The works involve:

• Removal of 4 existing VCW and fabrication, supply, and installation of replacement guide rails in four VCW chambers
• Refurbishment of existing drain valves to minimise leakages during operation of the gates
• Detailed design, fabrication, supply and installation of lifting equipment for removal/replacement of the VCWs
• Refurbishment of the 4 existing VCWs for use in refurbishment works for other gates
• Dismantle and storage of temporary lifting equipment and gate restraints

The works to refurbish the Coolmunda Dam Gates Variable Counterweights are being undertaken in a brownfield environment, with the dam fully operational. Our project team have been collaborating with the team from Sunwater to manage access, inspections and operational constraints whilst undertaking the works.

Adding to the complexity has been the operation to extract the 15 tonne counterweights from the vertical gate chambers, with a traditional crane unable to complete the lift 3 of the 4 counterweights. To overcome this hurdle, the Abergeldie project team designed and constructed an innovative custom lifting frame which will be used to lift the remaining counteweights for Gates 1 and 2 and retained for use on future gate refurbishments at Coolmunda Dam.

Once completed, the refurbished Coolmunda Dam Gate Variable Counterweights will be more reliable and enhance the dam's dependability during weather events.