By 1860 new guns and tactics were being introduced which led to new weapons of war, from the rifled gun to torpedoes and mines. The Thames was a vital trade route for England, and housed numerous important naval sites including Chatham Dockyard. The 1860 Royal Commission on the Defence of the United Kingdom led to the construction of about 70 forts and batteries in the United Kingdom, one of which was Slough Fort.
The primary role of Slough Fort when built was to protect against any landing by enemy forces on the nearby beaches. It was a small Fort built between Cliffe, Coalhouse and Shornemead and the forts at the mouth of the Medway, Garrison Point and Grain.
The land was acquired in 1861 and the Fort was built over the next few years. Initially, the Fort was an artillery tower, mounting seven 7-inch rifled breech loaders (RBLs) mounted in casemated positions.
Between October 1889 and December 1891 additional batteries were built on either side of the Fort, each accommodating two guns, a mixture of 9.2-inch and two 6-inch breech loaders on disappearing mounts. At this time the original tower was partially covered with earth, for protections and three 3-pdr Quick Fire guns were mounted on the roof of the Fort to combat Torpedo Boats. The casemates, that previously held the guns, were converted to barrack accommodation.
In 1902 a Recreation Building was built just outside the Fort Gate, apparently after complaints from the locals about drunken soldiers in the evenings.
In 1906 two 9.2-inch guns were installed western detached battery, with underground works between the two barbette mounts. The other detached battery remains unchanged until 1907 when the single 9.2-inch and 6-inch guns on a disappearing mounts were removed.
During World War 1 the Fort was used to monitor all shipping using the Thames, but by 1917 the two remaining 9.2-inch guns were removed.
The Fort was abandoned in 1920 and sold in 1929. However, in 1938 the Fort was again activated to protect the Thames. There are two mounts built on the ramparts of the Fort, apparently to hole 4-ins Naval Guns. One of the mounts is now cleared, and another is being exposed, having been buried under a water tank. Reports indicate that these guns were never mounted.
The Fort is slowly being restored by a dedicated group of volunteers. Slough Fort Volunteers Group, https://www.facebook.com/Slough-Fort-Volunteers-Group-869178483172446/.
The main Fort and East Wing battery have been cleared, while one pit of the West Wing battery is open. The remaining 6-ins pit is still buried, but the plan is to uncover this in the future.
Attached is a Fort Log from David Moore, https://www.victorianforts.co.uk/data.htm.