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.
As put by Tom Koutsantonis
The Tonsley East Substation will play an instrumental role in building the River Torrens to Darlington Project, and the ramping up of work on the plant represents a real milestone.
Following on from extensive preparatory works – such as ground investigations, the relocation of utilities and demolitions – the building of the substation is the first example of genuine construction on the motorway.
It will occupy the site of the large former Mitsubishi building that used to front South Road, and it will help provide a dedicated and reliable source of energy for the crucial initial stage of the Project.
Not only will the substation provide power for the two huge tunnel-boring machines that will excavate the parallel 4km Southern Tunnels, but will also form part of the ongoing energy supply to the tunnels once they are completed and fully operational.
The arrival and installation of two world-class transformers is a significant milestone for the establishment of the Tonsley East Substation.
Construction of the substation over the coming year means that it will be well and truly established before the scheduled start of TBM activity in 2026.
It will also serve as a precedent for a second substation to power the TBMs that will excavate the parallel Northern Tunnels from 2029.
The decision to build the two facilities allows the T2D Project to draw on a dedicated energy source without needing to tap into Adelaide's wider power distribution network.
As put by SA Power Networks CEO Andrew Bills
It is always exciting to partner with State and Federal Governments to deliver a significant new electricity supply for a major project of great benefit to the community. This is a game-changing infrastructure project for South Australia and it is exciting to be involved.
Whether it is this important transport project, development of the major defence industry at Osborne, or projects such as the new Women's and Children's Hospital, reliable and dedicated electricity supply is absolutely crucial. This new substation will meet the significant demand and specific voltage requirements to power the tunnel boring machines as well as long-term power needs for the north-south corridor.
