Italian R-class submarine
Romolo-class submarine (Romolo)
|Length:||86.5 m (283 ft 10 in)|
|Beam:||7.86 m (25 ft 9 in)|
|Draft:||5.34 m (17 ft 6 in)|
|Test depth:||80 m (260 ft)|
|Capacity:||600 tonnes (591 long tons) of cargo|
The R-class or Romolo-class submarine was a group of submarines built for the Royal Italian Navy (Regia Marina Italiana) during World War II. They were designed as blockade running transport submarines for transporting high-value cargo from Europe to Japan and vice versa. Axis-occupied Europe lacked strategic materials such as tungsten, tin and some commodities such as rubber.
Design and description
The R-class submarines displaced 2,155 metric tons (2,121 long tons) surfaced and 2,560 metric tons (2,520 long tons) submerged. The submarines were 86.5 meters (283 ft 10 in) long, had a beam of 7.86 meters (25 ft 9 in) and a draft of 5.34 meters (17 ft 6 in). They had a cargo capacity of 600 tonnes (591 long tons). 
For surface running, the boats were powered by two 1,300-brake-horsepower (969 kW) diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 450-horsepower (336 kW) electric motor. They could reach 13 knots (24 km/h; 15 mph) on the surface and 6 knots (11 km/h; 6.9 mph) underwater. On the surface, the R class had a range of 12,000 nautical miles (22,000 km; 14,000 mi) at 9 knots (17 km/h; 10 mph); submerged, they had a range of 110 nmi (200 km; 130 mi) at 3.5 knots (6.5 km/h; 4.0 mph).
The boats were only armed for self-defense with three 20-millimeter (0.79 in) light anti-aircraft guns. Some boats may have been equipped with a pair of internal 45 cm (17.7 in) torpedo tubes in the bow and stern.
Twelve boats were ordered, but only two were completed, by Tosi:
- Remo, named after Remus, launched 28 March 1943 — Sunk by the British submarine HMS United 15 July 1943 in the Gulf of Taranto
- Romolo, named after Romulus, launched 21 March 1943 — Sunk by Allied aircraft near Augusta 18 July 1943.
The remaining 10 hulls were scuttled incomplete and scrapped after the war.
- Italian submarines of World War II
- Merchant submarine
- German submarine Deutschland, an unarmed transport submarine built by Germany in World War I.
- Chesneau, p. 307
- Bagnasco, p. 166
- 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.
- 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.