Spar (platform)

[1] The deep draft design of spars makes them less affected by wind, wave, and currents and allows for both dry tree and subsea production.

Spars are permanently anchored to the seabed by a spread mooring system composed of either a chain-wire-chain or chain-polyester-chain configuration.

[2] The cylinder comprises a number of tanks; the lowest contains ballast, mid-water and/or extracted oil, the upper, air for buoyancy.

Shell's attempted deep sea disposal of the platform in the 1990s created a massive environmental backlash by Greenpeace.

[7] The world's deepest production platform is Perdido, a truss spar in the Gulf of Mexico, with a mean water depth of 2,438 m (7,999 ft).