Tonnage survey. What does it involve?

[Poignard]

If I wanted a tonnage survey (as opposed to a condition survey) carried out on my 28' sailing yacht before registering her, what would it involve?

Does the surveyor have to go on board or would external measurements be sufficient?

The boat is currently ashore in a yard in Brittany

 

[pvb]

I think internal measurements are involved.

 

[Momac]

Tonnage Surveys | Regulations | Knowledge & Advice | RYA - Royal Yachting Association
Note the prices are for boats in the UK

 

[Momac]

https://www.iims.org.uk/wp-content/uploads/2014/05/IIMS-Tonnage-Survey-Manual-Nov-2016-V2.pdf

 

[Mistroma]

The surveyor came on board when ours was "surveyed" in 2009. He said that he had done similar boats before and the only thing he measured was height in the saloon. I think it was from the lowest point in bilge to deck level and he said that he'd get other measurements from earlier jobs. I suspect he'd measured a 42i before but not a 42DS.

I said that they were a identical and he was really just there to make certain my boat was a 42DS and actually existed. He agreed that this was a reasonable interpretation of his role. An expensive way of getting measurements for a standard production boat.

I imagine it will vary from one surveyor to another. e.g. You might run into one who hasn't seen your type of boat before or one who has just finished measuring a fleet of them. The latter would probably just look at the boat and have a chat for a few minutes, a nice little earner.

 

[Momac]

, a nice little earner.

Not really unless a few boats can be done together in a day at one location and without much travelling involved - which isn't very likely .

 

[pandos]

If you are thinking of an Irish survey you need to look here...(after 2 glasses of wine I can see that I do not want to read it....)

S.I. No. 369/2007 - Mercantile Marine (tonnage) Regulations 2007

15. (1) (a) The gross tonnage (GT) of all ships of less than 15 metres length overall shall be determined by the following formula:
		GT = K1 V,
		where—
		K1 = 0.2 + 0.02 log10V or as specified in Schedule 2,
		V = a1(Loa . Bl . Tl),
		a1 = 0.5194 + 0.0145 Loa, but not to be taken less than 0.60,
		Loa = length overall,
		Bl = breadth, in metres, as defined in Regulation 2, and
		Tl = moulded depth, in metres, as defined in Regulation 2; in the case of an open boat, the upper terminal point for depth shall be the top of the upper strake or gunwale.
		(b) The net tonnage (NT) of all ships of less than 15 metres length overall shall be determined by the following formula:
		NT = 0.3 GT.
		(2) (a) The gross tonnage (GT) of existing fishing boats of less than 15 metres length overall may be determined by the following formula:
		GT = K1 V,
		where—
		K1 = 0.2 + 0.02 log10V or as specified in Schedule 2,
		V = a2(Loa . Bi . Ti),
		a2 = 0.4794 + 0.0255 Loa, but not to be taken as less than 0.60,
		Loa = length overall,
		Bi = main breadth to outside of plating/planking, and
		Ti = depth in hold from tonnage deck to ceiling/top of floor amidships, where “tonnage deck” means the second deck except in the case of single deck ships, in which case it means the upper deck; in the case of an open boat, the upper terminal point for depth shall be the top of the upper strake or gunwale.
		(b) The net tonnage (NT) of existing fishing boats of less than 15 metres length overall may be determined by the following formula:
		NT = 0.3 GT.

 

[pandos]

sorry the cut and paste is gone wrong ...but it is a complex calculation.... to me any way...

 

[Mistroma]

Not really unless a few boats can be done together in a day at one location and without much travelling involved - which isn't very likely .

I suppose it was value for money as he gave a date when he said would be in the marina anyway and was going to the adjacent marina next. I think his office was about 5-10 miles away and he did spend at least 5-10 minutes on the boat. About £145 well spent but he does have to give some to RYA after he emails the 3 measurements to them, they print the form and post it to me.

I could see that the single measurement he took was very skilled work and probably accurate to within approx. 5cm.

 

[Momac]

I could see that the single measurement he took was very skilled work and probably accurate to within approx. 5cm.

It's not the skill or accuracy of the measurement you were paying for .

 

[Mistroma]

It's not the skill or accuracy of the measurement you were paying for .

I think that was my point, anyone could do it. You just need to be a surveyor to email the measurments.

 

[vyv_cox]

When my boat was measured many years ago I seem to remember that the surveyor took about an hour and only used a tape measure.

 

[Momac]

I think on a leisure craft the tonnage measurement process is somewhat academic and a best guess would be sufficient . But as said there is an underlying need to avoid fraudulent activity by seeing the boat actually exists.

Is there any benefit to having the part 1 rather than part 3?

 

[pvb]

Is there any benefit to having the part 1 rather than part 3?

Any marine mortgages, etc, are usually logged by the registrar for Part 1 boats, so buyers can have some reassurance that the boat is free of encumbrances.

 

[rogerthebodger]

The tonnage calculation for a pleasure seems to an miss application of the concept of Gross Tonnage.

Tonnage - Wikipedia

Tonnage is a measure of the cargo-carrying capacity of a ship, and is commonly used to assess fees on commercial shipping. The term derives from the taxation paid on tuns or casks of wine. In modern maritime usage, "tonnage" specifically refers to a calculation of the volume or cargo volume of a ship. Although tonnage (volume) should not be confused with displacement (the actual weight of the vessel), the Imperial ton of 2240lbs is derived from the fact that a "tun" of wine typically weighed that much.

As a pleasure vessel is not a commercial ship and does not carry any cargo so its cargo carrying capacity is zero.

So if you are registering part 1 of 3 then gross tonnage is zero so why is measurement needed. Yes the existence of the vessel must be proven

Any comments by the learned forum members.

 

[Mistroma]

Just a stab in the dark. Inertia. That's the way they did it before pleasure sailing arrived on the scene and they continue to do it that way as it is easier than altering the system.

I remember wondering why my first Part 1 reg. boat document said that I owned 64/64ths of the boat. The explanation at the time was that it dated back to the days when merchants bought part of a ship. Two would own half and four a quarter etc. and they stopped splitting it at 64 as many merchants could afford that amount and the paperwork became ever more complex to track beyond that.

I've heard several other explanations relating to number of beams on old boats but none made much sense. It seems a convenient way to divide things by 2 each time and save complexity with some people ending up owning 66.666%, another 17.5% and so on. I've always though it was just a manageable way of managing part shares.

 

[vyv_cox]

The tonnage calculation for a pleasure seems to an miss application of the concept of Gross Tonnage.

Tonnage - Wikipedia

Tonnage is a measure of the cargo-carrying capacity of a ship, and is commonly used to assess fees on commercial shipping. The term derives from the taxation paid on tuns or casks of wine. In modern maritime usage, "tonnage" specifically refers to a calculation of the volume or cargo volume of a ship. Although tonnage (volume) should not be confused with displacement (the actual weight of the vessel), the Imperial ton of 2240lbs is derived from the fact that a "tun" of wine typically weighed that much.

As a pleasure vessel is not a commercial ship and does not carry any cargo so its cargo carrying capacity is zero.

So if you are registering part 1 of 3 then gross tonnage is zero so why is measurement needed. Yes the existence of the vessel must be proven

Any comments by the learned forum members.

It's Registered Tonnage, really a measurement of capacity. Our official displacement is just under 6 tons but our registered tonnage for the purposes of Part 1 is 9 and 13/100ths.

 

[rogerthebodger]

It's Registered Tonnage, really a measurement of capacity. Our official displacement is just under 6 tons but our registered tonnage for the purposes of Part 1 is 9 and 13/100ths.

Yes but is that the amount cargo you carry.

Is all the bridge, crew, engine and fuel volume included in a merchant ship registered tonnage.

I'm thinking out of the box

 

[Poignard]

Yes but is that the amount cargo you carry.

Is all the bridge, crew, engine and fuel volume included in a merchant ship registered tonnage.

There's gross and net tonnage. Net tonnage only consists of cargo carrying space.

I was once Second Engineer in a very old coaster and all the cabin doors, saloon door, etc. had brass labels screwed to them stating they were not cargo spaces. I can't recall what the wording was. I don't remember seeing such labels on later ships and I have an idea the system of tonnage measurement was changed by international agreement to something simpler.

 

[vyv_cox]

Yes but is that the amount cargo you carry.

Is all the bridge, crew, engine and fuel volume included in a merchant ship registered tonnage.

I'm thinking out of the box

There is a definition somewhere, you can probably find it. Some volume is subtracted from the total, engine etc., I forget all the detail.