HMAS Orion (S 71) was an Oberon class submarine of the Royal Australian Navy

Royal Australian Navy

The Royal Australian Navy is the naval branch of the Australian Defence Force. Following the Federation of Australia in 1901, the ships and resources of the separate colonial navies were integrated into a national force: the Commonwealth Naval Forces...

 (RAN).

Design and construction

The Oberon class was based heavily on the preceding Porpoise class

British Porpoise class submarine

The Porpoise class was an eight-boat class of diesel-electric submarines operated by the Royal Navy. This class was originally designated patrol submarines, then attack. They were the first conventional British submarines to be built after the end of World War II...

 of submarines, with changes made to improve the vessels' hull integrity, sensor systems, and stealth capabilities. Eight submarines were ordered for the RAN, in two batches of four. The first batch was approved in 1963, and the second batch (including Orion) was approved during the late 1960s, although two of these were cancelled before construction started in 1969, with the funding redirected to the Fleet Air Arm

Fleet Air Arm (RAN)

The Fleet Air Arm , known formally as the Australian Navy Aviation Group, is the division of the Royal Australian Navy responsible for the operation of aircraft. The FAA was founded in 1947 following the purchase of two aircraft carriers from the Royal Navy...

. This was the fourth time the RAN had attempted to establish a submarine branch

Royal Australian Navy Submarine Service

The Royal Australian Navy Submarine Service is the collective name of the submarine element of the Royal Australian Navy. The service currently forms the Navy's Submarine Force Element Group and consists of six Collins class submarines....

.

The submarine is 295.2 feet (90 m) long, with a beam

Beam (nautical)

The beam of a ship is its width at the widest point. Generally speaking, the wider the beam of a ship , the more initial stability it has, at expense of reserve stability in the event of a capsize, where more energy is required to right the vessel from its inverted position...

 of 26.5 feet (8.1 m), and a draught of 18 feet (5.5 m) when surfaced. At full load displacement, she displaces 2,030 tons when surfaced, and 2,410 tons when submerged. The two propeller shafts are each driven by an English Electric motor providing 3,500 brake horsepower and 4,500 shaft horsepower; the electricity for these is generated by two Admiralty Standard Range supercharged V16 diesel generators. The submarine could travel at up to 12 knots (6.5 m/s) on the surface, and up to 17 knots (9.3 m/s) when submerged, had a maximum range of 9000 nautical miles (16,668 km) at 12 knots (6.5 m/s), and a test depth of 200 metres (656.2 ft) below sea level. When launched, the boat had a company of 8 officers and 56 sailors, but by the time she decommissioned, the number of sailors had increased to 60. In addition, up to 16 trainees could be carried.

The main armament of the Oberons consisted of six 21 inches (533.4 mm) torpedo tubes. The British Mark 8 torpedo was initially carried by the submarine; this was later replaced by the wire-guided Mark 23. Between 1977 and 1985, the Australian Oberons were upgraded to carry United States Navy Mark 48 torpedo

Mark 48 torpedo

The Mark 48 and its improved ADCAP variant are heavyweight submarine-launched torpedoes. They were designed to sink fast, deep-diving nuclear-powered submarines and high-performance surface ships.-History:...

es and UGM-84 Sub Harpoon

Boeing Harpoon

The Harpoon is an all-weather, over-the-horizon, anti-ship missile system, developed and manufactured by McDonnell Douglas . In 2004, Boeing delivered the 7,000th Harpoon unit since the weapon's introduction in 1977...

 anti-ship missiles. As of 1996, the standard payload of an Australian Oberon was a mix of 20 Mark 48 Mod 4 torpedoes and Sub Harpoon missiles. Some or all of the torpedo payload could be replaced by Mark 5 Stonefish

Stonefish (mine)

Named after a venomous fish, the Stonefish influence mine is manufactured by a British company . Originally, the weapon was supplied to the Royal Navy, but it has also been exported to friendly countries such as Australia, which has both warstock and training versions of Stonefish.Stonefish mines...

 sea mines, which were deployed through the torpedo tubes. On entering service, two stern-mounted, short-length 21 inches (53.3 cm) torpedo tubes for Mark 20 anti-submarine torpedoes. However, the development of steerable wire-guided torpedoes made the less-capable aft-firing torpedoes redundant; they were closed off, and later removed during a refit.

Orion was laid down by Scotts Shipbuilding and Engineering Company

Scotts Shipbuilding and Engineering Company

Scotts Shipbuilding and Engineering Company Limited, often referred to simply as Scotts, was a Scottish shipbuilding company based in Greenock on the River Clyde.- History :...

 at Greenock, Scotland on 6 October 1972, launched on 16 September 1974, and commissioned into the RAN on 15 June 1977. The submarine's name comes from the constellation Orion

Orion (constellation)

Orion, often referred to as The Hunter, is a prominent constellation located on the celestial equator and visible throughout the world. It is one of the most conspicuous, and most recognizable constellations in the night sky...

: although a name with strong links to the Royal Navy (with six vessels operating as ), this was a break in RAN tradition, which used the names of explorers and pioneers for previous submariens.

Operational history

In 1987, Orion was awarded the Gloucester Cup, for being the RAN vessel demonstrating the greatest overall efficiency over the previous twelve months. Orion was the last submarine to receive the Cup until 2005, when it was presented to the Collins class

Collins class submarine

The Collins class is a class of six Australian-built diesel-electric submarines operated by the Royal Australian Navy . The Collins class takes its name from Australian Vice Admiral John Augustine Collins; all six submarines are named after significant RAN personnel who distinguished themselves in...

 submarine .

Decommissioning and fate

Orion paid off into reserve at Garden Island, Western Australia in 1996. She remained there for several years, until she was marked for disposal as scrap in September 2003. Efforts to hand her over to a State Government for preservation as a museum ship

Museum ship

A museum ship, or sometimes memorial ship, is a ship that has been preserved and converted into a museum open to the public, for educational or memorial purposes...

 or sinking as a dive wreck failed, and submissions for disposal companies were closed off on 6 August 2004. The submarine was sold off for scrapping

Ship breaking

Ship breaking or ship demolition is a type of ship disposal involving the breaking up of ships for scrap recycling. Most ships have a lifespan of a few decades before there is so much wear that refitting and repair becomes uneconomical. Ship breaking allows materials from the ship, especially...

, and was broken up by Tenix at Henderson, Western Australia

Henderson, Western Australia

Henderson is a suburb of Perth, Western Australia, located within the City of Cockburn.-History:The suburb of Henderson comprises land resumed by the Commonwealth Government in 1915 for defence purposes. A large naval base was planned by Admiral Sir Reginald Henderson, and the was area sometimes...

 in December 2006. The fin

Sail (submarine)

In naval parlance, the sail or fin of a submarine is the tower-like structure found on the dorsal surface of submarines...

 was given to the City of Rockingham and is now mounted as a permanent memorial at Rockingham Naval Memorial Park. The port propellor was donated to the Western Australia Maritime Museum.