By rosebell
Being inaugurated in March 2000, the Heysen Tunnels’ 25th anniversary has been celebrated by the South Australia government.
As the largest road project ever undertaken in South Australia at the time, these tunnels diverted traffic from Mount Barker Road, and the infamous Devil’s Elbow, onto the new section of the South Eastern Freeway, while significantly improving safety and travel times for drivers between Adelaide and the hills.
With a weekly advancement of 21m, crews excavated 500m of rock for each tunnel, up to 60mdeep, using a SW200 tunneling machine, typically deployed in heavy mining operations.
According to Project engineer Tim Wheaton: “It was a very complex and challenging project. The natural terrain site was very steep with limited access. To clear the land around the tunnels, they used a bulldozer which would be lowered down the hillside, connected to a cable and pulley mounted to another bulldozer located at the top. This was also how the head contractor, MacMahons, worked on the Mount Buller ski slopes which they owned at the time. Every time we did any blasting, we’d have to stop traffic and do a sweep through the area to make sure there weren’t any wayward bushwalkers in the vicinity.”
While the date of completing tunneling process was 1998, the excavation paved the way for the South Eastern Freeway realignment, making the Heysen Tunnels – named in honour of renowned artist Sir Hans Heysen – the first twin tunnels on the National Highway.
Before inaugurating the tunnels in 2000, a party was held on the newly laid road, and Tim Wheaton was among the hundreds of guests.
He said: “There was a charity gala prior to the opening, with the who’s who of Adelaide in attendance. The tunnels were chockers with people. They had the tables all in one tunnel, with the kitchen in the other so all the food was coming through the cross-passages.”
December 2024 was the date of completing a A$150m refit and safety upgrade of the tunnels.
Also upgrading the tunnel lighting and ventilation, installation of a new automated fire suppression system, as well as upgrading the Intelligent Transport System, were the contents of this project. The work included the installation of more than 1,000 LED lights, six overhead gantries and more than 140 CCTV and incident detection cameras.
