Union Pacific was seldom an enthusiastic Baldwin customer; most of its modern steam power came from Alco. But in 1952, the road acquired six AS-616 road switchers from Baldwin-Lima-Hamilton. Valued for their hefty 78,750-pound tractive effort, the 1,600-hp units were assigned to heavy yard service around the system and pretty much stayed in place for the rest of their lives. Engine 1263, for example, worked the North Platte hump along with a sister engine. But displaced by newer power by October 2, 1966, the unit is spending its final years in general switching. Traded to EMD by 1968, the 1263 will be scrapped in Omaha in 1968.