Marconi-class submarine

Leonardo Da Vinci, the most successful Italian submarine in World War II
Class overview
Operators	Regia Marina  Kriegsmarine  Imperial Japanese Navy
In commission	1940–1945
Completed	6
Lost	5
General characteristics
Type	Submarine
Displacement	1,195 long tons (1,214 t) (surfaced) 1,490 long tons (1,514 t) (submerged)
Length	76.5 m (251 ft 0 in)
Beam	6.81 m (22 ft 4 in)
Draught	4.72 m (15 ft 6 in)
Propulsion	Diesel-electric; 2 × CRDA diesel engines 2 × Marelli electric motors
Speed	17.8 kn (33.0 km/h; 20.5 mph) (surfaced) 8.2 kn (15.2 km/h; 9.4 mph) (submerged)
Range	Surfaced: 2,900 nmi (5,400 km; 3,300 mi) at 17 kn (31 km/h; 20 mph); 10,500 nmi (19,400 km; 12,100 mi) at 8 kn (15 km/h; 9.2 mph) Submerged: 8 nmi (15 km; 9.2 mi) at 8 kn (15 km/h; 9.2 mph); 110 nmi (200 km; 130 mi) at 3 kn (5.6 km/h; 3.5 mph)
Test depth	90 m (300 ft)+
Complement	57
Armament	8 × 533 mm (21.0 in) torpedo tubes (4 bow, 4 stern) 1 × 100 mm (4 in) / 47 caliber gun 4 × 13.2 mm (0.52 in) machine guns

The Marconi class was a class of six submarines built for the Royal Italian Navy (Italian: Regia Marina). The submarines were all launched between 1939 and 1940, and all but one, Luigi Torelli, were lost in the Atlantic during the Second World War.