The old Naval Yard was the main arsenal for the British Mediterranean Fleet between c 1760 and 1833, when the dockyard in Malta became predominant. However, between 1843 and 1860 various works to expand the facilities were undertaken, using convict and hired labour. Amongst the improvements was the extension of the ‘New Mole’ in 1851 to 1309 feet long in total and 130 feet wide.
In 1871, Captain Augustus Phillimore made the proposal that a new naval dockyard should be constructed in Gibraltar. Phillimore's scheme would lay dormant in the Admiralty for 22 years before it was put to Parliament in 1895. In 1896 the scheme was further extended with the creation of new moles and three dry docks which were completed by 1906. There were five main elements:
1 The extension of the Southern Breakwater (the New Mole) by a further 2700 feet (823 metres; including the 1000 feet (304.8 metres; agreed in 1893);
2 A detached breakwater or mole, 2720 feet (829 metres) long lying NNW between the North and South Breakwaters/Moles;
3 A large North Mole with coaling jetties and a viaduct;
4 An extended Naval Yard with three large graving or dry docks, docks, wharves, slipways for destroyers, engine pumping house, workshops, stores, offices, tramway et al.; and
5 The dredging of the harbour.