In 1876 the British gunmakers of Sir W. G. Armstrong of Newcastle upon Tyne offered to the Admiralty a gun weighing 102 tons with a bore of 17.76 inches but the British navy rejected it so Armstrongs sold the manufacturing rights to Italy who constructed several of these weapons and fitted four of them in each of their new battleships Duilo and Dandolo that were protected by 22 inches of steel.
The British now realised that these warships could stand off the Grand Harbour of Malta, impervious to the defending weapons and sytematically destroy eveything in and around the harbour. Almost panic–stricken, the British hastily commissioned guns of even greater calibre of at first 160 and finally 220 tons only to find that this specification was beyond the limits of the then manufacturing technology so swallowing their pride they ordered the 102 ton guns for both Gibraltar and Malta and these were the weapons that still stand at both places. They were actually manufactured at Woolwich Arsenal on the outskirts of London.
The gun required up to forty men to operate it under a battery commander and a master gunner with nine gunners. Twelve men dealt with ammunition, three the position finder and four the range finder. There was also a trumpeter, storeman, lampman and a fatigue man whilst a telephonist maintained contact with its twin at Fort Cambridge and a control station at Fort St Elmo. Besides the telephone there was back-up semaphore and signal mirror and it was intended that one gun should fire whilst the other was being re-loaded. The rate of fire was once every four minutes but when they tried to increase the rate at Gibraltar they split the barrel. It was never used in anger and was last fired for testing purposes on the 5th May 1905.