 The O 'Brien ships were also equipped with four twin 21 @-@ inch ( 533 mm ) torpedo tubes , for a total load of eight Mark 8 torpedoes . Although the General Board had called for two anti @-@ aircraft guns for the O 'Brien class , they were not originally outfitted with the weapons ; the later Sampson class was the first American destroyer class so armed . Likewise , there is no record of any of the O 'Brien ships being outfitted with mine @-@ laying apparatus . During World War I , most American destroyers were used in anti @-@ submarine warfare roles , and were equipped with depth charges and delivery systems , such as Y @-@ guns and depth charge <unk> . O 'Brien @-@ class ships were equipped with depth charges during the war , but no specific mentions of the types of depth charges used or delivery system are recorded in secondary sources . 
