A compliant piled tower design, it is 609.9 metres (2,001 ft) high, and was arguably the tallest free-standing structure in the world, until surpassed by the Burj Khalifa in 2010, although this claim is disputed since only 75 metres of the platform are above water. The multi-deck topsides are 64 metres by 43 metres by 18.3 metres high and hold 21 well slots, and the entire structure weighs around 43,000 tons. Around 8,000 m3 (50,000 barrels) of oil and 2,000,000 m3 (70 million cubic feet) of natural gas are extracted daily by the platform.
The platform is situated to exploit the Petronius field, discovered in 1995 in Viosca Knoll (block VK 786) and named after Petronius, the Roman writer. The seabed is 535 m (1,754 ft) below the platform. The compliant tower design is more flexible than conventional land structures to cope better with sea forces. It can deflect (sway) in excess of 2% of height. Most buildings are kept to within 0.5% of height in order to have occupants not feel uneasy during periods of movement.
Construction began in 1997 by J Ray McDermott with the seabed mooring system. The contract for the platform was budgeted at $200 million with total costs of around $500 million. The 4,000-ton North Module was installed in November 1998, but the attempt to install the slightly lighter South Module in December of that year ended with the unit on the seabed. A replacement module was built and installed by Saipem 7000 in May 2000.