What is an Oil Tanker?

An oil tanker – also sometimes referred to as a petroleum tanker – is a ship that is designed to transport oil. Oil of course is a highly valuable commodity which has a number of important applications for modern living. The vast bulk of this oil is imported from overseas and so of course oil rankers play a crucial role here. Not only do these tankers serve a crucial role in getting us the oil we need though, they are also crucial for the economy of countries that completely rely on oil exports to bring in finances.

Oil Tanker Classifications

Oil Tanker

There are actually a number of different types of ships that transport oil. Crude tankers for instance are oil tankers that transport vast quantities of unrefined crude oil from where it is extracted to the refineries. Product tankers on the other hand are a lot smaller and these take the oil from the refineries to the markets where they will be purchased. Even from there though, pipelines will transport the oil around the country and to the markets.

There are also a number of specialized tankers which include ultra large crude carriers which can carry 550,000 DWT. Replenishment oilers are naval ships which are designed to fuel moving vessels, while ore-bulk-oil carriers are floating storage units.

Between oil tankers and pipelines, pipelines are somewhat more efficient but have limited scope of course. Other than this, tankers are the most efficient method available and transport around 2,000,000,000 metric tons of oil each year. The cost of this transport comes to about two or three cents for each gallon.

Design and History

The first successful oil tanker was the Zoraster which was able to carry 242 long tons of kerosene cargo in iron tanks that were joined by pipes. In 1833 the design of tankers stepped forward to have multiple holds spanning the width of the ship – rather than using just one or two larger holds. These holds were then subdivided into port and starboard sections with a longitudinal bulkhead. This helped to prevent what is known as the ‘free surface effect’ whereby oil would slosh from one side to the other and eventually cause the ship to capsize.

The Colonel Swan is often thought of as the first ‘modern’ oil tanker. This was the first tanker with the horizontal bulkhead and included cargo valves operable from the deck. It also had a number of other safety features – including the ability to fill a ballast tank with seawater once the cargo was empty. 1956 saw the introduction of supertankers which were designed to navigate the Suez Canal.

Of course oil tanker fitouts have generally improved as time has gone on, while more safety precautions and remediation companies have helped to reduce oil spills and environmental damage.

The more oil tankers continue to improve, the more the economy will benefit and the more we will all be able to gain from increased availability of oil. With the energy crisis looming though, it will be interesting to see how the industry adapts.