Kusan-Auburn F-7 Diesel Locomotives
Kusan continued the same series of F-7 engines that AMT had earlier introduced. One way to tell the difference between an AMT and Kusan F-7 is to look at the roof line. AMT F-7's have a humped roof, whereas Kusan F-7's are straight. Kusan engines also have a "KMT" oval on the sides. These engines have a hefty 7-pole AC/DC Pittman motor, which is rated for operation up to 25 volts, and neoprene "Traction Tread" rubber tires are installed on all four drive wheels, thus making these engines very strong pullers. Kusan-Auburn also offered an optional "DUO-TRAC" system, for a slight additional charge, which enabled their locomotives and rolling stock to operate on either two-rail DC or three-rail AC track. For DUO-TRAC, the wheels on either side of an engine or train car are insulated from each other. A slide switch underneath the bottom of a DUO-TRAC engine has two settings: "2 RAIL" and "3 RAIL" and can be changed by the operator, depending on what type of track system they are using. The Texas Special, Santa Fe and Pennsylvania A units pictured below did not come with the DUO-TRAC upgrade, but the Southern and Chicago & North Western AA units did.