File:Maidstone West Signal Box - September 2022.jpg

English: Maidstone West Signal Box is designated at Grade II for the following principal reasons: * Rarity of type: it is one of only two remaining examples of Evans O'Donnell's own design of signal box out of an original 40, and the least altered of the two; * Architectural interest: of an impressive scale of three storeys high with two full storeys overhanging on cast iron brackets and 10 bays wide, and it is the only remaining signal box retaining Evans O'Donnell's characteristic windows; * Degree of alteration: intact apart from the replacement of the external staircase in steel and the roof covering; * Survival of operating equipment: it retains the original 1899 Evans O'Donnell lever frame with 115 levers and some block instruments including commutators and bells.

History 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.

Maidstone West "A" signal box was an Evans, O'Donnell & Company standard design, fitted with a 115 lever Evans, O'Donnell & Company Tappet frame, and was built for the South Eastern and Chatham Railway. It opened 4th June 1899, replacing an 1892 built signal box located a short distance to the south. The signal box was renamed Maidstone West "A" soon after opening and was further renamed Maidstone West on 29th September 1929 after the closure of Maidstone West "B" signal box.

The form of the signal box was influenced by the station's location on the side of a hill and on a bend which required the box to be raised up to give the signal man better vision along the line.

On 3 August 1944 the signal box suffered damage when a doodle bug landed nearby. The steel steps and toilet were added later in the C20.