Weight vs. Displacement

 
Walap42
 
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Walap42
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Joined  14-02-2013
 
 
 
14 February 2013 11:23
 

Hello:
I’m new here.  Do not be misled by the user name.  I have only dreamed of such a thing.  But, as the saying goes, a trip of ten-thousand miles begins with the first step - the 24 footer.

I have the lines, design WL, etc.  I was wondering if there is rule of thumb regarding the percentage of the hulls build weight that should not be exceeded with respect to the design displacement?

It looks like I may get a chance to start this long anticipated project.  I would like to know from the experienced out there about your experience with this issue.  I have, in theory, worked out most of the other issues, including a way to shunt the sail without leaving the cockpit area (Looks good on paper, anyway).

I want this small version of the dream to be robust enough for hops into the bumpy Atlantic, and still provision for more than a weekend.  Therefore dry weight comes into play. 

So is there a number like 30%, 50% or something to which one can benchmark?

By the way, where’s the profile place?  I do like to play by the rules, and having been asked, I would like to comply.

 
Gargen
 
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Gargen
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15 February 2013 07:04
 

Maybe not much of an answer, but i think it is very hard to generelize loading capacity after dry weight.
Take a look at boats of similar size and maybe more important, boats that are beeing used in a similar way that you plan to do.
I think John Harris boat madness have 50% weight/disp. But that could be 30% or something like that if built in carbonfibre and foam (with same load capacity)

Kid regards
/Garg

 
Walap42
 
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Walap42
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15 February 2013 08:48
 

Thanks for the reply.  In fact, I was kind of wondering about Madness, as it is our there.  I am thinking right now that 50% for wood isn’t too awful bad.  I look forward to other contributions.

Wonder why no one ever wieghed one of the original ones?

Thanks again.

Remember:  There are no stupid questions, only stupid people.

 
multihuller
 
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multihuller
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16 February 2013 00:00
 

It’s also dependend of the boat length, and what you want to do with the boat.
E.g. the 5m sporting proa P5 made weigh ready to sail around 50 kg, but can carry two crew with 150 kg.
On the other hand the cruising proa P12 with 12 m length has a displacment of 2,4 t on cwl including a payload of 0,8 t.
To weigh the original ones makes no sense because of the massive materials former boat builder must use. A caved log and thick planks result always in a bader relation.

 
luckystrike118
 
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luckystrike118
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12 March 2013 01:57
 
Walap42 - 15 February 2013 08:48 AM

Thanks for the reply.  In fact, I was kind of wondering about Madness, as it is our there.  I am thinking right now that 50% for wood isn’t too awful bad.  I look forward to other contributions.
Thanks again.

Hi (here could stand your name)!

No, there is no rule of thumb. But wood is not all that brings wheight to your boat and the rest is payload. Before building, you should be aware that there are a lot of things that count and must be built in.  Epoxy sheating, paint, mast, rigging, ropes, sails, motor, elektrik system, cuishons, safety equipment, sextoys, anchors, winches, turningblocks, nav eqiupment, and on and on and on. On a 24 footer that can easily be 100 - 150 kg!  Be aware of that wheight!

Best Regards, Michel

 
 
Luomanen
 
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Luomanen
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12 March 2013 14:30
 

Luckily my sex toys are all ultralight carbon.

 
luckystrike118
 
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luckystrike118
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13 March 2013 14:01
 
Luomanen - 12 March 2013 02:30 PM

Luckily my sex toys are all ultralight carbon.

If they have to be made from carbon, you seem to need a lot of it! Be aware of that black splinters!!!!! *smile*

Michel

 
 
Luomanen
 
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Luomanen
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13 March 2013 14:08
 

The magnesium ones were not compatible with the salt water environment!