Track ballast

For other uses, see Ballast (disambiguation).

Good quality track ballast is made of crushed stone. The sharp edges help the particles interlock with each other.
Track ballast supports railway sleepers, which carry railway track.

Track ballast is the material which forms the trackbed upon which railroad ties (UK: sleepers) are laid. It is packed between, below, and around the ties.[1] 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.[1] Ballast also physically holds the track in place as the trains roll over it. Not all types of railway tracks use ballast.[2]

A variety of materials have been used as track ballast, including crushed stone, washed gravel, bank run (unwashed) gravel, torpedo gravel (a mixture of coarse sand and small gravel), slag, chats, coal cinders, sand,[3] and burnt clay.[4] The term "ballast" comes from a nautical term for the stones used to stabilize a ship.[1]

  1. ^ a b c Solomon (2001), p. 18.
  2. ^ Tubular Modular Track
  3. ^ Kellogg, H. W. (1946). "Selection and Maintenance of Ballast" (PDF). American Railway Engineering and Maintenance-of-Way Association. Retrieved 27 March 2021.
  4. ^ Beyer, S. W.; Williams, I. A. (1904). The Geology of Clays. pp. 534–537. Archived from the original on 13 August 2010.