99F Transmission Line Replacement

Gateway Energy

Project: 99F Transmission Line Replacement

Owner: Transgrid

Engineering Contractor: Downer Group

Project Location: Central New South Wales, Australia (west of Sydney)

Design Location: Brisbane, Queensland, Australia

Background: One of the largest ever steel pole projects in Australia, Downer was engaged by Transgrid to rebuild the 100km long 99F Transmission Line. 99F is a 132kV line located in regional NSW and was originally built on timber H pole construction and was at end of life.

Detail: Over 580 base plate steel poles were supplied for the project.  Gateway Energy was selected early in the process based on our value proposition and fabrication capacity.  All poles were supplied specially galvanised “dulled”. Dulling, also known as shading or de-glaring entails the special application of galvanisation to the poles which stops reflection. Full load tests were also required to prove the designs.  Gateway Energy supplied all Hold-Down Bolt cages.

Benefits: Gateway Energy was able to work with Downer’s line designer to develop the most cost-effective solutions. Transgrid requested that we maintain a cross-arm design that they had used on other projects. We developed a connection design, built a full-scale model and tested it in a structural laboratory, measuring steel strain at critical points in the connection and the pole wall.  This was used to qualify the design.  We also performed full load tests on a number of poles to full satisfaction of client. Poles were all de-glared helped them to blend into the environment.

Other Locations: Gateway Energy also supplies similar projects in Wollongong, Newcastle, Canberra – ACT, Perth and Port Hedland – Western Australia