Croydon Bottleneck and south london improvements

[Peter stanley]

PROPOSALS TO IMPROVE SOUTH LONDON AND BRIGHTON LINE SERVICES

I present proposals to tackle the "Croydon Bottleneck" and improvements to services in South London.


CROYDON BOTTLENECK - some interim proposals



I am in general agreement with the proposals for solving the "Croydon Bottleneck". However, given that the project is unlikely to be completed for another 12-15 years, a large percentage of present-day commuters (especially those over 45) will not experience the benefits. I therefore suggest a few simple changes to timetables and routing that could be implemented now, with minimal cost and no changes to infra-structure, to reduce congestion at East Croydon.



1. Most trains to/from London bridge to be re-routed via the local (slow) lines at East Croydon, including all Thameslink services that run via Redhill. This would reduce conflict at Windmill Bridge Jct. between up fast London Bridge and down fast Victoria services and also at Stoats Nest Jct. where up services from Redhill cross the down fast line. Disadvantage: more conflict at S.Croydon where the up Oxted services cross local down line.



2. Reduce as far as possible the number of services between Victoria and the slow lines at East Croydon by re-routing all Caterham/Tattenham Corner services to run to/from London Bridge. This would eliminate the conflict that these services currently have at Selhurst where they cross the local Selhurst - West Croydon lines and where the up services cross the down fast from Victoria. Disadvantage: passengers would need to change at E.Croydon for Victoria.



3. Some Mid-Sussex line services (Bognor/Portsmouth/Southampton) to be re-routed via Sutton and Dorking. This would be most suitable if more of these services could work to/from London Bridge, as these could run on the fast line between London Bridge and Norwood Jct. and then calling at W. Croydon, Sutton, Dorking and Horsham where they would resume their normal route. The resulting train pathways through Sutton/Epsom would need some thought to avoid conflict with local services but the traffic density through this route is less than through E. Croydon so should not be a major problem. This change would also reduce conflict at Three Bridges, where down Mid-Sussex services have to cross the up fast Brighton line. In addition, it would provide more fast services between Dorking, Sutton and London Bridge. Disadvantage: increased journey times to/from Horsham and beyond as the Sutton/Dorking route is slower than the Brighton mainline.

To compensate for the resulting reduced service between Three Bridges and Horsham, Thameslink trains that currently terminate at Gatwick could be extended to Horsham.

Some of the Mid-Sussex Victoria services could be routed via Mitcham Jct. (as was the case until the 1970s) although this is less useful as it would introduce conflict at Streatham North Jct. where the down services towards Mitcham would need to cross the up fast to Victoria.



EXTENSION OF LONDON OVERGROUND CRYSTAL PALACE TO CLAPHAM JCT.

I propose extension of London Overground (LO) services from Crystal Palace to Clapham Jct. (via Balham) where they could then continue over the West London line to Willesden Jct. This would form a sort of "outer circle" and would bring a further five stations onto the LO network, namely:- Gipsey Hill, W. Norwood, Streatham Hill, Balham and Wandsworth Common. The service would be 4tph in each direction.

The advantages:

By providing a direct service from the above stations to both the East London line (Whitechapel/Shoreditch) and the West London line (Shepherds Bush/Willesden) journey times would be considerably reduced.

Reduced congestion on platforms/walkways at Clapham Jct. as these passengers would no longer have to change for LO services.

Increased frequency of services between Clapham Jct. and Crystal Palace.



One problem is that the line between Balham and Clapham Jct. is busy - 16tph in each direction in peaks and the Westbound LO services would need to cross the down local line from Victoria twice:- at Balham Jct. and at Clapham Jct. (as they would need to enter plat. 16). The potential congestion could be alleviated somewhat by truncating the London Bridge - Victoria southern service so that it terminates at Crystal Palace; not ideal but would have the advantage of freeing up some platform space at Victoria. The Victoria - W. Croydon service via Crystal Palace would remain, so there would still be an overall increase in services on the Crystal Palace - Clapham Jct. section (6tph compared to 4tph at present).


Any comments on these ideas would be welcome.


Peter Stanley

 

[swt_passenger]

Re-routing Mid-Sussex trains is fairly regularly suggested, but is usually believed to be near impossible, as there’s no capacity for them nearer London. (It came up in one of Network Rails many route strategies or studies for the Sussex area, I can’t remember which one.)

Also, there is a huge passenger demand towards Crawley, Gatwick, and East Croydon. You still need to take passengers where they want to go, after all...

 

[Peter stanley]

Any re-routing involves winners and losers but one idea to preserve a direct link between mid-Sussex line and Crawley/Gatwick/East Croydon (while still diverting some via Dorking) would be to extend the Thameslink services from Horsham down to Littlehampton/Bognor. or even as far as Portsmouth. This would be costly but given the large amount of housing development planned for this area I think a reasonable case could be made for it.

 

[JonathanH]

Any re-routing involves winners and losers but one idea to preserve a direct link between mid-Sussex line and Crawley/Gatwick/East Croydon (while still diverting some via Dorking) would be to extend the Thameslink services from Horsham down to Littlehampton/Bognor. or even as far as Portsmouth. This would be costly but given the large amount of housing development planned for this area I think a reasonable case could be made for it.

It isn't going to happen. The chances of the Arun Valley to Victoria services being diverted away from the Gatwick route are very close to nil. They don't present the sort of disruption that you suggest and there really isn't any likelihood of them going via Dorking because it is simply too slow and congested. As you note, the junction at Streatham isn't designed for a fast service to Sutton and Dorking. There are too many stations on the two track routes from Sutton to fit in a fast Arun Valley service to Victoria, London Bridge via Tulse Hill or London Bridge via West Croydon.

I'd be very interested to understand who you think stands to gain from the proposals you have suggested. It doesn't seem to be people who live in Horsham who would have a degradation of their service as a result of both this proposal and the proposal to run all Redhill services on the slow line.

On that point, in the evening peak, the full service to Redhill does run down the slow line and any problems at Purley soon affect all the service to Redhill. The timings of the up service to London and Peterborough which crosses at Stoats Nest all day mean that it doesn't fit on the slow lines.

2. Reduce as far as possible the number of services between Victoria and the slow lines at East Croydon by re-routing all Caterham/Tattenham Corner services to run to/from London Bridge. This would eliminate the conflict that these services currently have at Selhurst where they cross the local Selhurst - West Croydon lines and where the up services cross the down fast from Victoria. Disadvantage: passengers would need to change at E.Croydon for Victoria.

Part of the reason why the operators haven't already reduced the service between Victoria and the slow lines at East Croydon is because the station is not set up for huge numbers of people interchanging between services there. It just doesn't have the capacity. Therefore, assuming normal commuter numbers, they would be very wary of removing services from Redhill, East Grinstead or Tattenham / Caterham to Victoria because of passenger, not train, congestion.

 

[Peter stanley]

I do not think re-routing Caterham/Tattenham services to London Bridge would significantly increase passenger congestion at E. Croydon. Many passengers going to Victoria then use the tube for destinations in the West End such as Green Park, Oxford Circus and Westminster. These passengers would find it just as convenient to travel to London Bridge and change onto the Jubilee line, - no need to change at E. Croydon. This would help the situation at Victoria were the underground station often has to be temporarily closed during AM peak due to overcrowding (particularly on Victoria line northbound platform). Futhermore, I would still retain the Reigate - Victoria service so that passengers from Redhill and Purley would have a direct service to/from Victoria.

Regarding the Mid-Sussex line, I agree there is no easy solution. My proposal however, is the only way to free up train pathways on the E. Croydon - Gatwick section. The mid-Sussex line is the only one that can, in theory, be diverted - trains from Brighton, Eastbourne and Littlehampton via Worthing have no alternative but to go via E. Croydon. There would be some benefits - passengers at Dorking and Sutton would have more services to/from London and a direct link to the south coast. (My journey Horsham to London would take longer so nobody can accuse me of bias !!!).

 

[JonathanH]

I do not think re-routing Caterham/Tattenham services to London Bridge would significantly increase passenger congestion at E. Croydon. Many passengers going to Victoria then use the tube for destinations in the West End such as Green Park, Oxford Circus and Westminster. These passengers would find it just as convenient to travel to London Bridge and change onto the Jubilee line, - no need to change at E. Croydon. This would help the situation at Victoria were the underground station often has to be temporarily closed during AM peak due to overcrowding (particularly on Victoria line northbound platform). Futhermore, I would still retain the Reigate - Victoria service so that passengers from Redhill and Purley would have a direct service to/from Victoria.

The Caterham / Tattenham services already run to London Bridge with extra services to Victoria in the peak. If passengers found it convenient to use London Bridge they would already do so but, prior to March 2020, they managed to fill trains to both London Bridge and Victoria. The Victoria to Reigate / Gatwick train misses out the Purley stops in the evening peak to spread the Victoria demand properly.

I note your concern about Victoria Underground having issues in the morning peak but isn't that why they have just done a lot of work to increase the number of entrances to the station?

Regarding the Mid-Sussex line, I agree there is no easy solution. My proposal however, is the only way to free up train pathways on the E. Croydon - Gatwick section. The mid-Sussex line is the only one that can, in theory, be diverted - trains from Brighton, Eastbourne and Littlehampton via Worthing have no alternative but to go via E. Croydon. There would be some benefits - passengers at Dorking and Sutton would have more services to/from London and a direct link to the south coast. (My journey Horsham to London would take longer so nobody can accuse me of bias !!!).

Passengers at Dorking and Sutton would have the same (or a lower) number of services to London because the Arun Valley service would have to take over the path of an existing service. As a Horsham to London traveller you might recall that there wasn't room for Redhill passengers on the services on Saturday / Sunday mornings when they used to go that way. In normal times, it would be the same for people at Dorking or Sutton.

The East Croydon to Gatwick section of the route does not appear to be congested on the fast lines, not to the extent that removing Arun Valley trains would help. If every train stops at Gatwick and East Croydon, they simply follow each other on what is essentially a plain line. Stoats Nest Junction complicates it a bit but the number of services currently crossing there can be accommodated.

The problem on the Brighton line is that passengers at every station demand a train to both Victoria and London Bridge and Croydon is the place where the routes cross. Clearly that is what the work is all about. However, the other aspect of the work and as important in the planning is the length of the signal sections which weren't set up for a procession of 12-car trains on the slow side.

In another thread, 'Ianno87' set out some of the conflicts and issues that the work is looking to resolve. 2tph Arun Valley moving off the route is not going to solve any of the problems and would just create other ones.

If you ignore:

-Down Vic Fast / Up LB Fast
-Down LB Slow / Up Vic Slow
-Down Vic Fast / Up Vic Slow to Up Vic Fast
-Up Vic Slow / Down Vic Fast to Slow
-Down Vic-West Croydon / Up Vic Slow
-A multitude of limited standage areas
-The T106 overlap in Platform 5 at Croydon
-Etc.

Quarry Lines have a 2 minute headway, but certainly not 30tph at the moment. Plus schemes like the Reigate turnback will free up some Slow Line capacity to Gatwick.

Croydon helps you make better use of the capacity further south, so you can better write the timetable around constraints elsewhere.

The Quarry lines are not a problem if they have a 2 minute headway.

 

[Peter stanley]

I think the limiting factor at Victoria is not so much the entrances but the rate of clearance of the northbound Victoria line platform, with trains at 2 minute headway. I cannot see an easy solution to this apart from encouraging more commuters to use London Bridge or more to use an extended London Overground service thereby avoiding Victoria.

 

[London Trains]

Passengers at Dorking and Sutton would have the same (or a lower) number of services to London because the Arun Valley service would have to take over the path of an existing service. As a Horsham to London traveller you might recall that there wasn't room for Redhill passengers on the services on Saturday / Sunday mornings when they used to go that way. In normal times, it would be the same for people at Dorking or Sutton.

And if it was done, it would destroy services at Carshalton, Cheam, Epsom, Ashtead, Leatherhead and Boxhill & Westhumble, and would probably end up making Dorking to Horsham a shuttle. The only way it could be accommodated is to actually have it call at those stops, and effectively become what is the Victoria to Dorking / Horsham fast.

What's genuinely needed between Victoria and Horsham is to increase the frequency between both Victoria and Dorking (calling at Carshalton, Sutton, Cheam, Epsom, Ashtead, Leatherhead, Boxhill & Westhumble 2tph) from 2tph to 4tph, London Bridge and Epsom (fast to Norwood Junction then all stops) from 2tph to 4tph, Victoria to Epsom (Clapham Jct, Balham, all stops via Mitcham) fron 2tph to 4tph, and Dorking to Horsham from 1tph to 2tph off peak. Demand from Sutton is not too much lower than East Croydon, and East Croydon has 8tph fast to Victoria and 11tph off peak / 18tph peak fast to London Bridge (+2tph from West Croydon all day), whereas Sutton has 2tph fast to Victoria, 2tph slightly slower to Victoria, and 2tph to London Bridge.