The tonnage of a ship is its size or the amount of space that it has inside it for cargo
The unit of measure used in air conditioning to describe the heating or cooling capacity of a system One ton of heat represents the amount of heat needed to melt one ton (2000 lbs ) of ice in one hour 12,000 Btu/hr equals one ton of heat
Tonnage is the total number of tons that something weighs, or the total amount that there is of it
Tonnage is the carrying capacity of a ship By international agreements merchant vessels are measured by their total volume The figure calculated in this way is given in gross registered tons (GRT) The figure for net registered tons (NRT) is calculated by deducting the area of the crew quarters, fuel bunkers, engine rooms, etc from the GRT Often, especially in the case of tankers, the size is given in tdw (tons dead weight) This figure expresses the total carrying capacity of a ship in long tons (1 lt = 1016 kg) However, to calculate the exact cargo weight, the bunker, water and other stocks must be deducted from the tdw figure There are no fixed conversion rates between GRT, NRT and tdw The following can, however, be used a rough guide: NRT = 2 5 tdw; 1 GRT = 0 6 tdw; 1 tdw = 0 4 NRT
A ton of refrigeration is the amount of heat required to melt a ton (2000 lb ) of ice at 32o F, 288,000 Btu/24 h, 12,000 Btu/h, or 200 Btu/min
{i} total capacity of a ship (calculated in tons); weight of cargo carried in a ship (calculated in tons); tax imposed on a ship's cargo; size of a fleet of ships (measured by the combined capacity of all ships)