Sutton and Mole Valley Lines
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|Sutton & Mole Valley Lines|
|Type||Commuter rail, Suburban rail|
South East England
|Operator(s)||First Capital Connect
South West Trains
|Rolling stock||Class 319
Class 377 "Electrostar"
|Track gauge||1,435 mm (4 ft 8 1⁄2 in) standard gauge|
|Electrification||750 V DC third rail|
The Sutton & Mole Valley Lines are a group of railway lines constructed between 1847 and 1868 by the London, Brighton and South Coast Railway, the London and South Western Railway and the LBSCR-sponsored Horsham, Dorking and Leatherhead Railway.
The scheduled services run along the Sutton and Mole Valley Line include the commuter services in south London, Surrey and West Sussex operated by Southern, usually from London Victoria to Horsham via Sutton and Dorking. Some Southern services in peak hours on this line diverge at Leatherhead and (via the New Guildford Line) serve Effingham Junction and Guildford. They also terminate at London Bridge instead of London Victoria, and additionally call at West Croydon.
South West Trains operates services between London Waterloo and Leatherhead via Raynes Park and Epsom. Half of these services continue along the main line to Dorking, while others run to Guildford via Bookham and Effingham Junction.
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 (Bookham Branch)
- 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.
History of the route 
The railway lines used by this service were the result of several schemes:
- 1847: West Croydon to Sutton and Epsom railway opened by the London, Brighton and South Coast Railway (LB&SCR)
- 1856: Epsom and Leatherhead Railway authorised.
- 1857: Wimbledon and Dorking Railway authorised under the auspices of the London and South Western Railway, reached no further than Epsom. This is why services are run by South West Trains.
- autumn 1857: rival schemes to connect Shoreham Harbour with Horsham and Dorking. The London, Brighton and South Coast Railway (LBSCR) was eventually successful on 1 August 1859.
- 1 February 1859: Epsom and Leatherhead Railway opened
- 4 March 1859: Wimbledon and Dorking Railway opened
- 1 July 1861: Shoreham - Horsham opened
- 17 July 1862: Horsham, Dorking and Leatherhead Railway (LBSCR sponsored) authorised. Opened in two sections:
- 11 March 1867: Leatherhead to Dorking
- 1 May 1867: Dorking to Horsham
- 1865 Epsom Downs Line opened.
- 1868 The mainline route from London to Sutton via Hackbridge opened.
- 1901 Route from London Victoria to Sutton via Norbury Electrified AC
- 1938 Route London - Horsham fully Electrified DC and new signalling installed.
- 1978 The Portsmouth Harbour/Bognor Regis express services are diverted away from the line to serve Gatwick Airport and the route is downgraded including the removal of the passing loops at Cheam station. A peak hour service continues on this route, stopping at Sutton and Dorking.
- 1984 Dorking and Sutton both lose their peak hour 12 coach fast train services to London and the south coast.
- 1997 Thameslink 2000 is announced with promises of a dedicated King's Lynn to Guildford service via London Bridge & West Croydon and an upgraded Wimbledon Loop service to St Albans with 12 coach trains.
There are two tunnels on the line, built between 1860 and 1867.
Mickleham Tunnel is midway between Leatherhead and Box Hill & Westhumble. It is 524 yards long and runs through the lower chalk of Norbury Park, entering the hillside immediately north of one of the three viaducts over the River Mole. Restrictions imposed by the landowner, Thomas Grissell, meant that vertical ventillation shafts could not be constructed and the tunnel portals were given lavish architectural treatment.
Betchworth Tunnel is 1/4 mile south of Dorking. It is 385 yards long with a maximum gradient of 1 in 80. It runs through the upper greensand of the Deepdene Ridge to the east of the town. Construction difficulties delayed the line's opening south of Dorking. It collapsed on 27 July 1887, remaining closed for over six months.
Typical off peak journey times from London Victoria to Horsham (via Mitcham Junction) 
Based on the May - December 2006 timetable.
|Clapham Junction||2||6||6||4||London Waterloo, Southampton, Portsmouth Harbour|
|Balham||3||-||12||2||London Underground Northern Line|
|Mitcham Junction||4||-||20||2||Tramlink, Herne Hill, London Blackfriars, Luton|
|Sutton||5||25||29||4||Epsom Downs, West Croydon, Wimbledon|
|Epsom||-||35||40||4||Worcester Park, Raynes Park, Wimbledon|
|Leatherhead||-||42||-||2||Bookham, Effingham Junction, Guildford|
|Box Hill & Westhumble||-||47||-||1|
|Dorking||-||50||-||2||Dorking (Deepdene) station is five minutes' walk|
|Horsham||-||72||-||1||Three Bridges, Gatwick Airport, Littlehampton|
Typical off peak journey times from London Victoria to Epsom Downs (via West Croydon) 
Based on the May - December 2006 timetable.
Southern run additional services along the part of this line between London and West Croydon and are branded as "Metro" services.
The line between West Croydon and Sutton has 6 trains an hour off peak and 4 trains an hour during the peak unlike other stations further up the line.
|Battersea Park||2||4||2||Denmark Hill, London Bridge|
|Clapham Junction||2||9||4||London Waterloo, Southampton, Portsmouth Harbour|
|Balham||3||15||4||London Underground Northern Line|
|Streatham Common||3||20||4||Tulse Hill, London Bridge|
|West Croydon||5||31||4||Norwood Junction, London Bridge|
|Waddon||5||36||4||London Bridge (2 trains per hour)|
|Wallington||5||39||4||London Bridge (2 trains per hour)|
|Carshalton Beeches||5||42||4||London Bridge (2 trains per hour)|
|Sutton||5||45||4||Epsom, Horsham, Wimbledon, Mitcham Junction, Luton|
See also 
- Beechcroft G (2009). "Mickleham Tunnel". Railway Structures. Southern E-Group. Retrieved 16 August 2011.
- Capper I (2010). "Betchworth Tunnel". TQ1849. Geograph Britain and Ireland. Retrieved 14 August 2011.
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