Saturday 1 May 2021

CN Stuart Street Yard – GMD ‘Light Weight’ GP9


As is well known, Richard M Dilworth was the creator of the landmark, historically ubiquitous ‘General Purpose’ masterpiece locomotive series. Following the introductory 1,500 HP GP7 was the marginally more powerful GP9 at 1,750 HP. GP9’s enjoyed a long production run in both the US and Canada and were offered in several forms; with or without dynamic brakes, with or without steam generators, high nose or low nose to name some of the versions. North of the border CN collaborated with EMD affiliate GMD to create a uniquely Canadian variant; the go anywhere, lightweight version.

Following the introduction of the GP9 to subsidiary Grand Trunk Western the prior year, CN would acquire their first ‘off the shelf’, standard version GP9’s in 1955. So as to expand their utility on the railway’s vast expanse of secondary trackage, CN worked with the GMD London Ontario plant to create a reduced mass version. By fitting smaller fuel tanks and swapping out ‘Blomberg’ trucks for ‘Flexicoil’ style, GMD was able to shave off as much as nine tons from the standard GP9 weight. The first six of the featherweight GP9’s arrived in November of 1956 (CN 4496 – 4501) and CN would eventually assemble a fleet of 192. CN’s mostly western Canada based network of marginal track work would initially script their principal operational region. As the volume prairie trackage diminished, many of the underweight GP9’s migrated east, several of which would eventually call the Stuart Street Yard in Hamilton home.

GP9 4351, built 10/1959 by GMD London, was remanufactured by AMF Technotransport in 1993 as GP9RM 7277 and is still active. Note the larger 48” diameter cooling fans, a late model GP9 production feature, and centrally mounted air tank adjacent to the undersized fuel tank. Note also the early application of so called ‘ditch lights’ hung from the end handrails.

CN GP9 4207 was constructed by GMD London in June of 1957. Renumbered from CN 4589 in 1957, the lowered mass unit was remanufactured by Pointe St. Charles in 1990 into GP9RM 7269 and retired 2013. Note the longitudinal geometry fuel tank and lack of underbody mounted air reservoir. Many of the lightweight GP9’s had their air reservoirs installed inside the short hood.

CN GP9 4276, built 1/1959 by GMD London, was remanufactured by AMF Technotransport in 1993 as GP9RM 7082. Retired in 2019, the veteran unit was subsequently acquired by Dieselmotive Company Inc. and renumbered BUGX 7082. Note the top of hood mounted air line running from the short nose inside mounted air reservoir.

CN GP9 4338 was delivered by GMD in June of 1959. Remanufactured by Atelier Montreal Facility (AMF) 1992 as GP9RM 7045, the veteran unit would be retired 2011.

CN GP9 4385 was constructed by GMD in October of 1957. Renumbered from 4133 in 1984, the London graduate would be remanufactured in 1992 by AMF as GP9RM 7072, and retired 2007. FAIX leasing would subsequently acquire the unit as their FAIX 801. Both the SW1200RS and lightweight GP were constructed with Flexicoil trucks. While some of the Flexicoil truck assemblies carried on under remanufactured slugsets, all of the lightweight GP’s rebuilt into GP9RM’s received replacement Blomberg style trucks.