Prelude FLNG Pile Mobilisation and Transportation

Location: Browse Basin, Western Australia


Our team was engaged to conduct a marine transportation study of the Prelude FLNG anchor piles on behalf of the installation contractor. The 16 piles, which are 5.5 m in diameter at 62 m long and weigh over 650 Te, are the heaviest in the world and were loaded out from a heavy lift vessel in Indonesia where they were dressed and mobilised to the Browse Basin.


Our transport study investigated the unique requirements of encountering a cyclone during transport. We conducted a concept motions analysis to first identify the required barge size for the transportation, then, once the barges were procured, we undertook a stability and longitudinal strength analysis to assess suitability. From there, we conducted a motions analysis to assist in sea fastening design.

As part of the transport study, we also reviewed sub-contractor documentation, as well as tug suitability and tow rigging design.

Outcomes and benefits

The work we undertook was vital to the project. The stability analysis ensured no ballasting offshore, thereby reducing operational risk.

What’s more, the analysis also determined the lifting sequence of the piles, reduced the required number of rotations of the barges and confirmed the barges were towable at any stage of the installation process, reducing critical time in an emergency.

Our team’s collective experience enabled us to reduce the analysis cases to a critical few, reducing the time spent running models.

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