Italian submarine Pietro Calvi


Pietro Calvi was the lead ship of its class of two submarines built for the Regia Marina during the 1930s. Completed in 1936, she played a minor role in the Spanish Civil War of 1936–1939 supporting the Spanish Nationalists. The submarine made multiple patrols in the Atlantic Ocean during the Second World War, sinking seven Allied ships. Pietro Calvi was rammed and sunk by a British convoy escort in July 1942.

Design and description

The Calvi class was an improved and enlarged version of the preceding submarine cruisers. They displaced surfaced and submerged. The submarines were long, had a beam of and a draft of. They had an operational diving depth of. Their crew numbered 77 officers and enlisted men.
For surface running, the boats were powered by two diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a electric motor. They could reach on the surface and underwater. On the surface, the Calvi class had a range of at ; submerged, they had a range of at.
The boats were armed with eight torpedo tubes, four each in the bow and in the stern for which they carried a total of 16 torpedoes. They were also armed with a pair of [120 mm Italian naval gun|] deck guns, one each fore and aft of the conning tower, for combat on the surface. Their anti-aircraft armament consisted of two twin-gun mounts for [Breda Model 1931 Machine Gun|] machine guns.

Construction and career

Pietro Calvi was built by Odero-Terni-Orlando at their Muggiano, La Spezia, shipyard. Laid down in 1932, the submarine was launched on 31 March 1935 and completed in 1936.
During the Spanish Civil War, she unsuccessfully fired a pair of torpedoes each at the mail steamer and the 3946 GRT mail steamer during a patrol on 1–17 January 1937. During the night of 12/13 January she bombarded the port of Valencia.
The first patrol during the Second World War was from Liguria to the Atlantic Ocean, and lasted from 3 July to 6 August 1940. After overhaul at La Spezia, Pietro Calvi sailed on 6 October for a second Atlantic patrol reaching Bordeaux, France, on 23 October. The submarine suffered storm damage during its third patrol off the British Isles from 3 to 31 December. The fourth patrol was between the Canary Islands and the Azores from 31 March to 13 May 1941. She sailed on 1 August for a fifth patrol off the Canary Islands. During the sixth patrol from 7 to 29 December Pietro Calvi, and rescued sailors of the sunken German commerce raider. The seventh patrol was off Brazil from 7 March to 29 April 1942. The submarine sailed on 2 July for its eighth patrol. Pietro Calvi was rammed and sunk on 14 July by the British sloop which was able to briefly board the submarine before she sank. British ships rescued 35 of her crew of 78 men; among those killed was the commanding officer, Commander Primo Longobardo.