Argonauta-class submarine

The Argonauta-class submarine was the first sub-class of the 600 Series of coastal submarines built for the Regia Marina (Royal Italian Navy) during the 1930s. Some of these boats played a minor role in the Spanish Civil War of 1936–1939 supporting the Spanish Nationalists. Of the seven boats built in this class, only a single one survived the Second World War.

Design and description
The Argonauta class was derived from the earlier Squalo-class submarines. They displaced 650 LT surfaced and 800 LT submerged. The submarines were 61.5 m long, had a beam of 5.7 m and a draft of 4.7 m. They had an operational diving depth of 80 m. Their crew numbered 44 officers and enlisted men.

For surface running, the boats were powered by two 750 bhp diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 400 hp electric motor. They could reach 14 kn on the surface and 8 kn underwater. On the surface, the Settembrini class had a range of 5000 nmi at 8 kn; submerged, they had a range of 110 nmi at 3 kn.

The boats were armed with six 53.3 cm torpedo tubes, four in the bow and two in the stern for which they carried a total of 12 torpedoes. They were also armed with a single 102 mm deck gun forward of the conning tower for combat on the surface. Their anti-aircraft armament consisted of two single 13.2 mm machine guns.

Service
The seven Argonauta-class submarines saw action during the Second World War. Five were sunk in action during the conflict and a sixth was scuttled at the Italian armistice in 1943. The last surviving boat of the class was stricken in 1948.