Essay On Oil Tankers

The tanker family is known for carrying a wide range of cargo from gas and crude oil to alcohol and acids. The Tanker family include some of the world’s largest ocean going vessels.. At just under half a kilometre long, the world’s largest tanker is more than 4 times longer than the average football pitch.

An oil tanker, also known as a petroleum tanker, is a commercial vessel designed for the transport of bulk oil. There are three basic types of oil tankers:

• Crude tanker and

• Product tanker

• Spcailised tankers

The Crude Tankers is the largest of the tanker group, carry big volumes of oil from the oil producing countries, such as in the Middle East and Gulf area, to the refineries located in across the globe.

Product Tankers, generally

Fuel oil itself is very difficult to ignite, but its hydrocarbon vapours are explosive when mixed with air in certain concentrations. The purpose of the system is to create an atmosphere inside tanks in which the hydrocarbon oil vapours cannot burn.

Inert gas systems deliver air with an oxygen concentration of less than 5% by volume. As a tank is pumped out, it is filled with inert gas and kept in this safe state until the next cargo is loaded. The exception is in cases when the tank must be entered. Safely gas-freeing a tank is accomplished by purging hydrocarbon vapours with inert gas until the hydrocarbon concentration inside the tank is under about 1%. Thus, as air replaces the inert gas, the concentration cannot rise to the lower flammable limit and is safe.

As inert gas is introduced into a mixture of hydrocarbon vapours and air, it increases the lower flammable limit or lowest concentration at which the vapours can be ignited. At the same time it decreases the upper flammable limit or highest concentration at which the vapours can be ignited. When the total concentration of oxygen in the tank reaches about 11%, the upper and lower flammable limits converge and the flammable range