It enables trains to move by providing a dependable, low-friction surface on which steel wheels can roll. Early tracks were constructed with wooden or cast-iron rails, and wooden or stone sleepers. Since the 1870s, rails have almost universally been made from steel.
Railway track structure consists of rails, sleepers, fasteners, ballast and subgrade. The structure can be divided into two parts, the superstructure and the subgrade.
Railroad - Track, Locomotives, History: The modern railroad rail has a flat bottom, and its cross section is much like an inverted T. An English engineer, Charles Vignoles, is credited with the invention of this design in the 1830s.