In 1942, during WW2 there was a proposal to install seven new 5.25″ anti-aircraft guns on the rock, three of these went to West Battery on the south of the rock between Windmill Hill and Europa Point. The other four guns were mounted in a rebuilt Princess Anne’s Battery with work being completed many years later in 1956.

The new guns were Ordnance QF 5.25″ MKII on a 1B mounting and performed a dual anti-aircraft and coast defence role. When 5.25″ guns were deployed solely in an Anti Aircraft role they tended to have open backs (on a 1A mounting) but those at Princess Anne’s Battery were totally enclosed. They were able to fire an 80lb shell up to 55,000 feet with a maximum horizontal range of 27,000 yards (13.5 nautical miles).

Three of the emplacements have a semi sunken magazine and engine room to one side, while that for No. 4 gun is completely underground. The photo above was taken at No.1 Gun showing the davit (small crane) for lowering ammunition into the magazine.

At the rear of No.2 Gun there is a ramp leading down to doors which provide access to the Rocks network of tunnels. Although the overall network of tunnels is extensive with many entry points around the Rock, this particular entrance provides immediate entrance to Willis’s Gallery which is one of the Middle Galleries which date back to 1789. These are officially known as Lower Union Gallery, Upper Union Gallery, Queeens Gallery and Willis’s Gallery.