Fort Picklecombe was built near an earlier earthen battery dating back to the start of the 19th century. It was designed by Major (later Maj Gen) Whitworth Porter , and was built by Hubbard and Company. Constructed between 1864 and 1871, the fort was armed with forty two 9-inch and 10-inch muzzle loading guns, which were mounted in a semi-circular arc of two-storey casemates faced with granite blocks and iron shields. In the 1890s, it was rearmed with two 6-inch breech-loaders and two light quick firing guns. Not a single shot has ever been fired in anger from the fort. The Palmerston forts’ lack of war action led them to be dubbed Palmerston Follies, the fact that they were a deterrent was lost on their critics.