A quartet of SD60MACs were built by EMD to test Siemens alternating current traction equipment and the builder’s HTCR-II radial (steerable) truck. Constructed on a 74-foot frame, the 3,800 hp SD60MAC was painted in a unique Burlington Northern Cascade green and white scheme, with both BN and EMD lettering, and numbered 9500-9503. Soo Line tested the SD60MACs in 1993, and in this view, Nos. 9500, 9503 and 9502 are leading Soo Line train 430 at Green Island, Iowa, on a dreary October 17, 1993.