Efficiency of Wire Rope Terminations

Abstract

Nine wire rope terminations were evaluated with respect to true efficiency, service life, and sensitivity to poor workmanship in a comprehensive laboratory test program. The portion of the program concerned with true efficiency, as determined by pull tests to destruction, is reported here. Five diameter values of Lang and Regular construction ropes of the 6 × 19 and 6 × 37 class were used on the following wire rope terminations: Flemish Loop with Steel Sleeve and Thimble, Flemish Loop with Steel Sleeve, Wedge Socket, Swaged Socket, Turn Back Loop with Aluminum Sleeve and Thimble, Thimble Splice with Four Tucks, U-Bolt Clips with Thimble, Zinc Poured Socket, and Resin Poured Socket. The true efficiency was shown to be affected by termination type, rope type, and the interaction of these factors. The efficiency values measured in this test program are less than those reported in the literature which are based on the catalog breaking load rather than on the true breaking load. From a graphic and statistical analysis of the data it was possible to present a selection procedure for optimizing the efficiency.

Wire strain variations in normal and overloaded ropes in tension-tension fatigue and their effect on endurance

“…This suggests that the termination process introduces stress variations which negate the benefit of the original overload. The termination technique used in the test series was the 'thimble splice' which has been shown to be a less efficient technique than the resin socket method more generally used in experimental work [8].…”