SHIPS-IN-CLASS (6): HMAS Onslow (SS60/SSG60); HMAS Orion (S61); HMAS Otama (SS72/SSG72); HMAS Otway (S59); HMAS Ovens (S70); HMAS Oxley (S57)
LENGTH: 295.2 feet (89.98 meters)
BEAM: 26.5 feet (8.08 meters)
DRAUGHT: 18 feet (5.49 meters)
DISPLACEMENT (SURFACE): 1,600 tons
DISPLACEMENT (SUBMERGED): 2,400 tons
PROPULSION: 2 x Admiralty Standard Range V16 supercharged diesel generators with 2 x English Electric motors developing 4,500 shaft horsepower to 2 x shafts.
SPEED (SURFACE): 12 knots (14 miles-per-hour)
SPEED (SUBMERGED): 17 miles-per-hour (20 miles-per-hour)
RANGE: 8,690 nautical miles (10,000 miles; 16,093 kilometers)
Detailing the development and operational history of the HMAS Onslow (SS60 / SSG60) Diesel-Electric Attack Submarine.
Entry last updated on 6/22/2016.
Authored by Staff Writer. Content ©www.MilitaryFactory.com.
Australia's first submarine was HMAS AE1 commissioned in 1914 just prior to World War 1 (1914-1918). This vessel's legacy became a painful reminder of the dangers of undersea travel - the boat was lost at sea with its entire crew on September 14, 1914, its whereabouts unknown to this day. With its strategic position in the South Pacific, deep sea submarines remained important for Australian interests though maintaining an effective force proved a challenge for decades, initiatives often times done in by simple economics. The Australian submarine force was reduced to nothing on several occasions and none served under the Royal Australian Navy (RAN) flag during World War 2 (1939-1945). Australian bases at Brisbane and Fremantle, however, became critical to American, British, and other Allied submarines during the conflict and Fremantle rivaled only Pearl Harbor, Hawaii in importance for submarine support in the Pacific during World War 2.
Australian submarine fortunes changed during the Cold War years when it was decided by the government to allow purchase of submarines for training. This order then evolved to become a full-fledged submarine attack force based around the British-designed Oberon-class. The new group would number six-strong. The class proved very popular globally as twenty-seven were completed with these serving in the British Royal Navy, the RAN, the Brazilian Navy, the Canadian Navy, and the Chilean Navy in various numbers.
For the Australians, one of the boats of this foreign-born class became HMAS Onslow (SS-60) and her sisters were HMAS Orion (S-61), HMAS Otama (SS-72), HMAS Otway (S-59), HMAS Ovens (S-70), and HMAS Oxley (S-57). Onslow led a career from 1969 to 1999 before beginning her second career as a preserved museum ship at the Australian National Maritime Museum in Sydney.
She was ordered during 1963 and saw her keel laid down on December 4th, 1967 by Scotts Shipbuilding and Engineering Company of Greenock, Scotland. Launching commenced on December 3rd, 1968 and the vessel was formally commissioned on December 22nd, 1969 with the name of Onslow, the surname of Australian Chief Justice Sir Alexander Campbell Onslow (1842-1908) (also the name of a Western Australian town). Her fighting motto became "Festina Lente" - "Hasten Slowly" and her assigned homeport was HMAS Platypus Sydney.
As completed, HMAS Onslow displaced 2,030 tons when surfaced and 2,400 tons submerged. Her length was 295 feet with a beam of 26.5 feet and draught of 18 feet. When still under construction, her original crew complement numbered sixty-four but this was increased to sixty-eight by the time of her commissioning. Her machinery was conventional (as opposed to nuclear) with a diesel-electric mix used that was consistent with this period of submarine-building. 2 x Admiralty Standard Range supercharged V16 diesel generators drove her on the surface and 2 x English Electric motors drove her underwater. Drive power was sent to 2 x shafts located at the stern and Onslow could manage a surfaced speed of 12 knots and up to 15 to 17 knots when submerged. Range was out to 9,000 nautical miles and maximum depth was 660 feet. Onslow also carried a driver's access hatch to serve special forces elements - a feature not found on her sisters and special soundproofing measures were instituted in the class making them one the quietest submarines of their time.
Onslow held typical armament for an attack submarine with an armament suite led by 6 x 21" (533mm) torpedo tubes fitted to the bow (firing forwards). This was supplemented by 2 x 21" tubes in stern-facing mounts (later removed). The boat carried twenty torpedo reloads originally of the British Mark 8 type and then of the Mark 23 type before replacement by the American Mark 48 Mod 4 series. The boat was then modified to launch UGM-84 Sub Harpoon anti-ship missiles in place of torpedoes through an update in the early 1980s. It was at that time that she was also to lose her two stern-facing torpedoes which added no more tactical value due to the new generation of torpedoes being taken on for the bow tubes.
Onboard, Onslow utilized a mix of sensors and processing systems. An Atlas Elektronik Type CSU3-41 sonar system was fitted to the bow while a BAC Type 2007 array was added in a flank position. A rangefinding array was made up of the Sperry BQG-4 "Mircopuffs" system (a later feature installed) and radar included the Kelvin Hughes Type 1006 series system.
HMAS Onslow began her ocean-going career in 1970. In 1972, a disgruntled transfer disobeyed an order to close the forward ballast tank which led to the vessel taking a dangerously steep dive action. The valve was closed in time by another submariner and the boat was able to make it back to the surface unscathed. This incident led to the RAN submarine force accepting only volunteers in their ranks and not forced conscripts.
After assignment to ANZUK beginning July of 1972, Onslow was taken in for refit in May 1975 at the Cockatoo Island Dockyard. In 1980, she took part in "Exercise Kangaroo 3" which involved simulated attacks on moving surface warships. Onslow managed to "sink" all seven "enemy" warships in the scenario and proudly displayed the Jolly Rogers upon her return. In 1981, during a March joint exercise with the Royal New Zealand Navy (RNZN), one of Onslow's diesels began smoking with the boat submerged, causing carbon monoxide to fill the vessel. One crewmember died and a further eighteen blacked out while some 33% of the crew suffered from inhaling the gas. The cause of the engine malfunction was blamed on human error though the crew saw otherwise.
During 1982 to 1984 Onslow underwent a period of refit and had her weapons suite revised and updated systems and sensors installed. The support for Harpoon anti-ship missiles made her the first conventionally-powered boat to be given this useful attack feature. Onslow undertook several goodwill tours including visits to the United States and Canada in the period following.
During the early 1990s, the Oberon-class in Australian service was meeting its useful end. Four of the six boats were decommissioned by the middle part of the decade leaving just Onslow and Otama in active service. A hazing incident during 1995 brought about a stain to the Onslow's otherwise excellent career. The boat served in other exercises from then on including RIMPAC 1998 and was formally decommissioned on March 30th, 1999, HMAS Onslow. In April of that year, the boat was handed over to museum ownership for long-term preservation.