Search results
Results from the WOW.Com Content Network
The displacement or displacement tonnage of a ship is its weight. As the term indicates, it is measured indirectly, using Archimedes' principle, by first calculating the volume of water displaced by the ship, then converting that value into weight. Traditionally, various measurement rules have been in use, giving various measures in long tons. [1]
Gross tonnage. Gross tonnage is calculated by measuring a ship's volume (from keel to funnel, to the outside of the hull framing) and applying a mathematical formula. 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. [ 1 ]
In modern maritime usage, "tonnage" specifically refers to a calculation of the volume or cargo volume of a ship. Although tonnage (volume) should not be confused with displacement (the actual mass of the vessel), the long ton (or imperial ton) of 2,240 lb is derived from the fact that a " tun " of wine typically weighed that much.
Depending on design requirements, some ships have extremely large internal volumes in order to serve their duties. Gross tonnage is a monotonic and 1-to-1 function of the ship's internal structural volume. It does not include removable objects placed outside the deck or superstructure, like the shipping containers of a container ship.
Builder's Old Measurement (BOM, bm, OM, and o.m.) is the method used in England from approximately 1650 to 1849 for calculating the cargo capacity of a ship. It is a volumetric measurement of cubic capacity. It estimated the tonnage of a ship based on length and maximum beam. It is expressed in "tons burden " (Early Modern English: burthen ...
Net tonnage (NT, N.T. or nt) is a dimensionless index calculated from the total moulded volume of the ship's cargo spaces by using a mathematical formula. Defined in The International Convention on Tonnage Measurement of Ships that was adopted by the International Maritime Organization in 1969, the net tonnage replaced the earlier net register ...
Gross register tonnage (GRT, grt, g.r.t., gt), or gross registered tonnage, is a ship's total internal volume expressed in "register tons", each of which is equal to 100 cubic feet (2.83 m 3). Replaced by Gross Tonnage (GT), gross register tonnage uses the total permanently enclosed capacity of the vessel as its basis for volume.
Tonnage – a number derived from any of several methods to calculate the volume or other number indicative of a ship's cargo carrying capacity. Gross tonnage – GT – Not expressible in units of mass or weight but is based on the total volume of the vessel in cubic meter with a formula applied. GT replaced Gross register tonnage (GRT) which ...