Ten months of tunnelling for the Santos Gladstone Liquefied Natural Gas (GLNG) Narrows Crossing project recently came to an end, with the tunnel boring machine (TBM) breaking through to the reception shaft on Curtis Island.
The 4.3 km, 3.4 m diameter segmentally lined Narrows Crossing tunnel will house a portion of the 420 km pipeline that will deliver natural gas from the Surat and Bowen basins to the gas liquefaction processing facility on Curtis Island.
GHD is acting as the owner’s engineer and providing resident engineering services to Santos GLNG for the Narrows Crossing Project in Gladstone.
GHD Project Director Brendan Henry said “This is a huge milestone for Santos GLNG. The team successfully negotiated challenging tunnelling conditions to bring the tunnel in on schedule. The TBM is now being disassembled, and the tunnel cleaned, flooded and prepared for pushing through the gas pipeline.
“The project is located within a marine environment, and a key challenge was the mixed ground conditions at the tunnelling face. The ground conditions were mainly clay and soft alluvium, and when the tunnel approached Curtis Island, it changed to a formation of hard clay and rock with some gravel at the interface.”