Tag: Mount Gibson Iron

CONFIDENCE in the integrity and safety of the new seawall design for Koolan Island was crucial to ensure a collapse would not happen again, according to Mount Gibson Iron chief executive Peter Kerr. “The new design has a higher factor of safety and is fundamentally different to the original seawall, incorporating an impermeable cement-bentonite seepage barrier within the embankment,” he said. “This in-ground barrier, which is more than 430m long, 1.2m thick, and extends down to bedrock (over 40m at its deepest point), was installed by a specialist contractor (Keller) and protects the pit from tidal water flows, ensuring the structural integrity of the seawall embankment. “The structure also incorporates extensive monitoring instrumentation, including more than 150 sensors that enable...

By October 2018, the water level at the main pit was down about 20m from where it was when Mt Gibson began dewatering. Image: Mount Gibson Iron.   THE rebuild at Koolan Island is now 90 per cent complete and on track for completion in March next year, less than five years after Mount Gibson Iron was forced to close it following extensive flooding. Amy Blom spoke with incoming Mount Gibson Iron chief executive Peter Kerr about the rebuild and what else lies on the horizon for the miner.   Q. Koolan Island closed in 2014 following extensive flooding. What led to the decision to rebuild the seawall?   Mount Gibson approved the rebuild of the seawall in April 2017...