Gross tonnage

[penpal]

I need to find out how much the gross tonnage is for my new boat a Skilso 975 Arctic, the displacement is 4.5 tons, but i cannot find the gross tonnage, not even in the manual that came with it. I was registering the for a radio licence for this boat when asked the question, so I put 5 tons for now. Appreciate your help

 

[nicho]

As I understand it, Gross Tonnage is more to do with volume of the hull rather than dry weight or displacement. It dates back to the time when boats were taxed on the amount of cargo they could carry (or something like that). The gross tonnage is often much more that dry weight.

For example, our S48 has a dry hull weight of 16 tons (16000kgs), yet it's registered tonnage is 21.44 tonnes.

Estimating the Tonnage is part of the Part 1 Registry, and is carried out by a surveyor.

 

[PaulGooch]

As far as the ships radio license goes, i wouldn't worry. Leave it at your estimated 5 tons and forget it.

 

[nonitoo]

As far as the ships radio license goes, i wouldn't worry. Leave it at your estimated 5 tons and forget it.

Agree with that but, for your interest, read the following,

"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."

IIRC the tonnage was worked out at 100cuft/Ton.

All these tonnages are really meant to be used on large commercial vessels (the RN don't use the same either).

As said above, give an estimate and don't worry about it.

Tom

 

[dombuckley]

Did one of these recently: tonnage came out at 12.36.

As already stated, it's a measure of volume, not weight. As far as a radio licence is concerned, of absolutely no relevence to non-commercial vessels.