TransGrid has installed their first ever gas insulated switchgear (GIS) building as part of the rebuild of their 132 kV substation in Orange.
The 180 tonne GIS building was constructed offsite and transported to the substation to be installed in the building, marking a first for the NSW high voltage network operator.
The innovative approach taken by TransGrid to construct and fit out the GIS building offsite allowed the project timeframe to be dramatically reduced.
Constructed in Adelaide by Robin Johnson Engineering, the GIS building, measuring 30 metres in length was outfitted with Siemens 66kV GIS equipment from Germany.
The building left Adelaide in early November 2015 for the 1400 kilometre journey and received a full police escort before arriving safely in Orange a week later.
The transport and delivery of the building will be featured on Channel 7’s Outback Truckers.
While on the road, work at the substation site rapidly geared up for the building’s delivery. The foundations for the building involved a 2.8 metre 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 coordinated event, the truck and trailer with 136 tyres was carefully reserved and 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.