Construction began in 1973 , but commissioning was long delayed by an improvised limpet mine attack carried out by divers of the guerrilla organization Montoneros on 22 August 1975 . The date was chosen as a retaliation for the Trelew massacre three years before , when a number of leftist militants , most of them from the People 's Revolutionary Army ( ERP ) , were executed inside Almirante Zar air base , operated by the navy . The raid was allegedly planned in imitation of Operation Frankton , a British commando attack against German shipping in Bordeaux during World War II . The attack involved the use of a folding boat , frogmen and a limpet mine with of explosives , which was laid on the river bed below the destroyer after a failed attempt to attach the device to the hull . The ship 's bottom and electronics suffered severe damage , and completion was suspended for a year as a result of the attack
Trelew massacre
Trelew massacre
ARA Santísima Trinidad (D-2)