The SD40 was a popular locomotive in North America. It was used in large numbers by many railways. The SD40 puts out 3000 HP, has six-wheel C-C trucks, and has a top speed of about 65 miles per hour (105 km per hour).
CN placed it's first order in September 1967 and after the 5th order in December 1971 had 241 units which was more than any other railway. CN's units had snow shields over the engine air intakes, headlights in the low nose and the bell and horn between the number boards. They were delivered in the 1961 livery and most were repainted in the 1973 striped livery.