Japanese midget submarine attacks on Sydney, 1942 – Fact sheet 192
On the night of 29 May 1942, five large Japanese submarines positioned themselves 56 kilometres north-east of Sydney Heads. At 3.00 am the next day one of the submarines launched a reconnaissance aircraft. After circling Sydney Harbour the aircraft returned to its submarine, reporting the presence of 'battleships and cruisers' moored in the harbour. The flotilla's commanding officer decided to attack the harbour with midget submarines the next night. The next day the five submarines approached to within 11 kilometres of Sydney Heads, and at about 4.30 pm they released three midget submarines which then began their approach to Sydney Harbour.
The outer-harbour defences detected the entry of the first midget submarine at about 8.00 pm, but it was not identified until it became entangled in an anti-torpedo net that was suspended between George's Head and Green Point. Before HMAS Yarroma was able to open fire the submarine's two crew members destroyed their vessel with demolition charges and killed themselves.
The second submarine entered the harbour at about 9.48 pm and headed west towards the Harbour Bridge, causing a general alarm to be issued by the Naval Officer in Charge, Sydney. About 200 metres from Garden Island the submarine was fired on by the heavy cruiser USS Chicago. The submarine then fired its two torpedoes at the cruiser. One torpedo ran ashore on Garden Island but failed to explode. The other passed under the Dutch submarine K9 and struck the harbour bed beneath the depot ship HMAS Kuttabul where it exploded, killing 21 sailors (19 Royal Australian Navy and 2 Royal Navy). The submarine then slipped out of the harbour, its mission complete.
The third submarine was sighted by HMAS Yandra at the entrance to the harbour and was depth-charged. Some four hours later, having recovered, it entered the harbour but it was subsequently attacked with depth charges and sunk in Taylor Bay by vessels of the Royal Australian Navy. Both members of the submarine's crew committed suicide.
The two submarines that were recovered were identical, and their remains were used to reconstruct a complete submarine, which toured New South Wales, Victoria and South Australia before being delivered to the Australian War Memorial in Canberra in 1943, where it remains on display.
The records held by the National Archives and the Australian War Memorial on the midget submarine attack are listed in the table below.