Methodology for assessment of serviceability of aged transmission lines

The degradation of transmission line conductors is attributed to annealing, fatigue, corrosion, creep and in the case of an aluminium conductor steel reinforced (ACSR) construction, stress redistribution in the aluminium and steel wires. A methodology for monitoring and testing for the degradation mechanisms has been devised. Simple life expectancy models give confidence in the long term serviceability of conductors. The methodology and life expectancy models developed are based on examining and testing conductor samples that are representative of various stages of each of the degradation mechanisms. The conductor samples were removed from in service transmission lines that had over twenty years service.