Tankers are marine and river vessels for the transport and delivery of goods in liquid, semi-liquid or gaseous stateTheir cargo can be hydrocarbons products, such as crude oil or its variants in processed form, natural gas in different forms or products and raw materials in the food industry as molasses, alcohol or wine.
Some of the biggest ships ever produced are exactly tankers. Comparatively new tanker concept dating from the late 19th century.The construction and the technical structuring of tanker ships are stipulated by the IMO (International Maritime Organisation). These stipulations have been amended periodically so as to ensure that the underlying safety aspects of the transportation of such volatile elements are met without any compromises.
As specified earlier, different variances of liquefied freight necessitate the use of different kinds of tanker vessels.
Tanker ships are mainly classified on the basis of type of cargo and size of the vessel. Some of the most commonly used tankers are:
- Crude Oil tanker
- Chemical tanker
- Product tanker
- Gas tanker
Tanker vessels that are used for oil transportation through marine channels are referred to as oil tanker ships. The terminology of ‘oil tankers’ too by itself is a big domain and covers not just crude oil tankers but also those vessels that are used in the transiting of distilled and processed rock oil.Vessels that help in the transportation of such distilled rock oil in the form of gasoline, petrol and all petroleum based organic compounds, from their distilling units to the necessary dispersion centres are referred to as product tankers.
Liquefied gas tankers are designed and specialized in the transport of natural gasor propane, butane in liquid form, LNG / Liquid natural gas / and LPG / Liguid petroleum gas /.
According to its size tankers are divided into several main categories:
Very Lage Crude Carriers / VLCC /
Ultra Large Crude Carriers / ULCC /
Aframax-medium sized vessels with a size between 80 and 120 thousand tons DWT,
the main advantage of which is comparatively large size allowing them to operate in most ports around the world.
Panamax-50 to 80 thousand DWT, this type has size strictly consistent with those of the locks of the Panama Canal.
Suezmax-medium sized tankers deadweight tonnage (DWT) of between 120,000 and 200,000.
They are the largest vessels that meet the constraints of Suez and capable of transiting the canal laden. Typical Suezmax tanker is 275 m (900 ft) long, 48 m (157 ft) wide and 16.2 m (53 ft) depth corresponding to approximately 150,000 DWT.
Very Large Crude Carriers (VLCC)-sized large tankers between 180,000 to 320,000 DWT.
These tankers are able to pass through the Suez Canal and for this purpose are raztovarvanei loaded before and after him, the result is used extensively around the North Sea
Mediterranean and West Africa. VLCC can measure up to 1540 ft (470 m) long by 200 ft (60 m) in width, and has a project up to 66 feet (20 meters).
Ultra Large Crude Carriers (ULCC)-the largest tankers in the world with sizes ranging from 320,000 to 550,000 DWT.
Because of their enormous size, they require a custom built terminals. As a result, they are able to serve a limited number of ports in the world.
They are used mainly for very long distance transportation of crude oil, especially from the Gulf to Europe, Asia and North America.
Today, ULCC are among the largest vessels to supply standard size of 415 meters long, 63 meters wide and 35 meters draft.
According to SOLAS / Safety of LIfe at Sea / of 1978, crude oil tankers are equipped with inert gas system, washer system with crude oil tanks, separate ballast tanks, but by 2002 they necessarily built with a double bottom.