The four 'Archimede' class submarines were enlargements of the preceding 'Settembrini' design with ballasting rearranged to improve bunker capacity, An extra gun was also fitted, in keeping with the boats' 'ocean' role. All were launched in 1934 and, as part of their covert support of the Nationalist cause during the Spanish Civil War, the Italians transferred two to Spanish colours. These were the Archimede and the Torricelli and, to 'conceal' their transfer, two of the follow-on 'Brins' assumed their names. The three classes of boat formed a closely-related group, used extensively in colonial work.
That part of the Italian navy stationed in the Red Sea in June 1940 was cut off from the homeland and severely handled by the British as a threat astride the route from the Suez Canal eastward. The Galilei sank a Norwegian tanker less than a week after the outbreak of hostilities and announced her position further only two days later by stopping a neutral for examination. On the following day she was intercepted by the British anti-submarine trawler Moonstone, which inflicted damage that caused the boat to be filled with noxious fumes. Unable to dive, she fought it out on the surface. Far larger, faster and more heavily armed than her opponent she should have been successful had not the Moonstone shot up every gun's crew that emerged topside. With most of its officers dead, the demoralized crew surrendered. Captured, the boat assumed the British pennant P711 until her eventual disposal in 1946.
Galilei's replacement Torricelli was also apprehended by British forces. Forced to the surface near Perim Island, she engaged in a gun action with three 'K' class destroyers and a sloop. She was, inevitably, sunk but not before she had hit both the sloop and the destroyer HMS Khartoum. The hit on the latter was on one of the banks of torpedo tubes and, apparently, caused a compressed air explosion followed by the detonation of a torpedo warhead. The ship was destroyed.
Specification 'Archimede' class Type: sea-going submarine Displacement: 985 tons surfaced and 1,259 tons submerged Dimensions: length 70.50 m (231 ft 4 in); beam 6.83 m (22 ft 5 in); draught 4.10 m (13 ft 6 in) Propulsion: surfaced diesels delivering 3,000 bhp (2235 kW) and submerged electric motors delivering 1,300 hp (970 kW) to two shafts Speed: surfaced 17 kts and submerged 8 kts Range: surfaced 19000 km (11,805 miles) at 8 kts and submerged 195 km (121 miles) at 3 kts Armament: two 100-mm (3.9-in) guns, two 13.2-mm(0,52-in) machine-guns, and eight 533-mm (21 -in) torpedo tubes (four forward and four aft) with 16 torpedoes Complement: 55