
Helm Leasing SD40-2 6253, a former Union Pacific locomotive
For much of the period between the mid 1970s to early 1990s, the EMD SD40-2 was almost the "generic American locomotive", with almost 4,000 examples being sold. At the time of the model's introduction, many detested the new units for helping to replace many first-generation diesels, but today the type is itself a sought-after photo target as newer power begins to replace it. Combining the Dash-2 electrical systems in the proven SD40/645 engine combination, the SD40-2 proved to be more economical to operate than the more powerful SD45.
EMD produced no booster SD40-2s, but BNSF continues to operate several rebuilt units that predecessor Burlington Northern created from wrecked standard locomotives. EMD production ended in 1986, but many SD40s, SD45s and SD45-2s have since been rebuilt to SD40-2 configurations.

NS SD40-2s on Horseshoe Curve

Seven years after Conrail, this NS SD40-2 was still in blue
CSX 8063
FURX 3040 is a former B&O SD40 rebuilt to SD40-2 standard, which trailing 6253 is a former Burlington Northern SD40-3 rebuild.
Between 1974 and 1980, EMD built 312
SD40T-2 tunnel motor versions, these having their radiator intakes moved lower down to prevent overheating by taking in cooler, less exhaust-laden air closer to the bottom of tunnels. The Southern Pacific was the major customer, buying 229 with 4,400-gallon fuel tanks; those bought by the D&RGW had 4,000-gallon tanks.
The
BB40-2 variant is a rebuilt narrow-gauge version for use in South America, using two pairs of B trucks.
Locomotive Patent Plans - Print & Download
Missouri Pacific SD40-2 photo gallery
Roster of FURX locomotives