Boat Design Forums  |  Boat Design Directory  |  Boat Design Gallery  |  Boat Design Book Store  |  Thanks to Our Site Sponsors

Go Back   Boat Design Forums > Design > Boat Design
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 04-09-2010, 09:55 PM
stonedpirate stonedpirate is offline
Senior Member
 
Join Date: Nov 2009
Rep: 21 Posts: 315
Location: Australia
positive floatation?

Hello,

If i attached 2 torpedo shaped objects filled with foam to either side of my deck, similar to amas on proas but closer in, is that a standard way to keep a boat afloat if completely swamped?

I just dont have space on board for foam.

Any other ways to create positive bouyancy?

Thanks
Reply With Quote
  #2  
Old 04-09-2010, 10:32 PM
GTO GTO is offline
Senior Member
 
Join Date: Jul 2007
Rep: 84 Posts: 117
Location: Alabama
Your best bet is to just copy Yankee Girl and Gerry's method of provisioning, ie, load up on foods that float.

You could build with foam and glass. Then add water-tight lockers and a mast which floats. The inherent insulative properties of the foam might come in handy. The inevitable higher freeboard will aid in keeping the water out if you build in some serious water-tight hatches. You will be building something somewhat like a catboat anyway (L/B~=2). I wouldn't worry about adding a few extra inches for foam.

With just 10 feet to work with, there are only so many permutations that result in anything remotely approaching a decent boat that can actually sail AND provide any type of life supporting habitation

Since you're shooting for Serge's record, I suggest going to 11 feet in length. At this size, even an extra foot will help alot.
Reply With Quote
  #3  
Old 04-09-2010, 10:36 PM
alan white's Avatar
alan white alan white is offline
Senior Member
 
Join Date: Mar 2007
Rep: 1211 Posts: 3,325
Location: maine
The boat should be enclosed so that water has a hard time getting in. The problem with your situation is that you have to comprimise and decide whether you want extra food, water, and spares, or flotation. It would be sad if you sacrificed water for flotation and then died of thirst.
Ten feet is short. You could construct the hull with a core of foam, but again, less interior space or too wide.
The boat is certainly easy to make unsinkable with enough foam for a light condition---- but you'ld have reached a point where you had given up on continuing and had called for help.
Reply With Quote
  #4  
Old 04-09-2010, 11:08 PM
stonedpirate stonedpirate is offline
Senior Member
 
Join Date: Nov 2009
Rep: 21 Posts: 315
Location: Australia
So thats a negative on torpedos?

I have considered using a skirt for the hatch so when it is open and i am standing, no water can splash in the same as sea kayaks.

Just trying to come up with a plan incase of comple swamping.

Positive floatation with give me a raft to survive a storm and i can bail it out in calm weather.

Cant make it self rescuing without a lower cockpit on back.

Floation is my only option.
Reply With Quote
  #5  
Old 04-09-2010, 11:10 PM
stonedpirate stonedpirate is offline
Senior Member
 
Join Date: Nov 2009
Rep: 21 Posts: 315
Location: Australia
I will be using this hatch: http://www.winchsolutions.com.au/marine-deck-hatches/

And those round plastic screw in hatches for my lockers.
Reply With Quote
  #6  
Old 04-10-2010, 05:17 AM
masalai masalai is offline
masalai
 
Join Date: Oct 2007
Rep: 1689 Posts: 7,510
Location: SE Queensland, Australia
Wear a PF1 at all times... attached "pods" - - - 'will break free when you least expect, - and most depend on them to stay'... Fools law #1
__________________
Try to be helpful...
Remember that there are at least two sides for every story...
Reply With Quote
  #7  
Old 04-10-2010, 05:19 AM
stonedpirate stonedpirate is offline
Senior Member
 
Join Date: Nov 2009
Rep: 21 Posts: 315
Location: Australia
you high?
Reply With Quote
  #8  
Old 04-10-2010, 05:21 AM
masalai masalai is offline
masalai
 
Join Date: Oct 2007
Rep: 1689 Posts: 7,510
Location: SE Queensland, Australia
and dry, not on beer or wine yet...
__________________
Try to be helpful...
Remember that there are at least two sides for every story...
Reply With Quote
  #9  
Old 04-10-2010, 06:10 PM
dskira dskira is offline
Senior Member
 
Join Date: Apr 2008
Rep: 1305 Posts: 1,372
Location: Maine
Quote:
Originally Posted by stonedpirate View Post
So thats a negative on torpedos?

I have considered using a skirt for the hatch so when it is open and i am standing, no water can splash in the same as sea kayaks.

Just trying to come up with a plan incase of comple swamping.

Positive floatation with give me a raft to survive a storm and i can bail it out in calm weather.

Cant make it self rescuing without a lower cockpit on back.

Floation is my only option.
What you need is: a hammer, nails, pieces of wood, a piece of bamboo, a king size bed sheet, and put the fucker together and go sailing.
Boston has allready the lawyers lined up for the part of the will, but he does not know you are in this thread, so I have an advantage on him.
Go my friend, fast and........goodby.
Where did you put the safe?
Daniel
Reply With Quote
  #10  
Old 04-10-2010, 10:47 PM
stonedpirate stonedpirate is offline
Senior Member
 
Join Date: Nov 2009
Rep: 21 Posts: 315
Location: Australia
Funny the first 10 times....

Actually, wasnt that funny the first time.
Reply With Quote
  #11  
Old 04-11-2010, 05:45 AM
BertKu BertKu is offline
Senior Member
 
Join Date: May 2009
Rep: 130 Posts: 1,035
Location: South Africa Little Brak River
Quote:
Originally Posted by stonedpirate View Post
Actually, wasnt that funny the first time.
StonedPirate, have you considered a couple of canisters and airbags. Either in or at the outside of your boat.
Bert
Reply With Quote
  #12  
Old 04-11-2010, 06:58 AM
bhnautika bhnautika is offline
Senior Member
 
Join Date: Feb 2006
Rep: 547 Posts: 540
Location: australia
SP you could line the inside with 100mm of polystyrene or similar, you would get good insulation and buoyancy. You could also add a foam/fiberglass rubbing strake which would also add some more buoyancy.
Reply With Quote
  #13  
Old 04-11-2010, 08:01 AM
dskira dskira is offline
Senior Member
 
Join Date: Apr 2008
Rep: 1305 Posts: 1,372
Location: Maine
Quote:
Originally Posted by stonedpirate View Post
Funny the first 10 times....

Actually, wasnt that funny the first time.
Agreed, sorry about that.
But honnestly, you have to start building.
It is better to built something, it liberate from the unanswered question, because all the answers come as you built.
And if you make a bad boat so what, you learn something and start again.
On that size, experiment in real size is the way to go.
Think simple: a cork, with a ballast and a little sail, can float for ever and no storm ever will sink it.
Now the guy inside the cork, oh boy, he will be all black and blue and piuking all over. But so what.
As for the coutry you will visit? don't bother, they are not bad people.
If they don't like you, you will have free room and board
Daniel
Reply With Quote
  #14  
Old 04-11-2010, 08:24 AM
stonedpirate stonedpirate is offline
Senior Member
 
Join Date: Nov 2009
Rep: 21 Posts: 315
Location: Australia
you certainly have a flair for sarcasm..
Reply With Quote
  #15  
Old 04-11-2010, 10:20 AM
GTO GTO is offline
Senior Member
 
Join Date: Jul 2007
Rep: 84 Posts: 117
Location: Alabama
I don't believe Daniel was being sarcastic.
You admit you have no experience either building a boat or sailing a small boat.
No one here can really design a small boat that is certain to make *you* happy.
To design a 10 foot boat that provides for your mental and physical needs, requires the answers to way to many questions. Given that you haven't sailed, *you* don't even know the answers.

Both Gerry and Serge were boat people that had built and sailed on boats before. They *knew* what they wanted and needed. Even with that knowledge, they still had a tough time of it.

Build your first design as a cheap, throwaway prototype. Exterior grade construction plywood, use Titebond 2 and glue up some 2x4 or equivalent and shape as necessary for a mast. Build in your lockers, sleep area, and so forth. Use sand or rocks or scrap metal for ballast and go sail/live on the thing. No doubt you will figure out what works and what doesn't.

At the very least, do a mock up of the "living" area of the boat in cardboard, then live in it for a week! Even that will help point out ergonomic flaws in your design.

If you have the spare time and money to spend 500, or more, days floating around the earth, AND you really want to succeed in your adventure, I can't see where adding 6 - 9 months more for at least a little proper research and development is going to hurt you much.
Or to put it another way. How would you feel if you put all your money into the boat and provisions but then had to abandon it within your first 30 - 40 days out? Or made it to a country or two and then realized the boat just wasn't going to work so you have to ship it all home?

Slow down a bit and get it as close to right as you can, because there are lot of other things that can go wrong that you have no control over and you don't want to be wearing yourself out with the stuff you should have squared away before leaving.
Reply With Quote
Reply



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Displacement vs. positive ballast Haile Boat Design 8 11-15-2009 09:51 PM
Positive Floatation, Offset Engine Bracket Jarek Propulsion 0 09-23-2009 01:16 PM
Floatation question tsmart Fiberglass and Composite Boat Building 7 06-11-2008 03:33 PM
Floatation mskweres Materials 17 09-14-2006 11:32 AM
Positive Buoyancy Floatation foam & Ullage Equation trouty Boat Design 2 07-02-2004 09:29 AM


All times are GMT -5. The time now is 01:17 AM.


Powered by: vBulletin Copyright ©2000 - 2012, Jelsoft Enterprises Ltd.
Web Site Design and Content Copyright ©1999 - 2012 Boat Design Net