Ships carrying crude oil and petroleum products are limited by size restrictions imposed by several of the main thoroughfares of maritime navigation: the Panama Canal, the Suez Canal, and the Strait of Malacca. These size restrictions provide another way to classify the large tankers that carry most of global crude oil and petroleum product trade.
The Panama Canal, an important route connecting the Pacific Ocean to the Caribbean Sea and the Atlantic Ocean, currently has a limited role in global crude and petroleum product transport. The canal's current size restrictions means smaller vessels, with capacities of approximately 400,000-550,000 barrels of light sweet crude oil, are the only ships that can safely pass through the canal. These ships are referred to as Panamax tankers, and their smaller cargos lead to a higher per-barrel cost.
However, the Panama Canal is undergoing an expansion that will allow for the passage of larger vessels with capacities of approximately 400,000-680,000 barrels of crude oil. These larger tankers have the potential to increase crude and petroleum product transport through the canal. Larger vessels or vessels that are slightly over the draft limit can use the Trans Panama Pipeline, which runs parallel to the canal and has both the loading and unloading points for a complete transfer, but doing so adds to shipment costs. In addition to oil transit, the expansion of the Panama Canal, now slated for late 2015, will be able to provide passage for up to 80% of global shipping of liquefied natural gas (LNG). It currently allows passage of only a small percentage of LNG shipping and only shipping by the smallest of LNG tankers.