The EMD Dash 2 is a line of diesel-electric locomotives introduced by General Motors' Electro-Motive Division (EMD) on January 1, 1972.[1] Designations of these models were those of the former models with "-2" added (e.g., the SD40 was replaced by the SD40-2). They retained the basic specifications of the earlier models in terms of power output and most other features, but introduced a number of improvements to the locomotives' internal systems, specifically the electrical systems and the trucks of the locomotives. These were intended to improve availability, efficiency, and ease of maintenance.
One major improvement was a modularized electrical control cabinet, allowing maintenance by unit replacement and the use of common parts. These concepts were first tested on the DDA40X.