The element of surprise was lost when the midget submarines approached antitorpedo netting in the harbor. Allied forces were alerted when one of the Japanese craft became entangled in the netting. The American heavy cruiser Chicago then opened fire on the vessel but only inflicted damage on the shore. The failure to hit the midget submarine notwithstanding, the Japanese elected to scuttle their boat.
A second midget submarine avoided the nets and launched its torpedoes. One failed to detonate, but the other hit an accommodation ship, the explosion killing 19 servicemen and wounding 11 more. The fate of this midget submarine is unknown, although presumably it sank during the attack. The crew of the third midget submarine, after being hunted for hours by a collection of Australian light warships, chose to commit suicide. Contributing to the attack of their diminutive counterparts, the fleet submarines, joined by I-21 and I-29, shelled Newcastle and Sydney with their deck guns and sank three merchantmen with gunfire and torpedoes as they left port, before retiring to base.
After the raid, the Allies recovered one of the midget submarines. Following its study by naval architects, it went on a tour of Australia in an effort to raise the morale of the Australian people. Today it is on display at the Australian War Museum in Canberra.
The Japanese submarine attack against Sydney was the last executed by Japanese naval forces against Australian ports in World War II.
Eric W. Osborne
Carruthers, Steven L. Australia under Siege: Japanese Submarine Raiders, 1942. Sydney, Australia: Solus Books, 1987.; Clark, Hugh V. To Sydney by Stealth. Sydney, Australia: Angus and Robertson, 1966.