Part of the X-2 class designed by commander Curio Bernardis with just two unit’s the X2 and 3. The armament consisted of 1-3” anti aircraft guns and 9 mine tubes for totally 18 mines. After 1918 apparently also 2-17.7” torpedo cages in the main flooding trunk. Launched at the Ansaldo shipyard, Sestri, Ponente on 29 December 1917, finally laid up on 16 September 1940. Described as slow and worse manoeuvrable. With a displacement of 403,3 (surfaced)-467,7 (submerged) tons were her dimensions 42,6 x 5,5 x x3,1 metres or 139’9” x 18’1”x 10‘2“. Her crew numbered 22-23 men. The Sulzer diesels and 2 Ansaldo electric motors supplied via two shafts respectively 650 bhp and 325 hp allowing a speed of 8,2 (surfaced)-6,3 (submerged) knots. Fuel bunker capacity 18 tons. Range 1.30 miles with a surfaced speed of 6,5 knots and 96 miles with a submerged speed of 4 knots.
