Annapolis-class destroyer

The Annapolis class destroyer escort was a class of ships that saw service with the Royal Canadian Navy and Canadian Forces from the 1960s-1990s.

The RCN had intended to place a six ship order under the Mackenzie-class of destroyer escorts; however, the last two vessels were built to the St. Laurent-class DDH design and were classed under the new Annapolis-class designation. Both ships spent the majority of their career split between Canada's Pacific and Atlantic coasts with the Annapolis being at Esquimalt and Nipigon at Halifax.

The two Annapolis-class destroyers were built late enough to incorporate the helicopter hangar retrofitted to the St. Laurent-class. HMCS Nipigon underwent a DELEX (DEstroyer Life EXtension) refit in 1982 to upgrade combat, radar and weapons systems and HMCS Annapolis followed in 1984. Nipigon remained in the fleet until 1998 as a trials ship for the ETASS Mod 5 towed sonar system which was a precursor to the CANTASS (Canadian Towed Array Sonar System) that is currently fitted on the Halifax-class of frigates. Except for the replenishment ships HMCS Protecteur and Preserver, Nipigon was the last steam-powered warship to serve in the Canadian Forces.

These ships were among the first to take a new approach to helicopter operations from small warships. Unlike the British, who fitted a small helicopter (Westland Wasp) on their frigates with only a minimum of redesign, the RCN decided to use the far more capable and sophisticated CH-124 Sea King. The disadvantage of this approach is the fact that a considerable amount of surface area on the mothership has to be sacrificed to accommodate the helicopter. On the other hand, the helicopter itself is far more capable and can operate even in poor weather conditions: a considerable advantage in the polar region.