Long Lance, Japanese Torpedo

Model 93 Type 22 Torpedo

Dimensions	24" by 29'6" 0.61m by 9.0m
Weight	6107 lbs 2770 kg
Range	24,000 yards (22,000 m) at 49 knots 39,000 yards (36,000 m) at 41 knots 48,000 yards (44,000 m) at 37 knots
Warhead	1080 lbs 470 kg
Propulsion	Oxygen fuel
Accuracy	1.4 degrees at 14 miles 2 degrees at 27 miles

The Long Lance was the finest torpedo in the world at the start of the Pacific War, and remained so until well after the war ended. It used pure oxygen rather than compressed air, giving it enormous range and rendering it nearly wakeless. The Japanese Navy conducted extensive tests against hulks prior to the war, a practice neglected by the other powers, and the Long Lance was quite reliable and surprisingly safe to handle once the bugs were worked out.

The accuracy figure for the torpedo shows that a Long Lance had only about a 1 in 20 chance of actually hitting a battleship at 14 miles, so the long range seems like an extravagance. However, the Japanese reaction when ambushed at night was to immediately launch shoals of the torpedo in the direction of the enemy, which increased the hit probability. This proved to be a horribly effective tactic in the Solomons. The very large warhead ensured heavy damage when a hit was secured: Few destroyers ever survived a hit from a Long Lance, and even the toughest cruiser could absorb no more than three solid hits before succumbing.

Because of the long range and nearly invisible wake of the Long Lance, its existence remained a secret well into the war. Hits from the Long Lance were often attributed to mines or an undiscovered submarine. It took the capture of Japanese documents to convince Allied naval leaders that the Japanese had come up with such a capable weapon.

The Japanese always referred to this weapon as the Type 93 Model 22 Torpedo. The name "Long Lance" appears to have been an invention of famed U.S. Navy historian Samuel Eliot Morison.

References

Campbell (1985)