by Tony Cook and Randy Keller/photos as noted
Denver & Rio Grande Western (D&RGW) was a solid supporter of General Motors’ Electro-Motive Division (EMD) products. As the second-generation EMDs arrived, and the merits of six-axle motive power became popular, Rio Grande bought 3,600-hp SD45s (5315–5340) beginning in 1967. As EMD’s line evolved in 1972 with “Dash 2” entries, the road went big for the 3,000-hp Tunnel Motor SD40-2 variant. Rio Grande began collecting SD40T-2s in 1974 with successive orders building a fleet of more than 70 examples (5341–5413) by spring 1980.
The road was ready for Tunnel Motors a few years later, but builder EMD wasn’t, and offered Rio Grande its 3,500-hp SD50 with the promise that increased horsepower and traction slip control would mean an investment of fewer units (17 SD50s versus the planned 20 more SD40T-2s). To prove its case, EMD SD50s were evaluated by Rio Grande and an order was placed for 17 units delivered in 1984. The assumption would be the usual numbering plan would have been used for those planned Tunnel Motors with 5414 being the class unit for this mid-1980s addition to the fleet, which turned out to be SD50s. Rio Grande skipped the remaining 5400-series numbers and placed its SD50s up at 5501 to 5517.
ABOVE: D&RGW 5411 at Denver, Colo., on May 19, 1980. Rio Grande invested in EMD’s SD40T-2 with orders through-out the 1970s (the first in late 1974). As the 1980s began, the railroad planned another Tunnel Motor order with EMD. —Dean Motis photo, Kevin EuDaly collection
The group was built by EMD during August and September 1984. Coming off EMD’s assembly floor after a run of Chessie System SD50s (B&O 8576–8595), Rio Grande’s SD50s retained traits from those Chessie units with “mailbox slot” openings on battery box doors and a bell mounted on the long hood. The units left La Grange, Ill., without the signature nose light; however, a stop at Mid-America Rail in Kansas City remedied this oversight and the 17 units went to work in early fall 1984…
ABOVE: D&RGW 5504 and 5502 roll through a snaking curve at Castle Rock, Colo., on October 6, 1987, on the Joint Line between Denver and Colorado Springs. —Jim Boyd photo, Kevin EuDaly collection
ABOVE: Union Pacific 9847 at Kansas City, Kan., in October 2003. This was Rio Grande 5504 originally. The unit received Southern Pacific livery before Union Pacific took over the road in 1996. UP numbered this SD50 5098, then 9978, and finally 9847 in June 2002. —Photographer unknown, Paul Wester collection