It took time, but after a while, the cat started to trust the workers, and shortly after that, the master mechanic brought him to a vet for a checkup.Because of that, the cat’s fur started getting dirty so the crews nicknamed it “Dirtbag.” Later it was shortened to “Dirt.”“The engine house and machine shop are very dirty, noisy environments.Dirt got very wise, very fast, quickly figuring out where not to be when locomotives and cars were moving, or work was being performed,” the railroad’s staff wrote.Dirt would often spend his days wandering or sleeping in the large shop complex, but employees say he would always come out to see visitors during the daily 2:30 p.m. shop tour.When the tour was over and the guests got their fill of the famous cat, he’d go back to his hiding spot."