Dash 2

EMD Dash 2 modules.
EMD Dash 2 modules.

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. 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.

Changes[]

Minor externally visible changes common across the whole line include the following:

Models[]

The Dash 2 line was highly successful. The models offered included the following:

Rebuilds[]

In addition, many other earlier locomotives were rebuilt to Dash 2 standards by numerous locomotive rebuilders and railroad shops.

Among the most popular rebuilds are SD40, SD45, SD40T-2 and SD45T-2 into the functional equivalent of an SD40-2, although the frame, carbody and trucks remain the same as on the "donor" locomotive. In many cases, the rebuilds are identified as, for example, an SD40-3 or an SD40M-2, or an equivalent distinguishing identification. In some cases, the locomotive is identified simply as an SD40-2, although it is clear through physical examination that it is a rebuild. Once so rebuilt, the locomotive enters the owner's fleet as if it were a true SD40-2, arguably the most versatile and reliable diesel-electric locomotive of its time, if not all-time.

Although not as popular as the SD40-2 rebuilds, GP40s, GP39/SD39s and GP38/SD38s have also been rebuilt to the equivalent of GP40-2s, GP39-2/SD39-2s and GP38-2/SD38-2s, so significant were the reliability and serviceability advantages of the Dash 2 line.

Subsequent models[]

Models subsequent to the Dash 2 line, for example SD50, SD60 and SD70, et al., incorporated Dash 2 improvements at the outset. In this context, the model suffix -2 is only applicable to the 40 Series, although -2 has been applied to certain variations of the later models.

References[]

  1. ^ Solomon, Brian. American Diesel Locomotives. Voyageur Press. pp. 145–. ISBN 9781610606059. Retrieved 13 August 2014.