Network Rail is carrying out essential improvements to the railway between Brighton, Gatwick Airport and East Croydon over three weekends in January, with passengers asked to plan their journeys in advance.

Buses will replace trains on the Brighton Main Line between Gatwick Airport and Purley / East Croydon, as well as the branch lines between Reigate and Redhill, and between Redhill and Tonbridge.

The first three weekends of closures are:

Saturday, January 10 and Sunday, January 11
Saturday, January 17 and Sunday, January 18
Saturday, January 24 and Sunday, January 25

The main line between Brighton, Gatwick and London will be closed for three weekends while engineers are at work. Picture courtesy of Govia Thameslink Railway

placeholder image — The main line between Brighton, Gatwick and London will be closed for three weekends while engineers are at work. Picture courtesy of Govia Thameslink Railway

Additional engineering works will take place on Sunday, February 1, Saturday, March 21 and Sunday, March 22, and Sunday, May 3, with the Brighton Main Line being closed between Brighton / Lewes / Hove and Three Bridges.

Lucy McAuliffe, Network Rail Sussex route director, said: “The busy Brighton main line is among the most complex and congested routes in the country, with the infrastructure being some of the oldest and most intensively used.

“Because of this, we need to carry out this work to try to prevent delays to passenger journeys.

“We know that closing the railway at any time of the year causes inconvenience, but with the Brighton main line being a key route for the leisure and tourism industry on the south coast, we are using this typically quieter time on the railway to carry out these vital works, in an attempt to avoid having to close the railway during busier times of the year.

“I’d like to thank passengers for their patience and understanding while our teams work hard to improve the infrastructure on this critical stretch of railway.”

Key improvements to boost reliability and safety as part of the work include:

Track renewal: Installing new rails and conductor rail, plus refurbishing switches and crossings to improve performance with new rail at Purley, between Earlswood and Horley and between Merstham and Coulsdon South.
New electric conductor rail will be installed between Redhill and Reigate and the busy Stoats Nest Junction, between Purley and Coulsdon South, will also be refurbished.
Earthworks: Strengthening a cutting north of Merstham to provide stable foundations and prevent landslips.
Drainage: Repairing the drainage systems along three miles of track at Caterham to manage water effectively and reduce potential delays.
Bridges: Installing wheel timbers – long blocks of wood that support the track – at the Intersect bridge near Godstone and the Brighton Road bridge at Coulsdon South to maintain structural integrity.
Access points: Adding a new road-rail access point near Purley for Network Rail’s construction vehicles to access the track and make repairs.

Jenny Saunders, Southern and Thameslink's customer service director, said: “The main line between Gatwick and East Croydon is one of the busiest in the country.

“It's a vital link for hundreds of thousands of commuters and leisure travellers visiting London, Gatwick and the south coast.

“Over the next three weekends, engineers will be hard at work ensuring our Southern, Thameslink and Gatwick Express services on this line will be safe and reliable for years to come. This does mean that there will be some disruption to journeys, and your trip is likely to involve a bus.

“We'll have staff on hand at our stations to keep you on the move, and my advice is to check your journey online before you leave using a journey planner.”

With no weekend closures on the trunk Brighton Main Line route planned for the summer months when the railway is generally much busier, there will be some weekend closures in the latter half 2026 and Network Rail will provide details on those closer to the time.