Railway Accidents

Traditional track structure
Notwithstanding modern technical developments, the overwhelmingly dominant track form worldwide consists of flat-bottom steel rails supported on timber or pre-stressed concrete sleepers (referred to as railroad ties in the US), which are themselves laid on crushed stone ballast.
Most railroads with heavy traffic use continuously welded rails supported by ties (sleepers) attached via tieplates (baseplates) which spread the load. A plastic or rubber pad is usually placed between the rail and the tieplate where concrete ties (sleepers) are used. The rail is usually held down to the tie with resilient fastenings, although cut spikes are widely used in North American practice.
Timber sleepers (ties) may be of hardwood or softwood, and are customarily treated with creosote or other wood preservative. Pre-stressed concrete sleepers (ties) are often used where timber is scarce and where tonnage and/or speeds are high.