Throughout the years, torpedo boats have changed form of use, and, by WW II, were not utilized in assignments, which they originally had previous to WWI.
Already, during the first years of the century, torpedo boats had been utilized on the high seas , but the experience gained from WW I put into evidence their scarce qualities as tactical units, task for which destroyers definitely gained the upper hand. The Treaty of Washington didn’t set particular limitations to this type of unit. In the 1930, the London Naval decided not to place limitations on all units of less than 600 tons, and also for those not exceeding 800 tons, provided that speed be less than 20 knots and there were no torpedo launchers.
The Regia Marina, within the limits set by these agreements, laid down the torpedo boats of the Spica class with a standard displacement of 630 tons. Later on, it was recognized that ships of this type had to have a greater fuel capacity so to remain for a longer time at sea . Construction began of 4 escorts of the Pegaso class.
During the war, it was made evident the impelling necessity of having units capable of escorting convoys with anti-aircraft and antisub capabilities, therefore construction began on 16 escorts of the Ciclone class followed the Pegaso. Finally, in 1942, construction began of a new class of 16 torpedo boats of the Ariete class, which was an improved Spica, but only one, the Aries, entered service. While for the torpedo boats of the Sirio class the limit of the standard displacement (set by both the treaty of Washington and the London Naval Conference) of 600 tons was almost observed , in the following series displacement was to be much greater. The Perseo class reached 642 tons, the Climene class 652 tons, the Gabbiano class 679 tons, and the Ariete class 757 tons.
For the escort, instead, such limitations were not taken into consideration and the Pegaso class had a standard displacement of 855 tons and the Ciclone class of 925 tons. Torpedo launchers, on the ancient torpedo boats, included the numerous of the P.N. class dating back to 1915-18, constituted the only type of armament. In the new torpedo boats and escort, torpedo launchers were less relevant, while anti-aircraft and antisub weapons were strengthened.
During the war, the originally installed 40 mm and the 13,2 mm guns, were replaced with 20 mm ones, better suited for anti-aircraft defense. Particularly on the Ciclone class, the anti-aircraft armament was constituted by 8 of such guns since construction. The experience gained during the war brought about the elimination of one of the 100-mm gun, which was replaced by a twin 20-mm gun.
The antisub armament, constituted by 2 depth charges launcher on the Spica, was increased to 4 on the Pegaso and on the Ciclone. Some units of this class had 6 of them; all units were provided with apparatuses for the search and location of submarines, and at the end of the war some units also received a RADAR.
Adapted and translated from the book “Guida alle navi d’Italia”, by Gino Galuppini, published in 1982 by Arnoldo Mondadori Editore.