Main access tunnel completed for Kidston hydro project

The tunnel, which will provide permanent access to the power station cavern, was excavated in high quality rock conditions. It now gives access for the power station cavern lower bench excavation works and fit-out.

Following an incident of water ingress at the north Queensland jobsite in September 2022, Genex Power decided to realign the tunnel away from the zone of fractured material encountered in the original tunnel heading. While this resulted in an additional 436m for the realigned tunnel, it reduced the overall risk of the underground works. The project’s EPC contractor – a McConnell Dowell and John Holland Group joint venture – started tunnelling works on the realigned route in December 2022.

Genex says the tunnel completion marks a major milestone for the underground works and the overall de-risking of the project.

Genex CEO Craig Francis said the completion of the realigned tunnel was a major milestone.

“We are extremely pleased with the way in which the Genex and EPC contractor teams responded to the water ingress event last year, completing the redesign and recommencing production with minimal delay. This has limited the time and cost impacts of the water ingress event on the overall project,” he said.

“Today’s milestone is extremely significant, as it enables Genex and its stakeholders to draw a line under one of the material outstanding risk items for the underground works. Importantly it moves us one step closer toward commencing the power station fit-out works ahead of energisation later in 2024.”

Last year, Mott MacDonald principal engineer Clare Onal gave a presentation on the project to the annual joint BTS and MinSouth meeting. For a full report on the presentation, click here