All seagoing ships of 24 m in length and above require an „International Tonnage Certificate 1969“ (ITC 69), ships of less than 24 m in length a (national) tonnage certificate. The length is to be measured according to article 2, paragraph 8 of the International Convention on Tonnage Measurement of Ships, 1969 – (ITC).
Ships that are used in international trade and have a length *) of more than 24 m, according to the International Tonnage Convention – London 1969 – measured. After this process, the contents of all closed-end ship spaces (molded line) calculated (ie from keel to funnel) to inner edge skin measured and then. Certain open spaces are discarded and therefore not included in the calculation of the volume.
The tonnage certificate reflects the result of the measurement of the volume of the ship’s spaces and shows both, the gross tonnage and the net tonnage. These tonnage figures affect, inter alia, harbour dues, canal- and pilotage charges, safety requirements, technical equipment, number of crew, fleet- and traffic statistics as well as the registration and the insurance of ships.
Transit charges for the Suez- and the Panama canal are calculated according to different provisions, which are reflected by special Suez- and Panama canal tonnage certificates.