|Displacement:||1,331 long tons (1,352 t) surfaced
1,965 long tons (1,997 t) submerged
|Length:||277 ft (84 m)|
|Beam:||25 ft (7.6 m)|
|Draught:||17 ft (5.2 m)|
2 × 2200 HP Fiat diesel engines
2 × 900 HP electric motors
|Speed:||17 knots (20 mph; 31 km/h) surfaced
8.5 knots (9.8 mph; 15.7 km/h) submerged
|Armament:||8 × 533 mm (21 in) torpedo tubes (6 bow, 2 stern)
2 × 120mm/45 guns
4 × 13.2 mm (0.52 in) machine guns
The Calvi-class was a class of three submarines built by Oderno-Terni-Orlando in Genoa for the Royal Italian Navy (Italian: Regia Marina). The submarines were built in 1935, and all three served in the Mediterranean at the start of the Second World War. The boats were transferred to the BETASOM German submarine base at Bordeaux in August 1940. In December 1941 the boats were used for a rescue mission of 254 sailors from the sunken German auxiliary cruiser Atlantis. 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 guns.
Pietro Calvi (pennant number CV) was launched 31 March 1935. The first war patrol was from Liguria to the Atlantic Ocean, 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 from 3 to 31 December 1940. The fourth patrol was between the Canary Islands and the Azores 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 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 HMS Lulworth. Three officers and 32 sailors survived.
|3rd||20 December 1940||Carlton||5,162 gross register tons (GRT)||freighter from convoy OB 260; 4 survivors from a crew of 35|
|7th||25 March 1942||Tredinnick||4,589 GRT||freighter, no survivors|
|7th||1 April 1942||T.C. McCobb||7,452 GRT||tanker; 24 killed; first US ship sunk by an Italian submarine|
|7th||9 April 1942||Eugene V.R. Thayer||7,138 GRT||tanker; 11 killed|
|7th||April 1942||Balkis||2,161 GRT||freighter|
|7th||April 1942||Ben Brush||7,691 GRT||tanker; 1 killed|
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. Finzi sailed on 7 September 1940 and passed the Strait of Gibraltar on 13 September for an Atlantic patrol to Bordeaux on 29 September. Admiral Karl Dönitz visited Finzi on 30 September to welcome Regia Marina 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 Calvi, Finzi and Tazzoli rescued sailors of the sunken raider Atlantis. Finzi sailed for Operation Neuland on 6 February 1942 and returned on 31 March. Finzi returned to the Caribbean Sea for an eighth patrol from 6 June to 18 August 1942. On 26 November 1942 Finzi sailed for a ninth patrol to Brazil; but mechanical problems required return to base on 10 December. Finzi patrolled the west African coast from 11 February to 18 April 1943. Conversion to a transport submarine was never completed; and the boat was scuttled at Le Verdon-sur-Mer on 25 July 1944.
|7th||6 March 1942||Melpomese||7,011 GRT||tanker, no casualties|
|7th||6 March 1942||Boren||4,528 GRT||freighter; no casualties|
|7th||10 March 1942||Charles Racine||9,957 GRT||tanker; no casualties|
|10th||28 March 1943||Granicos||3,689 GRT||iron ore freighter sank in less than 30 seconds, one survivor from a crew of 31|
|10th||29 March 1943||Celtic Star||5,575 GRT||freighter, 2 killed|
- For other Italian submarines named Enrico Tazzoli, see Italian submarine 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 from 21 June 1940 to 2 July. The second was an unsuccessful attempt to pass the Strait of Gibraltar from 30 July to 9 August 1940. After overhaul at La Spezia, 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. Tazzoli sailed on 7 April 1941 to patrol between Freetown and the Azores; and shot down an attacking Bristol Blenheim 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 Calvi, Finzi and Tazzoli rescued sailors of the sunken raider Atlantis. Tazzoli sailed for Operation Neuland 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, Tazzoli sailed for Japan on 16 May 1943 and was sunk by aircraft in the Bay of Biscay on 23 May.
|3rd||12 October 1940||Orao||Yugoslavia||5,135||Freighter shelled then torpedoed while radioing; 2 killed|
|4th||27 December 1940||Ardanbahn||United Kingdom||4,980||No survivors from freighter of unescorted Convoy OB 263|
|5th||15 April 1941||Aurillac||United Kingdom||4,248||Freighter, 1 killed|
|5th||7 May 1941||Fernlane||Norway||4,310||Freighter with ammunition cargo, no casualties|
|5th||10 May 1941||Alfred Olsen||Norway||8,817||Tanker, no casualties|
|6th||19 August 1941||Sildra||Norway||7,313||Tanker, no casualties|
|8th||6 March 1942||Astrea||Netherlands||1,406||Freighter|
|8th||6 March 1942||Tonsbergfjord||Norway||3,156||Freighter; 1 killed|
|8th||8 March 1942||Montevideo||Uruguay||5,785||Freighter; 14 killed|
|8th||10 March 1942||Cygnet||Greece||3,628||Freighter; no casualties|
|8th||13 March 1942||Daytonian||United Kingdom||6,434||Freighter; 1 killed|
|8th||15 March 1942||Athelqueen||United Kingdom||8,780||Tanker; 3 killed|
|9th||2 August 1942||Kastor||Greece||5,497||Freighter; 4 killed|
|9th||6 August 1942||Havsten||Norway||6,161||Tanker; 2 killed|
|10th||12 December 1942||Empire Hawk||United Kingdom||5,032||Freighter|
|10th||12 December 1942||Ombillin||Netherlands||5,658||Freighter|
|10th||21 December 1942||Queen City||United Kingdom||4,814||Freighter, 6 killed|
|10th||25 December 1942||Doña Aurora||United States||5,011||Freighter, 7 killed|
- Marcello class at regiamarina.net
- Blair, Clay (1996). Hitler's U-Boat War, The Hunters 1939-1942. Random House. ISBN 0-394-58839-8.
- Brice, Martin (1981) Axis Blockade Runners of World War II Naval Institute Press ISBN 0-87021-908-1
- Campbell, John (1985). Naval Weapons of World War Two. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-459-4.
- Erminio Bagnasco, (1977) Submarines of World War Two, Cassell & Co, London. ISBN 1-85409-532-3
- Kafka, Roger & Pepperburg, Roy L. (1946) Warships of the World Cornell Maritime Press