MLW Switchers

These notes were compiled by David Othen and are based mainly on articles by Leslie Ehrlich published in CN LINES magazine. Thanks to Leslie Ehrlich, Stafford Swain and Ed Barry for proofreading these notes and making helpful comments and to George Carpenter and Bill Linley for permission to use many photographs from their extensive collections. The photos are copyright and the copyright holder should be contacted for high resolution scans, reprints or permission to use a photograph.

History
Between 1941 and 1959 CNR acquired 317 ALCO and MLW switchers, including 51 S-2s, (31 built by ALCO) 49 S-3s, 128 S-4s (about 30 built by ALCO), 29 S-7s, 11 S-12s and 49 S-13s. Clearly CNR, unlike CPR, preferred the turbocharged 539 and 251 (S-13) prime movers, the only non-turbocharged units being the 49 S-3s.
The S-7 and S-12 models are unique to Canadian National.
The MLW S-2, S-3 and early S-4 models had riveted carbodies while the late S-4, S-7, S-12 and S-13 models had welded carbodies. The late MLW S-4 units and subsequent models had the number indicators on the long hood moved from the side to the front.
In 1958 MLW introduced a new car-body with a single front rather than two side radiator grilles, higher underframe (usually with a step near the front) and higher cab roofs permitting the installation of more insulation and this is seen on CNR's S-12s and S-13s.
Up until 1960 S-2s, S-3s and S-4s operated in yards all across Canada but by 1961 they were probably all allocated to the Central and Eastern regions of CNR where they were joined by the new S-7s, S-12s and S-13s.
In the mid-1960s fifteen S-3s were converted to slugs. On CN from 1969 to 1975 all remaining S-2s, S-3s and S-4s built prior to 1954 were retired but on GTW some soldiered on until 1983. By 1985 all S-4s, S-7s and S-12s had been retired and 22 S-13s had been upgraded/modified by CN into the 8700, 300 and 100 series. The last S-13 was retired in 1997.

Liveries
On the CNR, ALCO and MLW switchers built between 1947 and 1950 were delivered in the black paint scheme with large Morency orange side panels (CNR Orange No 10). S-3s and S-4s built from 1951 to 1954 were delivered in the black paint scheme with ochre-yellow (CNR Yellow No.11) striping and long rectangular letter-boards with curved ends along the top of the hood, as well as a red tilted-wafer monogram on the side of the cab. CNR switchers delivered between 1955 and 1959 wore the same black-and-yellow paint scheme, but with a maple leaf monogram in place of the tilted wafer. Steam-locomotive-style numbers were used from 1951 to 1956, then "Railroad Roman" numbers were applied to locomotives delivered between 1957 and 1960. GTW and CV S-2s were originally all black with yellow or gold road numbers on the hood doors and tilted wafer monograms on the cabs. The earliest units (delivered between 1941 and 1943) had thin yellow or gold striping along the top of the hood and the frame, while GTW S-2s delivered between 1943 and 1947 either had CNR style Morencey orange side panels or were painted similar to earlier units but without the stripes on the hood and frame and larger tilted-wafer monograms on the cabs. GTW and CV S-4s were painted similar to CNR S-4s delivered in the 1950s.

In 1961 the CN symbol was introduced and as locomotives were repainted the new scheme was used but, of course, unrepainted locomotives continued to operate for many years (some into the mid-1970s). The dates below indicate the livery that would have been used if the locomotive was repainted at that time. The orange used (CN Orange No.11) initially had a reddish hue but gradually a more "high-visibility" orange was used.

1961-1972: Black carbody, red-orange ends, grey (almost white) stripe around frame, grey (almost white) logo and road number.
1973-1985: Black hood, orange nose, orange cab, reflective yellow striping around frame, grey logo and road number.
GTW 1972 to early 1990s: Blue carbody, red-orange ends, white lettering, white stripe around frame, white handrails.
CV 1973 to end: Green carbody, two yellow stripes broken by yellow CV logo.
1985-1997: Black carbody, orange ends, orange cab front, reflective yellow striping around frame, grey logo and road number with gold trim. Applied only to S-13s rebuilt at Moncton shops.
No S-13s (the last units to survive) received the current CN single grey stripe/orange cab paint scheme.