The Brighton Main Line (BML) from Victoria (and London Bridge) needs more capacity. This has been known for years but more recently it has been clear that demand has been accelerating and showing no indication of easing up in the future. Whilst there may be alternative long-term approaches possible, if a significant improvement to Sussex services is required in a reasonable medium-term timescale, there is no alternative to upgrading the existing line.
Its time to start to get down to the nitty-gritty and go along the line and look forensically at where the problems are and what can be done about them. We start at Victoria station. This part of the Sussex saga is not as extensive as some will be because there is relatively little to say and details of medium term plans not yet available.
The Victoria Conundrum
One of the curiosities of Victoria station is just why platform utilisation is so low during peak hours. Clearly, if the number of platforms remains the same, this needs to improve if more trains are to be run. The issue is whether platform utilisation is low because of track capacity limitations or whether it is the inability to improve platform utilisation itself that is the problem.
The measure of platform utilisation is tphpp (trains per hour per platform). As this article is about the Brighton Main Line we concentrate on the platforms (9-19) that serve this line. These are the trains that go via Clapham Junction. The lines serving platform 1-8 are historically known as the Chatham Lines and trains generally go via Bromley South though a notable exception is the Nunhead route to Lewisham and beyond.
You would have thought that the Brighton side of the station with its 11 platforms (9-12 slow and 13-19 fast) would have little or no problem handling any expected requirement of an electrified four-track railway operating with multiple-unit rolling stock. It is also not as if the approach was particularly constrained in terms of the number of tracks. There are currently nine tracks over Grosvenor Bridge which takes the railway over the Thames and of those are five are dedicated to BML services. These track approaching the station are currently assigned as three fast track and two slow ones but there is no overriding necessity for such rigid division.
Similarly one would have thought that nine approach tracks in total over Grosvenor Bridge was more than enough for 19 platforms in total. This would appear to be the case because when the railway-supporters’ favourite 1960s construction firm of Marples-Ridgeway [¶] rebuilt Grosvenor Bridge they actually made it possible to have ten tracks but it would appear that only nine are used nowadays with the easternmost trackbed slowly being reclaimed by the inevitable Buddleia that is starting to appear.
The Cannon Street Comparison
For the purposes of looking at the Brighton main line into Sussex we really ought to concentrate on the three lines over Grosvenor Bridge that are dedicated to the fast lines and the seven platforms that fan out from them. That is platforms 13 and 14 which serve Gatwick Express trains and the five other fast “Sussex” platforms 15–19.
The comparison between Sussex Fast lines into Victoria and the lines into Cannon Street is especially relevant. Between London Bridge station and Cannon Street (exclusive) the track layout goes from two tracks south of the river at the east of Borough Market Junction to three tracks before fanning out to serve seven platforms. The approach to Victoria fast Sussex platforms (including Gatwick platforms) goes from two tracks south of the river at Battersea to three (reversible, up, down) over Grosvenor Bridge and then to seven platforms. It is true that Cannon Street has one or two trains empty departing via the western side of the Borough Market triangle towards Metropolitan Junction but that is more to do with getting around a problem with throughput at London Bridge station and not so much any restriction at or approaching Cannon Street.
Cannon Street currently handles 25tph in the height of the peak which means each an average tphpp of over 3.5. In contrast, the fast BML lines into Victoria manages just 16 in the peak hour which is an average of less than 2.3tphpp.
So what’s the problem ?
So the question has to be asked: Can there really be a limitation on capacity at Victoria when Cannon Street (and other comparable termini) seem to be able to manage far more? Well certainly until recently it did seem that Network Rail thought that there was little that could be done – then again for years they said that about East Croydon.
Network Rail’s Long Term Planning Process route specification for Sussex published early in 2014, when referring to “the Brighton Line” side of Victoria station states:
The Fast line side of the station is accessed by three tracks, an Up and Down Fast and a reversible approach.[…] The Slow line side of the station has just two approach tracks – an Up and Down Slow.
The limited number of approach tracks to both the Slow and Fast line platforms (constrained by the width of the alignment into Victoria, the Grosvenor River Bridge and approaching viaducts south of it), means that even provision of additional platform faces at Victoria in the long term would have a limited benefit in terms of additional peak paths.
This does seem awfully hard to believe. As an explanation it is most unsatisfactory. Five tracks does not seem to a particularly limited number of approach tracks. If it is inadequate then why is there a disused trackbed on the bridge? One would not have thought eleven platforms would be a particularly onerous constraint for what can hardly be described as long distance services.
Don’t blame it on the TOC
The above somewhat unsatisfactory quote makes no mention of Southern Railway being rather leisurely with train preparation yet if that was the reason one would have thought Network Rail would have been quick to point the finger at the TOC. It is almost certain that the extended preparation perceived by some as the cause is actually the consequence of the limited station capacity. If the trains cannot be turned around any quicker then one might as well take advantage of the time to clean and re-bowser the trains. To put it another way, it is important not to confuse cause and effect.
Cause for speculation for the cause
In the absence of any official plausible explanation for the limited capacity on the fast Brighton Lines out of Victoria we offer our own explanation:
- The capacity is limited because it was only signalled for the capacity required at the time when last resignalled.
- For this reason extra platforms on their own would only be of marginal value. The bottleneck would remain.
- The only realistic way to free up capacity for the BML fast lines at Victoria is to comprehensively redesign the track layout and signalling.
- Comprehensive redesign has not been suggested in the past because the amount of extra capacity it would provide would be extremely limited due to restrictions elsewhere (notably Clapham Junction and East Croydon) and it would be extremely expensive for very little gain.
It is hard to be definitive as to what the issues are with the limited signalling capacity but one would have thought that an obvious restriction is the two unidirectional fast tracks across Grosvenor Bridge. This is not helped by the single bi-directional track being the westernmost one of the three. It the bi-directional one was the centre track this would lead to much more flexibility. The current combination must restrict opportunities for trains to cross without conflict. If all three tracks were bi-directional and there was trackwork on either side of the bridge to facilitate changing from one track to another one would presume that there would be far more flexibility and a consequent increase in capacity.
One thing Victoria does not appear to lack is platforms though Network Rail reports have in the past simplistically suggested this is a problem. It has to be said that this is treated with scorn by many industry insiders.
It is easy to see that platforms aren’t always used as effectively as they could be. Platforms 13 and 14 are dedicated to Gatwick services. The service to Gatwick is every 15 minutes and the current policy is for there to be a train ready and waiting in the platform at all times (it is similar at Paddington with Heathrow Express). The result is that platforms 13 and 14 are each used by only 2 trains per hour – acceptable for long distance services but a bit of a luxury for a non-stop service that is scheduled to take just 30 minutes. To make things worse the trains are usually only 5 carriages long and rarely anywhere near full. If platforms at Victoria really were at a premium then it would be unlikely that Gatwick Express would be allowed to use two of them so inefficiently.
In complete contrast to the Gatwick platforms in particular and the BML fast platforms in general it is worth noting that the BML slow platforms handle 16tph – the same as the fast ones. The dramatic difference is that they do this with just four platforms (4tphpp) and two approach tracks. It can be seen that in the case of the slow lines it probably is true that more platforms need to allocated to the services if an increase in train frequency is to be achieved. It does not follow from this that overall Victoria is lacking in platforms.
If you thought the BML was bad …
We have commented on how bad utilisation of platforms is on the BML fast lines at Victoria station but you really don’t have to go far to find even worse overall utilisation. In fact all you have to do is wander over to the Chatham side of the station where there are eight platforms for the relatively few SouthEastern trains and the occasional special such as the Orient Express. This used to leave from platform 8 but now leaves from platform 2.
There can be little doubt that the low occupancy rates for the SouthEastern platforms are down to the limited capacity on the two track approach lines as they traverse suburban south London. The problem is a combination of the result of the two tracks having to provide for both slow and fast services and timetabling restrictions caused by Herne Hill junction.
The apparent surfeit of platforms on the Chatham Line has led to many rail insiders suggesting the obvious solution if the number of platforms were a problem on the Brighton Line and that is to reallocate one or more from the Chatham Line. One could think of it as the Lady Bracknell solution to platform allocation.
We don’t want to get ahead of ourselves too much but Network Rail are talking of substantial upgrades of the Brighton Main Line and yet when doing so the problem of train capacity at Victoria hardly gets a mention. In Control Period 5 (the current one) Network Rail intends to make substantial changes to the concourse so that it can handle more passengers satisfactorily.
The rumour is of a new track layout at Victoria by 2019. One has to presume that Network Rail have seen the light and that this is the case. It would make a significant difference and it is hard to see Network Rail’s plan for upgrading the BML working without this essential piece of the jigsaw. It is a shame more details are not known but, based on crude playing around with simple figures, it does look as if there is plenty of opportunities for Victoria station to handle more trains although very difficult to give any idea of a meaningful figure. So, the early indications are that capacity at Victoria is not a fundamental limitation when planning to upgrade the Brighton Main Line but the exact level potential benefits that can be unlocked is neither available for nor deducible by those who don’t have the necessary inside knowledge.
¶ – This is a facetious comment not intended to be taken at face value. Please don’t supply us with a potted biography of Mr Marples.