The ''Calvi'' class was a

class Class or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used differentl ...

of three submarines built by Oderno-Terni-Orlando in

Genoa Genoa ( ; it, Genova ; lij, Zêna ). is the capital of the Italian region of Liguria and the sixth-largest city in Italy. In 2015, 594,733 people lived within the city's administrative limits. As of the 2011 Italian census, the Province of ...

for the

Royal Italian Navy The ''Regia Marina'' (; ) was the navy of the Kingdom of Italy (''Regno d'Italia'') from 1861 to 1946. In 1946, with the birth of the Italian Republic (''Repubblica Italiana''), the ''Regia Marina'' changed its name to '' Marina Militare'' (" ...

( it, Regia Marina). The submarines were built in 1935, and all three served in the Mediterranean at the start of the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ...

. The boats were transferred to the

BETASOM BETASOM (an Italian language acronym of ''Bordeaux Sommergibile'' or ''Sommergibili'') was a submarine base established at Bordeaux, France by the Italian '' Regia Marina Italiana'' during World War II. From this base, Italian submarines participa ...

Atlantic submarine base at

Bordeaux Bordeaux ( , ; Gascon oc, Bordèu ; eu, Bordele; it, Bordò; es, Burdeos) is a port city on the river Garonne in the Gironde department, Southwestern France. It is the capital of the Nouvelle-Aquitaine region, as well as the prefect ...

in August 1940. In December 1941 the boats were used for a rescue mission of 254 sailors from the sunken . After ''Calvi'' had been sunk, ''Finzi'' and ''Tazzoli'' were selected for conversion to " transport submarines" in order to exchange rare or irreplaceable trade goods with Japan. Cargo capacity of 160 tons reduced reserve buoyancy from 20–25% to 3.5–6%; and armament was reduced to defensive

machine gun A machine gun is a fully automatic, rifled autoloading firearm designed for sustained direct fire with rifle cartridges. Other automatic firearms such as automatic shotguns and automatic rifles (including assault rifles and battle rifles) ar ...

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 Beam may refer to: Streams of particles or energy *Light beam, or beam of light, a directional projection of light energy **Laser beam *Particle beam, a stream of charged or neutral particles **Charged particle beam, a spatially localized grou ...

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 vesse ...

of . They had an operational diving depth of . They had an operational diving depth of . Their crew numbered 77 officers and enlisted men.Chesneau, p. 305 For surface running, the boats were powered by two

diesel engine The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-ca ...

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 and torque and rotation, usually used to connect ...

. When submerged each propeller was driven by a

electric motor An electric motor is an electrical 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 wire winding to generate for ...

. 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 .Bagnasco, p. 152 The boats were armed with eight

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 each in the bow and in the stern for which they carried a total of 16

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

es. They were also armed with a pair of

deck guns 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 ...

, 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

Ships

''Pietro Calvi''

''Pietro Calvi'' ( pennant number CV) was launched 31 March 1935. During the Spanish Civil War, she unsuccessfully fired a pair of torpedoes each at the

mail steamer Packet boats were medium-sized boats designed for domestic mail, passenger, and freight transportation in European countries and in North American rivers and canals, some of them steam driven. They were used extensively during the 18th and 19th ...

and the 3946 mail steamer during a patrol on 1–17 January 1937. During the night of 12/13 January she bombarded the port of

Valencia Valencia ( va, València) is the capital of the autonomous community of Valencia and the third-most populated municipality in Spain, with 791,413 inhabitants. It is also the capital of the province of the same name. The wider urban area al ...

. The first patrol during the Second World War was from

Liguria it, Ligure , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = , demographics1_footnotes = , demographics1_title1 = , demographics1_info1 = , demographics1_title2 ...

to the

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

, and lasted from 3 July to 6 August 1940. After overhaul at La Spezia, ''Calvi'' sailed on 6 October 1940 for a second Atlantic patrol reaching Bordeaux on 23 October. ''Calvi'' suffered storm damage during its third patrol off the

British Isles The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isles, ...

from 3 to 31 December 1940. The fourth patrol was between the Canary Islands and the

Azores ) , motto =( en, "Rather die free than subjected in peace") , anthem= ( en, "Anthem of the Azores") , image_map=Locator_map_of_Azores_in_EU.svg , map_alt=Location of the Azores within the European Union , map_caption=Location of the Azores wi ...

from 31 March to 13 May 1941. ''Calvi'' sailed on 1 August 1941 for a fifth patrol off the Canary Islands. During the sixth patrol from 7 to 29 December 1941 ''Calvi'', ''Finzi'' and ''Tazzoli'' rescued sailors of the sunken raider ''Atlantis''. The seventh patrol was off

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

from 7 March to 29 April 1942. ''Calvi'' sailed on 2 July 1942 for its eighth patrol. ''Calvi'' was rammed and sunk on 14 July 1942 by convoy SL 115 escort . Three officers and 32 sailors survived.

''Giuseppe Finzi''

''Giuseppe Finzi'' (pennant number FZ) was launched 29 June 1935. The first war patrol was from Cagliari to the Atlantic, and lasted from 5 June to 10 July 1940. The submarine sailed on 7 September 1940 and passed the Strait of Gibraltar on 13 September for an Atlantic patrol to

, France, on 29 September. Admiral Karl Dönitz visited ''Giuseppe Finzi'' on 30 September to welcome sailors to the German base. The third patrol near the British Isles from 24 October to 4 December 1940 revealed that the diesel engine air intake was too exposed for North Atlantic winter weather. The fourth patrol was near the Canary Islands from 10 March to 17 April 1941 and the fifth patrol was off Gibraltar in August. During the sixth patrol from 7 to 29 December 1941 , ''Giuseppe Finzi'' and rescued sailors of the sunken German

commerce raider Commerce raiding (french: guerre de course, "war of the chase"; german: Handelskrieg, "trade war") is a form of naval warfare used to destroy or disrupt logistics of the enemy on the open sea by attacking its merchant shipping, rather than enga ...

. The submarine sailed for

Operation Neuland Operation Neuland (New Land) was the German Navy's code name for the extension of unrestricted submarine warfare into the Caribbean Sea during World War II. U-boats demonstrated range to disrupt United Kingdom petroleum supplies and United ...

on 6 February 1942 and returned on 31 March. She returned to the

Caribbean Sea The Caribbean Sea ( es, Mar Caribe; french: Mer des Caraïbes; ht, Lanmè Karayib; jam, Kiaribiyan Sii; nl, Caraïbische Zee; pap, Laman Karibe) is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexico ...

for an eighth patrol from 6 June to 18 August 1942. On 26 November 1942 ''Giuseppe Finzi'' sailed for a ninth patrol to Brazil; but mechanical problems required return to base on 10 December. The boat patrolled the

West African West Africa or Western Africa is the westernmost region of Africa. The United Nations geoscheme for Africa#Western Africa, United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Ghana, Guinea, ...

coast from 11 February to 18 April 1943. Conversion to a transport submarine was never completed, and the boat was seized by the Germans on 9 September 1943 when Italy surrendered to 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 explicit agreement has been worked out among them. Members of an alliance are called ...

. Renamed ''UIT21'' in German service, she was scuttled at

Le Verdon-sur-Mer Le Verdon-sur-Mer (, literally ''Le Verdon on Sea'') is a commune in the Gironde department in Nouvelle-Aquitaine in southwestern France. Population See also *Communes of the Gironde department The following is a list of the 535 communes o ...

on 25 August 1944 to prevent her capture by advancing Allied forces.

''Enrico Tazzoli''

''Enrico Tazzoli'' (pennant number TZ) was launched 14 October 1935. It was named after Enrico Tazzoli, a martyr of the Italian wars of independence. The first wartime patrol was off the coast of

North Africa North Africa, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in ...

from 21 June to 2 July 1940. The second was an unsuccessful attempt to pass the Strait of Gibraltar from 30 July to 9 August 1940. After overhaul at La Spezia, ''Enrico Tazzoli'' sailed on 2 October 1940 and passed the Strait of Gibraltar on 7 October for an Atlantic patrol to Bordeaux on 24 October. The fourth patrol was off the British Isles from 13 December 1940 to 6 January 1941. The boat sailed on 7 April 1941 to patrol between

Freetown Freetown is the capital and largest city of Sierra Leone. It is a major port city on the Atlantic Ocean and is located in the Western Area of the country. Freetown is Sierra Leone's major urban, economic, financial, cultural, educational and po ...

and the Azores; and shot down an attacking

Bristol Blenheim The Bristol Blenheim is a British light bomber aircraft designed and built by the Bristol Aeroplane Company (Bristol) which was used extensively in the first two years of the Second World War, with examples still being used as trainers until ...

while returning to port on 23 May. The sixth patrol was again off Freetown from 15 July to 11 September 1941. During the seventh patrol from 7 to 27 December 1941 , and ''Tazzoli'' rescued sailors of the sunken German

. The submarine sailed for

on 2 February 1942 and returned on 31 March. The ninth patrol was again to the Caribbean from 18 June to 5 September 1942; and the tenth patrol was to Brazil from 14 November 1942 to 2 February 1943. After conversion to a transport submarine, ''Enrico Tazzoli'' sailed for Japan on 16 May 1943 and was sunk by aircraft in the Bay of Biscay on 23 May.Brice, pp. 131–133

References

Notes

Sources

* * * * * * *

External links

Classe Pietro Calvi
Marina Militare website {{WWII Italian ships Submarine classes Submarines of the Regia Marina Ships built by OTO Melara