HMAS Orion

The Oberon class was based heavily on the preceding Porpoise class 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. This was the fourth time the RAN had attempted to establish a submarine branch. The submarine was long, with a beam of , and a draught of when surfaced. At full load displacement, she displaced 2,030 tons when surfaced, and 2,410 tons when submerged. The submarine could travel at up to on the surface, and up to when submerged, had a maximum range of at , and a test depth of below sea level. The main armament of the Oberons consisted of six torpedo tubes. Between 1977 and 1985, the Australian Oberons were upgraded to carry United States Navy Mark 48 torpedoes and UGM-84 Sub Harpoon anti-ship missiles. Orion was laid down by Scotts Shipbuilding and Engineering Company at Greenock, Scotland on 6 October 1972, launched on 16 September 1974, and commissioned into the RAN on 15 June 1977. The submarine was due to enter service in 1975, but faulty high-power electrical cabling had been installed in Orion and sister boat ; stripping out and replacing the cabling delayed each submarine's construction by two years. The delay meant that the two boats could be fitted with Micropuffs rangefinding sonar during construction, and have additional electronic surveillance equipment installed. Orions name comes from the constellation Orion: although a name with strong links to the Royal Navy (with six vessels operating as ), this was a break from the RAN's traditional use of the names of explorers and pioneers for submarines. The submarine's motto of "Orbe Circumcincto" (Latin for "All around the world") refers to the visibility of the constellation from any point on Earth. ==Operational history==

Orion was the first ever Australian vessel to visit a German port. On her delivery voyage from Scotland in 1978, Orion recorded communications and any other signals emitted from Libyan Navy vessels around the ports of Tripoli, Benghazi, Darnah and Tobruk at the request of the United Kingdom and the United States. As Orion and Otama were fitted with specialist intelligence gathering equipment, they were regularly deployed on surveillance and spying operations, earning them the nickname "Mystery Boats". Activities were part of the broader Western nations' intelligence-gathering apparatus, and included surveillance off the coasts of China, India, Vietnam, and Indonesia, tailing of Soviet Pacific Fleet units during operations in the Pacific and Indian Oceans, and observation off the Soviet base at Vladivostok. Orion was the last submarine to receive the Cup until 2005, when it was presented to the 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 or sinking as a dive wreck failed, and submissions for disposal companies were closed off on 6 August 2004. The submarine was sold for scrapping, and was broken up by Tenix at Henderson, Western Australia in December 2006. The fin was given to the City of Rockingham and is now mounted as a permanent memorial at Rockingham Naval Memorial Park. The port propeller was donated to the WA Maritime Museum. In November 2011, authorisation was granted to establish a new Australian Naval Cadets unit in Jindabyne, New South Wales, named New Training Ship (NTS) Orion after the submarine. In addition to the name, the cadet unit will use Orions badge and motto. ==Citations==