Sutton & Mole Valley Lines - Technical Information

Technical Information

The line from Raynes Park to Horsham via Epsom and Dorking (including the Bookham Branch) is known to commuters as the Mole Valley Line (seven out of the fifteen stations on this route are situated in the Surrey district of Mole Valley). The full title Sutton and Mole Valley Lines is used for the lines north of Epsom via Sutton. Confusingly, all of the commuter services run by Southern which terminate or call at Sutton are, regardless of origin or destination, branded as Sutton and Mole Valley Line services.

The Sutton & Mole Valley Lines include (in order of construction):

• West Croydon to Epsom via Sutton
• Epsom to Leatherhead
• Raynes Park to Epsom
• Leatherhead to Horsham via Dorking
• Leatherhead to Effingham Junction
• Peckham Rye to Sutton via Mitcham Junction

None of the lines leads directly to a London Terminus, however scheduled services use the South Western Main Line to access London Waterloo, the Brighton Main Line to access London Victoria and either the Brighton Main Line (via Norwood Junction) or the South London Line (via South Bermondsey) to access London Bridge.

The following branch lines are associated with the Sutton and Mole Valley Line, but are considered separate:

• Motspur Park to Chessington South (Chessington Branch)
• Sutton to Epsom Downs (Epsom Downs Branch)
• Sutton to Wimbledon (Wimbledon Loop)

The line is electrified at 750 V DC third rail. Class 456 and Class 455 electrical multiple units are used, although semi-fast and stopping services to Horsham from London Victoria are frequently operated by Class 377 Electrostars. Up to the early 1980s, express services to Littlehampton and Bognor Regis were routed along this line and called at Sutton, Dorking, Horsham and stations to the south coast along the Arun Valley Line & West Coastway Line.

The maximum line speed is 50 mph, except for 20 mph restrictions at Clapham Junction, Streatham Junction, Mitcham Junction, Raynes Park, West Croydon, Sutton and Epsom; 30 mph restrictions at Dorking and the approach to London Victoria; and two 75 mph sections, between Box Hill and Westhumble and Dorking, and between Dorking and Holmwood. Signalling between London Victoria and Ewell East (including the Epsom Downs Branch) is controlled by London Victoria (VC); between London Waterloo and Box Hill and Westhumble by Wimbledon (W); between Box Hill and Westhumble and Warnham by Dorking signal box (CBK); between West Croydon & Waddon and Warnham & Horsham by Three Bridges Signalling Centre (T).

Platform lengths are eight cars except for Sutton, Dorking and Horsham which can accommodate 12 car trains.