From 1946 until the last engine was built in 1959 there were over 250 GE 70 ton switchers built. The intent was to produce a locomotive best suited for switching, branch lines and transfer service. The end cab was determined to be used based on the instillation of a six cylinder 600 horsepower Cooper-Bessemer engine. Power to the wheels was done using four GE traction motors.

Variations of these engines were ordered new as well as over time being altered by their owners.