stern well. The stern well had a roller top to close it off from following seas. As with the British Type 12 design, the provision for long-range homing torpedoes (in this case BIDDER [Mk 20E] or the US Mark 35 were included. However, they were never fitted. Machinery The vessels of the St. Laurent class had two Babcock & Wilcox water tube boilers installed. The steam produced by these boilers was directed at two geared steam turbines which powered two shafts, providing to drive the ship at a maximum speed of . The ships had an endurance of at . DDH conversion Following successful trials aboard the frigate and sister ship , plans to convert the St. Laurent class took shape. Th development of the beartrap, installed in during her 1962–63 conversion, finalized the concept. By keeping the aircraft secure, the beartrap eliminated the need for deck handling from landing to the hangar, or from hangar to takeoff. In the conversion to a helicopter-carrying vessel, St. Laurent was gutted except for machinery and some forward spaces. The hull was strengthened, fueling facilities for the helicopter and activated fin stabilizers installed. The fin stabilizers were to reduce roll in rough weather during helicopter operations. All seven St Laurents were fitted with helicopter platforms and SQS 504 Variable Depth Sonar (VDS). The single funnel was altered to twin stepped funnels to permit the forward extension of the helicopter hangar. To make room for the helicopter deck, the aft 3-inch mount and one of the Limbos were removed. The two 40 mm guns were also removed. Following the conversion, the displacement remained the same at standard load but at full load, it increased to . Operational history After commissioning, St. Laurent was sent to the United States to work up and be evaluated and then proceeded to visit the United Kingdom. While there the ship was part of the escort for the royal yacht on a state visit to Sweden. She was then stationed to the west coast where she performed various diplomatic duties. Prior to undergoing her conversion to a DDH, she was test fitted with the variable depth sonar (VDS). In 1959 the Canadian government ordered that the St. Laurent class be modernized, even though the class was relatively new. This was based on the fact that the St. Laurent class was no longer capable of fighting the new nuclear submarines