Shell’s mammoth $12bn plus floating LNG (FLNG) unit Prelude FLNG left Samsung Heavy Industries (SHI) shipyard in South Korea in the early hours of this morning to start its 3,000-nautical-mile (5,550-kilometre) journey to Australia.

Sources said the 600,000-tonnes floater – the biggest floating structure ever constructed – is due to leave SHI under tow at 0500 in a carefully planned operation that has been kept under close wraps in what has been described as “the biggest secret on Geoje Island”.