Conversation so far:
Describe the Afra tanker scale.
AFRA uses a scale that classifies tanker vessels according to deadweight tons, a measure of a ship's capacity to carry cargo
Why was the Afra tanker scale developed?
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.
What are supertankers?
Supertankers are the largest tankers, and the largest man-made mobile structures. They include very large crude carriers (VLCC) and ULCCs with capacities over 250,000 DWT.
Describe supertankers' invention.
The first oil tankers were two sail-driven tankers that were built in 1863 on England's River Tyne. first ocean-going oil-tank steamer, the Vaderland, was designed and built by Palmers Shipbuilding and Iron Company of the United Kingdom for the American-Belgian Red Star Line in 1873,
What are the important factors led to supertankers' development?
In the early 1850s, oil began to be exported from Upper Burma, then a British colony. The oil was moved in earthenware vessels to the river bank where it was then poured into boat holds for transportation to Britain.
What was the role of the Six-Day War in supertankers' development?
The most instantaneous impact was on shipping rates. Oil tankers, en route from the Arabian Gulf to Europe, were forced to take the much longer route around Africa, creating a surge in demand in the time-charter market that was not immediately met by supply.
How many barrels can a VLCC ship carry?
They include very large crude carriers (VLCC) and ULCCs with capacities over 250,000 DWT. These ships can transport 2,000,000 barrels (320,000 m3) of oil/318,000 metric tons.
What is the largest VLCC ship in the world?
Batillus
What new problem did increased scale create for VLCC ships?

Question: Describe crude oil washing
Self-contained rewrite: Describe crude oil washing for supertankers.