what does gross tons mean?

Question

like on the titanic its weight was 45,000 gross tons?
wat does it mean
i am a pilot and they did not teach me gross tons!
any 1 help

Answer 1

Gross Tonnage (GT) refers to the volume of all ship's enclosed spaces (from keel to funnel) measured to the outside of the hull framing. It is always larger than gross register tonnage, though by how much depends on the vessel design. . It was a measurement of the enclosed spaces within a ship expressed in "tons" – a unit which was actually equivalent to 100 cubic feet.

Tonnage measurements are now governed by an IMO Convention (International Convention on Tonnage Measurement of Ships, 1969 (London-Rules)), which applies to all ships built after July 1982. In accordance with the Convention, the correct term to use now is GT, which is a function of the moulded volume of all enclosed spaces of the ship.

It is calculated by using the formula GT = K * V, where V = total volume in m3 and K = a figure from 0.22 up to 0.32, depending on the ship’s size (calculated by K = 0.2 + 0.02log10V). GT is consequently a measure of the overall size of the ship.

Net tonnage (NT) is based on a calculation of the volume of all cargo spaces of the ship. It indicates a vessel’s earning space and is a function of the moulded volume of all cargo spaces of the ship.

A commonly defined measurement system is important; since a ship’s registration fee, harbour dues, safety and manning rules etc, are based on its gross tonnage, GT, or net tonnage, NT.

Answer 2

Gross Ton Weight

Answer 3

STUDY THIS MY FRIEND! And slowly. Believe me I've worked hard at this and this is your answer! …

Let's start with a quote …

"Gross tonnage: is the measurement in register tons of the INTERIOR CAPACITY of the ENTIRE ship"¹ (Capitals added - this is in fact the precise answer to your question. But please do read on)

"Register ton measurement: is the measurement based on a ton of 2240 lb. occupying 100 cu. ft."¹

"Net tonnage: is the tonnage in register tons upon which payment is made, and is the space available for CARGO AND PASSENGERS."¹ (Capitals added).

Fine. So let's interpret this …

Your 45,000 gross tons, therefore, means that the Titanic could boast 45,000 x 100 cu. ft. of INTERIOR CAPACITY.

That's 'all told'. The lot! The entire interior capacity!
45,000 x 100 cubic feet.

Each ONE HUNDRED CUBIC FEET of which was POTENTIALLY capable of accommodating a mass of 2240 lb. Or 1 ton. (Whether that mass be made up of air, people, drinking water, fuel, cargo or for that matter, salty sea!)

"Potentially" ! … And there's the rub:-

Lots of places within the vessel (in her particular case for example, consider the 'buoyancy' chambers), while they would indeed constitute 'interior capacity', would not be suitable for the carriage of CARGO AND PASSENGERS - these of course go in 'suitable' places.

Such places are therefore the NET tonnage. (And upon this tonnage the dues are charged).

Add to these places ALL the other places that are 'unsuitable' for the carriage of cargo and passengers and you have your GROSS TONNAGE.

In summary then, 'gross tonnage' = all the interior places that are suitable for the carriage of cargo and passengers (net) … PLUS all the interior places that are not! (= gross)! …

Yes? … Agreed? …

Wow! What a really good question! I've learned a lot here myself! Thank you.

[Basically, 'gross' and / or 'net' tonnage must be considered as totally separate and distinct from 'displacement' - the mass of the vessel. It's all to do with interior capacity. After all, if you think about it, 45,000 tons does seem a bit shy for the "weight", "mass" or "displacement" of a hunk of iron the size of the Titanic! With or without load / cargo!]

Note, with regard to Mark T's comments, the Titanic wasn't built after 1982 and these, imperial, rules would have been used for calculating her dues. But the principles (moulded volume etc) have always been the same. To calculate this, look up Simpson's rule. Very accurate. Alternatively, the Trapezoidal rule is easier, but less accurate.

Answer 4

The term 'Gross Weight' or 'Gross Vehicle Weight' with regards to HGV's means that that amount is the most that the vehicle is ever allowed to weigh. If the GVW is 38 Tons and when loaded the vehicle is weighed at say 39 Tons then it's considered overweight and therefore illegal to drive on the public highway until it's weight it reduced to it's GVW or less.
I don't know about boats or ships but the term is the same so I can only guess that's what it means.
Perhaps the most the Titanic was designed to weigh with all passengers,crew,equipment and fully fuelled was 45,000 Tons?

Answer 5

It is NOT a weight as some people think but a measure of the size of the craft and the calculation is laid down in international standards. As a pilot you should know how big a ship is and the international measure is GROSS TONNAGE

Answer 6

Gross ton is also called a long ton, 2240 pounds.

I also found gross tonnage as a volume measurement of 100 cubic feet.

Answer 7

Well done Mark t. Just right gross tonnage is a measurement of volume. So net tonnage is just the cargo carrying space.

Answer 8

The volume of all the vessels enclosed spaces.

Answer 9

for the titanic it meant the actual weight without passengers or luggage or fuel.

Answer 10

Includes everything, the ship and everything on board. Gross versus net.