Boat number

[single]

What exactly is this number for?

View attachment 51351

 

[theoldsalt]

Part One Register

 

[single]

Part One Register

So what do the numbers mean, especially the last bit?

 

[theoldsalt]

So what do the numbers mean, especially the last bit?

The number is your registration number and the last figures are the registered tonnage.

The registration document should have been handed to you by the vendor/broker when you purchased the vessel and you should then have notified the registry of your ownership providing proof using the bill of sale.

https://www.gov.uk/register-a-boat/the-uk-ship-register

http://andrewjackson.co.uk/factfiles-item.php?item=282

plenty more info on-line if you google "ships part 1 registration"

 

[FullCircle]

So what do the numbers mean, especially the last bit?

Registered Tonnage - this from Plomong around 2006
Gross Tonnage is the volume of all that is below the Tonnage Deck plus spaces between the tonnage deck and the upper deck, plus enclosed spaces on the upper deck (deckhouses, etc). Usually expressed in Moorson Tons (Volume in cu. ft divided by 100).

Register Tonnage or Net Tonnage (not registered - register) is gross tonnage less the volume of spaces that do not earn, such as engine rooms, bunkers, accomodation, etc., again expressed in Moorson Tons.

For small ships in the UK, it used to be accepted to calculate Register Tonnage as:
RT = (0.45 x L x B x D) / 100
where all measurements are in ft, L and B are overall and D is the distance between the underside of the deckhead in the saloon on the centreline and the lowermost point within the hull, excluding such items as pump wells in the bilges.

 

[single]

Registered Tonnage - this from Plomong around 2006
Gross Tonnage is the volume of all that is below the Tonnage Deck plus spaces between the tonnage deck and the upper deck, plus enclosed spaces on the upper deck (deckhouses, etc). Usually expressed in Moorson Tons (Volume in cu. ft divided by 100).

Register Tonnage or Net Tonnage (not registered - register) is gross tonnage less the volume of spaces that do not earn, such as engine rooms, bunkers, accomodation, etc., again expressed in Moorson Tons.

For small ships in the UK, it used to be accepted to calculate Register Tonnage as:
RT = (0.45 x L x B x D) / 100
where all measurements are in ft, L and B are overall and D is the distance between the underside of the deckhead in the saloon on the centreline and the lowermost point within the hull, excluding such items as pump wells in the bilges.

So mine is about 9 tonnes?

 

[theoldsalt]

So mine is about 9 tonnes?

That is registered tonnage (achieved by dimentions) not to be confused with displacement (actual weight)

(Tons not Tonnes)

 

[Tranona]

So mine is about 9 tonnes?

But nothing to do with weight or displacement. Tonnage is derived from "tuns" - barrels of wine which was the original unit of measure before the method described by FullCircle was adopted. The old and new are very similar in outcome.

The purpose of measuring was because in the past, harbour dues and light dues were based on registered tonnage of the ship, so there is every incentive for owners to persuade measurers to maximise allowances and minimise the tonnage. Irrelevant now for pleasure craft as they no longer pay light dues (although reintroduction was proposed a few years ago to raise taxes) and harbour dues are usually now based on length for pleasure craft.

 

[FullCircle]

So mine is about 9 tonnes?

9 tonnes carrying capacity, but the numbers are nonsense anyway