Material provided by Sandvik
Four Sandvik roadheaders will play a key part in delivering a major Australian tunneling project with infrastructure company ACCIONA for Transport for NSW.
First came the Sydney Harbour Bridge and then the Harbour Tunnel. Now, Sydney is getting a new way of crossing its famous harbour and Sandvik machines will play an important role. Sustainable infrastructure company ACCIONA has purchased four Sandvik tunnelling roadheaders for use in delivering Stage 2 of the Western Harbour Tunnel project.
Two Sandvik MT720s and two MT721s will be used to excavate the Sydney-renowned Hawkesbury-Sandstone, enabling the creation of a stretch of twin tunnel between Birchgrove and the Warringah Freeway in Cammeray. When complete, the project will make it safer and easier for Sydneysiders to travel through their city.
The first Sandvik roadheader is commissioned, onsite, and has commenced excavation. The remaining machines are due for delivery to the Western Harbour Tunnel sites in 2024.
Drew Taylor, Business Line Manager for Mechanical Cutting at Sandvik, says the choice of the Sandvik roadheaders for the project is a great reflection on it’s reputation for reliability and productivity. “This is a major piece of infrastructure for Sydney,” he says. “ACCIONA has been awarded the contract to deliver Stage 2 of the project and they, in turn, are relying on Sandvik roadheaders to fulfil the critical role of materials excavation north of the Harbour.”
The flagships of the roadheader fleet
Drew notes that the Sandvik MT720 has a long and proven track record of working on large infrastructure projects worldwide and also at numerous other locations in Sydney. The new Sandvik MT721 comes prepared for the digital future with increased system control and automation capabilities including tele-remote operation.
“These machines are the flagship product of our roadheader range and are engineered to cut hard and abrasive rock with a compressive strength of up to 180 MPa in exceptional cases,” he says. “One of their key selling points is their throughput, which is a lot higher than almost all the competitors. They help achieve target excavation rates while also maintaining extremely high levels of safety and operator comfort.”
ACCIONA was awarded the contract to design and build Stage 2 of the Western Harbour Tunnel project in December 2022. A key aspect of its proposal was tunnelling under the harbour floor with a tunnel boring machine, thereby avoiding the need to dredge.
When complete, the project will comprise 6.5 kilometres of twin three-lane tunnels, stretching from the Warringah Freeway in Cammeray, under Sydney Harbour, to the WestConnex interchange at Rozelle. This will alleviate congestion on the Anzac Bridge, Sydney Harbour Bridge and Sydney Harbour Tunnel.
Sandvik ICUTROC® low speed-high torque cutting technology
Drew explains the Sandvik MT720 and Sandvik MT721 are electrically powered and feature a powerful transverse cutter head mounted on a robust telescopic boom. This delivers optimum cutting power and high productivity and energy efficiency, which in turn lowers operating costs. The cabin is fully pressurized and air conditioned and the operator seat is ergonomically positioned for ease of operation. The whole machine can be comfortably operated using two arm controls.
Both the Sandvik MT720 and MT721 have maximum cutting heights of 6.6 metres and a cutting width of 9.1 metres.
Sandvik CUTRONIC® semi-automated cutting system
All machines on the project have the latest CUTRONIC® system installed, and ready for operation. Sandvik’s semi-automated cutting system is designed for increased productivity and improved mechanical excavation accuracy. Some of CUTRONIC® key features include a cut-path planning system that consistantly plans and optimizes machine performance, including a fast-profiling tool to enhance accuracy in tunnelling applications.