The Oneida & Western was not a true railroad in the traditional sense but rather a coal operator with its own fleet. The need for such a fleet had its origins in the coal boom of the 1970s and the resulting shortage of L&N cars and motive power to move the coal. Beginning in 1979, the O&W purchased SD40-2 locomotives (built to L&N standards), coal gons, and cabs to ensure a constant supply of cars and power for its unit trains which loaded primarily on the Cumberland & Manchester Branch of the L&N’s Cumberland Valley Sub, though the O&M’s parent company, Shamrock Coal, had a loader on the Straight Creek Branch as well. These trains were operated by L&N (later Seaboard and CSX) crews in Kentucky, Tennessee and Virginia. It was owned by the Shamrock Coal Company, and it’s mint green equipment earned the O&W unit train the nickname “Green Train.” Early green trains were routed on the CV Sub through Norton, VA and connections to the Clinchfield, but later routings took the trains south on the L&N’s old Knoxville and Atlanta main.