Enhancing capability of Captain Cook Graving Dock: Thales team removes and replaces 20 tonne main flooding valve

The Captain Cook Graving Dock (CCGD) at Garden Island Sydney is among the largest ship repair docks in the Southern Hemisphere and a critical asset for the Australian Defence Force. Due to 75 years of continuous operation, the dock's main flooding valves required replacement, starting with 'Valve 10.' This complex project highlights the Garden Island Team's skills and capability.

The CCGD is immense, measuring 350m long and 45m wide, with a 230-million-litre reservoir drained at the rate of an Olympic pool every 40 seconds. This requires significant power for flooding and draining, primarily done by two main flooding valves that manage about 600,000 litres per minute.

Installed in 1943 by Glenfield & Kennedy Pty Ltd, the valves needed an upgrade after continuous use for over 70 years. The project began in 2018 with a feasibility study on logistics and safety, moving to detailed design in 2019, then faced Covid-related delays from 2020 to 2022.

In July 2022, the valve was dispatched to Sydney, initiating the planning of critical activities like HSE requirements, docking movements, and testing Thales’s double isolation system. The valve replacement relied on a double isolation system to prevent flooding during the replacement, using an inflated plug in the valve pit culvert and a stop log gate to seal it off.

Over two days, a 20-person team completed the seamless removal and replacement of ‘Valve 10’ safely and efficiently.

I am immensely proud of the team for having planned and executed this activity with excellence, including outstanding safety practices, and it’s a testament to their skill and the “capability” they represent at Garden Island to support the RAN." Max Kufner, VP Above Water Systems