bow flare

[DCockey]

Originally Posted by michael pierzga

Bow stem profile

?????

[tunnels]

Flared bows are really quite easy to plank as its just a matter of getting the plank in the right angle and it bends to fit quite easy . the narrower the plank the better the fit and the quicker you can plank just that area , Then we used to simply ply the rest of the hull.every boat had a flared bow!, if it wasnt flared it was wet and the smaller fore deck was harder to stand on to pull the anchor up !!
Spent many a school holiday fishing with my fater and had to pull up the anchor from 150 feet of water and up to my knees in ocean swells coming over the bow . no electric winches in them days just brute strength .

[tunnels]

Originally Posted by viking north

For the fun of it I did a quick scan thru my liberary of designs for the Home Builder, "The study catalogue of Glen-L marine caught my eye in that some of their larger power craft seem to have flare in their plywood builds. One feature i did notice, those with what looks like flare also have some clipper curve built into the bow. Possibly this is how they encourage flare development into the ply flat panel in that area.--

Used to spit the sheet back aways and then push it naturaly into place and the fit a triangular piece in the spit . . But its much easyer to plank it with 3 or 4 inch wide planks just where the flare is then scarf the join where the ply and planks meet with a doubler of ply on the back side !!. The planks we always used solid wood veneers and was much easyer and quicker to work with .

[Mr Efficiency]

Flared bows aren't often seen on sailboats, so we can assume that for 270 degrees out of the possible 360, of headings, they have drawbacks.

[viking north]

This was just curiosity on my part as i have never built what i considered a flared bow section. Tunnels,I can see where strip or caravel planking would certianlly simplify the process--less torture: on the builder, the ply, or back yard microbalooning(auto body filler) , Interesting --- Geo.

A yacht is not defined by the vessel but by the care and love of her owner--

[tunnels]

I was just a kid in high school and used to go the a old shed across the road because they were bulding a old style boat that had a heap of flare in the bow had 3 skins of KAURI PLANKING and thousands of brass shoe tack holding the skins into the glue and was my job to bend the nails and hold a piece of steel so the guy could hit the nails flush then into the wood . Took ages to do but didnt mind helping build a boat . the whole boat was done like that botton ,topsides and transom curves every where never seen another boat like it before or since !!1957 it was !!

[ancient kayaker]

I haven’t yet mastered all the boating terminology.

I understand flare refers to the concave curve of the planking most easily seen in the bodyplan view. In a boat with ply sides - not tortured - I have seen the angle of the outward slope of the sheer planks called flare, but I don’t think that is correct. What is the proper term for this angle?

[tunnels]

flare !! as in flared out !!
Was done to give a bigger fore deck and to be able to get the front of the cabin further forward and more room inside . Had the tendancy to stop spray and splash when butting into a head sea . Had to be a little care full on a big rolling seas because of the lack of bouyancy in the front and could almost bury the nose and ship green water over the front and up the screen . Used to happen a lot so the front screen was always thick and well fixed in place . Was all the rage in late 1950s/60s/70s , its mainly seen on bigger boats these days to get big foredecks

[viking north]

Terry as i've always understood it, it referrs generally to the bow area and any outward curve of the planking working up near and including the sheer is referred to as flare.Technically I suppose there could be flare in the mid section or the stern also(the opposite of tumble home). The old fishermen often quote: " she must be a wet one, not much flare or she'll be nice and dry with that much flare." I.E different amounts of flare in this case. As i prev. mentioned i've never had the opportunity to build a craft with what i would consider Flare in the bow. The most flare i've ever seen in a hull was the modified Novie's used here in the Northumberland Straight area (Gulf of St. Lawrence).They have what I would consider extreme flare in their bows to keep them dry in the close spaced steep seas common to the area. Look like an aircraft carrier coming toward you.

[rwatson]

Besides the 'digging in and broaching' problem for flared bow yachts - I didn't see anyone mention the other problem with flared bow on a yacht - the aerodynamic effects.

A sailing yacht on a reach would have a distinct performance drop with a flared bow as the fore-sail gets turbulent air from the flare.

[JosephT]

I'm into racing and all I can say is any blow flare catches wind, which is not good. The best bows are round on top and have a low wind profile. They catch less wind and allow the boat to maneuver easier on the water. Anything beyond this on the hull/bow/deck is window dressing. Speed = simple.

[Tad]

Originally Posted by DCockey

a concave stem with a developable suface is possible if and only if the waterlines immediately aft of the hollow portion of the stem are concave.

An example of a boat side with a concave stem which is a single developable surface with continuous curvature is attached.

I assume this was done in the interest of intellectual curiosity? Because so far it don't look good to me and seems to create more problems than it might solve. Bending one corner of the plate the "wrong way" will produce a nasty bulge in any real life situation.....It already looks nasty in Rhino....certainly not fair in any sense that I would consider. The chine edge of your plate won't mate with a fair bottom plate........

If you require this shape in a real boat this is not the way to do it. Diagonal planking or cold-molding can easily be fit to a surface curved in two directions.

[DCockey]

Originally Posted by Tad

I assume this was done in the interest of intellectual curiosity?

Correct. Not intended to be a "real" design. But it does demonstrate what's required to have concave stem with a developable surface.

Because so far it don't look good to me and seems to create more problems than it might solve. Bending one corner of the plate the "wrong way" will produce a nasty bulge in any real life situation.....It already looks nasty in Rhino....certainly not fair in any sense that I would consider. The chine edge of your plate won't mate with a fair bottom plate........

If you require this shape in a real boat this is not the way to do it. Diagonal planking or cold-molding can easily be fit to a surface curved in two directions.

Agree that it's not a particularly good shape for a boat, though it is fair in the ense that the curvature is continuous and the surface can be unrolled flat without any stretching or gores. The chine was arbitrary, though it had to have a reverse curve which results in the "bump".

[kapnD]

Found this photo, a clear example of what flare is all about.
Illustrates very well the function of the "Carolina Flare".
This type of boat is almost always cold molded in plywood and epoxy, never heard of any structural problems resulting from the extreme flare.

[viking north]

Yup- thats flair alright in this part of Canada we call it the Northumberland Straight Flair. Possibly as extreme as flair can get.