At the war’s start, the Mark 10 had been in service on the older S-boats for a
decade. The warhead of the Mark 10 carried 497 pounds of T.N.T. in 1941; later
it was converted to carry 485 pounds of torpex. Fitted with the Mark 3 contact
detonator, the Mark 10 had a range of 3500 yards at a speed of 36 knots.
The Mark 14 was the latest in U.S. torpedo technology in 1941. While still
21 inches in diameter, it had been designed to be superior in almost every
way. The Mark 14’s normal range had been increased to 4500 yards at a
speed of 46 knots, but was also capable of a greater range of 9000 yards at a
lower speed setting of 31.5 knots (although in practice this was rarely
used). The warhead held 507 pounds of T.N.T. when first issued, but was
later improved to carry a 668-pound torpex payload. The crucial difference