Transporting Oil around the World
Tankers have carried oil around the world since the 1870s. As demand for oil grew, so did the ships. The largest oil tanker today is the ULCC class, or Ultra Large Crude Carrier, which can carry up to 2.5 million barrels of oil. VLCCs (Very Large Crude Carriers) transport roughly 2 million barrels of oil on a single voyage. Smaller tankers carry oil along coasts and inland waterways.
As a result of the Exxon Valdez oil spill in 1989, modern oil tankers are built with double hulls. If the outer hull is breached, the inner one will contain the cargo and prevent it from spilling.