[Yofloto]

Originalmente publicado por Inspectorate

Se refiere al arqueo bruto del barco. Es un volumen, aunque coloquialmente, se habla de toneladas, porque antiguamente se median las TRB o Toneladas de Registro Bruto. Estas toneladas son toneladas Moorson y no son una unidad de peso sino de volumen.

El GT de un barco se calcula según lo dispuesto en un Convenio internacional: Convenio Internacional sobre arqueo de buques de 1969.

Tiene íntima relación con el esfuerzo pesquero de cada país, pues la "capacidad de pesca" de un Estado se determina en atención a esta medida, independientemente de otras dimensiones, del conjunto de su flota pesquera. Cada país tiene un "cupo" y no puede pasarse. De ahí que cuando un barco se desguaza, se aporten su GTs para construir otro.

Las Administraciones Autonómicas, en un esfuerzo por renovar su flota pesquera, subvencionan, la construcción de pesqueros nuevos, y utilizan éste término para determinar la cuantía de la subvención.

Bueno, espero te hayas hecho una idea, lo he redactado de prisa y corriendo y sin demasiado rigor.

Salutem.

P.D.:
Si se te da bien el inglés:

International Convention on Tonnage Measurement of Ships, 1969

Adoption: 23 June 1969
Entry into force: 18 July 1982

Introduction
Gross tons and net tons

Introduction
The Convention, adopted by IMO in 1969, was the first successful attempt to introduce a universal tonnage measurement system.

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 Convention provides for gross and net tonnages, both of which are calculated independently.

The rules apply to all ships built on or after 18 July 1982 - the date of entry into force - while ships built before that date were allowed to retain their existing tonnage for 12 years after entry into force, or until 18 July 1994.

This phase-in period was intended to ensure that ships were given reasonable economic safeguards, since port and other dues are charged according to ship tonnage. At the same time, and as far as possible, the Convention was drafted to ensure that gross and net tonnages calculated under the new system did not differ too greatly from those calculated under previous methods.

Gross tons and net tons
The Convention meant a transition from the traditionally used terms gross register tons (grt) and net register tons (nrt) to gross tons (GT) and net tons (NT).

Gross tonnage forms the basis for manning regulations, safety rules and registration fees. Both gross and net tonnages are used to calculate port dues.

The gross tonnage is a function of the moulded volume of all enclosed spaces of the ship. The net tonnage is produced by a formula which is a function of the moulded volume of all cargo spaces of the ship. The net tonnage shall not be taken as less than 30 per cent of the gross tonnage.

Gracias mil.

Desconocía que al arqueo bruto se le llamara GT.

Me sorprende que se pretenda aumentar el arqueo bruto por encima de los volúmenes bajo cubierta... no es lógico porque a ese peso adicional no hay ningún volumen susceptible de ser sumergido que lo sostenga.

Salud.