An Aframax ship is an oil tanker smaller than 120,000 metric tonnes and with a breadth around 42-44 m and therefore would not be able to pass through the original Panama canal. The term is based on the Average Freight Rate Assessment (AFRA), a tanker rate system created in 1954 by Shell Oil to standardise shipping contract terms.Due to their favorable size, Aframax tankers can serve most ports in the world. These vessels serve regions that do not have very large ports or offshore oil terminals to accommodate very large crude carriers and ultra-large crude carriers. Aframax tankers are optimal for short- to medium-haul crude oil transportation. Aframax class tankers are largely used in the basins of the Black Sea, the North Sea, the Caribbean Sea, the South and East China Seas, and the Mediterranean. Non–OPEC exporting countries may require the use of this type of vessel because the harbors and canals through which these countries export their oil are too small to accommodate the larger Suezmax or the larger still very large crude carriers and ultra-large crude carriers.