During the Second World War, the Canadian Pacific Railways transformed major portions of their main shops in Montreal and Calgary to build munitions, naval guns, gun mounts and tanks.
By the end of the war, CPR shops had turned out over 1,400 Valentine tanks, 75 main engines for Corvette warships, 3,000 naval guns and 2,000 anti-submarine detectors.
The CPR reorganized their entire shop system for the war. The Angus Shops in Montreal, was turned over to building Valentine tanks and munitions. The Calgary Ogden Shops were dedicated to building naval guns for Canadian, British and US navies, and the Weston Shops in Winnipeg, became the main center for building locomotives.