sentences:  In the 1968 USS "New Jersey" re-activation for service off Vietnam, the 20 mm and 40 mm batteries were removed.In the 1980s re-activation, all the ships with 20 mm and 40 mm batteries had them removed, and four Phalanx CIWS mounts were added to all.The Oerlikon 20 mm anti-aircraft gun was one of the most heavily produced anti-aircraft guns of the Second World War; the US alone manufactured a total of 124,735 of these guns.