Capacity

[funbun]

Rowing catamaran.

 

[Kayak Jack]

An inexperienced guy, with some engineering background here, asking a question. It seems to me, that the bottom of an outrigger should have a LARGE amount of arc. Say, the bottom edge at center, is 6" - 10" below the ends. This way, if you are leaning over and need just a kiss of stability, that's all you get. A straight bottomed outrigger would engage the entire hull all at once, creating a lot of unnecessary drag.

 

[seedtick]

I think you're on the right track Jack but about 5 posts up funbun said he wanted an outrigger to displace his weight (250lb) in case he went overboard.

I reckon it's so he can climb back in if a catfish pulls him overboard. An outrigger that supports itself plus 250 lb would have a total displacement of 4+ cu ft. There's all sorts of geometries that'll give 4 cu ft but it's essentially a sealedbox 6" wide, 12" deep and 8+ feet long. Finesseing that into a triangular cross section with a curved apex would be fun but may be more work than really necessary

 

[oldsparkey]

I think you're on the right track Jack but about 5 posts up funbun said he wanted an outrigger to displace his weight (250lb) in case he went overboard.

If he would get a cat big enough to pull him out of the boat then I would suggest a really good ... BFD. Attached to it one of the 12 GA bang sticks that they use around here to kill sharks. They also use them to dispatch ( kill) the really large Gators during the hunting season for them.

Any cat big enough to yank him out of the boat is one..... SERIOUS FISH.

The Bang Stick.
http://www.bluewaterhunter.com/shopsite ... ticks.html

Chuck.

 

[seedtick]

i like the concept
but where does the water in the barrel go when you fire it?

 

[Wannabe]

Through the fish,Seedtick.
Bob

 

[seedtick]

I was thinking about Newton's third law in this situation - the one about for every force of action there's an equal and opposite force of reaction

as a bullet is fired in a barel full of air - the air is compressed and exists ahead of the bullet out the end of the barrel

now if the barrel is full of non-compressable water, the water has to exit the barrel at the same speed as the bullet or you'll feel a significant backward force

so here i am with a barrel full of water and the end jammed up against the rear end of shark and i pop the cap on a .44 magnum

who suffers the most?

i'm sure the device works, i just don't understand it yet

 

[oldsparkey]

There is no barrel to speak of , the end of the shell is almost at the open end of the gun ( for better words). The bullet or shot in the cartridge does do some damage :roll: but it is the escaping gases that really do the destruction.
What little water that is in there has no effect on the performance of the bang stick and does not put the diver into any danger. To put it mildly , they perform and do the job quite well.

Chuck.

 

[seedtick]

thanks Chuck

the no barrel part makes sense

I was thrown off by their safety page that said if you shorten the bang stick, it becomes a "weapon" and may have to be registered - I assumed shortening meant cutting the barrel

 

[oldsparkey]

They are referring to the length of the shaft holding the head of the bang stick ( the serious part of the outfit) . Plus they no not recommend the use of it out of the water. Which some of the guys hunting gators do with it since they are not swimming with them. :roll:

Chuck.

 

[funbun]

I think you're on the right track Jack but about 5 posts up funbun said he wanted an outrigger to displace his weight (250lb) in case he went overboard.

I reckon it's so he can climb back in if a catfish pulls him overboard. An outrigger that supports itself plus 250 lb would have a total displacement of 4+ cu ft. There's all sorts of geometries that'll give 4 cu ft but it's essentially a sealedbox 6" wide, 12" deep and 8+ feet long. Finesseing that into a triangular cross section with a curved apex would be fun but may be more work than really necessary

Thanks. I could make a hard chine outrigger 6" x 6", then turn it on it's side forming a diamond shape makes it 12 inches since the long side of a triangle is equal to the sum of the short sides. Then again, I never did well in math.

 

[Kayak Jack]

The math is easy enough to get a pretty good guesstimate of volume.

 

[Jimmy W]

Thanks. I could make a hard chine outrigger 6" x 6", then turn it on it's side forming a diamond shape makes it 12 inches since the long side of a triangle is equal to the sum of the short sides. Then again, I never did well in math.

Not quite right, long side squared is equal to sum of squares of the short sides on a triangle with a 90 degree angle. Trying to draw a triangle with 2 sides 6 inches and one 12 inches you would end up with a straight line.

 

[FrankAS]

to do a pirogue, you have to do triangles. later keith

Keith, wouldn't you get a reasonable approximation, if instead of computing all the geometric shapes you were to take ½ the draft you were looking at and use it for the LxWxD then multiply x2?