FAST/HAL Tie and Fastener Experiments

The objective of the Fast Accelerated Service Testing Heavy Axle Load Tie and Fastener Experiments was to quantify the performance of wood and concrete ties and associated fastening systems under the FAST Heavy Axle Load (HAL) train. The experiment was conducted on the 5- and 6-degree curves of the High Tonnage Loop (HTL), with total tonnage accumulation of 160 million gross tons (MGT). There were no failures of any of the wood or concrete ties during the test period. Fastener stiffness measurements performed on wood ties indicated the cut spike system allowed at least twice the lateral rail head displacement of any elastic fastener at a L/V ratio of 0.5 (40,000 pounds vertical force and 20,000 pounds lateral force). The cut spikes also showed as much as five times the rate of lateral restraint degradation as the elastic fasteners over the 160 MGT period at the 0.5 L/V ratio. However, at L/V ratios of 0.25 or less, the lateral displacement allowed by the cut spikes were nearly identical to the elastic fasteners. Comparison of static rail rotation data taken during the 33-ton axle load phase of testing at FAST indicates 70-100 percent higher values are being recorded under the 39-ton axle load consist. Flexural cracks were observed during the initial 90 MGT on 3 percent of the concrete ties in test. The cracks all occurred on the low rail side of the tie between the rail seat and the tie center and were caused by negative bending of the tie. Similar cracks were also observed on one of the concrete ties designed for tangent track. There were no new cracks noted after 90 MGT. None of the cracked ties were removed from track; some remained in service for 140 MGT after crack initiation. Similar cracking was not noted during the 33-ton axle load phase. Measurable tie plate cutting was recorded only in the softwood ties in Section 25. The cutting occurred primarily on the field side of the high and low rail plates causing a decrease in the cant of the rails. Data from the 33-ton axle load phase of FAST indicated more vertical cutting of the plate, as opposed to the differential cutting seen during the HAL program. However, the amount of vertical cutting measured during both programs was very similar. Dynamic strain data were collected on the tops of three consecutive Burlington Northern 100 concrete ties in Section 03 to quantify tensile strains produced by negative bending between the rail seats. The measurement was performed under a train of equal numbers of 33- and 39-ton axle load cars to determine the effect of increased axle load. The data indicated little difference in dynamic strain response due to axle loading, except at the tie centers where an approximate 13 percent increase was recorded for those strains above the 90th percentile of the distribution.

  • Record URL:
  • Corporate Authors:

    Association of American Railroads

    Transportation Test Center, P.O. Box 11130
    Pueblo, CO  United States  81001

    Association of American Railroads Technical Center

    3140 South Federal Street
    Chicago, IL  United States  60616

    Federal Railroad Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Read, Dave
  • Publication Date: 1991-12

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 111p

Subject/Index Terms

Filing Info

  • Accession Number: 01666430
  • Record Type: Publication
  • Report/Paper Numbers: FRA/ORD-91/23, R-795
  • Contract Numbers: DTFR53-82-C00282
  • Files: TRIS, ATRI, USDOT
  • Created Date: Mar 12 2018 1:52PM