Collision Bulkheads

sailor of fortune

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I have not seen or boarded lots of Cape Island style Novi boats, but the first thing I have noticed is lack of a collision bulkhead. Is this common or just the ones I have been on. What would be the reasoning behind it? There is one in Fairhaven that I looked at last fall and it made me wonder.
 

sailor of fortune

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I don't mind slow, but I would like a fighting chance to stop down flooding if I hit a half submerged container at night.
 

hmscapecod

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So what is the point of them now a days? I can see why ships have them.. but de boats? Your bow is up and out of the water and if you hit something, it doesnt seem like it will do much. Why not run the bunks all the way to the stem? Would this make the bow stronger?
 

Powderpro

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So what is the point of them now a days? I can see why ships have them.. but de boats? Your bow is up and out of the water and if you hit something, it doesnt seem like it will do much. Why not run the bunks all the way to the stem? Would this make the bow stronger?

I run my bunks all the way to the bow, I've never had a "crash" bulkhead in any of the boats I have finished. I guess it's a preference thing, I prefer not to have one ;).
 

Bill

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Bumping this thread ,, I know they aren't actually going to help for a collision because they have a hole cut out or a hatch.. But how many boats have one? I'm more interested in tieing the hull and top together while supporting the top. But goddamn it's a difficult piece to make.. I spent the night marking the spot with a rotary lazer level and made a template from shims but then when I cut it .. Not even close.. Sitting in garage frustrated . Back at it tomorrow. Don't judge me by my template

image.jpg
 

CaptDave

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I may be wrong but I believe if you are building a DE boat which will have an OMCI it is required.

§ 179.210Collision bulkhead.
(a) A vessel of more than 19.8 meters (65 feet) in length must have a collision bulkhead.
(b) A vessel of not more than 19.8 meters (65 feet) in length must have a collision bulkhead if it:
(1) Carries more than 49 passengers;
(2) Operates on exposed waters;
(3) Is of more than 12.2 meters (40 feet) in length and operates on partially protected waters; or
(4) Is constructed of wood on or after March 11, 2001, and operates in cold water.
(c) A double-ended ferry required to have a collision bulkhead must have a collision bulkhead at each end of the vessel.
 
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Toolate

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Toolate

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F/V First Team

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This is what it looks like making a pattern for the deck of an 18 foot boat

74443_144082772310247_8015447_n.jpg


Easy peasy
 

Toolate

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There is always a little space around, no matter how careful you do it or how many points you do, but that's what hull & deck putty is for. Additionally you won't get hard spots telegraphing through your hull if you keep it away a bit and putty it in place.

You can always tell a boat that has a bulkhead hard against the hull, damn contusion is what you're seeing.
 

Sailorgp

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I've read that gluing strips of corrugated cardboard around the edge of a bulkhead before tabbing into place will give it the needed space to prevent hard contact with the hull which is to be avoided
 

Kaiser

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Faro Arm, software and 5 axis cnc machine will make a nice bulkhead.

So i get the idea that one should space the bulkhead and putty but the putty has enough flex in it that it wont telegraph?

Composite materials are complex enough that it is hard for me to contemplate there reactions to forces.

Good stuff for the lawn mower, shower or better yet the run back from the canyons!
 
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