International Convention on Tonnage Measurements of Ships, 1969 (TONNAGE 1969)

General Detail

General Information

  1. Type: Convention
  2. Date of signature:
  3. Place of signature: London, United Kingdom
  4. Depositary:
  5. Date of entry into force: 18/07/1982


Transport and telecommunications

Sub category

Maritime shipping and load lines



What is it about?

The Convention provides for gross and net tonnages, both of which are calculated independently. Previously, various systems were used to calculate the tonnage of merchant ships. Although all went back to the method devised by George Moorsom of the British Board of Trade in 1854, there were considerable differences between them and it was recognized that there was a great need for one single international system. The rules apply to all ships built on or after 18 July 1982, while ships built before that date were allowed to retain their existing tonnage for 12 years after entry into force.

Why is it relevant?

The Convention is relevant as it creates an international standard and eliminates the differences that existed between the various measurement systems that predated it, providing in their place a unified and consistent method for calculating ship tonnage.

Additional Information




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