By Lynda Myer
In order to providing power of the TBMs that are due to dig the first two tunnels for South Australia’s River Torrens to Darlington project (T2D), construction works of a dedicated electricity substation has been commenced.
Being located on the site of a recently demolished former Mitsubishi building in Adelaide, the Tonsley East Substation is slated to be built, owned and run by SA Power Networks and will constitute part of the project’s Southern Laydown Area.
As the first construction in direct relation to the T2D project, the new facility is going to supply electricity to the TBMs and then to the two parallel 4km Southern Tunnels following their completion in 2030. The responsibility of work will be up to SAPN and its subsidiary Enerven.
March 2023 was the date of starting construction after the site clearance, and completion of ground investigations and detailed design of the substation, construction, while it is expected to take almost one year to complete.
Installing two 66,000-volt transformers were installed at the Tonsley East Substation in early August, the substation will be fully operational well ahead of the expected start of TBM works on the Southern Tunnels. A similar one will be established in the Richmond area to power the TBMs that will build the 2km Northern Tunnels.
The purpose of launching these substations is ensuring that TBM operations have a reliable and dedicated source of electricity.
Considering as the most significant infrastructure project ever undertaken in South Australia, the T2D Project is 10.5km long and the final and most complex section of Adelaide’s 78km North-South Corridor.
Two sets of twin three-lane tunnels, lowered and ground-level motorways, as well as overpasses and underpasses and upgrades at key intersections are the subsets of this project, whereas more than half of the project is due to be tunnels.
In April, the potential bidders for the main construction contract were asked to lodge a formal Expression of Interest, while in July, the South Australian government released a market call for land for the project’s tunnel segment precast facility. The determined date for inauguration of the site is by mid-2024, allowing works on the precast manufacturing facility to start after the main contract has been awarded, which is also expected in mid-2024.
The 2025 is scheduled date for commencing the main construction works, while tunneling works for the Southern Tunnel planned to start in 2026. The entire T2D Project will be open to traffic in 2031.
