In May, 1971, Union Pacific is using its new U50C’s in high-speed service out of East Los Angeles, where the 5003 is being serviced at the open-air engine facility. UP gambled big on the 5,000-hp units, purchasing 40. Lighter and shorter successors to the moderately successful U50’s, they are equipped with weight-saving aluminum wiring, which frequently catches fire. The C-C trucks inherited from GTEL 8,500-hp turbines are already developing cracks. Leaking water coolant, inconstant oil pressure, and melting dynamic brake grids will doom them, and all will be gone by 1976