Italian R-class submarine

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 2155 t surfaced and 2560 t submerged. The submarines were 86.5 m long, had a beam of 7.86 m and a draft of 5.34 m. They had a cargo capacity of 600 t.

For surface running, the boats were powered by two 1300 bhp diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 450 hp electric motor. They could reach 13 kn on the surface and 6 kn underwater. On the surface, the R class had a range of 12000 nmi at 9 kn; submerged, they had a range of 110 nmi at 3.5 kn.

The boats were only armed for self-defense with three 20 mm light anti-aircraft guns. Some boats may have been equipped with a pair of internal 45 cm torpedo tubes in the bow and stern.

Boats
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.

The sail of submarine R12 is now exhibited as a monument on the seafront of Gaeta.