Removal Criteria Establishment and Verification in the USA

RoundTable – WIRE ROPE DISCARD CRITERIA - Zurich 1989

This discussion traces the development of wire rope removal, or discard, criteria in the U.S. beginning with studies sponsored by the Bureau of Mines in 1906, and publication of specific criteria in 1915 in ''Bureau of Mines Bulletin No. 75''. With wide acceptance of industry concensus standards in the 1960s and enactment of the federal Occupational Safety and Health Act (OSHA) in the early 1970s, a research program was undertaken by the Wire Rope Technical Board (WRTB), an independent trade association of domestic wire rope manufacturers. Graphs and narrative summarize eight phases of WRTB
research over 12 years, beginning in 1976. Significant findings include verification of the applicability of broken wire removal criteria developed in the 1906-15 studies for standard 6x19 classification ropes, and evidence that these criteria may be unnecessarily restrictive for some 6x36 classification ropes. The WRTB research also established that use of swivel end attachments on rotation-resistant ropes appears to contribute to premature rope failure, that new removal criteria are needed, and that use of swivel end attachments should be discontinued in rotation-resistant ropes. Tests also demonstrated that attainment of accepted broken wire removal criteria is not critically related to rope strength.