Introduction: Internal corrosion is a major factor limiting the life of Aluminium Conductor Steel Reinforced (ACSR) and a crucial stage in the corrosion process is the loss of zinc from the central galvanised steel strands.

Once this galvanising is lost the aluminium strands are subject to galvanic corrosion and the conductor deteriorates rapidly. The effects of this form of internal corrosion are not visible or detectable by infra-red methods until the conductor is near to failure.

Objectives: Phase 1 of Cormon ACSR Equipment replacement. National Grid are seeking a replacement of the existing overhead line corrosion detector. This project investigates the requirement for a new corrosion detector. This project is a preliminary phase to identify the requirements of National Grid and to understand the costs and timescales that would be involved in developing, testing and trialling an Overhead Line (OHL) corrosion detector.