sentences:  It replaced the Mark 8 torpedo on surface ships with tubes that could accommodate the longer Mark 15; this primarily included destroyers built after 1930.Older destroyers, primarily the "Wickes" and "Clemson" classes, continued to use the Mark 8, as did PT boats early in World War II.During the war 9,700 were produced at Newport and at the Naval Ordnance Station Forest Park, Illinois.