which kind of keel is better ?

[hyboats]

See the attached pictures:p

[gonzo]

I see a forepeak and an engine room. What are you asking for ?

[tinhorn]

I prefer the keel with big motors attached.

[apex1]

I like them attached to the bottom.......

[wardd]

I like them attached to the bottom.......

and in the water not up in the air

[CatBuilder]

The OP has labeled the pictures. I think he's talking about stringers and calling them keels??

[gonzo]

OK, but better for what?

[hyboats]

OK, but better for what?
The first one only with stringers, the second one with big keel. I want to know which one is stronger ? :confused:

[hyboats]

I see a forepeak and an engine room. What are you asking for ?
The second one is a boat hull, not forepeak

[Petros]

either design can be made stronger than the other. There are different reasons for using one design over another, and it is not strength. Usually it has to do with the designers goal for the hull. Shallow draft, weighted keel, directional stablity, displacement hull vs. planing hull, etc.

So the question of "which is better?" can only be answered if we know what is your design objective for the hull.

[apex1]

This is a keel

http://upload.wikimedia.org/wikipedia/de/thumb/d/d6/Fluegelkiel.jpg/220px-Fluegelkiel.jpg

and this is one

http://upload.wikimedia.org/wikipedia/commons/thumb/f/f7/Wooden_hull_being_repaired.jpg/220px-Wooden_hull_being_repaired.jpg

And this is not a keel:

http://www.boatdesign.net/forums/attachments/fiberglass-composite-boat-building/46707d1282526925-kind-keel-better-keel-fill-foam.jpg

So then,

what do you want to know hyboats?

[hyboats]

This is a keel

http://upload.wikimedia.org/wikipedia/de/thumb/d/d6/Fluegelkiel.jpg/220px-Fluegelkiel.jpg

and this is one

http://upload.wikimedia.org/wikipedia/commons/thumb/f/f7/Wooden_hull_being_repaired.jpg/220px-Wooden_hull_being_repaired.jpg

And this is not a keel:

http://www.boatdesign.net/forums/attachments/fiberglass-composite-boat-building/46707d1282526925-kind-keel-better-keel-fill-foam.jpg

So then,

what do you want to know hyboats?
This is a 18ft cuddy boat hull
I usually call it keel, now I want to know why this boat use this kind of (keel), not stringers ? why some boats only with stringers ? :confused:

[Herman]

The picture with the engines in has stringers laminated "in situ" which is a lot of work.

The picture which is repeated above has received reinforcing from a laminated part.

Both options I guess are on the other end of the scale, with below picture in between:

http://www.boattest.com/images-gallery/News/formula353fastech-construction.jpg

As for the why: It all depends on requirements by the builder. If you plan on doing 100 boats, I would never laminate stringers in situ. Way too much work. I would opt for the second picture, or even better, the one I submitted. I feel the one you gave is more engineered for practical interior requirements then for reinforcing. They did fill it with foam, I see, to generate buoyancy. (and probably stiffness...) This is probably one of the boats which will be on this forum in 10 years, in the "water logged foam" section.

[apex1]

Thanks Herman.