The class D10 referred to a series of ten-wheelers of the Canadian Pacific, which, with a total number of 507, were widely used throughout Canada. They were simple in construction and easy to maintain, but had a larger boiler than ten-wheelers of the 19th century and a superheater. The first locomotives were built as camelbacks, but were rebuilt after about two years. Unlike most locomotives in Canada, they did not have a completely enclosed cab.

No. 784 in its original form as Camelback

Railway and Locomotive Engineering, January 1906

There were the subclasses D10a to D10k, which also showed differences within a subclass. Basically they all used the same firebox, but different numbers of tubes and different superheaters. The driver diameter was 63 inches and the stroke of the cylinders was always 28 inches. For cylinder diameter and boiler pressure, either the combination of 22.5 inches and 180 psi or smaller cylinders with 21 inches and a boiler pressure increased to 200 psi were used. By installing arch tubes in the firebox, its heating surface later increased. The retirements took place between 1938 and 1965.