HMS A7

Template:Infobox ship imageTemplate:Infobox ship careerTemplate:Infobox ship characteristics

HMS A7 was an Template:Sclass2 submarine built for the Royal Navy in the first decade of the 20th century. She sank in a training accident in 1914 with the loss of her entire crew. Efforts to salvage her failed and her wreck is a protected site. Diving on her is prohibited without a licence from the Ministry of Defence.

Design and description

A7 was a member of the first British class of submarines, although slightly larger, faster and more heavily armed than the lead ship, Template:HMS. The submarine had a length of Template:Convert overall, a beam of Template:Convert and a mean draft of Template:Convert. They displaced Template:Convert on the surface and Template:Convert submerged. The A-class submarines had a crew of 2 officers and 9 ratings.

For surface running, the boats were powered by a single 16-cylinder Template:Convert Wolseley petrol engine that drove one propeller shaft. When submerged the propeller was driven by a Template:Convert electric motor. They could reach Template:Convert on the surface and Template:Convert underwater. On the surface, A7 had a range of Template:Convert at Template:Convert; submerged the boat had a range of Template:Convert at Template:Convert.

The boats were armed with two 18-inch (45 cm) torpedo tubes in the bow. They could carry a pair of reload torpedoes, but generally did not as doing so that they had to compensate for their weight by an equivalent weight of fuel.

Construction and career

A7 was ordered as part of the 1903–04 Naval Programme from at Vickers. She was laid down at their shipyard in Barrow-in-Furness on 1 September 1903, launched on 21 January 1905 and completed on 13 April. She sank in Whitsand Bay, Cornwall on 16 January 1914 with the loss of her crew whilst carrying out dummy torpedo attacks on Template:HMS in conjunction with submarine Template:HMS. A disturbance in the water was seen which thought to be caused by the crew of A7 attempting to blow water from her ballast tanks in a desperate attempt to reach the surface. The location was marked with a buoy and Pygmy returned to Plymouth Sound to report on the disaster. Pygmy returned to the site in the afternoon but was unable to locate the buoy as the weather had deteriorated. It then took five days to relocate the submarine, she was found in Template:Convert depth with Template:Convert of her stern buried in the muddy seabed and with her bow Template:Convert off the bottom, raised at an angle of 30°. Several attempts were made to salvage her over the next month by attaching a hawser to the towing eye on the bow or wrapping steel hawsers around her hull, but her stern was too deeply embedded in the mud and the hawsers parted without pulling her out. She lies today where she sank, buried up to her waterline in a flat, mud seabed in about Template:Convert of water. In 2001, she was declared as one of 16 wrecks in British waters designated as "Controlled Sites" under the Protection of Military Remains Act by the British Government and which cannot be dived without special permission.

In 2014 the SHIPS Project team in Plymouth completed an archaeological investigation of the A7 submarine, having been granted a licence by the UK Ministry of Defence.

External links

• MaritimeQuest HMS A-7 Pages
• HMS A-7 Roll of Honour
• SI 2008/950 Designation under the Protection of Military Remains Act 1986
• 'Submarine losses 1904 to present day' - Royal Navy Submarine Museum
• The A7 Project - an archaeological investigation of HM submarine A7 Template:Webarchive