Arup will prepare concept design and tender documentation, which will lead to the tender process for the tunnel’s construction contract.
The tunnel is for Arrow’s multibillion dollar liquefied natural gas (LNG) project on Curtis Island, off Gladstone in central Queensland, Australia. It will transport CSG from Gladstone to the Arrow LNG Plant on the island. The tunnel to Curtis Island will be one of the longest offshore tunnels in Queensland and will take approximately three and a half years to build and fit out.
Conceptual design will be carried out by Arup’s Brisbane office. The tunnel will have a 4m internal diameter and house high-pressure gas pipeline and other utility services.
Arrow Energy chief executive officer Andrew Faulkner said that Arup would begin work immediately on the tunnel’s design and specifications. “The tunnel will have a smaller footprint than if we were to construct a pipeline on the seafloor,” he said. “There will be entrance and exit points, but no overwater construction.”
The tunnel will be excavated approximately 35m beneath the Gladstone Harbour seabed, with the entrance located in Gladstone’s Yarwun area and the exit at the southern end of Curtis Island. The entire route runs through stable rock. “Australia has a number of experienced tunnelling contractors so we are confident the tunnel will be built to the highest standard,” said Faulkner.