'Botched maintenance' keeps $1.5b warships stranded

Bungled maintenance may have damaged the engines of Australia's two new $1.5 billion warships which have been forced to remain in dock for over a month.

The upkeep of the hi-tech engine systems aboard the 27,000-tonne amphibious assault ships HMAS Canberra and HMAS Adelaide has left navy chiefs grasping for answers, reports The Daily Telegraph.

In addition to their primary military role, the vessels, designed by Spanish shipbuilder Navantia, can also be deployed in humanitarian disasters but neither could leave Sydney Harbour when Cyclone Debbie struck in Queensland last month.

It is understood engineers have been flown out from Spain to try to solve the problem in time for exercises with the US Navy in the winter.

Navantia is concerned that the engines were installed by engineers from Siemens before maintenance was carried out by BAE engineers, according to the Telegraph.

The engine problems came to light when HMAS Canberra was taking part in sea trials off the Queensland coast earlier this year. An investigation found maintenance and oil changes had not been carried out correctly. The same problem was discovered on HMAS Adelaide.

Both vessels are scheduled to take part in the Talisman Sabre exercises with American ships in July.