Brighton Main Line Improvement Project

In October 2018 and February 2019, we will be carrying out a major project to improve reliability and performance for passengers on the Brighton Main Line

The work will focus on the Victorian-era Balcombe, Clayton, Patcham and Haywards Heath tunnels and the railway, which runs through them. A major programme to stem leaks into the tunnels and provide reliable drainage will take place, while the third rail power supply, and signalling will all be replaced or upgraded.  Elsewhere on the closed section, track will be renewed and sets of points, which enable trains to switch between tracks, will be replaced.


The Brighton Main Line is a key rail artery connecting Gatwick Airport and the south coast to London.

 This project is a key part of a £300m government-funded programme to tackle delay hotspots and boost the reliability of the railway in the south east, cutting delays and providing a better, more reliable rail service to the 300,000 passengers who travel on the Brighton Main Line each day.

The stretch of railway where engineers will be working is responsible for more delays to Southern and Thameslink passengers than any other.

 Without this programme of work, reliability on the Brighton Main Line will deteriorate in the months and years ahead, leading to more delays for passengers across the South East.

The work will prevent further deterioration in performance and bring about a significant reduction in delays on the Brighton Main Line and associated routes.

Key dates

The work will take place between Saturday October 20 to Sunday October 28 2018 and from Saturday February 16 to Sunday February 24 2019. No trains will run between Three Bridges and Brighton or between Three Bridges and Lewes on these dates.

The two closures have been carefully planned for school half-terms, when passenger numbers are lower and some people may be able to be more flexible with their travel plans or take holiday.

Passengers wishing to travel on these dates will need to allow considerably more time for their journeys and should expect to use either diverted trains via longer routes or a replacement bus or coach to connect with rail services.

 Keeping people informed

 We will launch a large scale passenger communications campaign targeting all travellers affected by the blockades.  The campaign will ensure that passengers and businesses are fully aware of the closures, the impact on journeys, the alternative travel options available to them and the benefits the work will bring for the region.

Information on how this affects your journey will become available. Visit

For more information on this project please call our helpline on 03457 114141 or visit