In 1963 EMD fielded a four-unit set of demonstrators – two of the new 2,500-hp GP35s bracketing a pair of its 5,000-hp twin-diesel DD35s. UP, which had already committed itself to the cabless DD’s, liked the combination as a replacement for its Big Blow turbines, and bought two dozen of the geeps and 27 of the DD’s, and, in 1964 started running sets on fast freights over the Omaha-Los Angeles route. Here, on a gorgeous summer day in 1965, such a combination behnd GP35 749 storms Archer Hill east out of Cheyenne. Already on the erecting floor at EMD: 15 of the double diesels with cabs, the new DD35A model.