The Captain Cook Graving Dock at Garden Island, Sydney, recently marked 75 years of near-continuous service. The 347-metre-long dry dock has been called the RAN’s “most important strategic asset”, servicing an average of 27 ships per year.
At the time of construction, the Graving Dock was the largest and most complex engineering task ever undertaken in Australia. It was surpassed only by the Snowy Mountains Hydro Scheme in the 1950s. Since 1998, it has been operated and maintained by Defence partner Thales Australia.
Superintendent Garden Island Defence Precinct Captain Gavin Irwin said the Graving Dock plays an integral role in maintaining a fleet capable of preserving maritime security for the nation and regional partners.
“The dock is a critical infrastructure asset which ensures we can continuously sustain an agile and lethal naval capability,” CAPT Irwin said.
“The facility also highlights the close ties the Royal Australian Navy has with industry as a strategic partner in maintaining our capability.”
With the closure of Cairncross Dock in Brisbane, the dry dock at Garden Island is now the only one in Australia capable of holding the Navy’s larger fleet units.
The facility is one of the largest of its kind in the southern hemisphere, and is the last remaining facility in Australia that is capable of docking ships with a displacement of over 12,000 tonnes. Recently, HMA Ships Bribane (III) and Gascoyne (II) entered the graving dock.
Two underwater gates, known as caissons, separate the dock from the harbour. These are the oldest structural vessels in the Navy and enable sections of the dock to be drained separately.
The dry dock is emptied by three massive centrifugal bronze pumps, which have the capacity to empty the dock in eight hours at a rate of 320,000 litres per minute – equivalent to emptying an Olympic-size swimming pool in 37 seconds.
The Captain Cook Graving Dock was officially opened by the Governor-General of Australia His Royal Highness the Duke of Gloucester on 24 March 1945.