Effectiveness
When compared with the type 93 torpedo which was surface vessel launched, kaitens had the obvious advantages of having a pilot to guide the weapon, and being launched from a submerged submarine. Despite these advantages, however, they were not nearly as effective round-for-round as the highly successful type 93 torpedo on which they were based. Sources from the United States claim the only sinkings achieved by kaiten attacks were the fleet oiler USS Mississinewa on 20 November 1944 with the loss of 63 men, a small infantry landing craft (LCI-600) with the loss of three men and the destroyer escort USS Underhill on 24 July 1945 with the loss of 113 personnel.
Contrary to the above, some Japanese sources give much larger numbers of kaiten successes. Reasons given for this discrepancy are the fact that the submarine launching the kaiten could only listen for the impact of their weapons, also the size of the explosion after the attack on the USS Mississinewa gave the impression of a much larger number of ships sunk.
American losses accredited to kaiten attacks came to a total of 187 officers and men. The losses of kaiten crews and support staff were much higher. In total 106 kaiten pilots lost their lives (including 15 killed in training accidents and two suicides after the war). In addition to the pilots, 846 men died as eight Japanese submarines carrying kaiten were sunk and 156 maintenance and support personnel were also killed. This contrasts markedly with the success of the Kamikaze pilots.
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