The Anonymous Widower

Untangling The Brighton Main Line

I like difficult problems and getting more capacity out of the Brighton Main Line between London and Brighton is one of the most difficult problems on the UK rail network.

I have just read this document on the Government web site, which is entitled Brighton Main Line – Emerging Capacity Strategy for CP6.

Most of the problems are at the London end of the line and can probably be blamed on the fact that the Brighton Main Line was built by two companoes; the London Brighton and South Coast Railway and the South Eastern Railway.

There is this little history lesson in the document.

The London and South Western Railway, which operated today’s Wessex Route area for example, was able to grade separate almost all of its major junctions between London and Basingstoke in the Victorian era. The London, Brighton and South Coast Railway which operated the Brighton Main Line was unable to fund grade separation at key junctions. Even when further opportunities presented themselves for remodelling with stimulus funds in the 1930s, the by then amalgamated Southern Railway, despite developing plans for several grade separations, chose to prioritise the South West Main Line (delivering the grade separation of slow and fast lines north of Wimbledon).

The only sorting of the line done in recent years, was the creation of the Thameslink opening in the 1980s.

But as with many British Rail projects of the era, it was not done rigorously, with all major junctions, stations and other issues fully sorted.

A section in the document lists some of the bad points on the line and some possible solutions. Going South they are as follows.

Victoria Main Line Platforms

The document talks of a major reorganisation of the operation of the station. This is said.

The terminus of the BML, Victoria has seven terminating platforms available to Fast Line services although two of these are dedicated to the 4tph Gatwick Express service to simplify access for airport passengers. This leaves the remaining platforms to handle a higher volume of traffic. Development either side and above the station means the options for building additional platforms at the terminus are extremely limited.

Could it be that there has been a bit too much development around the station?

Clapham Junction Main Line Platforms

The document says this about Clapham Junction’s affect on services.

Clapham Junction is the key platform-based constraint on the route into Victoria. The station has single Up BML Fast and Down BML Fast platforms, and the majority of Fast Line services call here. The platforms have a booked dwell time of one minute and a platform re-occupation time of two minutes3 . This effectively pegs the maximum theoretical capacity of the BML Fast Lines into Victoria at 20tph – although when combined with constraints elsewhere on the route it is effectively less.

The solutions proposed at Clapham Junction station are complex and would probably be difficult to impl;ement given space and political considerations.

Windmill Bridge Junction

This is a major junction just North of East Croydon station, where one set of lines goes North-West through Selhurst and Clapham junction stations to Victoria and another set of lines goes North-East through Norwood Junction and New Cross Gate stations to London Bridge.

To complicate matters, Selhurst Depot lies in the junction, as this Google Map shows.

Windmill Bridge Junction

Windmill Bridge Junction

Selhurst station is at the top by the depot and East Croydon station is to the South.

The document says this should be done.

Grade separation of remaining flat junction conflicts (Down Victoria Fast with Up London Bridge Fast) and Up London Bridge slow with Down Victoria slow) under development.

Effectively, this means putting a flyover to separate trains going to London Bridge from those coming from Victoria.

At least the map shows that there is some green space between the two sets of lines.

East Croydon Station

This station is another station with not enough capacity. This is said in the document.

East Croydon has three Fast Line platforms but their use is complicated by the track layout at the London end of the station that involves conflicting moves between Up London Bridge fast and Down Victoria fast services at Windmill Bridge (listed above), as well as requiring reversible use of Platform 2.

The solution is mapped out in the document.

Scheme providing an additional 1 Line platforms and or 2 platforms under development. associated track layouts Scheme would also provide additional track East Croydon to Windmill Bridge Junction and track layout and signalling changes in the immediate East Croydon area including to relieve platform 4 and 5.

I think with all the development going on around East Croydon station, that this might help the addition of extra platforms. Wikipedia gives more details about the future development of East Croydon station.

South Croydon Junction

This junction just south of South Croydon station causes conflicts, where Oxted Line services conflict with down slow services.

This Google Map shows South Croydon station and the junction.

South Croydon Station And Junction

South Croydon Station And Junction

The document says this about a solution.

No viable solution currently available. Relief of other constraints may allow current layout to remain, as the flat junction constraint predominantly affects Slow Line services (although potentially constrains the pathing of services that use the Fast Lines north of Croydon).

But it is now probably more complicated as longer trains are proposed for the Uckfield Branch.

Stoat’s Nest Junction

The wonderfully-named Stoat’s Nest Junction is south of Purley station and causes the odd delay. The document talks about a solution.

A grade separation option for Up Slow to Up Fast moves under development.

It is probably a smaller but important project.

Gatwick Airport

There will be twenty trains an hour through the station at Gatwick Airport.

Given the investment being put into the station by Gatwick and the importance of the station as a hub, I feel that a way could be found to use the station to squeeze some more capacity out of the line.

Keymer Junction

Keymer Junction is south of Wivelfield station and causes delays =. The document says this about a solution.

Several options under consideration from grade separation to a third track option – case yet to be proven and would not be required if reliability and capacity uplift was focused on Gatwick inwards only.

This is one solution, that I think will be a bit different, as it could unlock capacity in Brighton and on the two Coastway Lines.

Crossrail 2

You may wonder how Crossrail 2 will affect the Brighton Main Line?

There are three stations in common between the two lines.

  • Victoria
  • Clapham Junction
  • Balham

Will passengers switch between the two lines at stations before Victoria?

If they do, the major effect will be to perhaps free-up Victoria station by a small amnlunt.


There would appear to be several places where capacity improvements can be made.

But don’t be surprised if something radical happens at Gatwick!

If a second runway were to be built at the airport, then this would need more capacity to London, which would have effects on the trains south of the airport.

February 10, 2016 - Posted by | Transport/Travel | ,


  1. I think that the conflicts at East Croydon could be resolved by taking full advantage of the excellent grade separation at both ends of Norwood Junction station.

    Cease all services between the Oxted lines and Victoria (fast lines). All Oxted line services should go to London Bridge and (excluding diesels) become part of Thameslink.

    Oxted services should operate single-line working between Norwood Junction and Sanderstead, with East Croydon’s easternmost platform island acting as the passing loop.

    The sets of tracks between Windmill Bridge Junction and South Croydon:

    Western pair for Victoria (fast)

    Central pair for London Bridge

    Eastern bi-directional track for Oxted services – all to/from London Bridge, as Thameslink.

    All Thameslink services at East Croydon not running to Oxted, Caterham or Tattenham Corner, should use the eastern pair of tracks from Purley to Gatwick Airport
    All Victoria Fast services should use the western pair of tracks, between Purley and Gatwick Airport via Redhill

    The only work required to Windmill Bridge Junction would be:

    New single track connecting Up London Bridge Thameslink, with Up Victoria Slow.
    Enables grade-separated convergence and divergence between Selhurst and East Croydon’s Purley platform island.

    Comment by Ben H | February 11, 2016 | Reply

  2. My expertise was and probably still is writing schedulers for the resources of large projects So when it comes to bow to your superior knowledge.

    But there’s one big difference. If say you order a particular way of working that is sensible on a large construction projec, the workforce may moan, but they see your point and go along with it.

    But rail passengers and especially commuters have their patterns of behaviour and you can’t muck about with services. Look at the fuss there was when Network Rail wanted to reverse the Sutton Loop services at Blackfriars.

    So to swap the Oxted Line services to London Bridge from Victoria is a non-no and would lead all the way to the European Court.

    Services on the Oxted Line are well short of what I think is an accep[table service of four trains an hour of at least six coaches.

    Comment by AnonW | February 12, 2016 | Reply

  3. […] post was suggested by a comment by Ben H on my post called Untangling The Brighton Main Line. He said this about Oxted Line […]

    Pingback by An Ideal Oxted Line « The Anonymous Widower | February 13, 2016 | Reply

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