SP's loaded Oil Cans circle the Loop, with the head end passing over the last cars with near perfection. SD40R, No. 7300, the "class" locomotive for this SP rebuilt engine type, is leading today's consist. For many years, the BKDOU sported EMD power almost exclusively.
The EMD SD (special duty) series are a strong and reliable kind of locomotive which still serve America's rails today. They have proved themselves reliable by clocking in several million miles of freight service over several decades.