Crude oil tankers can further be classified based on either their occupation or their sizes. The smallest tanker is about a thousand tons of dead weight while large oil crude tanks can up to about 5500000DWT. In terms of efficiency, crude oil tankers are the second position to the pipeline, moving a total of 2 billion metric tons each year. The cost of transportation using tankers is relatively cheap amounting to average of 2-3 US cents per US$ gallon.
Advancement in technology has facilitated designing of highly specialized crude oil tankers. The most remarkable specialized crude oil tanker is the so called naval replenishment oil; this tanker is specially designed to enable it to fuel a moving vessel. Crude oil tankers like other means of transport are involved in the accident from time to time, the consequences however, has been always severe has compared to other vessels of transportation, this is because the oil spillage in the oceans cause dead of many fishes and other aquatic organisms, this means that a lot of stringent measures must be put in place to ensure that the tankers are well designed.
It is also quite important for you to understand the basic information about each crude tanker, the owner of the tanker normally wants to maximize freight apart from need for solvent customers ready to signed good contracts. The person that needs to hire the tanker oil tanker is termed charter of the vessel.