Slough Fort

Slough Fort

A Royal Commission fort built in 1867 and substantially redeveloped and extended between 1889 and 1891, with further modifications during the early twentieth century. The fort is constructed of Kentish ragstone and brick with granite dressings, with brick and concrete used for later armament, range-finding and control post positions.

The fort has a D-shaped plan with a curved façade facing north towards the coast. It surrounds an open stone-flagged parade ground with a ground floor and flat roof. The ground floor contains a north range of seven casemates, while the south range comprises chambers flanking a central fort entrance passage. Two stair turrets at the south-east and south-west corners provide access to the roof.

The principal south elevation is faced in rusticated Kentish ragstone with fine granite dressings to the entrance gate and sandstone lintels to windows. A central projecting bay with paired windows flanks the central gate, with recessed bays to the west and east containing paired windows, and further recessed bays at the extremes with single windows and access doors to former ammunition stores. Infantry loopholes are found throughout. The original metal-plated fort gates are flanked by pulleys for a former drawbridge.

The roof level contains the remnants of an 1867 infantry fire step and access stairs. To the west and east are post-1892 modified quick-firing gun emplacements with ammunition lockers and possible gun shelters. A range-finder position associated with wing batteries of 1889–91 is also present, along with a further modified quick-firing gun emplacement. A World War I Battery Command Post occupies the south range. The north elevation is masked by an 1889–91 earthwork.

The interior of the north range contains seven casemates without embrasures (blocked in 1889–91) and spiral stone staircases. The internal north elevation of the south range shows stock brick in mainly English bond with gauged flat brick arches over windows, some now altered. The south elevation of the north range features a combination of brick and iron arches with pillars reflecting late nineteenth-century modifications.

The fort was built following the 1859 Royal Commission on the Defences of the United Kingdom, in response to a perceived French threat. It was positioned to link the Medway defences with other new forts in the Thames Estuary. The 1889–91 modifications added two wing batteries, each accommodating two disappearing guns. Early twentieth-century changes included modifications to armaments and the erection of a Battery Command Post during World War I to operate in conjunction with a Port War Signal Station to the east. The Army withdrew in 1920 and the fort was sold in 1929, when it was used to house a small zoo. In the early 1960s it was converted to stables. Modern stable buildings and modifications are not of special interest.

The listing relates to the main D-shaped fort only. The external earthwork defences, wing batteries, the well protecting wall and the probable gun detachment shelter are protected by scheduled monument status.