Sitting in Union Pacific's JR Davis Yard is UPY 1007. Built by General Motors Electro-Motive Division in October 1977 as Missouri Pacific GP38-2 2145, this locomotive became UP GP38-2 645 following the UP-MP merger in 1982. In the quest for lower emission locomotives, Progress Rail, a subsidiary of Caterpillar Inc. (which now owns EMD), has been designing various locomotives for use in areas with heavier-than-normal air pollution. The Electro Motive EMD24B model, seen here (and which Union Pacific classes as GP22T4, as seen on the cab) is one such low emission locomotive. Beginning with a GP38-2, the rebuilt/repowered units are each powered by a Tier 4 compliant V-12 Caterpillar 3512D HD Industrial Diesel prime mover with a Kato alternator and rebuilt D78 traction motors, rated at 2,000 hp and use urea. The conversions are done at Progress Rail's facility in Patterson GA. And don't be fooled by the fan and bulge above the word "UNION" on the hood – these locomotives do not utilize dynamic braking, as indicated by the sticker that reads "LOAD BOX ONLY – NO DYNAMIC BRAKE" under that bulge's grille. UP operates their EMD24Bs (again, what they call GP22T4s) in both local and yard service in northern California. (Roseville, California – June 17, 2023)
