Expansion Effects as a Cause of Deterioration in Suspension Type Insulators

In seeking causes for the rapid deterioration which has been encountered in suspension type insulators, two leading hypotheses, viz., porosity and mechanical cracking through expansion effects, have been advanced by different groups of investigators. These are briefly outlined in the paper, after which the author presents data in support of the latter. Some of the operating problems attendant upon insulator deterioration are also discussed.