Gandy dancer is a slang term used for early railroad workers in the United States, more formally referred to as section hands, who laid and maintained railroad tracks in the years before the work was done by machines. The British equivalents of the term gandy dancer are navvy, originally builders of canals, or inland navigations, for builders of railway lines, and platelayer for workers employed to inspect and maintain the track. In the Southwestern United States and Mexico, Mexican and Mexican-American track workers were colloquially traqueros.

Track ballast is the material which forms the trackbed upon which railroad ties are laid. It is packed between, below, and around the ties. It is used to bear the compression load of the railroad ties, rails, and rolling stock; to facilitate drainage; and keep down vegetation that can compromise the integrity of the combined track structure. Ballast also physically holds the track in place as the trains roll over it. Not all types of railway tracks use ballast.