Double-hulled tanker Double-hulled tanker A double-hulled tanker refers to an oil tanker which has a double hull. They reduce the likelihood of leaks occurring than in single-hulled tankers, and their ability to prevent or reduce oil spills led to double hulls being standardized for oil tankers and other types of ships including by the International Convention for the Prevention of Pollution from Ships or MARPOL Convention. After the Exxon Valdez oil spill disaster in Alaska in 1989, the US Government required all new oil tankers built for use between US ports to be equipped with a full double hull. A number of
Oil tanker but can be made from new-built hulls Shell España first used a tanker as an FPSO in August 1977. An example of a FSO that used to be an oil tanker is the "Knock Nevis". These units are usually moored to the seabed through a spread mooring system. A turret-style mooring system can be used in areas prone to severe weather. This turret system lets the unit rotate to minimize the effects of sea-swell and wind. Oil spills have devastating effects on the environment. Crude oil contains polycyclic aromatic hydrocarbons (PAHs) which are very difficult to clean up, and last