HMS Amphion was an Active-class scout cruiser constructed for the Royal Navy, launched on 4 December 1911 and completed in March 1913. She measured approximately 405 feet (123.4 meters) in length between perpendiculars, with a beam of 41 feet (12.5 meters) and a draught of 14 feet 6 inches (4.4 meters). Displacing around 3,340 long tons (3,394 tonnes) at normal load and up to 3,945 long tons (4,008 tonnes) at deep load, the vessel was crewed by 289 officers and ratings. As an Active-class ship, Amphion was powered by turbines and designed for high speed to operate with destroyer flotillas. Her armament comprised ten breech-loading 4-inch (102 mm) Mk VII guns, arranged with two on the forecastle, six amidships (three on each broadside), and two on the quarterdeck, all capable of firing shells up to 11,400 yards (10,400 meters). Her secondary armament included four quick-firing 3-pounder guns and two submerged 18-inch (450 mm) torpedo tubes. Her lightweight protection featured a curved deck with 1-inch (25 mm) thick slopes and a 4-inch (102 mm) protected conning tower. Ordered under the 1910 Naval Programme, Amphion was laid down at Pembroke Dockyard's No. 5 Slipway on 15 March 1911 and launched by Mrs. Mundy. She was commissioned on 2 April 1913 and initially served with the 4th Battle Squadron of the First Fleet before transferring to the 1st Light Cruiser Squadron in May 1913, and later acting as flotilla leader for the 3rd Destroyer Flotilla by June 1914. At the outbreak of World War I, Amphion was assigned to the Harwich Force, tasked with patrolling the North Sea. Notably, on 5 August 1914, she participated in the engagement with the German auxiliary minelayer SMS Königin Luise, successfully sinking her after a brief engagement. However, on the following day, Amphion struck a mine off the Thames Estuary, which detonated beneath her bridge, causing catastrophic damage. The explosion broke her keel and set her on fire, leading to her rapid sinking within 15 minutes. The loss resulted in 132 crew members killed, making her the first Royal Navy ship to be lost during World War I. Her wreck remains a protected site today.

This description has been generated using GPT-4.1-NANO based on the Vessel's wikidata information and then modified by ShipIndex.org staff.