Plan to remove Croydon rail bottleneck

[Horizon22]

Turn left at Selhurst. An early signalling stage could make that chord suitable for passenger trains and allow reversing in platfrom 1, but not a good place for a reversal

But how to reverse at Norwood Jn?

Not ideal to block the middle bidirectional road during the reversal.

Terminate at Selhurst, then run empty stock via chord to depot and reverse in siding next to carriage washer road.
Anoher option might be to do a big anti-clockwise loop. Left at Selhurst, via chord (upgraded for passenger), through Platfrom 1 at Norwood Jn, then turn left to Crystal Palace and back to Balham.

Operationally, it might be interesting if some sort of "rounder" service was possible; going on the Up and Selhurst into Platform 1 at Norwood Junction then via Streatham Hill. Would replace the West Croydon service and vice versa. Not thought it through any further mind you!

 

[JonathanH]

Operationally, it might be interesting if some sort of "rounder" service was possible; going on the Up and Selhurst into Platform 1 at Norwood Junction then via Streatham Hill. Would replace the West Croydon service and vice versa. Not thought it through any further mind you!

Might work in the anti-clockwise direction Selhurst to Norwood Junction but not at all practical the other way round (cross all lines at Norwood Junction on the flat) so probably not worth pursuing.

 

[Horizon22]

Might work in the anti-clockwise direction Selhurst to Norwood Junction but not at all practical the other way round (cross all lines at Norwood Junction on the flat) so probably not worth pursuing.

Yes that is the drawback - even if it goes into P5, it has to cross the mainline.

 

[SECR263]

There is a map of the 1965 Greater London Rail Network on line which shows a London Bridge to London Bridge via Selhurst service. The Crystal Palace Spur down to Sydenham is shown as limited use but there is no key to the map. I have tried to copy the link from the site. https://www.flickr.com/photos/davidh73/31031289370/in/photostream/ I think I remember going via the yards on a service train as I needed to get from Forest Hill to Tulse Hill mid 60's.

 

[30907]

There is a map of the 1965 Greater London Rail Network on line which shows a London Bridge to London Bridge via Selhurst service. .... I think I remember going via the yards on a service train as I needed to get from Forest Hill to Tulse Hill mid 60's.

The various services between Norwood Junction and Selhurst (the actual routings varied) used two single-track connections in the old tangle of lines there. This is the best layout diagram I can find ATM, the green dotted lines are the relevant ones.
Norwood Fork Junction

 

[Peter Sarf]

There is a map of the 1965 Greater London Rail Network on line which shows a London Bridge to London Bridge via Selhurst service. The Crystal Palace Spur down to Sydenham is shown as limited use but there is no key to the map. I have tried to copy the link from the site. https://www.flickr.com/photos/davidh73/31031289370/in/photostream/ I think I remember going via the yards on a service train as I needed to get from Forest Hill to Tulse Hill mid 60's.

The various services between Norwood Junction and Selhurst (the actual routings varied) used two single-track connections in the old tangle of lines there. This is the best layout diagram I can find ATM, the green dotted lines are the relevant ones.
Norwood Fork Junction

Back in the days of 4-SUBs I remember services that terminated at Clapham Junction. There were also services that never got to Croydon but turned round at Selhurst plus Norwood Junction - these probably headed back to london Bridge as you say but maybe also shuttled to Clapham Junction ?.

 

[swt_passenger]

Is the proposal a couple of years ago for more terminating capacity at stations beyond WEST Croydon still alive? Is it related to this project in terms of reducing the number of trains terminating at East Croydon?

...and if so would any service destination changes be seen as temporary?

 

[Peter Sarf]

Is the proposal a couple of years ago for more terminating capacity at stations beyond WEST Croydon still alive? Is it related to this project in terms of reducing the number of trains terminating at East Croydon?

...and if so would any service destination changes be seen as temporary?

I suppose the reversing siding just to the South West of West Croydon satisfied that. It was meant for the TfL services to Dalston (378s) but I have seen 377s use it.

That reversing siding must be far more use than the bay platform that requires a conflicting move from the Down line across the Up line to get to the bay platform. I never understood why platforms for terminating trains were not put between the through lines/platforms.

 

[swt_passenger]

I suppose the reversing siding just to the South West of West Croydon satisfied that. It was meant for the TfL services to Dalston (378s) but I have seen 377s use it.

The reversing siding must be far more use than the bay platform that requires a conflicting move from the Down across the up lines. Never understood why platforms for terminating trains were not put between the through lines/platforms.

There was another more recent proposal for another turnback location further along as well though, I can’t remember exactly where I read it now.

 

[Peter Sarf]

There was another more recent proposal for another turnback location further along as well though, I can’t remember exactly where I read it now.

Mmm. I vaguely recall talk of somewhere like Wallington, could be more than ten years ago ?. Would make sense to reverse before Sutton. Plus I think there might be the space for two through lines between the platform lines.

 

[JonathanH]

Mmm. I vaguely recall talk of somewhere like Wallington, could be more than ten years ago ?. Would make sense to reverse before Sutton. Plus I think there might be the space for two through lines between the platform lines.

'Pedantic of Purley' wrote about it on London Reconnections in November 2018

As far as I know there are no plans for West Croydon as it is too expensive for what it achieves. The only thing in the pipeline is an eventual 6tph London Overground. Turnback will be achieved by reinstating the centre track turnback to the west of Wallington station. Whether or not this means 3tph, or 6tph, in passenger service as far as Wallington is far too early to say.

https://www.londonreconnections.com/2018/a-study-in-sussex-part-14-the-beginnings-of-big-changes/ - search for 'Wallington turnback'.

That reversing siding must be far more use than the bay platform that requires a conflicting move from the Down line across the Up line to get to the bay platform. I never understood why platforms for terminating trains were not put between the through lines/platforms.

The problem appears to be that both London Overground and Southern want to run trains that terminate at West Croydon. Reconfiguring the platforms at West Croydon to have a central reversal platform would appear to be a pretty substantial project in confined space. Obviously the London bound platform was built out at one point but there doesn't seem to be space for a different layout.

 

[Bald Rick]

I suppose the reversing siding just to the South West of West Croydon satisfied that. It was meant for the TfL services to Dalston (378s) but I have seen 377s use it.

That reversing siding must be far more use than the bay platform that requires a conflicting move from the Down line across the Up line to get to the bay platform. I never understood why platforms for terminating trains were not put between the through lines/platforms.

The revers8ng siding was always intended for use by Southern services, to free up the bay for Overground services.

There was another more recent proposal for another turnback location further along as well though, I can’t remember exactly where I read it now.

Wellington. Not sure where it is in the development cycle.

 

[Peter Sarf]

'Pedantic of Purley' wrote about it on London Reconnections in November 2018


https://www.londonreconnections.com/2018/a-study-in-sussex-part-14-the-beginnings-of-big-changes/ - search for 'Wallington turnback'.



The problem appears to be that both London Overground and Southern want to run trains that terminate at West Croydon. Reconfiguring the platforms at West Croydon to have a central reversal platform would appear to be a pretty substantial project in confined space. Obviously the London bound platform was built out at one point but there doesn't seem to be space for a different layout.

Really needs the road and shops bridge over the line replacing so that the country end throat is wider. Moving the platforms towards London is probably easier. Note the the bay (which is on the up side) ends up higher than the through lines/platforms at the buffers so probably dead level along its length.

The revers8ng siding was always intended for use by Southern services, to free up the bay for Overground services.



Wellington. Not sure where it is in the development cycle.

I am pretty sure all London Overground services use the turn back siding never the bay. I have noticed 377s in there as well on occasions. But things might have changed since 2019 ?.

Minor Typo W*a*llington - Just in case some one goes rummaging and end up nearer Birmingham !.

 

[MarkyT]

Something that could help at West Croydon is sacrificing the siding on the up side at the London end to move the crossover and bay turnout a little further north which would get them out of the overlap for the up platform starting signal. There is a shorter restricted clear overlap available for when the junction is in use today, but that delays incoming up trains by holding the approach signal at red for a delayed yellow. There is even sufficient space available for construction of a second terminal platform and some scope for extended standage.

Layout Today:


Overlap conflict removed:


Second bay platform added:

 

[edwin_m]

That reversing siding must be far more use than the bay platform that requires a conflicting move from the Down line across the Up line to get to the bay platform. I never understood why platforms for terminating trains were not put between the through lines/platforms.

As mentioned, if it was added after the original construction the station would need re-building, but also extra land would be needed either end to allow the lines to splay out, so between that and the greater area of platform the land take for the station would be quite a bit more. Any bridges in this area would need re-building too. If the splays were too short the reverse curves would limit the speed of non-stopping trains.

 

[MarkyT]

As mentioned, if it was added after the original construction the station would need re-building, but also extra land would be needed either end to allow the lines to splay out, so between that and the greater area of platform the land take for the station would be quite a bit more. Any bridges in this area would need re-building too. If the splays were too short the reverse curves would limit the speed of non-stopping trains.

I don't believe there are any regularly scheduled passenger trains that pass through West Croydon non-stop, only ECS mostly at the beginning and the end of the operational day, and a handful of freights.

 

[swt_passenger]

Wellington. Not sure where it is in the development cycle.

Thanks Bald Rick, that’s the place I read about. I think now it may have been in one of those fairly regular TfL wish lists about LO capacity.

 

[Bald Rick]

Thanks Bald Rick, that’s the place I read about. I think now it may have been in one of those fairly regular TfL wish lists about LO capacity.

I meant Wallington of course!

 

[edwin_m]

I don't believe there are any regularly scheduled passenger trains that pass through West Croydon non-stop, only ECS mostly at the beginning and the end of the operational day, and a handful of freights.

I'm sure you're right - I was thinking more about the general case than specifically West Croydon.

 

[30907]

Back in the days of 4-SUBs I remember services that terminated at Clapham Junction. There were also services that never got to Croydon but turned round at Selhurst plus Norwood Junction - these probably headed back to london Bridge as you say but maybe also shuttled to Clapham Junction ?.

CLJ terminators - was that while Victoria was being resignalled and tracks were OOU?
Selhurst - once the new layout was in use would have gone into the depot, not sure about Norwood Jn because Down Local to Depot isn't so easy

 

[London Trains]

I do think it would be possible to fit 4 terminating platforms (2 islands) next to Platform 1 if the siding was removed, which would solve a lot of problems in one go.

However I cant see any way of it working due to every terminating service conflicting with the 6tph (currently) from the Sutton direction.

The only possible solution I see would be to have the terminating lines connect to a separate set of tracks where the siding currently is, which then descend into a cut and cover tunnel which runs under the current line, resurfacing either side of the current tracks before Windmill Bridge Junction and joining.

 

[dewsnapsliding]

I am pretty sure all London Overground services use the turn back siding never the bay. I have noticed 377s in there as well on occasions. But things might have changed since 2019 ?.

That used to be the case, until approx 2 years ago, the Overground now terminates exclusively in the bay platform and the turn back is used for terminating Southern services.

Perhaps the bay isn't long enough for extended trains?

 

[Peter Sarf]

Something that could help at West Croydon is sacrificing the siding on the up side at the London end to move the crossover and bay turnout a little further north which would get them out of the overlap for the up platform starting signal. There is a shorter restricted clear overlap available for when the junction is in use today, but that delays incoming up trains by holding the approach signal at red for a delayed yellow. There is even sufficient space available for construction of a second terminal platform and some scope for extended standage.

Layout Today:
View attachment 79012

Overlap conflict removed:
View attachment 79013

Second bay platform added:
View attachment 79014

Oh yes. You have reminded me. Yes, because of that siding (which I have never seen used) the area has enough length to move the station further NE (to the right in your diagrams). There should then be enough room for a throat at both ends (allowing "the lines to splay out"). As for width I know that at the SW end (where the station buildings are) there is a car park which must have been an ex-railway yard. So I think you are right in thinking there is room enough for four platforms. I would make the terminating happen in the middle two roads and rebuild the station buildings which could allow a better exit towards the bus station.

Incidentally there were originally three tracks under the main road at the SW (left) end as there was a short bay for the Wimbledon branch. The up through platform was lengthened by burying that short platform road. But if the whole lot were to be moved towards the NE/London then three tracks could get under the bridge. Either utilise three tracks in conjunction with the reversing siding feeding two centre platforms OR I would like to see the tram run along there. I mean along the SE side (bottom of your diagrams where the down through is currently. This would make the trams avoid a busy and dangerous road junction almost above the railway. The trams currently run parallel to the line along roads and those roads get almost down to rail level either end of my idea.

That used to be the case, until approx 2 years ago, the Overground now terminates exclusively in the bay platform and the turn back is used for terminating Southern services.

Perhaps the bay isn't long enough for extended trains?

Ah well that shows how out of date i am. I thought the bay platform was still used by Southern services even when things had gone 10-car. But the new reversing siding is VERY long.

 

[swt_passenger]

The land alongside the bay platform at West Croydon appears to have been sold in 2017 - (or at least approved for disposal by ORR). The responses to the consultation suggest no one is interested in having more terminating platforms, or stabling sidings there:

https://orr.gov.uk/__data/assets/pdf_file/0014/25061/west-croydon-station-land-disposal-decision-document.pdf

 

[MarkyT]

The land alongside the bay platform at West Croydon appears to have been sold in 2017 - (or at least approved for disposal by ORR). The responses to the consultation suggest no one is interested in having more terminating platforms, or stabling sidings there:

https://orr.gov.uk/__data/assets/pdf_file/0014/25061/west-croydon-station-land-disposal-decision-document.pdf

Important to CARS as it involves a land swap agreement with a housing association for some property near East Croydon station that is neccesary for the work planned there. Avoids a more risky and expensive compulsory purchase option presumably.

 

[hwl]

Something that could help at West Croydon is sacrificing the siding on the up side at the London end to move the crossover and bay turnout a little further north which would get them out of the overlap for the up platform starting signal. There is a shorter restricted clear overlap available for when the junction is in use today, but that delays incoming up trains by holding the approach signal at red for a delayed yellow. There is even sufficient space available for construction of a second terminal platform and some scope for extended standage.

Layout Today:
View attachment 79012

Overlap conflict removed:
View attachment 79013

From what I understand addressing the overlap issues is part of the plan (but not a 2nd bay). Moving the s&c further north and using higher speed s&c geometry means the junction blocking time for conflicting moves reduces.

Gloucester Road junction is also planned to get grade separated hence anything heading north post the works has much better chance of clear run to Selhurst/Norwood Junction than currently.

 

[hwl]

Thanks Bald Rick, that’s the place I read about. I think now it may have been in one of those fairly regular TfL wish lists about LO capacity.

From what I understand the plan wasn't LO (5cars) to Wallington but moving all the Southern West Croydon terminators (8/10car) to Wallington so the long tern extra 2tph LO services can use the centre turnback siding at West Croydon instead.

 

[hwl]

I do think it would be possible to fit 4 terminating platforms (2 islands) next to Platform 1 if the siding was removed, which would solve a lot of problems in one go.

However I cant see any way of it working due to every terminating service conflicting with the 6tph (currently) from the Sutton direction.

The only possible solution I see would be to have the terminating lines connect to a separate set of tracks where the siding currently is, which then descend into a cut and cover tunnel which runs under the current line, resurfacing either side of the current tracks before Windmill Bridge Junction and joining.

With the planned changes West Croydon will be able to handle the extra 2 LO trains.
One of the big south London gains with the CARS scheme is that more of the suburban trains can go to East Croydon than currently which will be very popular as regards connections.
The track changes in the latest iteration north of the East Croydon to and around Windmill Bridge Junction allow more suburban trains to go to ECR than the previous iteration.

 

[edwin_m]

Oh yes. You have reminded me. Yes, because of that siding (which I have never seen used) the area has enough length to move the station further NE (to the right in your diagrams). There should then be enough room for a throat at both ends (allowing "the lines to splay out"). As for width I know that at the SW end (where the station buildings are) there is a car park which must have been an ex-railway yard. So I think you are right in thinking there is room enough for four platforms. I would make the terminating happen in the middle two roads and rebuild the station buildings which could allow a better exit towards the bus station.

Incidentally there were originally three tracks under the main road at the SW (left) end as there was a short bay for the Wimbledon branch. The up through platform was lengthened by burying that short platform road.

One track worth of extra width is nowhere near enough for the splay needed to insert an island platform with bay between the through tracks. There would be enough space in the station itself (considering it already has that amount of platform width), but because the track curves have to be relatively gentle, extra width is needed for some distance off both ends of the platforms. New platforms have to be straight or nearly so, so the old trick of tapering the ends of the platforms no longer works.

 

[Bald Rick]

One track worth of extra width is nowhere near enough for the splay needed to insert an island platform with bay between the through tracks. There would be enough space in the station itself (considering it already has that amount of platform width), but because the track curves have to be relatively gentle, extra width is needed for some distance off both ends of the platforms. New platforms have to be straight or nearly so, so the old trick of tapering the ends of the platforms no longer works.

You can still taper platforms, as has been done at London Bridge for example. But not as much as those with ‘grandfather rights’, either in narrowness or the proportion of the platform where it applies. Raynes Park up platform is the best example I know of.