" On Seas Contested: The Seven Great Navies of teh Second World War "
　　Vincent P. O'Hara, W. David Dickson, Richard Worth 著

ITALY
C. WEAPON SYSTEMS
1. Gunnery
2. Torpedoes 　　　　　　　　　　←今日はここ
3. Antisubmarine Warfare 　　　>153-157
4. Mines

C. WEAPON SYSTEMS
2. Torpedoes
　Italian torpedoes were generally reliable and working detonators and low wander and malfunctioning values ( 5 percent and
1 percent, respectively, according to tests conducted in the summer of 1937 ). Germany imported nearly a thousand Italian
aerial torpedoes*1, and the Japanese copied features of an Italian high-speed version*2.
　The fire-control systems introduced on the destroyers and the modern torpedo boats in 1937 determined solutions using
directors in the bridge wings with a calculating apparatus, a rate-of-change-of-bearing<原文ママ> instrument
( teleniclinometro cinematico ) in the crow's nest, and binocular sights and tables fitted in each bank of tubes.*3
War experience would show, however, that the night fire-direction systems, which worked based on estimated range and target
speeds, were ineffective, and many captains preferred to aim by eye.
　At the beginning of the war, Italy had an inventory of 3,660 torpedoes, including 1,689 modern 21-inch weapons, 648
modern, and 1,323 old 17.7-inch torpedoes ( see table 4･2 ). Production was 50 per month but increased to 120 per month
by late 1941. Italian torpedoes sank or damaged 216 ships.