Since before the '50s, and through the '90s (throughout both Korean & Vietnam wars) the U.S. Navy's Naval Technical Training Center (NTTC) – Treasure Island, was operational. Multiple Maintenance Skills were part of the curriculum there, including training of Electronic Technicians (ET) in Radiation and Detection equipment (RADIAC), Communications & Radar systems, as well as training of Shipfitter and Damage Control Technicians, which also covered Nuclear Biological & Chemical (NBC) Warfare Decontamination (DECON) techniques. In 1972 a new U.S. Navy Rate consisting of the old Shipfitter and Damage Control Technician ratings was created. This New U.S. Navy Rate was Hull Maintenance Technician (HT). The Navy later realized that Damage Control is such a large responsibility, it needed a rating specifically tasked with those duties, hence the reemergence of the Damage Controlman Rating in 1988.