METHODS OF FIREPROOFING WOOD BRIDGES AND TRESTLES, INCLUDING FIRE-RETARDANT PAINTS

Specimens of southern yellow pine and Douglas fir were treated with creosote, a 60:40 mixture of creosote with coal tar, and a 50:50 mixture of creosote and petroleum in the continuing investigation of methods of fireproofing wood bridges and trestles. Laboratory burning and temperature measuring apparatus were described. Weight losses after burning, internal temperatures during burning, evaporation rates of the paints, ratio of burned oil to burned wood, toxicity studies of residual preservatives, and performance specifications were studied. Under standard fire testing conditions creosote-treated specimens loose more weight than creosote-tar or creosote-petroleum treated specimens at retentions of 30 and 20 lbs per cubic foot. Creosote-tar treated timber looses more weight than creosote-petroleum treated timber. At low retentions no significant difference is apparent. Protective coating integrity is a function of the insulation it confers to the surface so that internal temperatures do not reach the boiling range of the preservative oils. The same protective coating confers different degrees of protection placed on aged timber as opposed to freshly treated timber. Aging of timber or evaporation of low-boiling constituents in preservatives influence protective coating adhesion. Timbers with high preservative retentions require more time to reach the same conditions as adjacent timbers in structure with lower preservative retention.

  • Corporate Authors:

    American Railway Engineering Association

    59 East Van Buren Street
    Chicago, IL  United States  60605
  • Publication Date: 1958

Media Info

  • Features: Figures; Photos; Tables;
  • Pagination: p. 762-795
  • Serial:
    • AREA BULLETIN
    • Volume: 59
    • Publisher: American Railway Engineering Association

Subject/Index Terms

Filing Info

  • Accession Number: 00052383
  • Record Type: Publication
  • Source Agency: Association of American Railroads
  • Report/Paper Numbers: Proceeding
  • Files: TRIS
  • Created Date: Jul 15 1974 12:00AM