The publication of this Project Assessment Conclusions Report (PACR) represents the final step in the RIT-T process. It relates to AusNet’s plans to replace deteriorated porcelain disc and end of life composite insulators which serve to safely support/connect the transmission line phase conductors on the transmission towers. This project is focused on the replacement of Doulton type insulators, following a failure in January 2024 along the HWTS-SMTS 500kV #2 line which caused a conductor drop and line outage.
AusNet has followed the AER’s RIT-T application guidelines to analyse and rank the economic cost and benefits of the investment options considered in this RIT-T. As explained in the Project Specification Consultation Report (PSCR), which we published on 6 March 2025, as the identified need in this case arises from the condition of insulators, there are no credible non-network options that could address this identified need. In effect, the nature of the risk is asset-related and cannot be mitigated by a non-network option given the significant costs of retiring the assets.