Australian hull steel to be used for Aussie built N-subs

The federal government has moved to ensure Australian-made steel will be used in the construction of Australia’s conventionally-armed nuclear-powered submarines when they are built at Osborne Naval Shipyard in Adelaide, subject to a qualification process.

The Australian Submarine Agency has entered into a contract with Australian steel manufacturer, Bisalloy Steels, for the qualification of Australian steel for use on Australia’s future SSN-AUKUS submarines.

Bisalloy developed specialty steels under earlier government contracts which were used in the manufacture of Australia’s six Collins class submarines, also built at Osborne.

Since then Bisalloy has become a recognised international supplier of hull steels, as well as armour steel for protected vehicles, including the Bendigo-made Thales Bushmaster Infantry Mobility Vehicle.

Israeli company Plasan and NSW manufacturer Bisalloy Steel are providing armour protection for the first three Hunter class frigates being built by BAE Systems Australia for the Royal Australian Navy (RAN).

The new $15 million contract will put Australian products at the forefront of our submarine construction, according to Defence Industry Minister Pat Conroy.

He said in a statement that a comprehensive qualification process, involving more than 4,500 tests, is expected to be completed in the first half of 2025.

According to the statement: “We are committed to supporting Australian industry support the AUKUS trilateral supply chain.”

Bisalloy Steels will perform advanced heat treatment processes on the raw plate steel to produce high grade submarine pressure hull steel that meets or exceeds both the UK and US standards.

The raw plate steel will be supplied by another Port Kembla steelmaker, BlueScope, as for the Collins.

Conroy said: “The qualification of Australian steel is an important step in the Australian Government’s strategy for acquiring state-of-the-art conventionally armed nuclear-powered submarines.

“The strength and quality of Australian steel will keep Australian submariners safe in the SSN-AUKUS nuclear-powered submarines for decades to come, just as it does today on our Collins Class submarines.”

The qualification of the steel to both the UK and US standards will increase the resilience of the AUKUS trilateral supply chain, according to the statement.

Not only will the steel produced under this contract be used for qualification purposes, it will also be used to develop the necessary welding procedures, and used in early production demonstration activities occurring ahead of the commencement of construction of Australia’s first SSN-AUKUS submarine later this decade.

“The AUKUS partnership presents one of the biggest uplifts in Australia’s industrial and defence capability in our history.

“The signing of this contract is a clear demonstration of the progress being made on, and the Albanese Government’s commitment to the construction of conventionally armed nuclear-powered submarines in Australia and support for future Australian jobs.”

Australia will receive three Virginia class submarines built in the US in the 2030s, to be followed by locally built SSN-AUKUS submarines likely in the 2040s.

Conroy said: “Crucially, this contract will support jobs in an industry which is not only of strategic importance but also a source of innovation and employment, and part of the Australian fabric.”

Further reading:
Bisalloy specialist steels at 40 is going international
Plasan and Bisalloy to provide armour for Hunter class frigates

Picture: Bisalloy