| MILW SD10 544, Bensenville, Illinois, April 9, 1986, photo by Chuck Zeiler. Built in October 1953 (c/n 18309) on EMD Order 6516 as MILW SD7 2223, later renumbered 523. When it was rebuilt into a SD10, it was renumbered 544, classed as 18.5-ERS-6 (reflecting the increase in horsepower from the as-delivered 1500 to 1850), and later became DME 544. The Milwaukee Road rebuilt seventeen SD-7's and four SD-9's starting in late 1974 and continuing until January 1976, designating the 21 rebuilt locomotives as SD-10's, classed 18-ERS-6 (1800 horsepower - E(MD) Road Switcher - 6 axles). The boxy structure on the roof behind the cab is a Horst air filter, which most of the rebuilt units had, but the last six (556-561) received a lower profile Farr air filter. Also during the rebuilding process, the air reservoirs were changed from a vertical stacked arrangement to horizontal to keep them out of harms way in the event of a derailment. |