Gross

I'm curious as to the gross tonnage (not displacement), of the different vessels that folks*on TF own.*Have you calculated your GT, or did that info come with your boat? *KJ*********************

KJ wrote:
I'm curious as to the gross tonnage (not displacement), of the different vessels that folks*on TF own.*Have you calculated your GT, or did that info come with your boat? *KJ*********************

Click to expand...

*El Capitan, are you asking for the actual weight of the vessel or the admeasure for documentation purposes?

35' w/l x 13.4' max beam x 4' max draft, hard chine semi-displacement

Documented: 19 gross tons, 15 net tons

Displacement:* 26000 lbs 50% wet


-- Edited by Jay N on Saturday 21st of January 2012 09:29:05 PM

According to our documentation, our 1973 fiberglass GB36 is 18 gross tons, 15 net tons. Our weight in the Travelift slings is 28,000 pounds which I assume is our displacement.

Moonstruck wrote:KJ wrote:
I'm curious as to the gross tonnage (not displacement), of the different vessels that folks*on TF own.*Have you calculated your GT, or did that info come with your boat? *KJ*********************

Click to expand...

*El Capitan, are you asking for the actual weight of the vessel or the admeasure for documentation purposes?

*
The GT that I am asking about is calculated on "the moulded volume of all enclosed spaces of the ship".* The reason I'm asking is that my insurance co. wants to know the Gross Tonnage of my boat. They made it quite clear that they were not asking for the displacement or dead weight. Yes, I will need it for documentation also.*

*
I think they use a ship's GT to determine manning requirements or something like that. I was just wondering if someone had a similar design, they might know their vessels GT.* It might save me some research.**

*
I was going to send the equation to Stephen Hawkins.* ******KJ

*


-- Edited by KJ on Saturday 21st of January 2012 09:54:42 PM

The Coot has a gross tonnage (a measure of volume, not weight) of 15 for USCG documentation purposes.* The builder provided the three dimensions (length - 35.8', hull depth - 5.2'*and hull width - 12.3') on the documentation application I submitted to the USCG.* The USCG calculated the tonnage based on those dimensions.* The USCG-calculated tonnage does not measure the boat's actual volume.

This explains it: https://homeport.uscg.mil/cgi-bin/st/portal/uscg_docs/MyCG/Editorial/20090212/TG%201%20CH-2.pdf?id=735ba2907abe7fa497d4246ba867ed4582205fa9

The USCG uses the simplified method to measure tonnage.* I'm unaware of the use of the formal method for small boats*(under 79 feet in length)*such as ours for any purpose.


-- Edited by markpierce on Saturday 21st of January 2012 11:10:02 PM

Gross tons are usually a determination made by the boat's designer.

If you can't find a documented sistership that has one, you may need to talk with a naval architech.

KJ wrote:*Yes, I will need it for documentation also.*

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We did not have to supply the tonnage information when we had our boat documented after we bought it.* However.... the boat had been documented by the previous owners--- our documentation number is the same as theirs had been--- so the USCG obviously had the data on record.

If your boat has been documented by a previous owner (unless you're the original owner) it may be that the data for your boat is already on record.

And is it possible that production boats like Grand Banks, etc. have "standard" tonnage figures for each model that the USCG already has on record or can get if they want it?


-- Edited by Marin on Sunday 22nd of January 2012 01:50:23 AM

The USCG has just about all designs on file if more than a few have been documented in the past. Call the National Vessel Documentation Center and they can tell you.* I think you can also get the simplified calculation form from their website and download it.* It's very easy to do...harder to accurately measure your boat.* I used to get those forms when I had to teach the 200Ton masters course.

Your insurance company is suspect if they need it from you.

Was your vessel previously documented and/orsurveyed?* Strange the surveyor didn't list it.* Of course*they usually just copy it from your documentation paperwork

*

My 2003 Monk 36's*documentation*certificate reads: 21 GRT, 16 NRT.

For the first time I'm noticing the*measurements on the Cert. of Documentation read** Lenght 36, Breadth 13,* Depth 6.7.

I am not sure what they mean by "depth" the draft is 4', is "depth" a different measurement than "Draft"?

Except for a name change I have only had the doc's that were with the boat

*renewed so the original information was supplied by a previous owner.

Anybody know?

Steve W

Thanks.* All good info.* I found a really cool website that had the data; "BoatInfoWorld.com".

KJ

psneeld wrote:
*

Your insurance company is suspect if they need it from you.

*

*

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*Why would that be?

Steve wrote:
My 2003 Monk 36's*documentation*certificate reads: 21 GRT, 16 NRT.

For the first time I'm noticing the*measurements on the Cert. of Documentation read** Lenght 36, Breadth 13,* Depth 6.7.

I am not sure what they mean by "depth" the draft is 4', is "depth" a different measurement than "Draft"?

Except for a name change I have only had the doc's that were with the boat

*renewed so the original information was supplied by a previous owner.

Anybody know?

Steve W

Click to expand...

*Basically those measurements are to determine how much coal or cargo you can carry. Interior volume.

KJ wrote:psneeld wrote:
*

Your insurance company is suspect if they need it from you.

*

*

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*Why would that be?

*Because they should either have it on file or be able to find it in a second.

I'm on my 3rd documented boat and the insurance companies have never asked for it.* Either they don't care... or my cut is they really don't have a clue about boats...even the big marine ones (yes they brokers do but not the underwriters)...until you get into the ones that insure lots of commercial vessels or SHIPS woth hundreds of millions.

Look here for answers..

*

http://www.uscg.mil/hq/msc/docs/CG-5397.pdf

It's apparent that many recent posters*have not read the document I linked earlier on the simplified calculation of tonnage.

Thanks guys, I got the data.

Our 47' is 30 tons gross, 24 tons net

OK, here's how I look at it. My holding tank is 25 gallons, times 8#/gallon = 200#, = .090909 GROSS tons.

Beyond that, I really don't care.

I couldnt agree more, Carey. That's all that matters...lol!

Carey wrote:
OK, here's how I look at it. My holding tank is 25 gallons, times 8#/gallon = 200#, = .090909 GROSS tons.

Beyond that, I really don't care.

Click to expand...

*It's not that important.



*


-- Edited by KJ on Monday 23rd of January 2012 01:53:21 AM

edited.....


-- Edited by Giggitoni on Monday 23rd of January 2012 01:35:23 PM

You're right, it's not.

markpierce wrote:
It's apparent that many recent posters*have not read the document I linked earlier on the simplified calculation of tonnage.

Click to expand...

*I tried the link but couldn't get it to work.

That's odd.* It worked before.* Try googeling.* I found the site in five minutes.

KJ wrote:
I'm curious as to the gross tonnage (not displacement), of the different vessels that folks*on TF own.*Have you calculated your GT, or did that info come with your boat? *KJ*********************

Click to expand...

*The Eagle was registered when we bought her at 45 ton gross and 36 ton net.* The original marketing material shows 70,000 lbs or 35 ton net. When we pull, the actual was 39+ ton.* However she only had 200 gallon of diesel, so if we added another 1000 gallons of diesel, and filled the water tanks she would be about 43 ton.** So 36 to 45 ton seems a reasonable range.

Phil Fill wrote:KJ wrote:
I'm curious as to the gross tonnage (not displacement), of the different vessels that folks*on TF own.*Have you calculated your GT, or did that info come with your boat? *KJ*********************

Click to expand...

*The Eagle was registered when we bought her at 45 ton gross and 36 ton net.* The original marketing material shows 70,000 lbs or 35 ton net. When we pull, the actual was 39+ ton.* However she only had 200 gallon of diesel, so if we added another 1000 gallons of diesel, and filled the water tanks she would be about 43 ton.** So 36 to 45 ton seems a reasonable range.

*The weight of the vessel has NOTHING to do with the documented Gross Tonnage

Marin's favorite book, Chapman's, has a good description of tonnage, displacement and documentation*that applies to smaller vessels. At least it appears in*my 1983 version.

I got the info that I was inquiring about.*Thanks for all the input.

I think we can put this thread to rest.******** KJ*******************

On USCG Form 5397 Section 5 asks for shape of hull. There are 4 options. None are perfect choices. With a semi-displacement Nordic Tug, it looks more like an integrated keel (sailboat) on the bow and a powerboat near the stern. Which is the best response? (Or, does it matter despite threat of $20,000 fine and boat forfeiture?)