Italian submarine Atropo (1938)

Atropo was one of three Foca-class submarine minelayers built for the Regia Marina (Royal Italian Navy) during the late 1930s.

Design and description
The Foca-class submarines were improved versions of the preceding Pietro Micca. They displaced 1305 LT surfaced and 1625 LT submerged. The submarines were 82.85 m long, had a beam of 7.17 m and a draft of 5.2 m. They had an operational diving depth of 90 m. Their crew numbered 60 officers and enlisted men.

For surface running, the boats were powered by two 1440 bhp diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 625 hp electric motor. They could reach 15.2 kn on the surface and 7.4 kn underwater. On the surface, the Foca class had a range of 7800 nmi at 8 kn, submerged, they had a range of 120 nmi at 7 kn.

The boats were armed with six internal 53.3 cm torpedo tubes, four in the bow and two in the stern, for which they carried eight torpedoes. They were also armed with one 100 mm deck gun for combat on the surface. The gun was initially mounted in the rear of the conning tower, but this was re-sited on the forward deck later in the war in the surviving boats and the large conning tower was re-built to a smaller design. Their anti-aircraft armament consisted of two pairs of 13.2 mm machine guns. The Focas carried a total of 36 mines that they ejected through chutes in the stern.

Construction and career
Atropo was laid down by Cantieri navali Tosi di Taranto at their Taranto shipyard on 10 July 1937, launched on 20 November 1938 and completed on 14 February 1939.