IJN
Japanese Submarine

Ship History
Built at the Sasebo Navy Yard, commissioned and based in the Yokosuka Naval District. Conversion to a midget submarine carrier on November 10, 1941.

Wartime History
On November 17, 1941 officers of the Special Attack Unit are briefed on the Hawaii Operation. The I-24 is assigned to Captain Sasaki Hankyu's Special Attack Unit with the I-16, I-18, I-20 and the flagship, the I-22.

Pearl Harbor Attack
At the start of the suprise attack on Pearl Harbor, the I-24 is in position 10.5 miles WSW of the entrance to Pearl Harbor. At 03:33, the I-24 launched HA-19 midget submarine.

Sydney Harbor Attack
On May 29, 1942 I-21 launches its Glen to reconnoiter Sydney Harbor. At 0420, it circles twice over the harbor near where the heavy cruiser USS CHICAGO (CA-29) is anchored. First thought to be an American plane, RAAF fighters are sent to intercept, but are unsuccessful. The Glen returns and reports sighting a "battleship". Captain Sasaki orders an attack on Sydney harbor by his midget submarines. On May 30, 1942 the I-24 arrives off Sydney.

31 May 1942: The Attack on Sydney: 7.5 miles E of Sydney. At 1740 the I-24 launches her midget. At 2207, all vessels in the harbor are alerted of the presence of an enemy submarine. The CHICAGO (CA-29) spots the HA-17 and fires on it with its AA guns at the same time HA-21 is entering the harbor.

1 June 1942: At 0029, the HA-17 fires one 17.7-inch torpedo at the CHICAGO. It explodes under HMAS Kuttabul killing 21 sailors and damaging the moored Dutch submarine K-IX. Another torpedo runs aground on the east side of Garden Island.

The wreck of the HA-17 (M24) is never found and her crew is MIA thereafter.

3 June 1942: After lingering outside Sydney to recover the midgets that fail to return, the I-24 and the other submarines finally give up and switch to commerce warfare. E of Sydney, 35 miles SE of Norah Head. At dusk, the I-24 is recharging her batteries on the surface when her lookouts spot the 4,734-ton Australian coastal steamer AGE. Cdr Hanabusa fires a torpedo at the steamer, but misses. The I-24 next fires four rounds from her 140-mm deck gun at the AGE, but does no damage. The AGE radios that she is under attack and disappears into the night. Hanabusa, thinking he has sunk the steamer, claims a victory in his report. 27 miles E of Sydney. About 90 minutes later, the I-24 fires two torpedoes at the 4,812-ton Australian merchant IRON CHIEFTAIN that is en route from Newcastle to Whyalla with a cargo of coke and materials for a shipyard. One torpedo hits her portside amidships. Her heavy load drags her to the bottom in about five minutes.

5 June 1942: 17 miles off Wollongong. The I-24 chases the 3, 362-ton Australian merchant ECHUNGA that is enroute from Whyalla to Port Kembla but fails to damage to her.

8 June 1942: Four miles off Sydney. After midnight, the I-24 surfaces then opens fire with its deck gun on the Harbour Bridge. Within four minutes, the I-24 fires ten shells at 30-second intervals. None hit the bridge. Only one of the shells explodes and demolishes part of house in the eastern suburbs. The other duds cause but minor damage. The Australians turn on their searchlights, but the I-24 crash dives before the shore batteries can return fire. The shelling causes no casualties, but some of Sydney's residents panic and flee the city in fear of a Japanese invasion. A P-400 piloted by Cantello takes off at night to intercept the submarine, but crashes immediately thereafter.

9 June 1942: SE of Jervis Bay. Shortly before daybreak, the I-24 sights the 7,748-ton British merchant ORESTES. Cdr Hanabusa attacks her twice with torpedoes, but they explode prematurely. The I-24 then surfaces and shells the merchant with her 140-mm deck gun. She gets a single hit, but does not sink the ORESTES. As no fire is visible, Cdr Hanabusa decides to abandon the attack.

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