The sound comes from Trainz Ultimate Collection, the early Trainz simulator release that bundled routes, locomotives and cab sounds for PC players. It represents the Atchison, Topeka and Santa Fe Railway version of the EMD SD40-2, a real six-axle diesel locomotive introduced in 1972 that became a workhorse across North America. Trainz creators shared and reused locomotive audio like this in custom sessions and videos, which kept specific engine start and shutdown clips circulating among rail simulator fans long after the original release.