BL 7.5-inch Mk II – V naval gun

Mark II guns were originally developed to suit India's coast defence requirements. During World War I several reserve guns made for India but still in the UK were employed as coast defence guns in the UK. They were scrapped or sent to India soon after the war.[3]

Starboard secondary Mk V battery on HMS Minotaur

These were built and employed specifically as naval guns and were mounted as secondary armament as a heavier alternative to 6-inch guns, on the following ships :

• Warrior-class armoured cruisers laid down 1903–04, commissioned 1906–07
• Minotaur-class armoured cruisers laid down 1905, commissioned 1908–09

Forward port Mk III casemate guns on Swiftsure, Gallipoli 1915

Mk III gun from Swiftsure being transported in Belgium in 1917. Photo by Ernest Brooks.

Mark III guns were built by Elswick Ordnance to arm the battleship Constitución they were building for Chile. Britain acquired them by default when she bought Constitución in 1903 to avoid the risk of the ship being acquired by Russia. Constitución became HMS Swiftsure in British service.

Swiftsure was decommissioned in 1917 and her guns were used for coast defence in Britain, as siege guns on the Belgian coast near Nieuport for attacking German batteries, and on M15-class monitors.

Mark IV guns were made by Vickers for the battleship Libertad they were building for Chile. Britain acquired them by default in 1903 when she bought Libertad together with Constitución. Libertad became HMS Triumph in British service.