Bull Sand Fort

This is an offshore fort constructed between 1915 and 1918, with later minor alterations. It is built of reinforced concrete and brick, clad with rivetted steel armour plating, and includes a timber and steel jetty. The fort is circular on plan, with an octagonal base and a balcony at sea level, and a polygonal jetty extending to the southwest. It comprises three floors, a basement, a magazine below sea level, and a central, two-storey observation tower.

The fort's design features plain railings to the balcony and jetty. Rows of windows are present on the lower and middle floors, each with pairs of hinged steel shutters. The middle floor has groups of three projecting turrets on the north and south sides, facing the main shipping lanes. The central octagonal turrets, each supported by an attached cylindrical shaft, have a row of shuttered windows beneath a flat roof. The flanking semicircular turrets have conical bases and roofs and full-width shuttered openings.

The roof of the fort features a central cylindrical ventilation shaft, a rectangular, flat-roofed, armour-clad look-out tower with shuttered windows, two single projecting square observation turrets attached to the north and south sides, a roof balcony, a mast and radio aerials, angular armour-clad flat-roofed sections flanking a pair of east-facing gun emplacements, and a recessed segmental section of painted brick on the west side, containing seven windows with glazing bars and a pair of steel chimneys, accessed by a steel staircase from the jetty.

The fort, along with its smaller companion fort on Haile Sand, guarded the approaches to the Humber with gun batteries and a steel mesh anti-submarine net stretched between them. Bull Sand Fort had a full range of amenities, including its own fresh-water supply, to accommodate a garrison of 200. Its armament included two 6-inch guns and two 6-pounder guns. Construction involved an estimated 40,000 tons of concrete and steel, costing approximately £1,500,000. The forts were constantly manned during both World Wars and were frequently under attack from aircraft and submarines. The Army vacated the site in 1956, and it remained manned until the early 1960s when it was sold to the Humber Conservancy Board.