Submarines of the Imperial Japanese Navy
The submarines ("I-52"-class) were submarines of the Imperial Japanese Navy, designed and built by Mitsubishi Corporation, between 1943 and 1944, as cargo carriers. They were quite long and carried a crew of up to 94 officers and enlisted. They also had a long cruising range at a speed of .
Attack on Sydney Harbour
The Imperial Japanese Navy originally intended to use six submarines in the attack on Sydney Harbour: B1-type submarines , , , and , and C1-type submarines and . The six submarines made up the Eastern Attack Group of the 8th Submarine Squadron, under the command of Captain Hankyu Sasaki.