Figure 1.--Here Melbourne school children examine a Japanese midget submarine. It was raised to the surface after an action in Sydney Harbor and is being used as part of a traveling exhibition during November 1942, you can see the date one of the boys has written on the hull. This was one of three Japanese midget submarines which entered Sydney harbor (night of May 31, 1942). This occurred just days before the Battle of Midway. The Japanese after destroying the American carriers were planning Operation FS to sever the sea lanes between Australia and the United States. This attack was part of the opening phase of Operation FS. At the time, the American heavy cruiser 'USS Chicago', the Destroyer 'USS Perkins' and the destroyer tender 'USS Dobbin' were in Sydney Harbor. In the ensing actiom, two of the 46-ton Japanese submarines were sunk without doing any damage, but sub M24 fired two torpedoes, one of which sunk ferry 'HMAS Kuttabul', killing 19 Australian and 2 British sailors. The second torpedo ran ashore and did not explode. The M24 was sunk by the American destroyer 5 km from the coast, along with the two other submarines in the attack. This one was raised to the surface. Beginning with Pearl Harbor, the Japanese gave great publicity to their midget subarines. The crews lost in the five midget subs at Pearl Harrbor were honored as young gods--except for the one man who survived and surrendered. The sub is now on permant display in the National Military Museum.

Japan began the Pacific war with a large, highly diverse submarine fleet. Their fleet included midget submarines, manned torpedoes (essentialy underwater Kamakazes), medium-range submarines, purpose-built supply submarines (which surprisinhly were used more by the Army than Navy), long-range fleet submarines, submarines with high submerged speed, and submarines that carried strike aircrft. Japan had the most diverse and highly capable submarine fleet of any World War II beligerant. Incredibly with all these special capabilities, the specialty boats used the most were the midget subs--the least capable. The Japanese began building an advanced submarine, the I-class submarines. They were the largest submarines of the War, in fact the lare submarines since the advnt of nuclear power. These submarine reflected the needs of the Empire that Japan began to conceive in Southeast Asia and the Pacific. The I-boats were very large submarines, reflecting the vast distances involved in Pacific operations. The I-class were 350 ft long and had ranges of 20,000 miles, more than twice that of 7,000-8,000 mile range of the German U-boats. These boats were capable of cruises lasting 100 days. The largest of the Japanese subs, the I-400 class was 390 ft long overall, they displaced 5,900 tons--better than twice the size of the standard Americn boat. The I-400 class could each carry three floatplane bombers, the only such submarines in history . Japan built 41 submarines that could carry one or more aircraft, while the vast submarine fleets of the United States, Britain, and Germany did mot have a sinle boat that could launch a plain. The Japanese had smaller subs for coastal patrol, but the backbone of the fleet was the I-class boats. Japan deployed a substantial submarine force during the Pacific War. The Imperial Navy began the War with 63 ocean-going submarines. They added an additional 111 subs during the war. Out of that total of 174 boats, there were 128 boats lost -- an incredible loss rate.

Created: 3:54 AM 12/19/2015
Last updated: 3:54 AM 12/19/2015