A railroad tie/railway tie/crosstie (North America), or railway sleeper (Europe) is a rectangular support for the rails in railroad tracks. Generally laid perpendicular to the rails, ties transfer loads to the track ballast and subgrade, hold the rails upright, and keep them spaced to the correct gauge.
Railroad ties were traditionally made of wood, but pre-stressed concrete is now widely used especially in Europe and Asia. Steel ties are common on secondary lines in the UK; plastic composite ties are also employed, although far less than wood or concrete. As of January 2008, the approximate market share in North America for traditional and wood ties was 91.5%, the remainder being concrete, steel, azobé (red ironwood) and plastic composite.
Coarse aggregate is the standard material for track ballast, which provides drainage and resilience. On lines with lower speeds and axle-weights, sand, gravel, and even coal ash from the fires of steam locomotives have been used.
Up to 3000 ties are used per mile of railroad track in the USA, 2640 per mile (30 per 60 ft rail) on main lines in the UK. Rails in the USA may be fastened to the tie by a railroad spike; iron/steel baseplates screwed to the sleeper and secured to the rail by a proprietary fastening system such as a Vossloh or Pandrol are commonly used in Europe.
Read more about Railroad Tie: Fastening Rails To Railroad Ties, Other Uses, Ballastless Track
Famous quotes containing the words railroad and/or tie:
“... no other railroad station in the world manages so mysteriously to cloak with compassion the anguish of departure and the dubious ecstasies of return and arrival. Any waiting room in the world is filled with all this, and I have sat in many of them and accepted it, and I know from deliberate acquaintance that the whole human experience is more bearable at the Gare de Lyon in Paris than anywhere else.”
—M.F.K. Fisher (1908–1992)
“Don’t tie your shoes in a melon patch, and don’t adjust your hat under a plum tree.”
—Chinese proverb.