CODA recently participated in a site visit to the Harriet Alpha assets following their arrival at the Australian Marine Complex (AMC) in Henderson, providing an opportunity to observe progress on the offshore removal and onshore dismantling phases of the project.
The visit brought together representatives from CODA, Santos, Liberty Industrial, McDermott, and the Department of Energy and Economic Diversification. Attendees were provided with a detailed walkthrough of the offshore removal and onshore dismantling workflow, including load-in operations and the transfer of large structural components from barge to self-propelled modular transporters (SPMTs) for positioning within the laydown area.
Harriet Alpha, installed in 1985 and ceasing production in 2013, was a pioneering development in Western Australia’s offshore oil and gas industry and forms part of a broader decommissioning program across the region. Liberty Industrial was engaged by Santos to undertake a deconstruction and disposal study for the Harriet Alpha platform. Following the award of the engineering, procurement, removal and disposal (EPRD) scope to McDermott in 2024, Liberty Industrial partnered with McDermott in 2025 to deliver the safe receival, demolition, recycling and disposal activities of the retired platform, including the helideck, topsides, jacket and associated equipment.
With major components including the jacket, topsides and the “Pancake 4” section weighing approximately 1,480 tonnes, 1,440 tonnes and 185 tonnes respectively, the project achieved multiple milestones, including being the largest offshore platform removed from Australian waters at the time.
The Harriet Alpha decommissioning scope represents a significant example of the growing capability of the Australian offshore decommissioning sector. It sets a new benchmark for scale and execution, and reflects the progression toward a growing number of large-scale decommissioning programs across the industry.
CODA acknowledges and congratulates all project teams involved in delivering this stage of the work.
