GIS goes on a road trip

Orange 132kV substation rebuild
Orange 132kV substation rebuild
  • TransGrid delivers 180-tonne gas insulated switchgear as part of the Orange 132kV substation rebuild
  • Measuring 30m in length, the GIS building is outfitted with Siemens 66kV GIS equipment from Germany
  • The rebuild of TransGrid’s Orange substation is expected to be completed by February 2017

TransGrid has delivered a 180-tonne gas insulated switchgear (GIS) building, as part of the Orange 132kV substation rebuild. The offsite construction of a GIS building, which was transported to the site with the GIS fully installed in the building, marks a first for New South Wales’ high voltage network operator – allowing for a dramatically reduced project timeframe.

Constructed in Adelaide by Robin Johnson Engineering, the GIS building, measuring 30m in length, was outfitted with Siemens 66kV GIS equipment from Germany. Seimens energy management executive general manager Andrew Theodore said the building pushes the maximum transport envelope possible on Australian roadways.

“A building of this size is one of the largest road transportable buildings. Due to the size of the building there
was an intensive design process which saw the methodology change to minimise additional works on site,” Mr Theodore said.

Leaving Adelaide in early November for the 1400km journey, the building received a full police escort and arrived safely in Orange in November.

While on the road, work at the substation site rapidly geared up for the building’s delivery. The foundations for the building involved a 2.8m high cable basement referred to as the ‘bathtub’ to facilitate the pulling in and installation of 16 high voltage cables to connect to the distributor’s assets. To facilitate the GIS building delivery into its service position over the foundations, a temporary structure in the form of a trafficable platform was innovatively designed and constructed.

The temporary structure was designed with cylindrical metal supports from the floor of the ‘bathtub’ with steel beams bolted onto the supports to facilitate the reversing of the self-jacking trailer with the building on it. Once the building was aligned over the foundations, the building was lowered onto its final steel supports, which allowed the trucks and the trailer to move out, making the building self-supporting.

In a highly co-ordinated event, the truck and trailer with 136 tyres was carefully positioned into its final resting place with 150 tonnes of concrete later pumped into the base of the building to stabilise it.

The local distributor will now work to transfer across the in-feeds to the feeders and transformers from the existing air-insulated switchgear (AIS) to the newly installed GIS building.

The rebuild of TransGrid’s Orange substation is expected to be completed by February 2017, with both primary and secondary systems equipment to be replaced.