SD40-2.
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Builder :
General Motors Electro-Motive Division
Electricity :
DC
Length :
68' 10"
Width :
10' 4"
Height :
15' 8"
Weight :
194.5 tons
Cylinders :
16
Wheel Diam :
40"
Fuel Tank :
4000 gal
Max Speed :
70 mph
Horsepower :
3000 hp
     

Introduced in 1972 , Elector-Motive's DASH 2 line was all about making good things better. EMD's 645-engine locomotives were already well liked for their performance and dependability. They were the best selling machine on the market and nearly every major railroad was using them in large numbers. DASH 2 models were in essence improved variations of the models that preceeded them.

The most significant innivation of the SD40-2 over the earlier SD40 was the entirely revamped electrical system. Modular solid-state electronics were introduced to simplify the electrcal control system. Replacing traditional electrical circuits and relays dramatically reduced the number of electrical components, improved reliability, and eased maintenance. In the event of component failure, modular cards could be easily exchanged, making locomotive repair quick and easy.

From a performance perspective one of the most important attributes of the SD40-2 was the introduction of EMD's new HTC truck. This redesigned three-motor truck replaced the standard Flexicoil truck previously used. Similar in appearance to the Flexicoil truck, the HFC used an improved motor arrangement, better damping, and other innovations to achieve a more effective weight transfer and thus permit better wheel-to-rail adhesion.

The SD40-2 epitomizes the product quality for which Electro-Motive is known. It rapidly became the standard locomotive of the 1970's and 1980's. Almost 4,000 were built for service, making it by far the most common locomotive on American railroads.