High Quality Content by WIKIPEDIA articles! The term Royal Hudson refers to a group of semi-streamlined 4-6-4 Hudson steam locomotives owned by the Canadian Pacific Railway (CPR) and built by Montreal Locomotive Works (MLW). The engine was built in 1938. In 1939, King George VI allowed the CPR to use the term after Royal Hudson number 2850 transported the royal train across Canada with no need of replacement. These locomotives were in service between 1937 and 1960. Four of them have been preserved, and one was used for excursion service in British Columbia.