BL 7.5 inch Mk II – V gun

• Name — Ordnance BL 7.5-inch Mk II–Mk V guns • Origin — United Kingdom • Type — Naval gun Coast defence gun • Is Ranged — YES • Is Artillery — YES • Is Uk — YES • Service — 1905–20 • Used By — Royal Navy British India • Wars — World War I • Variants — Mks II, II*, II**, III, IV, V • Weight — 14½ - 16 tons barrel & breech • Part Length — 375 in; (50 calibre) • Cartridge — 200 lb • Caliber — 7.5 in • Velocity — 2765 to • Max Range — 14200 yd

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

• Illustration — 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

• Illustration — Forward port Mk III casemate guns on Swiftsure, Gallipoli 1915 • Illustration — 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 Triumph in British service.

• Illustration — 1906 RGF gun on Elephanta Island • Two Mk II coast-defence guns made by EOC in 1905 and RGF in 1906, on Elephanta Island, Mumbai, India. Photographs on Flickr