Transmission Line Hardware Contract – NIGUP 400kV

Initially operated at 220kV, the New Zealand NIGUP Transmission line will be designed and constructed for 400kV operation and built as double circuit.

New Zealand’s electrical transmission infrastructure continues to undergo a period of sustained investment to enhance its security and performance. In 2008 owner and operator of New Zealand’s National Grid, Transpower NZ Ltd created an Alliance relationship with United Group and Balfour Beatty (called the “Transpower Alliance”). The Alliance has been created to deliver the North Island Grid Upgrade (NIGUP) project : design, supply and construction of a 400kV capable, 3 phase, 50Hz AC transmission line approximately 186km long. The line runs from the central north island Whakamaru North Substation to the Brownhill switching station – approximately 9km south of Otahuhu, Auckland – although the Alliance’s scope excludes the actual substation works.

Initially operated at 220kV, the NIGUP Transmission line will be designed and constructed for 400kV operation and built as double
circuit. Each phase of each circuit is configured in a triple conductor bundle using Sulfur all aluminium conductor (AAAC). An OPGW
earthwire and Wolf ACSR earthwire will run atop the steel lattice tower line, with stringing to begin early 2011.

Partnership offers design, manufacture & supply
For the NIGUP project, Electropar formed a partnership with Salvi & Co. SpA (Italy) to meet the projects transmission line hardware requirements. The Electropar / Salvi scope includes design, manufacture and supply of all fittings and hardware for the tension, suspension and jumper phase conductors, all spacer dampers and stockbridge vibration dampers and all OPGW and earthwire fittings and assemblies. Electropar’s scope also includes overall tension / suspension / earthwire / OPGW string design responsibility, and management of compliance to contract specifications in terms of relevant mechanical, RIV, electrical and vibration type and batch testing.

Global Scale project
For Electropar, this is one of the largest contracts ever awarded to the Company, and represents delivery of components on a large scale even by global standards. For example, there are approximately 430 tower structures that require (among other things!) 4800 suspension string corona rings, 7200 Sulfur Armour Grip suspension units, 11,000 twisted clevis tongues and 19,000 Sulfur AAAC spacer dampers. Electropar’s Sales Director, Cam Wallace says “NIGUP is a rare opportunity to further develop Electropar’s knowledge, systems and processes for global scale EHV transmission projects. Projects of this size and complexity are a real challenge, but the Company is excited by being offered the opportunity to work with Transpower to deliver a top quality asset for the greater good of New Zealand. We will use the skills and experience gained here to develop Electropar’s presence in transmission the transmission line business in the Australian market, and further afield”.