Submarine attack
Written by ACM   
Monday, 02 June 2014
Of the three Japanese submarines that attacked Sydney Harbour on 31 May 1942, two were destroyed or disabled during the raid; the third disappeared and was located off Sydney's northern beaches by a group of amateur divers in November 2006.

Minimum material damage was caused by the attack, but 21 sailors were killed when the depot ship HMAS Kuttabul ( pictured below) was torpedoed.




At that time, the Harbour was protected by an intricate network of anti-submarine nets.

When a ferry left Circular Quay for the longer trip to Manly, it would leave the netted area to go into unprotected waters. As the net was opened a bell would be rung to announce this to passengers. As the ferry approached Manly another bell would be rung to announce the re-entry into protected waters.

There was a fear that enemy submarines would learn this and enter the protected harbour under a ferry.

At the same time, barbed wire and other obstacles were placed on the beaches to hinder enemy landings.

these were not empty fears, although the likelihood of attack diminished after the Japanese advance was halted in Papua New Guinea and the Coral Sea. Australia's Northern ports, especially Darwin, had already been heavily bombed by the Japanese.