Abstract

In an overhead electric and optical transmission system in which at least one of the overhead electric conductors incorporates an optical guide, the overhead electric conductor is mechanically secured to a tower or other rigid support structure by a mechanical connection in which an end of the overhead electric conductor is mechanically secured to and is electrically insulated from the tower or other rigid support structure by an elongate tension insulator having at least one throughbore, the optical guide of the conductor passes from the conductor through the throughbore of the tension insulator to an optical guide joint remote from the insulator, and the electric conductor is electrically connected to another electric conductor. The tension insulator may be a shedded body of porcelain or glass having a central throughbore or it may be a rod or tube of resin bonded glass fibre surrounded by a shedded sleeve of plastics material having at least one throughbore extending throughout the length of the wall of the sleeve.