Rapido Trains SW1200RS Operator's Manual - Prototype History
4
PROTOTYPE HISTORY
What exactly does the “RS” mean?
In short: Road Switcher. The SW1200RS is equally comfortable in the yard or on the
mainline.
As produced, the GMD (General Motors Diesel Division in London, Ontario) SW1200RS
differed from the standard SW1200 by having distinctive Flexicoil trucks (a GM design
offering improved suspension and ride quality versus the standard AAR-type switcher
truck); 62:15 gearing for a 65-mph top speed; multiple-unit capability; and large
headlight/numberboard fixtures on both ends. A 775-gallon fuel tank – vs. 500 gallons
on a comparable GMD yard switcher – helped the “RS” units venture beyond yard
limits. As with the standard SW1200, GM’s 12-cylinder 567C engine provided the
model’s 1200 hp.
Canadian National
CNR acquired a total of 192 SW1200RS units between 1955 and 1960, numbered
1204-1397 (there is no 1269 or 1270). Because they were internally pretty much
identical to the GMD-1, they received the same classification: GR-12. General Motors,
Road switcher, 1200 HP. There are two main spotting variations on the CN SW1200RS.
The earlier units, 1204-1290 (GR-12d/f/h/k/l) had a different style of number board
above the cab. As well, 1204-1318 and 1324 had EMD-style steps rather than the
usual Canadian straight steps. Contrary to modelling lore for those of us who pre-date
the internet, the 1200s and the 1300s have nearly identical hoods. The louvers are the
same.
Many CN SW1200RS locomotives were rebuilt into 7000-series locomotives in the
1980s, including 7100-7107. These are the famous “Sweeps,” a combination of
SW1200RS and GP9 uprated to 1350 HP. Man we would love to make those one day.
CN’s last SW1200RS was retired in 2014.
Canadian Pacific
Between April 12 and 20, 1957, CNR SW1200RS No. 1257 was loaned to Canadian
Pacific for evaluation out of Winnipeg, as CPR accelerated its dieselization timetable
and sought an effective “Branch Line Unit” (BLU) for service on low-density secondary
lines. This testing led to placement of CPR’s first order for this model, 31 units delivered
by GMD between June and October 1958 as Nos. 8100-8130 (class DRS-12a). They
arrived in CPR’s then-standard maroon-and-grey livery with Roman lettering, although
many units received script lettering prior to the introduction of the CP Rail Action Red
image in 1968.
CPR acquired two more groups of SW1200RS units: Nos. 8131-8146 (class DRS-12b)
in the spring of 1959, and Nos. 8147-8171 (DRS-12c) in mid-1960. Among the 1959
purchase were ten units (Nos. 8131-8140) earmarked for assignment to subsidiary
Dominion Atlantic Railway in Nova Scotia (but with standard CPR lettering), where they