Gross tonnage on SM
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Patrick McAneny
We checked in yesterday here in Montserrat and were charged ,based on gross tonnage,this has happened on other island as well. I think we are paying more than we should,because I believe our ship papers are wrong. Our papers show gross tonnage to be 58 GRT ,net 46 NRT. That sounds high to me,could someone confirm the correct tonnage?
Thanks, Pat SM Shenanigans |
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Richard Colebatch
Patrick,
Sailboat data below. Rgds Richard. FAO Hull Type:
Wing Keel
Rigging Type:
Masthead Ketch
LOA:
52.49 ft
LWL:
41.34 ft
Beam:
15.09 ft
S.A. (reported):
1,302.00 ft2
Draft (max):
6.73 ft
Draft (min):
Displacement:
35,274 lb
Ballast:
12,125 lb
S.A./Disp.:
19.45
Bal./Disp.:
34.37
Disp./Len.:
222.89
Construction:
FG
Ballast Type:
Iron
First Built:
1989
Last Built:
1998
# Built:
237
Builder:
Amel (FRA)
Designer:
Henry Amel & J. Carteau
Website:
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Pat,
Remember that Gross and Net Tonnage on your Ship's Papers IS NOT weight. It is a measure of volume of cargo a ship can carry that goes back to setting tax rates on shipping. Net is total less machinery space conceptually, but the formulas are a bit arcane. You can get more info on the USCG or NVDOC web pages, which has an easy way to get an approximate measure. Yours sounds exactly right - my Santorin, which weights some 22000 pounds, or 11 tons has a Gross Registered Tonnage (GRT) of 31 and 28 Net. Again, Registered Tons are cubic volume, not weight. Cheers, Craig Briggs, SN68 Sangaris |
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Pat, Your SM Gross Tonnage is: 27GRT Net Tonnage is 24GRT You should get your Certificate of Documentation changed to below. Best, CW Bill Rouse 720 Winnie St Galveston Island, TX 77550 +1(832) 380-4970 On Wed, Mar 13, 2019, 7:10 AM Patrick McAneny via Groups.Io <sailw32=aol.com@groups.io> wrote: We checked in yesterday here in Montserrat and were charged ,based on gross tonnage,this has happened on other island as well. I think we are paying more than we should,because I believe our ship papers are wrong. Our papers show gross tonnage to be 58 GRT ,net 46 NRT. That sounds high to me,could someone confirm the correct tonnage? |
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Jamie Wendell
Wow Pat that seems really high. I see Bill responded as well, but I can tell you with my Amel 54 my documentation shows 23 and 20 respectively. I would guess the 54 is a bit heavier and probably a bit more voluminous.
So I am surprised either way - maybe I am lucky? I do know that I weigh in at about 47,000 pounds. Was nice to see you in Les Saintes. Jamie Phantom, A54 |
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Ian Park
Craig
My Santorin has a big brass plate that says net tonnage is 15 and 1/4 and gross tonnage is 18+. But the spelling is tons. I know it refers to capacity, but I don’t know if there is a difference in where it was measured. In metric tonnes the Santorin is 10 tonnes. I give up ! Incidentally my Part 1 registration has the boat length at 12.3 metres ( rather than the 14 that it is). It has saved me money several times when a marina has just asked for my registration certificate! Ian Ocean Hobo |
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Pat, The terms Gross Tonnage and Net Tonnage are terms that were invented by I believe the British Royal Navy. They are calculated numbers that should tell you how much cargo a vessel is capable of carrying. These terms have little to do with weight of the vessel. On Wed, Mar 13, 2019 at 7:10 AM Patrick McAneny via Groups.Io <sailw32=aol.com@groups.io> wrote: We checked in yesterday here in Montserrat and were charged ,based on gross tonnage,this has happened on other island as well. I think we are paying more than we should,because I believe our ship papers are wrong. Our papers show gross tonnage to be 58 GRT ,net 46 NRT. That sounds high to me,could someone confirm the correct tonnage? |
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heinz@quetzal.berlin <heinz@...>
My sm2000 says 14t netto 16t groß
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Show quoted text
Fair Winds Heinz sm2000 292 Am 13.03.2019 um 11:40 schrieb Ian <parkianj@...>: |
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Heinz, That is the weight of the vessel, not the GT (Gross Tonnage) or NT Net Tonnage. Unfortunately, most countries use GT and NT on recreational vessel registration, confusing most of us. On Wed, Mar 13, 2019 at 3:24 PM heinz@... <heinz@...> wrote:
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Patrick McAneny
I should have mentioned that I knew tonnage was not the weight of the boat ,but a volume measurement . Still it seemed high and apparently that is the case and I will have it changed. Thanks for the correct numbers.
Pat SM Shenanigans |
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Olivier Beaute
Hello, a vessel's tonnage is indeed a volume (how much can this vessel carry). This international value is now expressed without unit's name. It was previously expressed in tons or tonneaux (for France). This "ton" is not equivalent to a metric ton which is the weight of 1000 liters of water, but it is equivalent to 100 cubic feet which is around 2.837 cubic meter Every country's authority has its own calculation for tonnage (from length, beam and inside height). This is why the tonnage of a Super Maramu is 30.14 in France and is, for instance 33.24 (gross tonnage) and 23.35 (Register tonnage) in UK. It will for sure be different for Australian or NZ or US flag. However, Pat's tonnage seems high. Olivier.
On Wednesday, March 13, 2019, 10:40:10 PM GMT+1, Patrick McAneny via Groups.Io <sailw32@...> wrote:
I should have mentioned that I knew tonnage was not the weight of the boat ,but a volume measurement . Still it seemed high and apparently that is the case and I will have it changed. Thanks for the correct numbers. Pat SM Shenanigans |
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Pat,
Here's a link to the US Coast Guard's Simplified Measurement Guide I mentioned.USCG Simplified Tonnage Guide You can use this for vessels under 79 feet. As Olivier points out different countries have different methods. You should work it out yourself, but, for your SM it would be ABOUT the following (I had to guess at a couple of numbers but you can fine tune it. GRT = (Hull volume + Deckhouse Volume) / 100 Where Hull Volume = S x K x L x B x D and Deck Structure Volume = Ls x Ds x Bs L, B and D are overall length, breadth and depth, but depth is measured from the deck edge to the bottom of the keel. You consider the Deck Volume to be 0 if it is less than the hull volume, which it is. S is a Shape factor which is 0.5 for sailboats. K is a Keel factor which is 0.75 for our shape of sailboat. So, let's use Richard Colebatch's posting for your SM dimensions. That is 52.49' in Length and 15.09' in Breath. Richard shows a Water Draft of 6.73' from the bottom of the keel to the water line and let me guess another 6' of freeboard to the edge of the deck. That would be a Depth of 11.73' (which seems about right as my Santorin's Depth is 10.5') So the SM Gross Register Tons (GRT) would be (they say to round feet to the nearest tenth): S x K x L x B x D 0.5 x 0.75 x 52.5 x 15.1 x 11.8 = 3507 / 100 = 35 GRT Then, NRT = M x GRT, where M is a Machinery factor which is .9 for sailboats, so NRT = .9 x 35 = 31 (you are instructed to truncate any fraction) So, it does seem your numbers are, indeed, way high and should be more like a GRT of 35 and NRT of 31. Bill Rouse's GRT 27, NRT 24 comes from his Documentation Certificate, I'm sure, but seems low as my Santorin is 31 and 28 and the USCG calculation above is pretty straightforward. Anyway, there are lot of other numbers in this thread that may have their origin in countries other than the US and/or may be weight based. Numbers that have fractions are definitely not US GRT/NRT, which are always whole numbers. Also, in the US the documentation is pretty much self reported with, seemingly, very little checking by the NVDOC. Whatever, your's seems high. The US Coast Guard's National Vessel Documentation center has a super new website that it very easy to navigate and you may be able to change your numbers on-line. Check it out. Cheers, Craig Briggs, SN68 with GRT 31 NRT 28 |
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eric freedman <kimberlite@...>
Kimberlite is documented in the USA with 28 gross tonnage and 25 net tonnage. That was provided by Amel when they had Kimberlite documented. Fair Winds Eric Kimberlite Amel Super Maramu #376
From: main@AmelYachtOwners.groups.io [mailto:main@AmelYachtOwners.groups.io] On Behalf Of Craig Briggs via Groups.Io
[Edited Message Follows] Pat, |
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CARA is USCG Documented: 26 GRT, 23 NRT
Denise McGovern s/v CARA SM #440 Chesapeake Bay |
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Here's what's been reported on this thread.
My only definite conclusion is that the government bureaucrats live by "garbage in - garbage out" with no concern for accuracy. Frankly, in the recreational market the number really is of little consequence and it's good our tax dollars are not going toward trying to make this accurate. I do have to give it to Ian for saving on his dock fees with that short Santorin, although I have heard that fiberglass shrinks a lot when immersed in water. Cheers around, Craig Briggs SN68 Sangaris |
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This thread is as long as an anchor thread.😀 On Thu, Mar 14, 2019 at 11:46 AM Craig Briggs via Groups.Io <sangaris=aol.com@groups.io> wrote: Here's what's been reported on this thread. |
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