Extending the Useful Service Life of Wire Hoist Ropes using Nondestructive Testing

Project ID: 3973
Principal Investigator: Daryl Little
Research Topic: Condition Assessment
Funded Fiscal Years: 2015
Keywords: wire rope, ndt, nondestructive testing, corrosion

Research Question

Can nondestructive testing (NDT) be used to accurately estimate the residual strength of wire ropes in order to determine the remaining useful life of the rope?

Need and Benefit

Many Reclamation sites utilize wire ropes that are approaching the end of their expected life cycle (~15-20 years). NDT could potentially yield results that suggest that the wire ropes are still suitable, while other criteria recommend replacement. If deemed more pertinent, the utilization of NDT could prevent premature replacement of ropes therefore extending the usable life, and reducing capital expenditure. Reclamation will also be able to improve dam safety, by utilizing NDT to examine wire ropes for personnel elevators, gate hoists, and the various cranes throughout Reclamation.

Contributing Partners

Contact the Principal Investigator for information about partners.

Research Products

Bureau of Reclamation Review

The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.

Extending the Useful Service Life of Wire Hoist Ropes using Nondestructive Testing (final, PDF, 2.6MB)
By Daryl Little
Publication completed on September 30, 2015

The wire hoist ropes at Shasta Dam exhibited corrosion on the surface as noted during routine visual inspection. In accordance with ANSI B77.1 and US Code of Federal Regulations 30 CFR 30 the ropes would require replacement as soon as possible. The wire ropes were replaced in 2012 and eleven wire rope sections were shipped to the Denver office. This research proposal involved having electromagnetic NDT performed on the rope sections to determine the condition of the wire ropes and identify problems or weak areas. Destructive testing of the wire rope sections were performed after the NDT completed. Testing was conducted for sections of rope exposed to multiple exposure conditions including atmospheric, fluctuating immersion (waterline) and full immersion. The test specimens were fitted with 100% efficient sockets, and underwent tensile testing until failure. Comparison of the test results from the destructive testing and the results of the NDT was done to determine the effectiveness of the NDTmethod.

The following documents were not reviewed. Statements made in these documents are those of the authors. The findings have not been verified.

Service Life Determination of Wire Hoist Ropes Using Nondestructive Testing (final, PDF, 1.2MB)
By Daryl Little (PI), Chrissy Henderson (PI)
Publication completed on September 30, 2016

This bulletin summarizes the research results and potential application to Reclamation's mission.

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Last Updated: 6/22/20