Performance of alternative tie material under heavy-axle-load traffic

摘要

TTCI provided manufacturers of alternative tie materials a place to test their newly-designed products and found some promising results. Some of the crosstie and fastener issues that the railroads face include: gauge strength, longitudinal rail restraint, lateral and vertical track stability, tie skewing, cut spike and screw spike uplift, spike-kill conditions, tie plate and hold-down-fastener fractures, tie plate cutting into the tie, tie checks and splits, effects of moisture and cost. In 2001, the U.S. Class 1 railroads spent $911 million in capital expenditures on crossties and $26.5 million on repair and maintenance of existing crossties. In 2003, the track engineering programs of seven major railroads and four regional/shortline railroads in North America called for the installation of approximately 15.3 million ties. Of that total, about 94 percent were new solid-sawn wood ties and about 1.5 percent were relay ties. The remainder was made up of almost five percent concrete, less than 0.1 percent steel and almost 0.4 per-cent plastic and alternative ties.