The Admiralty Pier Turret, or Dover Turret, is an enclosed armoured turret built in 1882 on the western breakwater of Dover Harbour in southeast England. It contains two Fraser RML 16 inch 80 ton guns, the biggest installed in the United Kingdom. Declared obsolete in 1902, it is currently part of the port and inaccessible, though the guns remain in place. Admiralty Pier Fort The Admiralty Pier Fort, as distinct from the Dover Turret, was commenced in 1872 as a small fort at the extremity of Dover Pier by adding a further extension and widening the pier. In January 1872 Edward Druce, the engineer in charge, reported that the diving bells had commenced preparing the foundations of the fort and in January 1874 Druce reported that the substructure of the fort had been completed at a cost of £19,718 4s 0d. The armament of the Admiralty Pier Fort was to be two 12-inch muzzle-loading rifled guns of 25 tons as these guns were the most powerful available at the time. Dover Turret In 1877 the Defence Committee noted that more powerful guns of 80 tons had been developed and they recommended that a turret be fitted on the Admiralty Pier Fort for two 80-ton guns. The Superintendent of the Royal Gun Factory had been asked for designs for a powerful gun for capable of penetrating 20 inches of iron at a range of 1,000 yards and it was these guns that were eventually used as armament for the turret on the Admiralty Pier Fort. The gun took 18 months to build and by September 1875 the first gun was ready. Following test firings at the Royal Arsenal the gun was hauled onto the barge Magog and taken to Shoeburyness. By 1881 Admiralty Pier Fort was mostly complete and ready to receive its guns. The turret to hold the guns was constructed by the Thames Ironworks and Shipbuilding Company of Blackwall. This turret had a frame of wrought iron clad with three layers of 7-inch armour with 2-inch layers of iron and wood between them. Its weight including the two guns was 895 tons and it revolved on 32 rollers. The Thames Ironworks also built the machinery for the turret. There were four steam engines: The loading engine for loading running back and raising the ammunition, the main engine for rotating the turret, the auxiliary engine to replace either of the