Nut and bolt joint for hV transmission line mast - has similar bolt holes in vertical and horizontal members with anti-corrosion layer removed adjacent to washers near bolt shank ends

摘要

The constructional detail relates esp. to the framework of a high voltage transmission line pylon, which requires mechanical strength combined with good electrical conductivity to ensure that the entire structure is properly earthed. Two frame members (8, 9) consist typically of an L-shaped stanchion (8) and a flat cross-bear (9) connected by a metal or alloy bolt (13), nut (16) and two washers (14, 17). The exposed faces of the main structural members are coated wtih a corrosion resistant material, for example paint, (21), which is removed in the immediate vicinity of the joint members, so that an electrical connection between the structural components is made through the bolt, nut and washers. During the construction phase the bolt holes are stopped by temporary plastic plugs which prevent the ingress of paint which would subsequently have to be removed.