Thiess is proud to have delivered a major milestone for Saipem Australia, principal contractor for the Santos GLNG Gas Transmission Pipeline Project by successfully tunnelling under the "The Narrows" off Gladstone to connect Curtis Island with the mainland.
The 4.3 kilometre under-sea tunnel has provided a conduit for installation of the pipeline without disturbing the marine environment.
Tunnelling commenced in April 2013 and the 100 metre-long, 277 tonne tunnel boring machine (TBM) has been operated around the clock on its journey to the tunnel reception shaft on Curtis Island.
Named Rose-Ella by the children at the local Rosella Park State School, the 4 metre diameter TBM also lined the tunnel as it went by installing more than 21,750 pre-cast concrete segments. A cement-based grout was injected behind the segment lining to permanently seal the tunnel which has a finished internal diameter of 3.4 metres.
In early February, the TBM "broke through" on Curtis Island…