 The ships were designed by the German shipyard Blohm + Voss as a development of the Portuguese Navy's s, designed by the Portuguese naval engineer Rogério de Oliveira in the late 1960s.All the ships of the class were built in Argentina at the AFNE "Río Santiago" shipyard, close to the city of La Plata in Buenos Aires Province.The contract was signed on 1 August 1979 and the pennant numbers P10-P15 were assigned until they were changed to P41-P46 in 1988.