Compensated Gross Tonnage (CGT) is an indicator of the amount of work that is necessary to build a given ship and is calculated by multiplying the

tonnage Tonnage is a measure of the cargo-carrying capacity of a ship, and is commonly used to assess fees on commercial shipping. The term derives from the taxation paid on ''tuns'' or casks of wine. In modern maritime usage, "tonnage" specifically r ...

of a ship by a coefficient, which is determined according to type and size of a particular ship. The standard CGT system was developed in 1977 by the

OECD The Organisation for Economic Co-operation and Development (OECD; french: Organisation de coopération et de développement économiques, ''OCDE'') is an intergovernmental organisation with 38 member countries, founded in 1961 to stimulate ...

so that inter-country shipbuilding output could be reasonably compared, as different types of ships require a greater or lesser degree of work relative to their

gross tonnage Gross tonnage (GT, G.T. or gt) is a nonlinear measure of a ship's overall internal volume. Gross tonnage is different from gross register tonnage. Neither gross tonnage nor gross register tonnage should be confused with measures of mass or weig ...

. For example, passenger ferry of a given size would require substantially more work to build than a

bulk carrier A bulk carrier or bulker is a merchant ship specially designed to transport unpackaged bulk cargo — such as grains, coal, ore, steel coils, and cement — in its cargo holds. Since the first specialized bulk carrier was built in 1852, eco ...

of the same size due to the differing design requirements, internal structure, and required level of detail, but simply comparing the gross tonnage or deadweight of each ship would incorrectly show that they took the same amount of work. When expanded on a national scale, this difference could greatly mislead people as to the actual maritime production capacity of a given country. The formula to calculate CGT was revised by the OECD in 2007.

References

External links

OECD: CGT system 2007
Revision of 2007 and calculation formula {{Ship measurements Shipbuilding Ship measurements