The Double-hulled tanker reference article from the English Wikipedia on 24-Apr-2004
(provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Double-hulled tanker

Spread the word about a children's charity with social media
A double-hulled tanker is a large tanker ship used for transporting liquids (usually petroleum).

The ship has two hulls to prevent the liquid cargo from spilling; if the outer hull is breached, the inner hull keeps the transported substance in place.

Double-hulled tankers were required after the Exxon Valdez oil spill. The United States Congress passed The Oil Pollution Act of 1990 requiring double-hull tankers now, but allowing the transportation companies until 2015 to replace existing tankers.