The cost of building the Royal Australian Navy’s planned French-designed attack-class submarine fleet and maintaining it is expected to cost A$225bn ($152.24bn).

The project to build the 12-strong attack-class fleet was previously estimated to cost around A$50bn ($33.83bn).

Appearing before a Senate estimates committee, Royal Australian Navy submarine programme head Rear Admiral Greg Sammut revealed that the cost of building the ships would be A$80bn ($54.13bn).

The overall projected cost component would also include A$145bn ($98.11bn) in maintenance costs to keep the submarines in service until 2080.

The building cost would cover acquiring equipment and systems for the attack-class submarines and delivering upgrades to wharves.

Officials indicated that the construction of the ships is expected to begin in 2024, as against the previously proposed schedule of 2022-23.

Australia is building the future submarines to replace the navy’s Collins-class vessels. The government awarded a contract to French firm Naval Group for the programme.

The first submarine in the class is scheduled to be ready for service in the 2030s.

The Australian Department of Defence (DoD) announced on 28 November that local firms Berendsen Fluid Power and H&H Machine Tools have been selected to support the attack-class submarine programme.

Berendsen Fluid Power and H&H Machine Tools will serve as the first Australian partners for major equipment design contracts.

Earlier this week, Naval Group awarded a subcontract to Babcock to provide the weapon discharge system (WDS) for the future submarines.