Signal box, 1921, constructed by the South Eastern & Chatham Railway.
Reason for Listing
Aylesford Signal Box, the first signal box to be built to the South Eastern & Chatham Railway's new design in 1921, a design adopted by Southern Railway after 1923, is designated at Grade II for the following principal reasons:
* Early date for type: built in 1921 it was the first signal box built to the South Eastern & Chatham Railway's new design;
* Rarity: it is the only signal box of the new design which was built for the South Eastern & Chatham Railway Company and is the only example of this design which also represents the standard design of the Southern Region after 1923;
* Degree of alteration: it is intact apart from a further window later inserted in an end wall to improve visibility and a small toilet addition;
* Survival of operating equipment: some block instruments, including 2 commutators and bells, remain and the locking room retains the iron frame of the original lever frame
* Group value: it is built at the end of a platform of Aylesford Railway Station which is listed at Grade II.
From the 1840s, huts or cabins were provided for men operating railway signals. These were often located on raised platforms containing levers to operate the signals and in the early 1860s, the fully glazed signal box, initially raised high on stilts to give a good view down the line, emerged. The interlocking of signals and points, perhaps the most important single advance in rail safety, patented by John Saxby in 1856, was the final step in the evolution of railway signalling into a form recognisable today. Signal boxes were built to a great variety of different designs and sizes to meet traffic needs by signalling contractors and the railway companies themselves.
Signal box numbers peaked at around 12,000-13,000 for Great Britain just prior to the First World War and successive economies in working led to large reductions in their numbers from the 1920s onwards. British Railways inherited around 10,000 in 1948 and numbers dwindled rapidly to about 4,000 by 1970. In 2012, about 750 remained in use; it is anticipated that most will be rendered redundant over the next decade.
Aylesford Signal Box was opened in 1921 on the extension to the branch line of the South Eastern Railway between Maidstone West and Strood which opened on 18 June 1856. It was one of the last signal boxes to be constructed by the South Eastern & Chatham Railway (SE&CR). It was the first box to be built to a new design by the company and went on to form the first standard design of the Southern Railway, created in 1923 by the amalgamation of the SE&CR, the London Brighton & South Coast Railway and the London & South Western Railway.
DATE: opened in 1921, it was one of the last signal boxes to be constructed by the South Eastern & Chatham Railway on the branch line between Maidstone West and Strood, which had been opened on 18 June 1856 by the South Eastern Railway. It was the first and only example of this revised design by the SE&CR which, after 1923, was adopted by the Southern Railway and designated their Type IIa.
MATERIALS: constructed of brown brick in English bond with some weatherboarding to the gables and a gabled slate roof.
PLAN: two storeys: three bays in length and two in width with steps, and later toilet at west end (which is not of special interest).
EXTERIOR: the box is accessed by an external flight of stairs from the platform. The west, north and east sides of the operating room are glazed with horizontally sliding sashes, each of four panes. Above the main lights are glazed top lights and shaped timber eaves brackets. The north side has an iron access balcony. The locking room has a central elliptical-arched fixed window of nine lights on the east side. A further metal-framed window with a concrete lintel has been fitted into the east wall to give the signal man a better view of the level crossing. This is not of special interest.
INTERIOR: the operating room has exposed weatherboarding to the roof and walls. A modern panel (not of special interest) has replaced the original lever frame but some block instruments, including two commutators and bells, remain. The locking room retains the iron frame of the lever frame.
Listed building text is © Crown Copyright. Reproduced under licence.