HMAS Platypus was built to the order of the Australian Government. After completion in March 1917, it passed to the control of the Admiralty until 25 March 1919 when it was commissioned into the Royal Australian Navy (RAN) at Portsmouth, under the command of Commander Edward Boyle VC RN, as a Submarine Depot Ship for 6 J Class submarines transferred as a gift from the Admiralty to the RAN.

Platypus sailed from Portsmouth on 8 April 1919 and with the submarines proceeded to Australia via the Suez Canal, arriving in Sydney on 15 July 1919.

HMAS Platypus in company with the J class submarines J1, J2, J4 and J5
 

HMAS Platypus with the J class submarines J1, J2, J4 and J5.

 

In February 1920 Platypus proceeded to Port Phillip where a submarine depot had been established at Geelong. In May 1922 the Naval Board decided to abandon the policy of maintaining a RAN Submarine Service. The 3 J class boats remaining in commission were paid off, and on 1 July 1922 Platypus proceeded to Sydney. On 12 July at Sydney, it paid off as a submarine depot ship and on the following day recommissioned as a destroyer depot and fleet repair ship. Operating with the fleet, mainly in home waters, it served in this role until 1929.

Meanwhile, in 1924, a Five Year Naval Development Programme had been approved by the Australian Government, which included the re-establishment of a RAN Submarine Service with a flotilla of 6 boats.

Two Royal Navy Odin class submarines were initially ordered. Named Otway (I) and Oxley (I), the submarines reached Sydney on 14 February 1929. Platypus returned to Sydney from a cruise in Queensland waters the following day. It paid off on 31 March 1929 to recommission in its former role as a Submarine Tender.

The reconstituted RAN Submarine Service suffered from the outset from the world wide naval retrenchments beginning in 1929. On 10 May 1930 Otway (I) and Oxley (I) were paid off into Immediate Reserve with provision for one day diving exercises per fortnight each boat. As a result it was decided to use Platypus as a depot ship at Garden Island, acting also as parent ship for the submarines.

Platypus paid off on 15 August 1929 and the following day commissioned as HMAS Penguin. In April 1931 Otway (I) and Oxley (I) were transferred to the Royal Navy.

Platypus continued in service as the depot ship at Garden Island, Sydney, under the name of Penguin until 26 February 1941 when it recommissioned as HMAS Platypus to resume seagoing service as a training ship.

In May 1941 it proceeded to Darwin. It was present in Darwin Harbour on 19 February 1942 when Japanese carrier borne aircraft made the first air attack on Australian soil. According to the official history of the RAN in the Second World War, ‘Platypus fought back hard, and though near-missed 3 times and with the lugger Mavie alongside its sunk escaped with damage in the engine room which immobilised her for some time.’

It remained in service as base ship, Darwin, until 1 January 1943 when it sailed for Cairns where it again served as base ship until May 1944.

At Williamstown, Victoria, on 12 June 1944, Platypus commenced a major refit and conversion of 2 of its 4 boilers to oil burning. The refit was completed in December 1944. On 5 January 1945 it left Sydney to proceed to New Guinea for service as a repair and maintenance vessel.

Platypus operated in the Madang, Hollandia and Morotai areas until the end of November 1945, returning to Australian waters in December 1945. On 12 February 1946 it departed Melbourne for Sydney on its final sea voyage under its own power.

 In April 1946 Platypus became the depot ship for ships in E class Reserve, in Sydney. In this role the ship was the floating headquarters and workshop for the personnel monitoring the dozens of RAN ships no longer in service but held in reserve, in Sydney, pending re-activation or disposal. This role continued until the bulk of the wartime vessels had either been re-activated or sold for scrap. Platypus was finally decommissioned on 1 November 1956.

Platypus was sold on 20 February 1958 to Mitsubishi Shoji Kaisha Ltd, of Tokyo, Japan, for scrap. It was docked at Garden Island in April 1958 to ensure its hull was still sound and to have various equipment and fittings removed. In June 1958 the Japanese salvage vessel Tukoshima Maru departed Sydney for Japan with Platypus, and the former Bathurst Class minesweeper HMAS Dubbo (I), in tow. Upon arrival both ships were broken up for scrap.

Specifications

HMAS Platypus (I)
Type
Submarine Depot Ship
Builder
John Brown and Co Ltd, Clydebank, Scotland
Laid Down
14 October 1914
Launched
28 October 1916
Launched by
Mrs Fisher, wife of the Australian High Commissioner to the United Kingdom
Commissioned
25 March 1919
Decommissioned
1 November 1956
Dimensions & Displacement
Displacement 3476 tons
Length 325 feet
Beam 44 feet
Draught 15 feet 8 inches
Performance
Speed 15.5 knots
Propulsion
Machinery 2 sets of triple expansion reciprocating steam engines, twin screws
Armament
Guns 1 x 4.7-inch gun
Awards
Battle Honours DARWIN 1942-43