Diesel of the Day 7/14: EMD SD70MAC

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The diesel of the day for today is the EMD SD70MAC. This was the first production alternating current traction equipped locomotive from EMD. 1,109 units were produced between 1993 and 2004. Alternating current (AC) is better for pulling trains than traditional direct current (DC) because the traction motors can be run under very heavy loads at low speeds continuously; doing so with DC motors would burn them up quickly. An example is pulling a heavy train up a mountain grade. Most railroads quickly adopted AC locomotives, though a few, like Norfolk Southern, continued ordering DC units because they were cheaper to buy. Most SD70MAC units remain in service today; they are powerful, reliable machines, with an EMD 16-710G3A two-stroke turbocharged V16 churning out 4,300 horsepower. These engines have an amazing sound to them; video provided on request! Today’s photo depicts CSX first generation SD70MAC number 4542 inside CSX’s Selkirk, New York service facility. (The unit in the background is a third generation model - notice the flared radiators at the rear.) Tragically, this one would be involved in a landslide a year after the photo was taken, and written off despite only minor damage. No crew members were injured.
Rest In Pieces, 4542