HMS Invincible was a Dreadnought Class Battle Cruiser laid down 2nd April 1906, launached 13th April 1907 and commissioned 20th March 1909. Displacement 17,526 tonnes, length 567 feet, beam 7 feet 6 inches, draught 25 feet. Propelled by Parson's geared steam turbines producing 41,000 shp. The ships complement was 784 but went up to 1,000 plus in war time. At the Battle of Jutland on 31 May 1916, she was the flagship of the 3rd Battlecruiser Squadron. She was hit in her "Q" turret by a salvo from Lützow, which blew the roof off the turret over the site. It was either this shell hit which caused a flash down the magazine, or a second shell in the same salvo, that penetrated the armour and exploded in the magazine, causing a massive explosion. The ship broke in two and sank with the loss of all but six of her crew of 1,021.