The present timetable has evolved over many years and is designed to optimise the available capacity into London Waterloo during peak periods. The capacity of the network is determined by the number of tracks and the spacing that trains can safely be operated per hour, known as the "headway". In general, on suburban services, the greatest overall capacity is provided by trains calling at all or most stations. A mixture of fast and slow trains actually reduces total passenger-carrying capacity per hour. An obvious example of capacity maximisation is the London Underground where all trains call at all, or most, stations because the level of passenger demand makes this the best overall solution to maximise passenger-carrying capacity. It does, of course, mean that journey times are longer from locations such as Epsom or Leatherhead.
The position at Walton-on-Thames or Surbiton is a reflection of the same need to maximise capacity. Most trains that serve these stations run as stopping trains on the slow lines as far as Surbiton and are then routed on the fast line from Surbiton to London Waterloo. If they were to stop at intermediate stations, the combination of fast and slow trains would reduce overall capacity on the fast lines.
We are constantly looking at ways to match capacity to demand. However, the fundamentals of the peak-train plan are locked into the overall capacity of the existing network, which is fully used. Only very substantial investment in new capacity would permit us to operate faster services from the more distant suburbs to London in the peak periods unless we were to reduce the number of trains calling at the inner suburban stations, such as Wimbledon, Earlsfield and Vauxhall, which is clearly unlikely to be acceptable to many of our commuters.
Stewart Palmer, Operations Director