Italian submarine Marcantonio Colonna

Marcantonio Colonna was one of four Pisani-class submarines built for the Regia Marina (Royal Italian Navy) during the late 1920s. Due to her age, her usefulness was limited, and she saw no real service during the war. The submarine was decommissioned in 1942 and scrapped the following year.

Design and description
Designed in parallel with the Mameli-class submarines, the Pisani class was larger accommodate more fuel and give them more range. They displaced 866 LT surfaced and 1040 LT submerged. The submarines were 68.2 m long, had a beam of 6.09 m and a draft of 4.93 m. They had an operational diving depth of 90 m. Their crew numbered 48 officers and enlisted men.

For surface running, the boats were powered by two 1500 bhp diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 550 hp electric motor. They could reach 15 kn on the surface and 8.2 kn underwater. On the surface, the Pisani class had a range of 5000 nmi at 8 kn; submerged, they had a range of 70 nmi at 4 kn.

The boats were armed with six 53.3 cm torpedo tubes, four in the bow and two in the stern for which they carried a total of nine torpedoes. They were also armed with a single 102 mm deck gun forward of the conning tower for combat on the surface. Their anti-aircraft armament consisted of two 13.2 mm machine guns.

Construction and career
Marcantonio Colonna was laid down by Cantiere Navale Triestino in their Trieste shipyard on 3 December 1925, launched on 26 November 1927, and completed on 10 July 1929.