Perla-class submarine (Perla)
|Preceded by:||Sirena class|
|Succeeded by:||Adua class|
|Length:||60.18 m (197 ft 5 in)|
|Beam:||6.45 m (21 ft 2 in)|
|Draft:||4.7 m (15 ft 5 in)|
|Test depth:||80 m (260 ft)|
The Perla-class submarines were the third sub-class of the 600 Series of coastal submarines built for the Royal Italian Navy (Regia Marina) during the 1930s. Of the ten boats built of this class, only three survived World War II.
Design and description
The Perla-class submarines were essentially repeats of the preceding Sirena class. They displaced 680 metric tons (670 long tons) surfaced and 844 metric tons (831 long tons) submerged. The submarines were 60.18 meters (197 ft 5 in) long, had a beam of 6.45 meters (21 ft 2 in) and a draft of 4.7 meters (15 ft 5 in).
For surface running, the boats were powered by two 600-brake-horsepower (447 kW) diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 400-horsepower (298 kW) electric motor. They could reach 14 knots (26 km/h; 16 mph) on the surface and 7.5 knots (13.9 km/h; 8.6 mph) underwater. On the surface, the Adua class had a range of 5,200 nautical miles (9,600 km; 6,000 mi) at 8 knots (15 km/h; 9.2 mph), submerged, they had a range of 74 nmi (137 km; 85 mi) at 4 knots (7.4 km/h; 4.6 mph).
The boats were armed with six internal 53.3 cm (21.0 in) torpedo tubes, four in the bow and two in the stern. One reload torpedo was carried for each tube, for a total of twelve. They were also armed with one 100 mm (3.9 in) deck gun for combat on the surface. The light anti-aircraft armament consisted of one or two pairs of 13.2 millimeters (0.52 in) machine guns.
|Ship||Builder||Launched||Date of loss||Fate|
|Ambra||OTO||28 May 1936||9 September 1943||Scuttled at La Spezia|
|Berillo||CRDA||14 June 1936||2 October 1940||Sunk by HMS Havock and Hasty near Egypt|
|Corallo||CRDA||2 August 1936||13 December 1942||Sunk by HMS Enchantress|
|Diaspro||CRDA||5 July 1936||1 February 1948||Struck|
|Gemma||CRDA||21 May 1936||6 October 1940||Sunk in error by Italian submarine Tricheco|
|Iride||OTO||30 July 1936||22 August 1940||Sunk in Tobruk by Swordfish aircraft from HMS Eagle|
|Malachite||OTO||15 July 1936||9 February 1943||Sunk by Dutch submarine Dolfin|
|Onice||OTO||15 June 1936||23 March 1947||Struck|
|Perla||CRDA||3 May 1936||9 July 1942||Captured by the British, transferred to Greek service as Matrozos. Broken up, 1954|
|Turchese||CRDA||19 July 1936||1 February 1948||Struck|
Iride and Onice were lent to the Nationalist side in the Spanish Civil War, renamed Gonzales Lopez and Aguilar Tablada respectively. They retained their Italian crews with a Spanish liaison officer. They were returned to the Italian Navy at the end of the conflict.
In 1940–42 Ambra and Iride were modified as carriers for "Maiale" manned torpedoes for use by the Decima Flottiglia MAS. The "Maiale" were carried in watertight containers on the deck of the submarines and the deck gun removed. In common with other Italian submarines the survivors were fitted with smaller conning towers in 1942–43.
Perla was stationed at Massawa on 10 June 1940; during its first mission against Allied shipping, the crew became intoxicated because of exhalations of methyl chloride (used to refrigerate the submarine), and after being ordered to return to the base it got beached. With most of its crew incapacitated, the submarine had to endure the attack of the destroyer Kingston, until the destroyer was driven off by Italian aircraft; afterwards, the submarine was refloated and towed to Massawa.
Perla remained inactive until, with the impending collapse of Italian resistance in East Africa, it was ordered for the four surviving submarines to leave and reach Bordeaux, the base for Italian submarines operating in the Atlantic Ocean. Given its small size and small endurance, Perla would require two refuels to make the trip of more or less 13,000 nmi (24,000 km); commanded by Lt. Bruno Napp, the submarine sailed on 1 March 1941. In an area south-south-east of Madagascar, Perla met the German auxiliary cruiser Atlantis, commanded by Bernhard Rogge. Rogge wrote in his memoirs that he expressed doubts to Napp about the feasibility of going all the way to Bordeaux and suggested to him to sail to Brazil or Argentina to be interned, only for Napp to politely reject the advice and declaring he would follow the orders he had been given, much to Rogge's admiration. After leaving Atlantis, Perla met the supply ship Northmark in the Atlantic for its second refuel. It finally reached Bordeaux on 20 May, after 81 days at sea.
Perla returned to the Mediterranean in October 1941; on 9 July 1942, it unsuccessfully attacked the corvette HMS Hyacinth, and, after being severely damaged by the corvette's counter attack, the crew tried to scuttle the submarine. The procedure was halted by a boarding party, leading to the submarine's capture. Taken over by the Royal Navy as P.712, in 1943 it was ceded to the Greek Navy, who renamed it Matrozos and used it till 1954.
- Bagnasco, Erminio (1977). Submarines of World War Two. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-962-6.
- Chesneau, Roger, ed. (1980). Conway's All the World's Fighting Ships 1922–1946. Greenwich, UK: Conway Maritime Press. ISBN 0-85177-146-7.
- Gardiner, Robert; Chesneau, Roger, eds. (1980). Conway's All the World's Fighting Ships 1922–1947. London: Conway Maritime Press. ISBN 0-85177-146-7.
- Rohwer, Jürgen (2005). Chronology of the War at Sea 1939-1945: The Naval History of World War Two (Third Revised ed.). Annapolis, Maryland: Naval Institute Press. ISBN 1-59114-119-2.