Foca-class submarine

The Foca class were a group of three minelaying submarines built for the Regia Marina (Royal Italian Navy) during the 1930s. All three sister ships played minor roles during the Second World War. One was lost to unknown causes while trying to lay a minefield off British Palestine in 1940, but the other two survived the war to be discarded in 1947.

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 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. Twenty mines were stored in a central chamber, while the remaining 16 mines were kept in two aft chutes through which the mines were ejected.

Service
The lead boat, Foca, was lost to unknown causes on 13 October 1940 while laying mines off Haifa. Atropo and Zoea, the second and third vessels of the class, were used after Italy's 1943 surrender by the Allies for anti-submarine training. Both were scrapped in 1947.