Italian submarine Pier Capponi

Pier Capponi was one of four Mameli-class submarines built for the Regia Marina (Royal Italian Navy) during the 1920s.

Design and description
The Mameli class was one of the Regia Marina's first classes of submarines to be built after the First World War. They displaced 810 LT surfaced and 993 LT submerged. The submarines were 64.6 m long, had a beam of 6.51 m and a draft of 4.3 m. They had an operational diving depth of 90 m. Their crew numbered 49 officers and enlisted men.

For surface running, the boats were powered by two 1550 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 7.2 kn underwater. On the surface, the Mameli class had a range of 4360 nmi at 8 kn; submerged, they had a range of 110 nmi at 3 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 10 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 single 13.2 mm machine guns.

Construction and career
Pier Capponi was laid down by Cantieri navali Tosi di Taranto at their Taranto shipyard on 27 August 1925, launched on 19 June 1927, and completed in 1929. She was commissioned on 19 January 1929. During World War II, the Royal Navy submarine HMS Rorqual (N74) torpedoed and sank her in the Tyrrhenian Sea south of Stromboli at 38.53333°N, 15.31667°W on 31 March 1941.