HMS ''A7'' was an
submarine
A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...
built for the
Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against F ...
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
{{unsourced, date=February 2021
A ministry of defence or defense (see spelling differences), also known as a department of defence or defense, is an often-used name for the part of a government responsible for matters of defence, found in states ...
.
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
The lead ship, name ship, or class leader is the first of a series or class of ships all constructed according to the same general design. The term is applicable to naval ships and large civilian vessels.
Large ships are very complex and may ...
, . The submarine had a length of
overall
Overalls, also called bib-and-brace overalls or dungarees, are a type of garment usually used as protective clothing when working. The garments are commonly referred to as a "pair of overalls" by analogy with "pair of trousers".
Overalls were ...
, a
beam
Beam may refer to:
Streams of particles or energy
*Light beam, or beam of light, a directional projection of light energy
**Laser beam
*Particle beam, a stream of charged or neutral particles
**Charged particle beam, a spatially localized grou ...
of and a mean
draft
Draft, The Draft, or Draught may refer to:
Watercraft dimensions
* Draft (hull), the distance from waterline to keel of a vessel
* Draft (sail), degree of curvature in a sail
* Air draft, distance from waterline to the highest point on a vessel ...
of . They
displaced on the surface and submerged. The A-class submarines had a crew of 2 officers and 9
ratings.
[Gardiner & Gray, p. 86]
For surface running, the boats were powered by a single 16-cylinder
Wolseley petrol engine
A petrol engine (gasoline engine in American English) is an internal combustion engine designed to run on petrol (gasoline). Petrol engines can often be adapted to also run on fuels such as liquefied petroleum gas and ethanol blends (such as ''E ...
that drove one
propeller shaft
A drive shaft, driveshaft, driving shaft, tailshaft (Australian English), propeller shaft (prop shaft), or Cardan shaft (after Girolamo Cardano) is a component for transmitting mechanical power and torque and rotation, usually used to connect ...
. When submerged the propeller was driven by a
electric motor
An electric motor is an Electric machine, electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a Electromagneti ...
. They could reach on the surface and underwater.
[ On the surface, ''A7'' had a range of at ; submerged the boat had a range of at .][Akermann, p. 120]
The boats were armed with two 18-inch (45 cm) torpedo tube
A torpedo tube is a cylindrical device for launching torpedoes.
There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units (also referred to as torpedo launchers) installed aboa ...
s 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
Vickers was a British engineering company that existed from 1828 until 1999. It was formed in Sheffield as a steel foundry by Edward Vickers and his father-in-law, and soon became famous for casting church bells. The company went public in 18 ...
. She was laid down at their shipyard
A shipyard, also called a dockyard or boatyard, is a place where ships are built and repaired. These can be yachts, military vessels, cruise liners or other cargo or passenger ships. Dockyards are sometimes more associated with maintenance a ...
in Barrow-in-Furness
Barrow-in-Furness is a port town in Cumbria, England. Historically in Lancashire, it was incorporated as a municipal borough in 1867 and merged with Dalton-in-Furness Urban District in 1974 to form the Borough of Barrow-in-Furness. In 2023 the ...
on 1 September 1903, launched on 21 January 1905 and completed on 13 April.[ She sank in ]Whitsand Bay
Whitsand Bay, situated in south east Cornwall, England, runs from Rame Head in the east to Portwrinkle in the west. It is characterised by sheer, high cliffs, dramatic scenery and long stretches of sandy beaches. The South West Coast Path runs t ...
, Cornwall
Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic ...
on 16 January 1914 with the loss of her crew whilst carrying out dummy torpedo
A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, su ...
attacks on in conjunction with submarine . 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.[Holt, Chapter 7] The location was marked with a buoy and ''Pygmy'' returned to Plymouth Sound
Plymouth Sound, or locally just The Sound, is a deep inlet or sound in the English Channel near Plymouth in England.
Description
Its southwest and southeast corners are Penlee Point in Cornwall and Wembury Point in Devon, a distance of abo ...
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 depth with of her stern buried in the muddy seabed and with her bow off the bottom, raised at an angle of 30°.stern
The stern is the back or aft-most part of a ship or boat, technically defined as the area built up over the sternpost, extending upwards from the counter rail to the taffrail. The stern lies opposite the bow, the foremost part of a ship. Ori ...
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 of water. In 2001, she was declared as one of 16 wrecks in British
British may refer to:
Peoples, culture, and language
* British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies.
** Britishness, the British identity and common culture
* British English, ...
waters designated as "Controlled Sites" under the Protection of Military Remains Act
Protection is any measure taken to guard a thing against damage caused by outside forces. Protection can be provided to physical objects, including organisms, to systems, and to intangible things like civil and political rights. Although th ...
by the British Government
ga, Rialtas a Shoilse gd, Riaghaltas a Mhòrachd
, image = HM Government logo.svg
, image_size = 220px
, image2 = Royal Coat of Arms of the United Kingdom (HM Government).svg
, image_size2 = 180px
, caption = Royal Arms
, date_es ...
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.[Holt, Chapter 1]
Notes
References
*
*
*
*
*
*
External links
MaritimeQuest HMS A-7 Pages
*
SI 2008/950
Designation under the Protection of Military Remains Act 1986
'Submarine losses 1904 to present day' - Royal Navy Submarine Museum
{{DEFAULTSORT:A07
A-class submarines (1903)
Protected Wrecks of the United Kingdom
1914 disasters in the United Kingdom
British submarine accidents
Shipwrecks in the English Channel
Maritime incidents in January 1914
Ships built in Barrow-in-Furness
Royal Navy ship names
1905 ships