Powering up for tunnelling operations
Work has begun to construct a dedicated electricity substation at Tonsley to power the huge machines that will excavate the first two tunnels for the River Torrens to Darlington Project.
The Tonsley East Substation – to be built, owned and run by SA Power Networks – is being established on the site of a recently demolished former Mitsubishi building fronting South Road and will constitute part of the Project’s Southern Laydown Area.
Work on the new facility – which will supply electricity to the tunnel-boring machines (TBMs) and then to the two parallel 4km Southern Tunnels once they are completed in 2030 – is the first construction to occur in direct relation to the T2D Project and will be undertaken by SA Power Networks and its subsidiary Enerven.
Construction began earlier this year following clearance of the site, completion of ground investigations and detailed design of the substation. It is expected to take about one year to carry out.
As part of construction of the substation, two 66,000-volt transformers were installed at the Tonsley East Substation in early August.
The transformers, each of which weigh 38 tonnes, were transported to the Tonsley site from the Wilson Transformer Company in Victoria.
The substation will be fully operational well ahead of the expected start of TBM works on the Southern Tunnels in 2026, with a similar one to be established in the Richmond area to power the TBMs that will build the 2km Northern Tunnels in 2029-2031.
The substations are being set up to ensure TBM operations have a dedicated source of electricity.
The 10.5km T2D Project will enable motorists to have a nine-minute journey from West Hindmarsh to Darlington, and complete the North-South Corridor’s 78km of non-stop motorway between Gawler and Old Noarlunga.