One of the things that made the Union Pacific interesting in the 1960s and 70s was the diversity of locomotive types. At one time, UP management encouraged experimentation in new locomotive technology. By 1970, the Union Pacific was a diesel locomotive spotter's dream come true! Witness this interesting grouping of diesels parked at Union Pacific's Provo servicing terminal on an overcast January day in 1977. From left to right: EMD GP20 #476, blt. July 1960, EMD DD35B, blt. 1964, EMD GP7 #114, blt. July 1953, EMD SDP35 #1400, blt. Aug 1965, EMD DD35 #73, blt. May 1965. Many of these unique EMD models would have required their own parts inventory, which must have been a nightmare for the mechanical department. By 1985, these interesting EMDs had all been sold for scrap when hundreds of new EMD SD40-2s and GE C30-7s made them surplus.
There are times when many engines, cars or cabooses are concentrated in a location. Such sites are for storage, economic reasons, active power needs or for rebuilding. For others, wear and tear have brought their usefulness to and end.
