Very Large Crude Carriers

Shipment from continent to continent is accomplished large tanker vessels, carriers or ships, which is the most economical method of shipment. These economies have produced the largest ships in the world, appropriately named Very Large Crude Carrier (VLCC), and Ultra Large Crude Carrier (ULCC) of size range between 160,000 to 550,000 dwt. Refined products are typically shipped in vessels of up to 40,000 dwt. Class rating. LNG or LPG vessels are typically in the range of up to 100,000 cubic meter (838,700 bbls.) capacity. 

Ships belong to the largest moving structures ever made. For example Very-Large Crude Carriers (VLCC) can be up to 500 m long and 60 m wide which means that the exposed area of the outer hull in some cases will exceed 50.000 m2 and the exposed area in e.g. the ballast tanks will be even larger - up to 230.000 m2. This implies the need for an enormous amount of paint. The vessel should be designed so that it is solid and robust and in a way so it can be maintained properly. 

Very Large Crude Carrier (VLCC)--see supertanker. 

Bright, A.W., et al, Research on electrostatic hazards associated with tank washing in very large crude carriers (supertankers) I. Introduction and experimental modelling, J. Electrostatics, 1, No. 1, February 1975. 

This escalation in tanker size has decreased vessel maneuverability. The standard World War II tanker of 15,000 dwt had a loaded draft of about 9 m and a length of 170 m, whereas the loaded 430,000 dwt very large crude carrier (VLCC) has a draft of about 27.5 m and a length of over 400 m, both adversely affecting maneuverability. In the event of a serious accident, involving a VLCC the polluting potential is also enormous, but the probable number of accidents for the same volume of oil transported is less because of the smaller number of vessels. It would take some 30 or more World War II vintage tankers to move the same volume of oil as one VLCC. Shipment of oil by double-hulled tankers would decrease the risk of loss for a relatively modest increase in cost. 

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