fire control with SPG-48 tracker (GUNAR). The two Annapolis-class destroyers were built late enough to incorporate the helicopter hangar retrofitted to the St. Laurent class and the "Beartrap" haul-down device. This allowed the destroyer escorts to deploy with one CH-124 Sea King helicopter. DELEX refit The DEstroyer Life EXtension (DELEX) refit was born out of the need to extend the life of the steam-powered destroyer escorts of the Canadian Navy in the 1980s until the next generation of surface ship was built. Encompassing all the classes based on the initial St. Laurent (the remaining St. Laurent, , Mackenzie, and Annapolis-class vessels), the DELEX upgrades were meant to improve their ability to combat modern Soviet submarines, and to allow them to continue to operate as part of NATO task forces. The Annapolis class received the same sensor and communications upgrades that others in the St Laurent family of ships received, including the installation of a new tactical data system (ADLIPS), updated radars and sonars, fire control and satellite navigation. They also received the new Canadian Tactical Towed Array Sensor or CANTASS which was a long-range towed sonar array that was affixed to the stern, which replaced the older VDS. The class also received a new lattice mast. They were given torpedo tubes to allow them to fire Mark 46 torpedoes. However, the Limbo mortar was removed in order to install the CANTASS. This visibly altered the overall appearance of the ships. Construction and career Nipigon was ordered in 1958, initially as a repeat Restigouche-class vessel. However, in 1959, the last two repeat Restigouches were altered to incorporate variable depth sonar and a helicopter landing area and became a separate class. The ship was laid down on 5 August 1960 by Marine Industries Ltd. at Sorel and launched on 10 December 1961. Her construction was overseen by Cdr Donald Clark CD, who also oversaw the laying-down and commencement of . She was commissioned into the Royal Canadian Navy on 30 May 1964 with classification number 266 and with the wife of the then Governor-General Georges Vanier, Madame Pauline Vanier, as her sponsor. She was actually the first vessel to commission in the class. In 1964, the ship escorted the royal yacht on its tour of Canada. On 18 October 1965, a fire broke out in the fuel-handling room, killing one and seriously injuring others. Eight crew members were evacuated to . Nipigon