How DO you shift an oil rig that's as heavy as 2,000 London buses? The answer is with the world's biggest boat and an operation akin to dismantling 'the mother of all Meccano sets'

Engineers have been working on a method of dismantling the giant oil rig since it stopped production six years ago from its position 115 miles north east of the Shetlands. Brent Delta is the first major North Sea rig to be decommissioned at an estimated cost of £500 million. When this potent symbol of British oil's heyday arrived at a scrapyard in Hartlepool last week - to be placed on a specially reinforced quayside which is now the strongest in Europe - its vastness attracted the crowds. Indeed, the story of its homecoming is a jaw-dropping feat of engineering 'firsts', involving the world's heaviest offshore lift by the world's largest ship, Pioneering Spirit, which is as long as six Boeing 747s and has deck space equal to six football pitches.