, it also means that anyone wanting to change could have switched to the Met at HotH (assuming the Met gets platforms in this scenario to replace those at FR)....but still.

 

[zwk500]

I would imagine that once OOC has NNML platforms,

Isn't this still an 'if ever'?

 

[mr_jrt]

The DfT at least put money on the table to ensure it could happen (re: the OOL bridge span, and planning passive space for a couple of platforms), so it's at least a bit more likely than anything happening at WH....

 

[35B]

I would imagine that once OOC has NNML platforms, then the "mainline" Chiltern services will use those, leaving just the metro services using Marylebone, and the headways for those would be less of an issue. Of course, it also means that anyone wanting to change could have switched to the Met at HotH (assuming the Met gets platforms in this scenario to replace those at FR)....but still.

Are you sure it would be that way round?

== Doublepost prevention - post automatically merged: 10 Sep 2025 ==

I can’t know for certain. I’m not an expert on that topic.

Isn't that the point? The idea of improving interchange isn't itself bad, but it has both benefits and costs. The assertions that it is such a good thing that all services should be built around an extra Chiltern stop for unproven demand shifts the balance towards net negative.

 

[SynthD]

It would be cheaper to pay every property owner on that West Hampstead street to have a permanent veranda for rain cover.

But just saying “There won’t be Met or Chiltern platforms and OSI is staying” is a little cold. Like yeah in the real world money could maybe be better used elsewhere.

We could skip justifying it and just imagine the station layout. The ideal station is one built in fields. What compromises are you willing to make for what already exists.

I would imagine that once OOC has NNML platforms, then the "mainline" Chiltern services will use those, leaving just the metro services using Marylebone,

No, the other way around. The Gerrards Cross trains would go to OOC. It leaves these five existing and two desired stations apart, still on a suburban service to Marylebone.

 

[Mgameing123]

Isn't this still an 'if ever'?

It will probably happen. The business case is

It would be cheaper to pay every property owner on that West Hampstead street to have a permanent veranda for rain cover.

We could skip justifying it and just imagine the station layout. The ideal station is one built in fields. What compromises are you willing to make for what already exists.

No, the other way around. The Gerrards Cross trains would go to OOC. It leaves these five existing and two desired stations apart, still on a suburban service to Marylebone.

Gerrards Cross, High Wycombe and Aylesbury via High Wycombe trains will 100%

 

[35B]

It will probably happen. The business case is

What business case?

 

[SynthD]

Gerrards Cross, High Wycombe and Aylesbury via High Wycombe trains will 100%

Which, stop at the Neasden or West Hampstead station on the Marylebone branch, or miss both because they’re on the OOC branch?

 

[Mgameing123]

What business case?

The Elizabeth Line

Which, stop at the Neasden or West Hampstead station on the Marylebone branch, or miss both because they’re on the OOC branch?

I’m saying those trains are probably going to be the candidates for OOC.

 

[zwk500]

It will probably happen. The business case is
[...]
The Elizabeth Line

Could you expand please?

I’m saying those trains are probably going to be the candidates for OOC.

So who's going to be left changing at Neasden?

 

[cle]

Based on the timetable one of the better places for a new build dynamic loop looks to be between Wembley Stadium and Sudbury Hill Harrow inclusive based on a stopper takes 8 minutes to cover the distance from arriving into Wembley Stadium until departure and the Fast taking 1 minute to cover the same distance.

Another one seems to be South Ruislip to Denham Golf Course, as it is 11 minutes for a stopper and 3 minutes for a fast. This could also allow both 2R28 & 2W58 to stop at both South & West Ruislip, thereby improving connections between North West London and Buckinghamshire.

Hmmmm... there aren't many 'stoppers' which do all stops. And as discussed, the Sudbury+Northolt Park group isn't a high potential / demand area.

I agree with the South Ruislip to Denham stretch - long enough to enable some dynamic passing, more so than Beaconsfield loops.

No, the other way around. The Gerrards Cross trains would go to OOC. It leaves these five existing and two desired stations apart, still on a suburban service to Marylebone.

It was planned that it would be 1 x High Wycombe, Oxford, Aylesbury (MKC at the time) and Banbury. Vs all inners.

Worth noting that the OOC/NNL line might also enable pathing, flighting or especially, skip-stopping options too.

 

[Mgameing123]

Hmmmm... there aren't many 'stoppers' which do all stops. And as discussed, the Sudbury+Northolt Park group isn't a high potential / demand area.

I agree with the South Ruislip to Denham stretch - long enough to enable some dynamic passing, more so than Beaconsfield loops.


It was planned that it would be 1 x High Wycombe, Oxford, Aylesbury (MKC at the time) and Banbury. Vs all inners.

Worth noting that the OOC/NNL line might also enable pathing, flighting or especially, skip-stopping options too.

I believe regardless of demand. The Sudbury Area needs to have a decent rail service on the Chiltern Line.

 

[zwk500]

I believe regardless of demand. The Sudbury Area needs to have a decent rail service on the Chiltern Line.

...why?

 

[Mgameing123]

Could you expand please?

So who's going to be left changing at Neasden?

People on the Aylesbury trains? It really depends on how Chiltern/GBR would make a timetable on the line. We can’t say for sure.

== Doublepost prevention - post automatically merged: 10 Sep 2025 ==

...why?

It would severely help provide better transport options for these people and if you actually make it attractive you can relieve the Piccadilly Line.

 

[The Planner]

Based on the timetable one of the better places for a new build dynamic loop looks to be between Wembley Stadium and Sudbury Hill Harrow inclusive based on a stopper takes 8 minutes to cover the distance from arriving into Wembley Stadium until departure and the Fast taking 1 minute to cover the same distance.

Another one seems to be South Ruislip to Denham Golf Course, as it is 11 minutes for a stopper and 3 minutes for a fast. This could also allow both 2R28 & 2W58 to stop at both South & West Ruislip, thereby improving connections between North West London and Buckinghamshire.

And thats the rub, you need to understand what the end game service spec (not always the timetable) will be before you can start drawing where infrastructure needs to be. What works now may not be good for any strategic aim.

 

[zwk500]

People on the Aylesbury trains? It really depends on how Chiltern/GBR would make a timetable on the line. We can’t say for sure.

So we're spending however much on the interchange when we don't even know anybody will use it. What journeys would somebody from Aylesbury be making where Neasden is a better interchange than Harrow-on-the-Hill, West Hampstead, or Marylebone?

It would severely help provide better transport options for these people and if you actually make it attractive you can relieve the Piccadilly Line.

So it's not regardless of demand, but rather considering the potential demand rather than the current. This is (finally) a coherent proposal.

 

[SynthD]

I’m saying those trains are probably going to be the candidates for OOC.

It won’t be all of them because it’s only a two platform station in the proposals. I’m curious if anyone thinks there’s room for more on the west side of Old Oak Common Lane. But it leaves us wondering what passengers could possibly use this interchange, as you’ve assigned the slower trains to use the West Hampstead or Neasden station and also the other branch. It depends what part of all this you like imagining.

if you actually make it attractive you can relieve the Piccadilly Line.

They chose new trains and signalling. It was the right decision.

It’s a shame the fast trains don’t stop, that would serve me well. But I just pay normal prices, so don’t consider me.

 

[BerkshireRails]

Hmmmm... there aren't many 'stoppers' which do all stops. And as discussed, the Sudbury+Northolt Park group isn't a high potential / demand area.

Only 2R47 the 16:23 London Marylebone to West Ruislip and 2R55 the 18:23 London Marylebone to West Ruislip seem to be all stops from London via Ruislip. There are no all-stop services to London via Ruislip. In my view, the low demand is partly due to the poor service of 1tph, stopping at most stations in the London area.

And thats the rub, you need to understand what the end game service spec (not always the timetable) will be before you can start drawing where infrastructure needs to be. What works now may not be good for any strategic aim.

Due to the close spacing of the stations in the London area, I doubt the stopper could be sped up by more than a minute or two. I thought it made the most sense to compare the current all-station stopper and fasts to find the shortest dynamic loop.

 

[mr_jrt]

Are you sure it would be that way round?

== Doublepost prevention - post automatically merged: 10 Sep 2025 ==

I figure the Aylesbury services have no option but to run to Marylebone. Those are suburban services, as are the High Wycombe services, which coming full circle, are also those which would serve the stations at the core of this thread.

...which leaves the "mainline" services, which could use those new platforms at OOC to free up capacity at Marylebone. The two platforms at OOC should be sufficient for those, but the suburban services would either need several more at OOC, or to split the suburban service provision between the two termini, which is not ideal.

If we were talking about linking up the High Wycombe services to Crossrail on the other hand, I'd agree that would make a lot more sense. But that doesn't really seem to be on the cards.

 

[cle]

People on the Aylesbury trains? It really depends on how Chiltern/GBR would make a timetable on the line. We can’t say for sure.

== Doublepost prevention - post automatically merged: 10 Sep 2025 ==


It would severely help provide better transport options for these people and if you actually make it attractive you can relieve the Piccadilly Line.

The Piccadilly line through Sudbury has plenty of capacity - it’s not like the hordes of Sudbury aren’t choosing Chiltern or the tube, they just don’t especially exist. As for Northolt, the Central line is far more useful.

There is no excess congestion or demand to resolve in that area really. And most Chiltern trains stopping there are extremely short too.