Military Wiki
River-class destroyer escort
HMAS Torrens DE-53.jpg
HMAS Torrens, with HMAS Yarra in the background
Class overview
Name: River
Builders: Cockatoo Island Dockyard
Williamstown Naval Dockyard
Operators:  Royal Australian Navy
In commission: 1961–1998
Completed: 6
Scrapped: 3
General characteristics
Type: Destroyer escort (previously anti-submarine frigate)

The River class was a class of six destroyer escorts (originally designated anti-submarine frigates) operated by the Royal Australian Navy (RAN). Plans to acquire four vessels, based on the British Type 12M (or Rothesay class) frigate, began in the 1950s. The first two vessels had some slight modifications to the design, while the next two underwent further changes. Two more ships were ordered in 1964, following the Melbourne-Voyager collision; these were based on the Type 12I (or Leander class) frigate.

By the 1990s, all six ships had left service. Two were sunk as part of tests, and a third was scutted as an artificial reef, while the other three ships were scrapped.

Design and construction

In August 1950, the Australian government announced plans to acquire a new class of anti-submarine warfare frigates, based on the British Type 12M (or Rothesay class) frigate design.[1] Originally six were planned, with construction to be split between Cockatoo Island Dockyard in Sydney and Williamstown Naval Dockyard in Melbourne, but only four were approved.[1] The first two ships, Parramatta and Yarra, were based directly on the Rothesay class, with changes to fire control system, air warning radar, and habitability to meet RAN operating conditions.[1] The second pair, Stuart and Derwent, were modified to carry a variable-depth sonar over the stern.[2] Although originally classified as frigates, the ships' designation was later changed to destroyer escort.[2]

In 1964, the aircraft carrier Melbourne collided with the destroyer Voyager, resulting in the destroyer's sinking.[3] In order to replace the lost capability, the Australian government ordered another two River class ships, Swan and Torrens.[3] Unlike the previous four, the new ships were based on the more advanced Type 12I (or Leander class) design.[3]

The ships had a displacement of 2,150 tons at standard load and 2,700 tons at full load.[4] They were 370 ft. (113m) long, had a beam of 41 ft. (12.5m), and a draught of 13 ft. (3.9 m).[4] Propulsion was provided by two double-reduction gearded turbines, which supplied 30,000 shaft horsepower (22,000 kW) to two propeller shafts, allowing the vessels to reach 30 knots (56 km/h; 35 mph).[4] Maximum range was 3,400 nautical miles (6,300 km; 3,900 mi) at 12 knots (22 km/h; 14 mph).[4] The ship's company consisted of 250 personnel.[4]

Weapons fit for the first four ships at commissioning consisted of two 4.5 inch Mark 6 guns in a single twin turret, two 40 mm Boforss in a twin mount, and two Limbo anti-submarine mortars.[5] During the 1960s, a quadruple Sea Cat anti-aircraft missile launcher was fitted in place of the Bofors, and one of the Limbo mortars was removed in favour of an Ikara missile launcher.[6] Stuart was the first RAN ship fitted with Ikara, and Derwent the first to carry Sea Cat.[2] In the early 1990s, the missile systems were removed from all active Rivers, with an Army RBS 70 unit available for use if required.[citation needed]

Operational history

During their careers, the River class ships spent most of their time in Australian waters or on multinational exercises, but were regularly deployed to the Far East Strategic Reserve, and saw service during the Indonesia-Malaysia Confrontation.[7]

During 1967 and 1968, Stuart and Yarra were used to escort the troop transport HMAS Sydney on voyages to Vietnam.[7]

During the mid-1970s, Yarra underwent a half-life refit, which included the removal of her remaining Limbo, and installation of a Mulloka sonar.[4] Parramatta underwent a more extensive modernisation during the late 1970s, with a new fire control system, modification of the boilers and electrical system, and habitability improvements.[4] Stuart and Derwent underwent similar modernisations between 1979 and 1985.[2] Modernisation was planned for Swan and Torrens during the mid-1980s, but a lack of funding meant that the ships only underwent a half-life refit.[3]

At the start of 1984, Stuart became the first RAN vessel permanently assigned to HMAS Stirling, the new base in Western Australia.[2]

In 1992, reports of sexual harassment aboard Swan prompted investigations by the Australian Defence Force and a Senate committee review.[7]

Decommissioning and fate

Yarra was decommissioned on 22 November 1985.[8] There were plans to keep her in service as a training vessel, but the decision was to keep HMAS Vampire active in this role, and Yarra was placed in reserve.[4] The other ships of the class were decommissioned during the 1990s.[7]

Derwent was sunk during explosives testing in 1994.[7] Swan was scuttled as an artificial reef in 1997.[7] Torrens was torpedoed by the Collins class submarine Farncomb during a weapons test in 1999.[7] The other three ships were broken up for scrap.[citation needed]


Note: although these ships are grouped together as a single class, there were many significant differences between the first two units, second two units (Type 12M) and the final two units (Type 12I).

Type 12M Type 12I Batch III
Displacement 2,560 tons 2,790 tons
Dimensions 113 metres (371 ft) (length)
12.5 metres (41 ft) (beam)
3.9 metres (13 ft) (draught)
113.3 metres (372 ft) (length)
13.1 metres (43 ft) (beam)
4.5 metres (15 ft) (draught)
Armament 2 x 4.5 inch (113 mm) Mark 6 guns
2 x Limbo anti-submarine mortars1
2 x 4.5 inch (113 mm) Mark 6 guns
1 x quad Seacat SAM launcher
1 x Limbo mortar
1 x Ikara ASW system
Propulsion 2 x English Electric steam turbines; 2 shaft; 30,000 shp 2 x English Electric steam turbines; 2 shaft; 30,000 shp
Speed 31.9 knots 30 knots
  • ^1 : All four of the Type 12M units were refitted with both the Seacat and Ikara missile systems, replacing 40 mm AA guns and Limbo mortars, and later Mark 32 torpedo tubes were added.


Stuart in Hong Kong Harbour in 1989

Name Builder Launched Commissioned Decommissioned Status
HMAS Parramatta (DE 46) Cockatoo Island Shipyard, Sydney 31 January 1959 14 July 1961 11 November 1991 Broken Up
HMAS Yarra (DE 45) Williamstown Naval Dockyard, Melbourne 30 September 1958 27 July 1961 22 November 1985 Broken Up
HMAS Stuart (DE 48) Cockatoo Island 8 April 1961 28 June 1963 26 July 1991 Broken Up
HMAS Derwent (DE 49) Williamstown Naval Dockyard 17 April 1961 30 April 1964 8 August 1994 Sunk during explosives test
HMAS Swan (DE 50) Williamstown Naval Dockyard 16 December 1967 20 January 1970 13 September 1996 Sunk as artificial reef
HMAS Torrens (DE 53) Cockatoo Island 28 September 1968 19 January 1971 1998 Sunk as target


  1. 1.0 1.1 1.2 Gillett, Australian and New Zealand Warships since 1946, p. 68
  2. 2.0 2.1 2.2 2.3 2.4 Gillett, Australian and New Zealand Warships since 1946, p. 70
  3. 3.0 3.1 3.2 3.3 Gillett, Australian and New Zealand Warships since 1946, p. 72
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 Gillett, Australian and New Zealand Warships since 1946, p. 69
  5. Gillett, Australian and New Zealand Warships since 1946, pp. 68–70
  6. Gillett, Australian and New Zealand Warships since 1946, pgs. 68, 71
  7. 7.0 7.1 7.2 7.3 7.4 7.5 7.6 Dennis et al., The Oxford Companion ot Australian Military History, p. 453
  8. Gillett, Australian and New Zealand Warships since 1946, pp. 69–70


  • Dennis, Peter; Grey, Jeffrey; Morris, Ewan; Prior, Robin (2008). The Oxford Companion to Australian Military History (2nd ed.). South Melbourne, VIC: Oxford University Press. ISBN 978-0-19-551784-2. OCLC 271822831. 
  • Gillett, Ross (1988). Australian and New Zealand Warships since 1946. Brookvale, NSW: Child & Associates. ISBN 0-86777-219-0. OCLC 23470364. 
  • Brown, David K.; Moore, George (2003). Rebuilding the Royal Navy (Warship design since 1945). London: Chatham Publishing. ISBN 1-86176-222-4. 

External links

This page uses Creative Commons Licensed content from Wikipedia (view authors).