The Japanese Attack on Sydney Harbor Was Had a “One in a Thousand" Chance of Success

October 21, 2020 Topic: History Region: Australia Blog Brand: The Reboot Tags: Raid On Sydney HarborTorpedoesWorld War IIJapanAustralia

The Japanese Attack on Sydney Harbor Was Had a “One in a Thousand" Chance of Success

In May 1942 a Japanese submarine force snuck into Sydney harbor in a daring suicide attack.

The year 1942 was one of crisis for the Allied cause in the Pacific. Until May, almost everything had gone in favor of Imperial Japan. In that month the Japanese were stalemated at the Battle of the Coral Sea. If the Japanese Navy had succeeded in capturing Port Moresby at the southeastern tip of the island of New Guinea, Australia would have been in dire straits. In this desperate time, the threat was still serious as the Imperial fleet could return at any time.

This was a threat the Australians felt more than any. The nation was large, resource rich, and relatively wealthy while simultaneously underpopulated, poorly armed, and isolated. Australia lacked the population required to support an army capable of resisting Japan. Much of its military was spread elsewhere with a portion lost in Singapore, and many of its troops were fighting the Germans and Italians in North Africa. Vast distances separated the island nation from its most vital allies, the United Kingdom and the United States. For the citizens of Australia it seemed as if a Japanese fleet would appear over the horizon any day.

Nevertheless, the country did what it could to prepare. Some 130,000 troops remained, though most were untrained. As far as possible, likely landing beaches were fortified with barbed wire, trenches, and antiaircraft positions. A nighttime blackout was ordered for all lights within six kilometers of the coast, though curiously lighthouses were allowed exception from the order. Much as in Britain, Australians prepared to move their children to the countryside away from likely bombing sites. With England stretched to the limit, Australia began to turn to America for the support it needed, at the time a controversial move to many Australians. It would take time for the Americans to move significant strength to bolster Australia’s defense, however.

Isolating Australia With Commerce Raiding

In the meantime, Japan continued to threaten. Imperial forces moved into the South Pacific, slowly closing a noose around the island nation. The Japanese knew that Australia would serve as a staging ground for the eventual Allied riposte and had to be neutralized. Australia was far too large a nation for Japan to physically invade and occupy; the Imperial Army was already stretched thinly, from northern China to remote outposts dotting the Pacific. However, the Japanese could seize a few more islands, such as Samoa, Fiji, and New Caledonia, among others. Using these islands as bases they could interdict the lines of communication between America and Australia, preventing the buildup necessary for a counteroffensive.

The setback at Coral Sea and the colossal defeat at Midway in June 1942 put a damper on that scheme, but Japan did not give up easily. An effective submarine campaign might well isolate Australia. Japanese naval doctrine called for using submarines as an adjunct to their surface battle line. Squadrons of subs would range ahead of the main fleet, hitting enemy forces and reducing their strength until the main Japanese armada could secure a decisive victory. Commerce raiding was a secondary mission but ultimately necessary. Given the requirements for surface ships elsewhere, submarines were the most readily available.

Midget submarines had been used at Pearl Harbor, but their mission was essentially a failure. Of the five tiny submersibles sent to wreak havoc along with the Japanese air attack, none achieved success and one almost ruined the element of surprise for the attack when it was spotted by the coastal minesweeper USS Condor and sunk by the destroyer USS Ward in the early morning hours of December 7, 1941. Still, the idea of using them for long-distance raids against enemy ports persisted, and the Japanese Combined Fleet’s commander, Admiral Isoroku Yamamoto, approved their deployment for two more attacks. One strike would be made in the Indian Ocean against British ships, while the second would be directed south to Australia.

The Imperial Japanese Navy’s 8th Submarine Squadron had responsibility for the midget submarines and the mother subs that carried them. Designated a Special Attack Group, the 8th was divided into two flotillas, East and West, with the Eastern Flotilla sent toward Australia. This force included six large submarines. Four of them, I-22I-24I-27, and I-28, were mother submarines that carried the midget subs into range of their targets. The other two, I-21 and I-29, carried floatplanes to perform reconnaissance. The squadrons each had a pair of submarine tenders, seaplane tenders, and armed merchant cruisers to support the subs.

The “Once-in-a-Thousand Chance”

On April 16, 1942, the East Flotilla left the port of Hashirajima on Japan’s Inland Sea. The group sailed to the naval base at Truk Atoll and prepared for the voyage to the target, Sydney, Australia. The Japanese plan was to launch their 46-ton midgets off the coast, close enough for them to sneak into the harbor and strike Allied naval vessels or merchant ships moored there. The crews were confident they could get into the harbor and carry out their attack, though they were less sure they could get back afterward.

The midget subs were attached to their mother vessels and had a hatch allowing the two-man crew to enter directly from the host submarine without surfacing. Each midget was just under 80 feet long and carried a pair of 18-inch torpedoes. With their electric motors they had a range of 150 nautical miles at five knots. The lead-acid batteries powering the motor could not be recharged after disconnecting from the mother. In case the crew was unable to rendezvous with the mother vessel, each midget had a scuttling charge to prevent capture. For this mission each sub had a junior officer in command with a petty officer as a navigator, responsible for steering. The commander could stand behind the navigator, manning a periscope.

Around May 18, the submarines left Truk and set course almost due south for the east coast of Australia. About a week later, I-29 launched its floatplane, a Yokosuka E14Y, Allied code name Glen, on a reconnaissance flight over Sydney. Arriving over the city just before dawn, the pilot and navigator surveyed the harbor and saw a large number of Allied warships moored around its various quays and docks. Their mission a success, they turned back to the I-29. Upon landing, however the Glen was damaged beyond immediate repair, unusable for the rest of the mission. At 1:30 the next morning, the Eastern Flotilla was ordered to make its attack on Sydney.

By May 29, five submarines had gathered some 35 miles off Sydney. As they prepared for their task, Vice Admiral Teruhisa Komatsu, commander of Submarine Squadron 1, sent a message from his flagship at Kwajelein: “In seizing this once-in-a-thousand chance, approach the enemy with the utmost confidence and calm.”

In the Indian Ocean, the Western Flotilla was carrying out its own attack against the British anchorage of Diego Suarez. This port in Madagascar had only been in British hands a few weeks after a stiff battle to capture it from Vichy France. This attack succeeded in damaging the battleship Ramillies, taking her out of service for a year. A tanker, the British Loyalty, was sunk. Unknown to the Japanese sailors off the Australian coast, the mission at Madagascar had met with some bad luck as well. Only one of the two midget subs sent against Diego Suarez had made it into the harbor.

Honoring the “Nine War Gods of Pearl Harbor”

On May 30, the Eastern Flotilla’s remaining floatplane was launched on a second reconnaissance of Sydney Harbor. The pilot, Flying Warrant Officer Susumu Ito, took off from I-22 and successfully overflew the harbor area, confirming the presence of enemy warships, including one battleship (the “battleship” was actually the American heavy cruiser Chicago). The next day the mother submarines moved closer to the harbor mouth, taking position six to eight miles from it. Within their submerged hulls, the midget crews began preparations.

Aboard I-22, Lieutenant Matsuo Keiu and his navigator, Petty Officer First Class Tsuzuku Masao, not only prepared their submarine and equipment but their souls as well. Alongside the crew of the mother sub, they worshipped at a small Shinto shrine complete with candles. In a small ceremony, they honored the nine sailors who had died making the midget submarine attack on Pearl Harbor six months earlier. These men were known popularly as the “Nine War Gods of Pearl Harbor.” A photograph of them was shown around. Next a citation from Admiral Yamamoto was read, and the group sat down to a meal together.

During the repast Matsuo asked I-22 assistant torpedo officer, 2nd Lt. Muneaki Fujisawa, to cut his hair. The young officer agreed and shaved Matsuo’s head closely. Fujikawa recalled that his young comrade seemed resigned to death on his mission. During the haircut Matsuo said aloud, “I wonder what my mother is thinking at this moment?” Tsuzuku wrote a letter to his brother telling his sibling he had been killed near Australia on May 31. Both seemed to accept their task and the probable doom that came with it. A purification ritual followed, and then a change into fresh, perfumed uniforms. Matsuo also donned a thousand-stitch belt, a sash designed to protect the wearer from harm. Finally, a tea ceremony was held, its purpose to instill a feeling of tranquility before the coming action.