Atrevida-class corvette
The "Atrevida" class was a class of six corvettes built for the Spanish Navy in the 1950s. Design and construction. In 1945, the Spanish State drew up a large construction programme to re-equip the Spanish Navy, which had many old and worn out ships, as shipbuilding had ground to a near halt during the Spanish Civil War and the Second World War. The programme included 18 destroyers, six corvettes, six submarines together with motor-torpedo boats and patrol vessels. The corvettes, the "Atrevida" class, were long overall and between perpendiculars, with a beam of and a  draught of . Displacement was standard and full load. Two Sulzer diesel engines rated at a total of drove two propeller shafts, giving a speed of . 100 tons of oil were carried, given a range of at . As designed, the ships had a gun armament of one 105 mm (4.1 in) dual-purpose gun, backed up by a close-in anti-aircraft armament of two 37 mm guns (in one twin mount) and twelve 20 mm anti-aircraft guns (in three quadruple mounts). Four depth-charge throwers were fitted, and 20 mines could be carried. The ship had a crew of  132. Construction of the first two ships of the class, and began at Bazán's (now Navantia) Cartagena shipyard in 1950, but economic problems slowed construction, and the remaining ships were not laid down until 1953. The first two ships were completed in 1954–1955, but US Mutual Defense Assistance Programme funding allowed the remaining four ships to be completed with modernised armament and sensors more suitable for anti-submarine warfare. The 105 mm gun was replaced by a single US 3-inch (76 mm) Mark 26 semi-automatic anti-aircraft gun, with short range anti-aircraft armament consisting of three  40mm Bofors L/70 guns. Anti-submarine armament consisted of two Hedgehog anti-submarine mortars, supplemented by eight depth charge mortars and two depth charge racks. Sensors consisted of SPS-5B surface search radar and QHBa sonar. Displacement increased to standard and full load. The four ships still under construction completed in 1959–1960, with "Atrevida" converting to the revised standard in 1960. Service. The unmodified "Descubierta" was stricken in 1971, with in 1973. It was planned to withdraw "Atrevida" and from service in 1979, but instead, all four ships were refitted for patrol work. Their sonar and anti-submarine armament was  removed and they were redesignated as "Patrullero de Altura" (PA). They patrolled in the Atlantic between Gibraltar and the Canary Islands until replaced by s from 1991. The last of the class, "Atrevida", was stricken in 1992.