Tanker (ship)

The market was also not geared towards transporting or selling cargo in bulk, therefore most ships carried a wide range of different products in different holds and traded outside fixed routes.

Different products require different handling and transport, with specialised variants such as "chemical tankers", "oil tankers", and "LNG carriers" developed to handle dangerous chemicals, oil and oil-derived products, and liquefied natural gas respectively.

Tighter regulation means that tankers now cause fewer environmental disasters resulting from oil spills than in the 1970s.

Amoco Cadiz, Braer, Erika, Exxon Valdez, Prestige and Torrey Canyon were examples of accidents.

Tank heaters may be required to maintain heavy crude oil, residual fuel, asphalt, wax, or molasses in a fluid state for offloading.

[5] For oil tankers, systems will need to be in place to manage operational hazards, including a means of producing and introducing inert gas into cargo tanks to prevent explosion.

[8] Tank lids and joints between pipes may need to be bonded to prevent static electricity from causing an explosion.

In 1954, Shell Oil developed the average freight rate assessment (AFRA) system, which classifies tankers of different sizes.

As of 2005, the United States Maritime Administration's statistics count 4,024 tankers of 10,000 LT DWT or greater worldwide.

Five other flag states have more than two hundred registered tankers: Liberia (520), The Marshall Islands (323), Greece (233), Singapore (274) and The Bahamas (215).

[13] Greece, Japan, and the United States are the top three owners of tankers (including those owned but registered to other nations), with 733, 394, and 311 vessels respectively.

[14] Including his calculations on the expansion and contraction of bulk oil, and other information for tanker officers, it went into multiple editions, and in 1915 The Petroleum World commented that it was "the standard book for computations and conversions.