[5][note 1] The class was powered by two Babcock & Wilcox boilers connected to the two-shaft English-Electric geared steam turbines creating 30,000 shaft horsepower (22,000 kW).

[6] The most noticeable change for the Mackenzies was the replacement of the forward 3-inch (76 mm)/50 caliber Mk 22 guns of the St. Laurent design[note 2] with a dual Vickers 3-inch/70 caliber Mk 6 gun mount and the presence of a fire-control director atop the bridge superstructure.

Encompassing all the classes based on the initial St. Laurent (the remaining St. Laurent, Restigouche, Mackenzie, and Annapolis-class vessels), the DELEX upgrades were meant to improve their ability to combat modern Soviet submarines,[9] and to allow them to continue to operate as part of NATO task forces.

This meant that the ships would receive the new tactical data system ADLIPS, new radars, new fire control and satellite navigation.

[3][11] The Mark 46 torpedo had a range of 12,000 yards (11,000 m) at over 40 knots (74 km/h; 46 mph)[11][12] with a high-explosive warhead weighing 96.8 pounds (43.9 kg).

In 1971, the destroyer, along with the replenishment ship Provider and the submarine Rainbow shadowed a seven-ship Soviet fleet in the Aleutian Islands.

[14][15] On 28 August 1972, Qu'Appelle accompanied Provider and the destroyer Gatineau on a four-month training cruise around the Pacific.

[7] Qu'Appelle underwent the DELEX refit in from 25 May 1983 to 13 January 1984 at the Burrard Yarrow shipyard at CFB Esquimalt.