Concrete Railroad tie
concrete ties on bnsf line north of yakima, washington concrete ties cheaper , easier obtain timber , better able carry higher axle-weights , sustain higher speeds. greater weight ensures improved retention of track geometry, when installed continuous-welded rail. concrete ties have longer service life , require less maintenance timber due greater weight, helps them remain in correct position longer. concrete ties need installed on well-prepared subgrade adequate depth on free-draining ballast perform well. concrete ties amplify wheel noise, wooden ties used in densely populated areas. on highest categories of line in uk (those highest speeds , tonnages), pre-stressed concrete ties ones permitted network rail standards. most european railways use concrete bearers in switches , crossing layouts due longer life , lower cost of concrete bearers compared timber, increasingly difficult , expensive source in sufficient quantities , quality.