In today’s globalised world commerce between countries is essential, however cargoes often have to travel vast distances from the seller’s location to reach the buyer’s location. Transporting goods by sea is usually the cheapest way to cover these distances. Due to the high tonnage of cargo that modern vessels are able to carry and the relatively low vessel operating costs the resulting cost of carriage per tonne of cargo is relatively low even in cases where cargo has been transported half way around the world.
Cargo shipping is usually carried out on either liner or a tramp trades.
The liner trades are named as such as they usually adhere to a schedule of ports of call with a pre-advertised timetable. Since the introduction of the container ships in the 1960’s the vast majority of vessels now operating on liner trades are container vessels. There are certain cargoes which are very difficult/impossible to containerise, these cargoes are referred to as ‘conventional’ cargo, or the more modern term of ‘break-bulk’ and the vessels used to transport these kinds of cargoes are termed general cargo ships.
The tramp trades are so called due to the fact that the vessels employed in these trades do not stick to a regular schedule, rather like a tramp they go where they can find cargo. These vessels carry bulk dry cargoes such as minerals, grains and timbers. Even though these vessels do not operate to a specific port rotation or dated schedule it is not uncommon to find a tramp vessel which has remained in a trade for an extended period of time, often filling up at one port, discharging at a second port and then returning empty (in ballast) to the first port to re-fill and repeat the voyage.
Vessels known as tankers carry bulk liquids and can be thought of as specialised tramps. By far the most common liquid cargo is crude oil, however tankers are also known to carry other cargoes such as gasoline, lubricants, chemicals and wine, among others. The tanker classification includes some of the worlds most sophisticated vessels, the LPG and LNG. These vessels are designed to carry liquefied petroleum gasses and liquefied natural gasses respectively.
In addition to the cargo vessels there are also special purpose vessels which come under the classification of commercial vessels, these vessels are not used for transporting cargoes but for (as the name suggests) special purposes such as research vessels, icebreakers, rescue boats, pilot boats and survey vessels among others.
With the exception of the special purpose vessels, commercial vessels are usually manned by a crew which consists of deck officers and marine engineers headed by a Captain.
Despite all the safety regulations currently in force which govern transport by sea it is still a perilous method of transport and there are roughly 200 vessels lost at sea each year which are never found. There are also numerous maritime disasters which occur each year which create severe human and environmental consequences and have vast financial implications.
These disasters often result in changes to current laws and regulations, and sometimes in the introduction of new regulations in an attempt to minimise the risks of future incidents. In this section we will investigate several disasters involving commercial vessels, and their consequences.