They were operated as army and navy forts, and named after their designer, Guy Maunsell. The forts were decommissioned in the late 1950s and later used for other activities including pirate radio broadcasting.
This artificial naval installation is similar in some respects to early offshore oil platforms. The twin concrete supporting towers were divided into seven floors, for crew quarters, dining, operational, and storage areas for several generators, and for fresh water tanks and antiaircraft munitions.
The towers were joined above the eventual waterline by a steel platform deck. QF 3.75 inch anti-aircraft guns were positioned at each end of this main deck, with a further two Bofors 40 mm anti-aircraft guns and the central tower radar.
In the early 21st century, in response to proposals to demolish the fort, a group called Project Redsands was formed to try to preserve it. Red Sands Fort are now abandoned.