Vibration in overhead conductors

The paper describes laboratory tests which give the static stresses in the various strands of conductors when subjected to certain tensions. These results are compared with those obtained from long-time vibration tests upon similar conductors while subjected to corresponding total tensions. It is concluded that unless the sharp bending at the support is relieved, vibration will cause fracture in a relatively short time. Decreasing the lay or the tension within economic limits will not alone insure against breakage. While the general principles discussed may be applied to any metallic conductor, the tests described were made upon steel-reinforced aluminium (S. C. A.) cable. Reference is made to available devices for the suppression of vibration; these obviously prevent breakage by removing the cause. The paper offers a diagnosis of the vibration trouble, and describes available remedies which experience has proved to be thoroughly efficient and reliable.