Brighton main line

Original proposals

There were six original proposals to build a railway between London and Brighton. The London and Brighton Railway (L&BR) emerged with an Act of Parliament of 15 July 1837 after a prolonged and expensive battle, with the most direct route, from the London and Croydon Railway (L&CR) at Norwood Junction to Brighton, using the L&CR from Norwood to London Bridge. A condition required by Parliament was that the railway should share its line between Croydon and Redhill with the South Eastern Railway main line to Dover. This clause gave rise to 60 years of disputes between the two companies.

Brighton line

Land use between London and Brighton was largely rural. The line was planned to traverse the North Downs, the Wealden ridge and the South Downs while avoiding steep gradients.

Due to the difficult terrain and relatively sparse population between Croydon and Brighton, the line by-passed several towns and villages on the London-Brighton road, such as Reigate and Crawley. Even so, it required substantial earthworks, notably through the North Downs at Merstham, with one of the largest cuttings in Britain; seven tunnels (Merstham, Balcombe, Haywards Heath, Clayton and Patcham initially, then Quarry and Redhill which were constructed later); and several embankments. To avoid steep gradients or detours, the 1,475-foot-long (450 m), maximum 96-foot-high (29 m) Ouse Valley Viaduct was built near Balcombe.

The line opened in two stages:

12 July 1841: Norwood Junction to Haywards Heath.

21 September 1841: to Brighton.

Branch lines

The branch line from Brighton to Shoreham-by-Sea was finished on 12 May 1840, before the main line, as it did not involve significant civil engineering works (all the materials arrived by sea from mainland Europe). The Newhaven section did not materialise until 1846, when the Brighton - Hastings line was opened by the Brighton Lewes and Hastings Railway. A few weeks later the L&CR, the L&BR and other railways in Sussex amalgamated to form the London, Brighton and South Coast Railway (LB&SCR).

Lines to Victoria

A branch line from Norwood to Crystal Palace was built in 1851, extending to Sydenham in 1854, Balham and Wandsworth in 1856, Battersea in 1858, and London Victoria in 1860. A cut-off line reducing the distance between East Croydon and Balham opened in 1862.

Quarry line

There were frequent disputes resulting from the companies' sharing of the busy section between East Croydon and Redhill. The LB&SCR owned the section between East Croydon and Coulsdon North, and the SER (later the South Eastern and Chatham Railway) from Coulsdon South to Redhill. Eventually the LB&SCR built the "Quarry Line", a by-pass for express trains between Coulsdon North and Earlswood, avoiding Redhill. It opened on 8 November 1899 (1 April 1900 for passengers trains).

Electrification

The line was the first UK main line to be electrified throughout. The LB&SCR electrified its South London Line on 1 December 1909 using an overhead high-tension single-phase system; within three years the line from Victoria to Selhurst railway station was also converted. In 1921 plans were drawn up to extend overhead electrification to Brighton,.^[1] In 1925^[2] it was extended toward the edge of today's Greater London at Coulsdon North, before being scrapped by the amalgamated operator under the 1923 grouping: Southern Railway which decided to standardise on the third-rail system of the former London and South Western Railway. In 1928/29 the lines began conversion to third-rail operation.

The change to third rail electrification was in place southward to Coulsdon North by 1929^[3] – to Three Bridges in the north of Sussex in July 1932, then reaching Brighton and West Worthing on the coast on 1 January 1933.^[4]

The third rail is electrified at 750 V DC, and in the early part of the 21st century had its power supply upgraded for the introduction of Electrostar stock by Southern. Traction current supply is supervised by Lewisham, Selhurst and Brighton electrical control rooms which will be superseded by the Three Bridges ROC.^[5]

Accidents

• In the Clayton Tunnel rail crash on 25 August 1861, a signaller mistakenly allowed a passenger train into the tunnel before the previous one had cleared it. 23 passengers were killed and 176 injured in the collision.
• On 8 March 1965, a freight train derailed at Streatham Common. All four lines were blocked, closing the route between Balham and Selhurst.^[6]
• On 16 December 1972, two electric multiple unit passenger trains collided at Copyhold Junction, West Sussex after the one of the drivers misread signals. Fifteen people were injured.^[7]
• In the Purley station rail crash on 4 March 1989, an electric multiple unit passed a signal at danger and collided with another just north of Purley station. Part of the front train fell down the embankment, killing five people and injuring 88.

Bi-directional signalling

Normal running and 'Bi-directional' signal outside Haywards Heath Tunnel

The line is divided into three sections of bi-directional signalling, which allows trains to cross over to the opposite line and run in the "wrong direction". These are:

• Balcombe Tunnel junction to Copyhold Junction (just north of Haywards Heath).
• Haywards Heath to Keymer Junction (just south of Wivelsfield).
• Keymer Junction to Preston Park.

Diversionary route

The section from Wivelsfield to Preston Park can be bypassed by turning eastwards onto the Lewes line at Keymer Junction. At Lewes trains can reverse to head westwards to Brighton via the East Branch line, rejoining the main line at Montpelier Junction. However this diversion does not allow trains to call at Burgess Hill, Hassocks, and Preston Park.

Branches from the line to Victoria

• between London Victoria and Battersea Park, the Chatham Main Line to North Kent
• at Battersea Park, the South London Line to London Bridge
• at Balham, the Crystal Palace Line via Crystal Palace^{[n 1]}
• at Selhurst, to West Croydon

Branches from the line to London Bridge

• between London Bridge and New Cross Gate, the South Eastern Main Line and South London Line
• at New Cross Gate, the East London Line to Highbury & Islington
• at Sydenham, the Crystal Palace Line to Streatham Hill and via Balham to London Victoria
• at Norwood Junction, via Crystal Palace to London Victoria, London Bridge and Blackfriars, and to West Croydon

Branches south of East Croydon

• at South Croydon, the Oxted branch line^{[n 2]}
• at Purley, the Caterham and Tattenham Corner Lines^{[n 3]}
• at Redhill, the North Downs Line to the west^{[n 4]}, and the Tonbridge branch^{[n 5]}
• at Three Bridges, the Arun Valley Line^{[n 6]} to Portsmouth via Horsham^{[n 7][n 8]}
• at Wivelsfield^{[n 9]} the East Coastway Line to Eastbourne and Hastings via Lewes direct, avoiding Brighton^{[n 10]}
• at Preston Park, a branch of the West Coastway Line to Littlehampton, avoiding Brighton^{[n 11]}
• at Brighton, the West Coastway Line; and the East Coastway Line to Eastbourne, Hastings and Seaford