Specifications The
London Naval Treaty (1930) put no limit on vessels of or under. Design work started in 1932 supervised by the general engineer Gustavo Bozzoni. Two prototypes,
Spica and
Astore, were completed in 1935 and sold to the Swedish Navy. The hull was long, the beam was , the draught was and the ships had an installed power of from 2-shaft geared turbines
Displacement was around and standard rather than the permitted by the treaty. There was a complement of 6−9 officers and 110 crew.
Armament The gun armament consisted of three
/47 caliber
dual-purpose guns in single mountings in 'A', 'X', and 'Y' positions and three or four twin Breda Model 1931 Machine Gun|
anti-aircraft machine guns, later replaced by 6 to 11
Breda 20/65 modello 35 20 mm cannon in various configurations.
Lupo replaced her eight machine guns by 1941 with three twin 20 mm guns; two abreast the
bridge and one between the
funnel and second main gun, leaving the former machine-gun platform immediately abaft the funnel vacant. The ships had minelaying equipment and room for twenty mines. They also carried four
torpedo tubes; two tubes for each side in the first group, with later groups having varying configurations including a centreline twin- and two single-beam mounts, before settling on two centreline twin mounts in the last vessels. Some earlier ships were reportedly refitted with the all-centreline arrangement during the war. Twenty-one
Spica-class torpedo boats were lost during the war, three mined by the submarine mine-layer , three sunk by submarines, seven by aircraft, seven by ships and one by a collision.
Construction batches Six ships of the
Climene group, , , , , and entered service from 1936 to 1937. Eight more Spica-class ships of the
Perseo group comprised , , and , , , and . The
Alcione group was a batch of sixteen ships, , , , , , , , , , , , , , , and that went into service in 1938. The
Alcione ships carried two twin torpedo-tubes on the centre line, except for
Libra,
Lince,
Lira,
Lupo that had four single tubes until 1941, by when the four single tubes had been replaced with two twin tubes. ==Ships==