More than 300 tonnes of huge steel ship components emerged on barges from the Forgacs shipbuilding yards, beginning a week-long journey by sea to South Australia.

The modular "blocks", as they are known, form part of the hulls for the Air Warfare Destroyers being built for the Royal Australian Navy in Adelaide.

The blocks are among 44 being built in Newcastle, with the three shipped out on Friday - including the first hull block - built at Carrington.

The blocks are being pieced together by the AWD Alliance in Adelaide, which is expected to deliver the first of three high-tech Destroyers to the navy in March 2016.

Forgacs says that about 750 people will work on its share of the project at its Carrington and Tomago shipyards.

"The workforce is doing outstanding high-quality work to help build some of the most advanced warships in the world," Forgacs managing director of ship building David Miller said.

The navy is spending $8 billion on construction of the three SEA 4000 Air Warfare Destroyers, which it says will hugely increase Australia's maritime defence capabilities.