Doncaster PSB - East Coast Main Line Upgrade

East Coast Main Line Upgrade

The Doncaster installation was the third major signal box to be commissioned on the East Coast Main Line, the previous two being King's Cross, completed in 1977 and Peterborough in 1973. Prior to the scheme's authorisation in 1974, train movement was controlled by a mixture of outdated semaphore and colour light signals operated from 52 signal boxes mainly containing mechanical lever frames, many dating from the 19th century.

Power signalling, however, was installed in two signal boxes, one at the north and the other at the south of Doncaster Station. The work was planned and some equipment was on site before World War II but the installation was not commissioned until 1949. Searchlight colour light signals and electric point machines were controlled from switch panels. The interlocking equipment was unique being a sequence switch interlocking system manufactured by Standard Telephone Company using telephone switching techniques to the technical specification of the signal engineer of the then Southern Area of the London and North Eastern Railway. The sequence switches consisted of a rotary contact shaft which was rotated to a route position and proved a circuit through contact wipers. Each switch had a "home" position and eleven route positions. When a route was initiated, a clutch was engaged on the appropriate switch to rotate it into its correct position thus setting up the appropriate interlocking circuits through other switches and relays. The installations proved to be remarkably reliable, serving a very useful purpose but were eventually life expired.

In association with the resignalling scheme, was a major programme of track improvements to enable trains to run at speeds of up to 125 mph. This was achieved by simplification and rationalisation of the track layout and realignment of curves at many places.

An early improvement was the adaptation of an existing railway bridge south of Doncaster to become a flyover enabling trains to and from the Lincoln line to cross over the main line without conflicting with the mainline trains.

The largest alteration to the track layout was in the Doncaster area where the work was staged over an extensive period.