This December 13/92 photo shows the "SW" end of CN SW1200RM number 7100, one of two members of class GS-413a. This view looks east off the Highbury Avenue overpass in London, Ontario.
Thursday, 1 November 2018
Throwback Thursday - "A Sweep is as Lucky as Lucky Can Be."
By Peter Mumby.
Between 1956 and 1960, CN acquired 192 model SW1200RS units from General Motors Diesel. By the mid 1980s plans were afoot to rebuild some of these little engines to make them better suited to current needs and conditions. Eighteen units, numbered 7300-7317, were rebuilt in 1987. Power remained at 1200 hp, and external appearance was little altered. Designated SW1200RM, CN classed them as GS-412a. However, the focus of this post is the smaller group of rebuilds, also designated SW1200RM, that were produced with a 1350 hp rating. Rebuilding occurred in 1985 and 1987. Numbered 7100-7107, these engines incorporated a number of GP9 components, most obviously the long hood. The cab end was left in its SW configuration, while the long hood was straight GEEP in appearance, leading railfans to dub them SWEEPS. The two examples illustrated in this post, 7100 and 7106, were originally CN 1241 and 1257, respectively. By the early 1990s, rebuilt GP9s in the 7000 and 7200 series were providing higher horsepower yard switcher options, so there were no further additions to this small group of SW1200RS rebuilds.