Attack on Sydney Harbour (1942): Japan's Midget Submarine Raid

The attack on Sydney Harbour took place on the night of 31 May – 1 June 1942, when three Japanese midget submarines slipped into the harbour to strike Allied warships. Their torpedoes missed the American cruiser USS Chicago but sank the depot ship HMAS Kuttabul, killing 21 sailors. The raid brought the Pacific War into the heart of Australia’s largest city.

Background

By mid-1942 Japan had swept across South-East Asia, captured Singapore and bombed Darwin. Sydney was a major Allied naval base, and Japanese planners hoped that a surprise strike there, timed to coincide with the attack on Midway, would damage Allied shipping and distract attention from the central Pacific.

A flotilla of five large submarines, I-21, I-22, I-24, I-27 and I-29, under Captain Hankyu Sasaki gathered off the coast. Three carried Type A midget submarines, each about 24 metres long, with a crew of two and two torpedoes. A reconnaissance seaplane from I-21 flew over the harbour on 30 May and confirmed the presence of large warships.

The raid

The three midgets, M-14, M-21 and M-24, were launched on the evening of 31 May. Sydney had an anti-submarine boom net and detection loops on the seabed, but they were incomplete and poorly monitored.

M-14 became entangled in the boom net soon after 8 pm. As patrol boats approached, the crew destroyed their craft with demolition charges, killing themselves.

M-24, crewed by Sub-Lieutenant Katsuhisa Ban and Petty Officer Mamoru Ashibe, got deep into the harbour. Shortly after midnight it fired two torpedoes at USS Chicago, anchored off Garden Island. Both missed. One ran aground without exploding; the other struck the seawall beneath HMAS Kuttabul, a converted ferry used as a sleeping ship for sailors. Kuttabul sank, killing 19 Australian and two British sailors. M-24 slipped out of the harbour and was never heard from again.

M-21, under Lieutenant Keiu Matsuo with Petty Officer Masaharu Tsuzuku, was detected in Taylors Bay and attacked with depth charges in the early hours of 1 June. The crew took their own lives before the submarine was raised.

Aftermath

Rear Admiral Gerard Muirhead-Gould, in charge of Sydney’s naval defences, was criticised for a slow and confused response. Yet he also ordered that the four Japanese crew recovered from M-14 and M-21 be given a funeral with naval honours, a decision that caused controversy at the time. Their ashes were later returned to Japan in a diplomatic exchange.

On 8 June 1942 Japanese submarines shelled the eastern suburbs of Sydney and the port of Newcastle. The damage was slight and no one was killed, but it deepened public alarm, and some anxious residents of harbourside suburbs moved away.

Key people

• Rear Admiral Gerard Muirhead-Gould, a Royal Navy officer in command of the Sydney naval area, who directed the response and later wrote the official report on the raid.
• Captain Howard Bode, commander of USS Chicago, who was ashore at a dinner with Muirhead-Gould when the alarm was raised.
• Lieutenant Keiu Matsuo, commander of M-21, a committed advocate of midget submarine operations, who died in Taylors Bay.
• Sub-Lieutenant Katsuhisa Ban, commander of M-24, the only midget to fire its torpedoes.
• Captain Hankyu Sasaki, who led the Japanese submarine flotilla off the coast.

Myths and facts

• Myth: The midget submarines were suicide weapons. Fact: They were not designed as such, and the mother submarines waited off the coast for several days to recover them, but the crews knew their chances of return were slim.
• Myth: The attack caused widespread damage in Sydney. Fact: The only ship sunk was Kuttabul; a Dutch submarine, K IX, was slightly damaged by the same torpedo blast, and the city itself was unharmed until the shelling of 8 June.
• Myth: The fate of M-24 was always known. Fact: It remained a mystery for 64 years until amateur divers found the wreck in 2006.

Legacy

The raised hulls of M-14 and M-21 were combined into a single craft that toured Australia to raise money for the war effort and is now at the Australian War Memorial in Canberra. In 1968 Matsuo’s mother visited Sydney and scattered cherry blossom petals on the water at Taylors Bay. The wreck of M-24 was found by amateur divers off Bungan Head in 2006 and is protected as a war grave.

Timeline

• 1942, 30 May: A seaplane from I-21 reconnoitres Sydney Harbour.
• 1942, 31 May, evening: Three midget submarines are launched off Sydney Heads.
• 1942, 31 May, about 8 pm: M-14 is caught in the boom net and later scuttled.
• 1942, 1 June, shortly after midnight: M-24 fires at USS Chicago; HMAS Kuttabul is sunk.
• 1942, 1 June, early hours: M-21 is depth-charged in Taylors Bay.
• 1942, 8 June: Japanese submarines shell Sydney and Newcastle.
• 2006, November: The wreck of M-24 is found off Sydney’s northern beaches.

Why it matters

The raid caused limited physical damage, but it shattered the sense that Australia’s cities were safe from attack. Coming in the same weeks as the Battle of the Coral Sea and the Battle of Midway, it showed how far Japanese power reached in 1942 and strengthened Australia’s resolve to defend its coast.