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Old 15-09-2013, 22:28   #1
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Tonnage?

Who gives it? How is it calculated?

When I obtained my folkboat this plate was on bulkhead, 3.91tonnes is about 7820lbs how is this possible when this boat is supposed to weigh 5000lbs?

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Old 15-09-2013, 22:53   #2
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Re: Tonnage?

My boat has a specified displacement of 13.5 tons, but weighs 19 tons.

I have a lot of stuff on board, but can't see it all being close to 11,000 lbs.

Full fuel and water tanks (big tanks) would count for 3,500 lbs however.

Don't know how the rated tonnage is calculated.
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Old 15-09-2013, 22:53   #3
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Re: Tonnage?

Tonnage as it is in the marine use, is a measure of volume, not weight. It (I believe) was originally the volume of the cargo hold of vessels. It is now the volume of the enclosed space on a vessel, other than machinery spaces. Your Folkboat is not overweight. By the way, I think folkboats are great. There have been several long voyages by CF members in them. I believe one was west coast to Hawaii, and another from Washington to Mexico. I am sure there are many other tales of how good the design is. ______Good Luck ______Grant.
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Old 15-09-2013, 23:01   #4
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Re: Tonnage?

Tonnage has nothing to do with the weight of your boat. It is a measure of how much wine a vessel can carry.

The word "tun" was originally a size of a cask used to ship wine from Spain & Portugal to England. In 1347 a tax of 3 shillings per tun was imposed and this was called "tonnage." A ship's size became known by the number of casks it could carry, and the word tonnage started being used to describe a ship's size.

It was found that if you took the length x the breadth x the depth of the hold under the deck and divided by 100 it was close to the number of casks. That is where we get the "Measurement ton" of 100 cubic feet per ton.

There are several kinds of tonnage: The first two are used by the tax collector. The next two are used by designers. The fifth and sixth are used by freight salesmen and canal operators and the last one is used by the USCG for documenting boats.

Gross Tonnage - is the internal volume in cubic feet of the vessel minus certain spaces above the main or "tonnage" deck, like stacks and ventilators, which are called "exemptions" .

Net Registered Tonnage - is obtained by deducting from the gross tonnage the volume of space that can't be used for paying cargo or passengers, that is to say the space occupied by the engines, the crew's quarter, the stores, etc.

Displacement Tonnage - is the actual weight of the water "displaced" by the ship and is usually quoted in long tons of 2240 lbs.

Light Displacement Tonnage - is the weight with nothing in it.

Loaded Displacement Tonnage - is the fully loaded weight to the maximum and is on her summer draft in salt water.

Deadweight Tonnage - is the difference between Light and Loaded

Displacement Tonnage....the actual carrying capacity of the vessel.

Panama & Suez Canal Tonnages - these are different from the internationally accepted definitions. There used to be a lot of variations between countries and the canal owners thought they were being conned, so they came up with their own definitions.

Simplified Measurement System - The USCG decided that all this was way too much for bureaucrats to deal with for yachts, so they came up with their own formula:

Take the horizontal distance between the outboard ends of the boat, not including rudders and bow sprits. Multiply that by the maximum beam outside to outside. Multiply that by the distance from the sheer line not including bulwarks or cap rails to the outside bottom of the hull not including the keel. Add the volume of the deck house/cabin top. Multiply by .5 for sailboats and .67 for power boats. Divide by 100. This will give you the "Gross Tonnage." Net tonnage is 90% of gross for sailboats and 80% for power boats.

It should now be obvious to anyone who's managed to get this far that your boat's "tonnage" no longer has anything to do with anything real; it only exists in the mind of some government bureaucrat.

Another bit of trivia...
Rummage was the manner in which the wine casks were stored in the hold of the ship and came to refer to the whole ship's cargo. after a voyage any unclaimed and damaged cargo was stacked on the dock beside the boat and offered for sale - a rummage sale. another word of French maritime origin.
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Old 15-09-2013, 23:07   #5
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Quote:
Originally Posted by peghall View Post
Tonnage has nothing to do with the weight of your boat. It is a measure
of how much wine a vessel can carry.

The word "tun" was originally a size of a cask used to ship wine from Spain & Portugal to England. In 1347 a tax of 3 shillings per tun was imposed and this was called "tonnage." A ship's size became known by the number of casks it could carry, and the word tonnage started being used to describe a ship's size.

It was found that if you took the length x the breadth x the depth of the hold under the deck and divided by 100 it was close to the number of casks. That is where we get the "Measurement ton" of 100 cubic feet per
ton.

There are several kinds of tonnage: The first two are used by the tax collector. The next two are used by designers. The fifth and sixth are used by freight salesmen and canal operators and the last one is used by the USCG for documenting boats.

Gross Tonnage - is the internal volume in cubic feet of the vessel minus certain spaces above the main or "tonnage" deck, like stacks and ventilators, which are called "exemptions" .

Net Registered Tonnage - is obtained by deducting from the gross tonnage the volume of space that can't be used for paying cargo or passengers, that is to say the space occupied by the engines, the crew's quarter, the stores, etc.

Displacement Tonnage - is the actual weight of the water "displaced" by the ship and is usually quoted in long tons of 2240 lbs.

Light Displacement Tonnage - is the weight with nothing in it.

Loaded Displacement Tonnage - is the fully loaded weight to the maximum and is on her summer draft in salt water.

Deadweight Tonnage - is the difference between Light and Loaded

Displacement Tonnage....the actual carrying capacity of the vessel.

Panama & Suez Canal Tonnages - these are different from the internationally accepted definitions. There used to be a lot of variations between countries and the canal owners thought they were being conned, so they came up with their own definitions.

Simplified Measurement System - The USCG decided that all this was way too much for bureaucrats to deal with for yachts so they came up with
their own formula:

Take the horizontal distance between the outboard ends of the boat not
including rudders and bow sprits. Multiply that by the maximum beam outside to outside. Multiply that by the distance from the sheer line not including bulwarks or cap rails to the outside bottom of the hull not including the keel.
Add the volume of the deck house/cabin top. Multiply by .5 for sailboats and .67 for power boats. Divide by 100.

This will give you the "Gross Tonnage". Net tonnage is 90% of gross for
sailboats and 80% for power boats.

It should be obvious to anyone who's managed to get this far that your boat's "tonnage" no longer has anything to do with anything real; it only exists in the mind of some government bureaucrat.

Another bit of trivia...
Rummage was the manner in which the wine casks were stored in the hold of the ship and came to refer to the whole ship's cargo. after a voyage any unclaimed and damaged cargo was stacked on the dock beside the boat and offered for sale - a rummage sale. another word of French maritime
origin.
Wow that's as far out as I could have ever expected an answer !!!!
Wasn't expecting this....Thank you Lady
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Old 15-09-2013, 23:08   #6
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Re: Tonnage?

cool stuff peg
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Old 15-09-2013, 23:21   #7
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Re: Tonnage?

Quote:
Originally Posted by peghall View Post
Tonnage has nothing to do with the weight of your boat. It is a measure of how much wine a vessel can carry.

The word "tun" was originally a size of a cask used to ship wine from Spain & Portugal to England. In 1347 a tax of 3 shillings per tun was imposed and this was called "tonnage." A ship's size became known by the number of casks it could carry, and the word tonnage started being used to describe a ship's size.

It was found that if you took the length x the breadth x the depth of the hold under the deck and divided by 100 it was close to the number of casks. That is where we get the "Measurement ton" of 100 cubic feet per ton.

There are several kinds of tonnage: The first two are used by the tax collector. The next two are used by designers. The fifth and sixth are used by freight salesmen and canal operators and the last one is used by the USCG for documenting boats.

Gross Tonnage - is the internal volume in cubic feet of the vessel minus certain spaces above the main or "tonnage" deck, like stacks and ventilators, which are called "exemptions" .

Net Registered Tonnage - is obtained by deducting from the gross tonnage the volume of space that can't be used for paying cargo or passengers, that is to say the space occupied by the engines, the crew's quarter, the stores, etc.

Displacement Tonnage - is the actual weight of the water "displaced" by the ship and is usually quoted in long tons of 2240 lbs.

Light Displacement Tonnage - is the weight with nothing in it.

Loaded Displacement Tonnage - is the fully loaded weight to the maximum and is on her summer draft in salt water.

Deadweight Tonnage - is the difference between Light and Loaded

Displacement Tonnage....the actual carrying capacity of the vessel.

Panama & Suez Canal Tonnages - these are different from the internationally accepted definitions. There used to be a lot of variations between countries and the canal owners thought they were being conned, so they came up with their own definitions.

Simplified Measurement System - The USCG decided that all this was way too much for bureaucrats to deal with for yachts, so they came up with their own formula:

Take the horizontal distance between the outboard ends of the boat, not including rudders and bow sprits. Multiply that by the maximum beam outside to outside. Multiply that by the distance from the sheer line not including bulwarks or cap rails to the outside bottom of the hull not including the keel. Add the volume of the deck house/cabin top. Multiply by .5 for sailboats and .67 for power boats. Divide by 100. This will give you the "Gross Tonnage." Net tonnage is 90% of gross for sailboats and 80% for power boats.

It should now be obvious to anyone who's managed to get this far that your boat's "tonnage" no longer has anything to do with anything real; it only exists in the mind of some government bureaucrat.

Another bit of trivia...
Rummage was the manner in which the wine casks were stored in the hold of the ship and came to refer to the whole ship's cargo. after a voyage any unclaimed and damaged cargo was stacked on the dock beside the boat and offered for sale - a rummage sale. another word of French maritime origin.
I felt like I was back at the academy.
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Old 15-09-2013, 23:22   #8
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Re: Tonnage?

Thanks. Honesty compels me to confess that I'm not the author...a guy named Glenn Ashmore posted on a forum (can't remember where) more than 10 years ago...I loved it and saved it.
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Old 17-09-2013, 13:34   #9
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Re: Tonnage?

Funny the origin of terms in the English language and how many commonly used terms are derived from maritime origins. It's always interesting to see the history.
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Old 17-09-2013, 14:13   #10
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Re: Tonnage?

Quote:
Originally Posted by peghall View Post
Tonnage has nothing to do with the weight of your boat. It is a measure of how much wine a vessel can carry.

The word "tun" was originally a size of a cask used to ship wine from Spain & Portugal to England. In 1347 a tax of 3 shillings per tun was imposed and this was called "tonnage." A ship's size became known by the number of casks it could carry, and the word tonnage started being used to describe a ship's size.

It was found that if you took the length x the breadth x the depth of the hold under the deck and divided by 100 it was close to the number of casks. That is where we get the "Measurement ton" of 100 cubic feet per ton.

There are several kinds of tonnage: The first two are used by the tax collector. The next two are used by designers. The fifth and sixth are used by freight salesmen and canal operators and the last one is used by the USCG for documenting boats.

Gross Tonnage - is the internal volume in cubic feet of the vessel minus certain spaces above the main or "tonnage" deck, like stacks and ventilators, which are called "exemptions" .

Net Registered Tonnage - is obtained by deducting from the gross tonnage the volume of space that can't be used for paying cargo or passengers, that is to say the space occupied by the engines, the crew's quarter, the stores, etc.

Displacement Tonnage - is the actual weight of the water "displaced" by the ship and is usually quoted in long tons of 2240 lbs.

Light Displacement Tonnage - is the weight with nothing in it.

Loaded Displacement Tonnage - is the fully loaded weight to the maximum and is on her summer draft in salt water.

Deadweight Tonnage - is the difference between Light and Loaded

Displacement Tonnage....the actual carrying capacity of the vessel.

Panama & Suez Canal Tonnages - these are different from the internationally accepted definitions. There used to be a lot of variations between countries and the canal owners thought they were being conned, so they came up with their own definitions.

Simplified Measurement System - The USCG decided that all this was way too much for bureaucrats to deal with for yachts, so they came up with their own formula:

Take the horizontal distance between the outboard ends of the boat, not including rudders and bow sprits. Multiply that by the maximum beam outside to outside. Multiply that by the distance from the sheer line not including bulwarks or cap rails to the outside bottom of the hull not including the keel. Add the volume of the deck house/cabin top. Multiply by .5 for sailboats and .67 for power boats. Divide by 100. This will give you the "Gross Tonnage." Net tonnage is 90% of gross for sailboats and 80% for power boats.

It should now be obvious to anyone who's managed to get this far that your boat's "tonnage" no longer has anything to do with anything real; it only exists in the mind of some government bureaucrat.

Another bit of trivia...
Rummage was the manner in which the wine casks were stored in the hold of the ship and came to refer to the whole ship's cargo. after a voyage any unclaimed and damaged cargo was stacked on the dock beside the boat and offered for sale - a rummage sale. another word of French maritime origin.
Excellent post!
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Old 17-09-2013, 14:15   #11
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Re: Tonnage?

Quote:
Originally Posted by deckofficer View Post
I felt like I was back at the academy.
Same here.
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Old 17-09-2013, 14:29   #12
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pirate Re: Tonnage?

Good one Peg..
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Old 17-09-2013, 14:54   #13
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Do you guys have to quote the entire post. I think we get it.
And thanks Peg
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Old 17-09-2013, 17:13   #14
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Re: Tonnage?

Yes, her post once again shows that she's not just a pretty face... first toilets, now tuns!

Thanks Peggy

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Old 17-09-2013, 17:35   #15
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Re: Tonnage?

Learn something new every day. I always thought it was grain, not wine.
Now if you ferment the grain --- lol
Thanks Peg.
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