After some stationary high-altitude testing by Union Pacific and Electro-Motive Division, the four 6,000 horsepower SD90MAC-H locomotives, got a workout with some tonnage. A test train consisting of 32 loaded hopper cars pulled by UP Nos. 8503, 8502, and 8505 splicing EMD’s test car, and EMD No. 8504 as rear DPU, was operated on UP’s Moffat Tunnel Subdivision. In this photo, the test train has just finished making the upgrade trip to Pinecliffe, Colorado, on February 10, 1998. The crew has now switched ends and brings the train back to Denver. Leading the way is EMD No. 8504, decked out in a special scheme for EMD’s 75th anniversary that was later affectionately nicknamed “Shamu.” I’m not sure it’s a good thing to have your brand new locomotive smoking so much!
