2018 24 Paper: Wivenhoe Guard Gate Refurbishment

In 2008 the first signs of corrosion on the roller system was observed on the guard gate system. A patch of the issue was conducted however it wasn’t until 2014 that the implications of the corrosion system were beginning to be realised.
The station was constructed at the same time as Wivenhoe Dam which meant that a large part of construction infrastructure was available at the time, but this was removed at the completion of the project.
As a low head machine (nominal 100m head) and relatively large output (250MW nominal) the componentry is excessively large and the infrastructure is insufficient to remove and refurbish componentry off site.
Many models and analysis of the guard gate mechanism were conducted and as time progressed it was apparent that significant remedial work needed to be done.
Due to the construction of the asset, removal was not an option so work needed to be done in situ. As outages only occurred every two years, it was four years before the rectification work commenced.
This paper focuses not only on the repair of the Unit 2, but also the lessons learnt along the way and the future work required to complete the repair and preserve the gates for their 100-year design life.

• Author: Ian Foy
• Exchange: 2018 - Albury AGL
• Company: CS Energy
• Topic: Asset Management, Civil, Design Life, Hydraulic Gates, Optimisation, Refurbishment
• Key Words: Corrosion, Gates, Guard Gate, Modeling, Rehabilitation, Repair