HMAS Tobruk (L 50) - Design and Construction

Design and Construction

In the late 1970s, it was decided that the Australian Army needed to be provided with a long-term sealift capability, preferably through the acquisition of a dedicated cargo ship. The chartering of civilian ships to provide this capability when required—as had been done with the merchant vessels Jeparit and Boonaroo during the Vietnam War—was considered and rejected, because Australian National Line was unable to provide the necessary level of support. It was decided that a purpose-built ship would be constructed for the role, and would be operated by the RAN. While the Army did not require that the ship be capable of beaching, the RAN set this as a requirement, to maximize the ship's flexibility. In 1975, the Navy successfully convinced Australian Military's Force Structure Committee to endorse this requirement over the Army's opposition, and the committee authorised the purchase of a Landing Ship Heavy (LSH) on 19 March 1975.

The ship's name was selected in 1976 and refers to the Siege of Tobruk during World War II, in which the RAN's so-called 'Scrap Iron Flotilla' supplied the besieged 9th Australian Division. She is the second RAN ship of this name; preceded by the Battle class destroyer HMAS Tobruk (D37).

Two designs were considered for Tobruk; a modified Sir or Round Table class landing ship logistics, in use with the Royal Fleet Auxiliary at the time, was selected for construction. Tobruk’s design was based on RFA Sir Bedivere, the second of the class, which had been modified following the Royal Fleet Auxiliary's experience with operating the class' lead ship, RFA Sir Lancelot. The Australian modifications to the design were kept to a minimum to simplify construction; the most significant changes were to improve the ship's ability to operate both large and multiple helicopters, fitting an operations room, and adding a derrick with a lift of 70 tonnes. Most of the other changes related to bringing accommodation conditions into line with Australian requirements. Like the other ships of the Round Table Class, Tobruk was built to commercial rather than military standards, and is unable to sustain as much damage as warships. The ship was fitted with different engines to those used in the British ships, which were proven unreliable early in Tobruk’s career.

Tobruk was built by Carrington Slipways Pty Ltd at Tomago, New South Wales. The company was selected following a competitive tender in May 1977, with contract negotiations completed on 3 November 1977. Construction of Tobruk formally began on 7 February 1979, when the ship's keel was laid. Tobruk was launched on 1 March 1980 and left the dockyard for the first time in December 1980. The ship's construction had been delayed by over four months by industrial disputes and her final price of $59 million was 42 percent more than originally estimated. The ship's sea trials were conducted in early 1981 off Newcastle and Port Stephens by a joint Navy-Army-civilian crew and fitting out was completed on 7 April 1981. Tobruk was handed over to the Navy on 11 April 1981 and was commissioned at Newcastle on 23 April.

Tobruk has received a number of modifications during her service. These include the removal of her two 40/60 Bofors guns in the mid-1990s.