In the early 1950s dieselization of yard and industrial switching services on Canadian National lines was well underway. After reviewing the available models from General Motors, ALCO, and Fairbanks Morse, management decided that the 1000hp switcher was to be the standard for yard service. The first such units were obtained during World War II when CNR purchased 31 Model S-2s from ALCO in the US. American subsidiaries received 21 of these units and 10 were for service in Canada. Thus began a long association with ALCO and later Montreal Locomotive Works, which would, by the end of the 1950s, see 268 units on the roster. Of the total, 141 of these were 1000hp model S-4s built by both ALCO and Montreal Locomotive Works. Units ordered for US lines, Central Vermont and Grand Trunk Western were all built by ALCO. Orders for Canadian lines were built at Montreal Locomotive Works. The locomotive orders were delivered starting in 1951 and ending in 1956.
Canadian National #8019, a model S-4, was delivered in a group of eight units, #8018-#8025, from Montreal Locomotive Works on September 11, 1952. The unit was designated as Class Q-6-c, later changed to Class MS-10c. The units were assigned across Canada during the 1950s but by 1961 all MLW units were re-assigned east of Winnipeg when sufficient General Motors units were available to cover yard duties in Western Canada. In reviewing CN assignment rosters we see that #8019 was assigned to Winnipeg in 1952, Vancouver in 1954, Saskatoon in 1956, Biggar Sask. in 1957 and after 1960 to duties in southern Ontario.
#8019 was retired and removed from the CNR roster on September 8, 1975 following a management decision to retire all MLW/ALCO switchers with 539 series prime movers.
The move toward larger rolling stock, increased competition from truckers and a high failure rate on the prime movers spelled the end for the units. Of all of the model S-4 switchers on the CNR roster, #8019 is the sole survivor in preservation.
In June 1976, #8019 was sold to Vancouver Wharves for switching duties at their operation in North Vancouver. Given #23, the unit worked the wharves until March 1987 when it was donated for preservation to the West Coast Railway Association.
