The East Croydon Problem – A Look At the Brighton Mainline


Given the impact it has on (and the commuters it carries to) London, it makes sense to take a brief look at some of the issues on the Brighton Main Line. It also makes sense to do so as a follow on from our look at Thameslink and the recent RUS.

The Brighton Main Line is quite simple and a complete contrast to its neighbour in the South-East sector. Effectively it features a single trunk line running from East Croydon to Brighton via Gatwick Airport in an almost perfect north-south alignment, with a series of branches running off from it. In general there are no shuttle services on the branches – just about every train starts from, goes through, or ends up in central London.

Over the years, great efforts have been made to improve capacity. The signalling allows for an intensive service and one would probably have to go for some kind of automatic train operation to improve significantly on what is already there. In terms of improvement possibilities, that really only leaves the other perennial favourite – lengthening the trains. Here too though, options are becoming limited as most of the trains are already 12 carriages long. There has been a long tradition of splitting trains en route to maximise overall throughput even if it is at the expense of journey times. Even Purley, which is still in the London suburbs (even if most of its inhabitants like to pretend it is in Surrey), sees the attachment and splitting of trains because there simply aren’t the paths available in the rush hour to run the Tattenham Corner and Caterham trains as separate services to London.

For years the critical factor preventing more trains from being run has been the lack of terminal capacity in London. The route diverges at East Croydon with some trains going to Victoria and others to London Bridge (and possibly onwards onto the Thameslink route). A few Thameslink trains currently have a tortuous journey to Blackfriars via Herne Hill, but anybody who has experienced this journey will know that it is not ideal. Furthermore, crossing the main South-Eastern route from Victoria to Bromley South on the flat at Herne Hill does nothing for maximising train paths in this area.

It is against this background that the Thameslink programme is seen as a potential saviour, because terminal capacity in London will no longer be the critical constraint providing sufficient Thameslink services make their way onto the Brighton Main Line. However, like a 1960’s road planner, one quickly discovers that when one removes a bottleneck at one location another one has a habit of popping up elsewhere.

In theory then, if Thameslink is up and running could there be more services on the Brighton Main Line?

Yes. A few. But there is a problem – East Croydon.

Be in no doubt, once Thameslink is complete East Croydon is going to be the critical factor on just about everything on the Brighton Main Line. North of East Croydon there is a spaghetti arrangement of tracks as the route diverge to go to Victoria and London Bridge.

There are six platforms at East Croydon, four lines to and from Victoria and four lines to and from London Bridge. Into this feeds two further tracks to and from West Croydon. So basically six lines through East Croydon and two emerging from West Croydon (West Croydon has a bay platform but lets not confuse things) need to be all sorted out into Victoria fast and slow or London Bridge fast and slow. We have the constraint of lack of platforms at East Croydon and a lack of flexibility in the junction north of the station. The situation is made worse by the lack of space. As this author can personally attest, there are times when a traveller can be standing on an unoccupied platform at East Croydon and see one’s train waiting outside the station, because the overlap is fouled by another train’s route having been set over the junction to the north of the platform.

This all begs the question – what is the solution?

Sadly there is no simple on, although two possibilities are covered in the recent RUS in quite some detail.

One idea is the so-called Brighton Main Line 2. Some details for this can be found at, although many pertinent ones seem to have been removed at some point recently.

BML2 is basically an extension and variation of the campaign to re-open the Uckfield to Lewes line, as proposed by a member of the public. Whereas in the past these ideas were usually just ignored, the campaign has obviously got to the stage where the RUS feels it has to rebut the whole thing. The idea is essentially to build a new tunnel under the South Downs so that trains can get from Brighton to Uckfield, hurry up the Uckfield line to Sanderstead, onto a re-opened line from Sanderstead to Elmers End and from there head onto the Hayes line. Services would thus reach London from Brighton without encountering the bottleneck at East Croydon.

The London and South East RUS, however, gives the scheme short shrift. Once the line gets beyond Ladywell, it returns to the situation where the there is no spare capacity. Crucially, part of the “disused” line is now also part of the Croydon Tramlink, and it is likely not as easy as the scheme’s backers think to displace this and run both tram and train services on adjacent single tracks. However, the other critical factor that the RUS latches onto is that East Croydon, Haywards Heath and Gatwick Airport are major destinations that people want to travel to – so there is not much point in going to a lot of trouble to avoid them.

The other idea that receives a mention in the RUS is to accept the inevitable and build a tunnel from south of Purley to Central London. This probably recognises that just surfacing north of Croydon simply moves the problem along the line. The need to go south of Purley (Stoats Nest Junction in fact) is recognition of the fact that the railway is largely on a high embankment from Purley to South Croydon and in a very steep deep cutting from South Croydon to East Croydon. This make it really difficult to find a suitable place for a tunnel portal north of Purley and in any case it would be better if all conflicts at Purley could be avoided.

The one thing the tunnel has going for it is that tunnels are not that expensive. As Crossrail has shown – it is the underground stations that really gobble up the money. By limiting intermediate stations to East Croydon and possibly Clapham Junction, the tunnels could be built relatively cheaply.

It is clear that this is just an opening shot and one suspects that if a tunnel were to be built, it would not happen in the next fifty years. The RUS offers no other solutions, however, and thus regards the relatively minor overcrowding as something we will just have to live with. As it states:

No appraisal undertaken, however given the relatively small size of the gap in relation to other routes it is likely that this scheme would provide poor value for money.

In a starker statement still it concludes:

Whilst no appraisal has been carried out it is unlikely this option would be affordable or represent good value for money in the time period concerned. However this conclusion should be kept under review, since it might become necessary in a high growth scenario.

So it appears that travellers of the Brighton Main Line should make the most of the Thameslink improvements, because for the foreseeable future there is little good on the horizon after that – just more and more crowded trains.

Written by Pedantic of Purley