The ''Foca'' class were a group of three

minelaying A minelayer is any warship, submarine, military aircraft or land vehicle deploying explosive mines. Since World War I the term "minelayer" refers specifically to a naval ship used for deploying naval mines. "Mine planting" was the term for ins ...

submarine A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited underwater capability.) The term "submarine" is also sometimes used historically or infor ...

s built for the (Royal Italian Navy) during the 1930s. All three

sister ship A sister ship is a ship of the same Ship class, class or of virtually identical design to another ship. Such vessels share a nearly identical hull and superstructure layout, similar size, and roughly comparable features and equipment. They o ...

s played minor roles during the

Second World War World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

. One was lost to unknown causes while trying to lay a minefield off

British Palestine Mandatory Palestine was a British geopolitical entity that existed between 1920 and 1948 in the region of Palestine, and after 1922, under the terms of the League of Nations's Mandate for Palestine. After an Arab uprising against the Ottoma ...

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 surfaced and submerged. The submarines were long, had a beam of and a

draft Draft, the draft, or draught may refer to: Watercraft dimensions * Draft (hull), the distance from waterline to keel of a vessel * Draft (sail), degree of curvature in a sail * Air draft, distance from waterline to the highest point on a v ...

of . They had an operational diving depth of . Their crew numbered 60 officers and men.Chesneau, p. 305 For surface running, the boats were powered by two

diesel engine The diesel engine, named after the German engineer Rudolf Diesel, is an internal combustion engine in which Combustion, ignition of diesel fuel is caused by the elevated temperature of the air in the cylinder due to Mechanics, mechanical Compr ...

s, each driving one

propeller shaft A drive shaft, driveshaft, driving shaft, tailshaft (Australian English), propeller shaft (prop shaft), or Cardan shaft (after Girolamo Cardano) is a component for transmitting mechanical power, torque, and rotation, usually used to connect o ...

. When submerged each propeller was driven by a

electric motor An electric motor is a machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a electromagnetic coil, wire winding to gene ...

. They could reach on the surface and underwater. On the surface, the ''Foca'' class had a range of at , submerged, they had a range of at .Bagnasco, p. 156 The boats were armed with six internal

torpedo tube A torpedo tube is a cylindrical device for launching torpedoes. There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units (also referred to as torpedo launchers) installed aboa ...

s, four in the bow and two in the stern, for which they carried eight

torpedo A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, such ...

es. They were also armed with one

deck gun A deck gun is a type of naval artillery mounted on the deck of a submarine. Most submarine deck guns were open, with or without a shield; however, a few larger submarines placed these guns in a turret. The main deck gun was a dual-purpose w ...

for combat on the surface. The gun was initially mounted in the rear of the

conning tower A conning tower is a raised platform on a ship or submarine, often armoured, from which an officer in charge can conn (nautical), conn (conduct or control) the vessel, controlling movements of the ship by giving orders to those responsible for t ...

, 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 machine guns. The ''Foca''s 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.

Boats

Service

The lead boat, ''Foca'', was lost to unknown causes on 13 October 1940 while laying mines off

Haifa Haifa ( ; , ; ) is the List of cities in Israel, third-largest city in Israel—after Jerusalem and Tel Aviv—with a population of in . The city of Haifa forms part of the Haifa metropolitan area, the third-most populous metropolitan area i ...

. ''Atropo'' and ''Zoea'', the second and third vessels of the class, were used after Italy's 1943 surrender by the

Allies An alliance is a relationship among people, groups, or states that have joined together for mutual benefit or to achieve some common purpose, whether or not an explicit agreement has been worked out among them. Members of an alliance are calle ...

for anti-submarine training.Bagnasco, p. 157 Both were scrapped in 1947.

Notes

References

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External links