Sydney Metro West – Western Tunnelling Package (WTP)

• GLC conducted a decarbonization study at the project's outset to identify the most impactful and cost-effective approach to offset at least 30% of Scope 1 and 2 emissions as per contract requirements.
• The study concluded that 100% GreenPower offers the least risk and highest value for meeting these goals, providing certification, supply stability, and price security.
• Design stage modelling shows that using GreenPower for all high-voltage electricity could reduce Scope 1 and 2 GHG emissions by up to 43%, surpassing the contract's offset target.

Through the large-scale reuse of treated water for TBM operations, GLC will achieve a high potable water replacement rate, significantly reducing WTP’s environmental impact and reliance on finite resources. This success demonstrates that, with collaboration and upfront investment, alternative water sources can be effectively utilized in large-scale tunnel projects without compromising production. Notably, GLC is achieving this during Stage 1 of WTP, which involves only the construction phase. Design stage modeling shows that up to 49.8% of potable water will be substituted with non-potable sources.

• Precast concrete tunnelling segments make up 35% of total concrete use on the Project.
• GLC partnered with Boral to develop a high SCM concrete mix to reduce Scope 3 GHG emissions.
• GLC invested $150,000, with Boral covering the remaining costs.
• The mix incorporates 50% SCM replacement, using Boral’s ZEP alkali slag activator and GGBFS.
• The mix includes 10% less cementitious material compared to traditional mixes.
• Estimated required volume for the Project: 95,196 cubic metres.
• This mix abates approximately 12,000 tCO2eq over the Project's duration.
• The mix contributes 23% of the overall GHG emissions reductions on the Project.

Australian First

​The WTP is Australia's first project to implement the A-TBM technology, which was previously proven on Malaysia's KVMRT Line 2. The autonomous system, using AI, advanced sensors, and control systems, reduces manual handling and enhances efficiency. A study by GLC's tunnelling engineers compared A-TBM with manual TBMs, revealing 8% higher efficiency, along with energy savings, improved steering accuracy, and increased productivity.

State First

Historically, using treated water in Australian tunnelling has been challenging due to TBM water quality requirements and associated risks. Mains-supplied potable water, being reliable and cost-effective (~$2.70/kL), has been the preferred option. In collaboration with Herrenknecht, GLC designed and commissioned the Rosehill Water Treatment Plant, treating groundwater and rainwater to meet A-TBM’s water and NSW EPA discharge standards. This innovation ensures consistent water quality for A-TBM operations, reducing potable water use and setting a new standard for sustainable water management in tunnelling.

Australian First

​​Construction projects traditionally use diesel generators for powering static equipment, but solar hybrid generators are increasingly replacing them to reduce carbon emissions, noise, and diesel consumption. However, typical solar hybrid generators need significant manpower and time for deployment. GLC, in collaboration with Black Stump Technologies, introduced a patented, rapidly deployable solar hybrid generator for the WTP. This innovative system only requires 0.5 manhours per 80kWp solar array, a significant improvement over traditional method. The generator will be used to power the Tunnelling and Infrastructure Academy throughout the project.

Australian First

The GuardDog drain filter uses Spilltration Husky absorbent filtration media, made from 100% recycled postconsumer waste. It effectively traps hydrocarbons, silt, and sediment (down to 53 microns) and absorbs up to 10 liters of hydrocarbons, releasing only clean water. Designed with heavy-duty plastic mesh, it can withstand being driven over by heavy trucks and machinery without splitting, unlike coir logs and silt socks.

Used three products from Isupply registry.

• GuardDog Drain filter
• Black Stump Technologies
• Grasshopper environmental