Development and Validation of "Forged Rings" for Base Plate Material Use

Abstract

The increasing size of transmission projects and transmission structures on those projects have put a strain on the supply of plate material commonly used for base plates. The availability of base plate material became an issue not only because of lead time (which could affect project scheduling) but because fewer mills were willing to produce base plate material meeting the specifications of our industry. This stimulated the pursuit of other available materials and sources that might be available to satisfy the increasing demand for large, thick base plates for galvanized and weathering structures. This process determined the forged ring material was the most advantageous for leadtime and material conformance to current design practice. It was then identified that three categories for control and validation were required: 1. Base plate design and detailing: The forged ring would provide a larger center hole than had previously been validated in testing. 2. Material properties: This will not be ASTM plate material. How will it be specified, controlled, certified and presented to the customer? 3. Welding procedures: Since this is new material to be welded, base weld procedures must be created for all base weld processes currently used and then independently tested.