 A very wide outer wet ditch blocked access from the riverside.The roof of the fort, accessed via steps up from the open battery, was altered substantially during the first half of the 20th century to accommodate new guns and other structures.These include emplacements for 5.5-inch and 6-inch guns as well as 12-pdrs, searchlight positions, shelters, an observation post, a fire control building, a machine-gun parapet on the north caponier and a Royal Navy monitoring station.