What is the difference between dead weight tonnage and gross tonnage?

Answer 1

Deadweight (DWT)and displacement are expressions of physical weight.

and GRT was a calculation of the number of 100 cubic foot 'boxes' a ship could accommodate in its enclosed space. NRT reflected the same figure, but just for the money earning spaces. Now the figure is based around cubic metres and is adjusted with a sliding figure to bring it more into line with the tonnages it was replacing.

Deadweight is how much the ship can carry, while displacement is how much water the ship has to move out of the way.

Tankers and bulk carriers will, more or less, have DWTs roughly two-thirds to double the GT. A container ship will have a DWT in close proximity to its GT, while passenger ships, gas carriers, and car carriers will have quite small DWTs compared to their GT.

To understand this a bit better, a cruise ship has lots of enclosed space. But the weight of the people it carries - even if they've overdone it on the buffet each day - isn't great.

A tanker of equivalent GT on the other hand, is full of oil and this weights a lot more.

Answer 2

Deadweight tonnage (DWT) refers to the weight of cargo, fuel, water, and supplies a ship can carry, while gross tonnage (GT) measures the total internal volume of a ship, including cargo space, crew quarters, and engine room. DWT is a better indicator of a ship's carrying capacity, while GT is used for regulatory and administrative purposes.