Alkimos Seawater Desalination Plant
Working 2.6 kilometres offshore in 20 metres of water and open-ocean swell conditions, Austral delivered the specialist foundation piling required for the outfall diffuser manifold at Water Corporation’s Alkimos Seawater Desalination Plant – critical infrastructure that will help strengthen Perth’s long-term drinking water security.
Austral installed 12 foundation piles, each measuring 1,050mm in diameter, 24 metres long and weighing approximately 24 tonnes. The piles were driven to 14 metres penetration into the seabed, exceeding the client’s initial drivability assessment that indicated potential refusal at 10 metres.
To provide certainty of installation, Austral undertook an independent drivability review and hammer selection process and designed, fabricated and deployed a purpose-built subsea pile guide frame to control pile pitching and alignment. Dynamic lifting from the floating vessel was undertaken using heave compensation, with subsea survey and as-built verification confirming final pile positions and levels.
Austral also completed detailed metocean assessments, analysing wind and wave conditions against vessel operational and survival limits to confirm safe barge operability. Works were delivered using Austral’s 400-tonne Pilbara SEMP jack-up barge and specialist suite of hydraulic and vibratory piling hammers.
With piling restricted to daylight hours to enable marine mammal observation, Austral combined specialist marine plant, in-house engineering and carefully planned offshore operations to successfully deliver the foundation system in a challenging open-ocean environment.
The Project
