On a rainy day in July 1981, Union Pacific EMD GP40X Nos. 9000 and 9001 sit at Council Bluffs, Iowa. Easily seen in this photo, flared radiators are distinctive feature of the GP40X. Experimental HT-B high-adhesion trucks were used beneath ten of the testbeds constructed for UP and Southern Pacific, while Santa Fe and Southern Railway copies received Blomberg trucks. Southern’s three units were also the only ones with high-noses.