[bolger] Re: Birdwatcher Keels
>his "Bluebird of Thorne" (26 Google hits) series. I think DP-B'sTwin keel = bilge keel. If you want a keelboat to stand up, that's what you do.
>conclusion is that you wouldn't use twin keels unless you had to.
>
>Howard
--
Craig O'Donnell
Sinepuxent Ancestors & Boats
<http://freepages.genealogy.rootsweb.com/~fassitt/>
The Proa FAQ <http://boat-links.com/proafaq.html>
The Cheap Pages <http://www.friend.ly.net/~dadadata/>
Sailing Canoes, Polytarp Sails, Bamboo, Chinese Junks,
American Proas, the Bolger Boat Honor Roll,
Plywood Boats, Bamboo Rafts, &c.
_________________________________
-- Professor of Boatology -- Junkomologist
-- Macintosh kinda guy
Friend of Wanda the Wonder Cat, 1991-1997.
_________________________________
I think DP-B's
a 28 and 40' in his gull series. Available with fin or twin keels. I
would have built the 19 but my basement was to small.
I talked with him about it and he says stability, recovery and
tacking angles should be very close but the additional wetted
surface area may hurt light wind performance.
Silver Gull 19 is really neat sharp looking little doryesque boat
with enclosed steering and junk rigs. Looks to be easy construction
with the exception of the strip deck. The boat can ride on a flatbed
trailer with minimal support, dry out on a tide, but requires 2'8"
draft to float. A bit deep for most folks. I would really like to
see one in person, i bet it's one of the cheapest most seaworthy
boat you can build in a few months with limited skill....i.e. i
could build it. One of the drawbacks is not much interior because of
the hull shape.....length on waterline is 13 and a halfish.
jason
> conclusion is that you wouldn't use twin keels unless you had to.Ain't no birdwatcher but tom mcnaughton offers a 19,working on a 24,
a 28 and 40' in his gull series. Available with fin or twin keels. I
would have built the 19 but my basement was to small.
I talked with him about it and he says stability, recovery and
tacking angles should be very close but the additional wetted
surface area may hurt light wind performance.
Silver Gull 19 is really neat sharp looking little doryesque boat
with enclosed steering and junk rigs. Looks to be easy construction
with the exception of the strip deck. The boat can ride on a flatbed
trailer with minimal support, dry out on a tide, but requires 2'8"
draft to float. A bit deep for most folks. I would really like to
see one in person, i bet it's one of the cheapest most seaworthy
boat you can build in a few months with limited skill....i.e. i
could build it. One of the drawbacks is not much interior because of
the hull shape.....length on waterline is 13 and a halfish.
jason
I have the 8th ed. (1973) and can't remember anything in it about
bilge keels. Nothing in the index either.
In "Sailing Yacht Design" (I have the 1971 third imp. of the 1966 2nd
ed.), Douglas Phillips-Birt devotes nearly five pages to what he
calls twin keels. There was a Lord Riverdale who must have spent
(wasted?) a large part of his fortune to building twin-keelers in
his "Bluebird of Thorne" (26 Google hits) series. I think DP-B's
conclusion is that you wouldn't use twin keels unless you had to.
Howard
bilge keels. Nothing in the index either.
In "Sailing Yacht Design" (I have the 1971 third imp. of the 1966 2nd
ed.), Douglas Phillips-Birt devotes nearly five pages to what he
calls twin keels. There was a Lord Riverdale who must have spent
(wasted?) a large part of his fortune to building twin-keelers in
his "Bluebird of Thorne" (26 Google hits) series. I think DP-B's
conclusion is that you wouldn't use twin keels unless you had to.
Howard
--- Inbolger@yahoogroups.com, craig o'donnell <dadadata@f...> wrote:
> I believe Skene's Elements of Yacht Design gives a formula for
bilge keels
No. Badger is a dory shape with a full length keel incorporating 4000 lbs
of lead and projecting 27" below the flat bottom.
Roger
derbyrm@...
http://derbyrm.mystarband.net/default.htm
of lead and projecting 27" below the flat bottom.
Roger
derbyrm@...
http://derbyrm.mystarband.net/default.htm
----- Original Message -----
From: "craig o'donnell" <dadadata@...>
>
> Well, I don't see a great problem with bilge keels on a BW. The righting
> capability has little to do with the CB.
>
<snip>
>
> 4. Isn't the junk-rigged "Badger" a flat-bottom bilge keeler?
>
Well, I don't see a great problem with bilge keels on a BW. The righting
capability has little to do with the CB.
1. Will add weight.
2. Simplest is prob steel plate welded to a flange bolted to the hull
bottom. Shaping the flange to the rocker might be troublesome. Bolger has
done this on several of his designs. See for example "Fin Keel Sharpie
Schooner"/Design 165 in MAIB June 1 2004.
Wood-epoxy bilge keels could be made but if you plan on hitting stuff they
will have to be strong. Carbon cloth or kevlar cloth qiuckly adds $$$ to
the project.
3. Might be less weatherly.
4. Isn't the junk-rigged "Badger" a flat-bottom bilge keeler?
I believe Skene's Elements of Yacht Design gives a formula for bilge keels
in terms of area, but I am not certain about this. Don't quote me.
--
Craig O'Donnell
Sinepuxent Ancestors & Boats
<http://freepages.genealogy.rootsweb.com/~fassitt/>
The Proa FAQ <http://boat-links.com/proafaq.html>
The Cheap Pages <http://www.friend.ly.net/~dadadata/>
Sailing Canoes, Polytarp Sails, Bamboo, Chinese Junks,
American Proas, the Bolger Boat Honor Roll,
Plywood Boats, Bamboo Rafts, &c.
_________________________________
-- Professor of Boatology -- Junkomologist
-- Macintosh kinda guy
Friend of Wanda the Wonder Cat, 1991-1997.
_________________________________
capability has little to do with the CB.
1. Will add weight.
2. Simplest is prob steel plate welded to a flange bolted to the hull
bottom. Shaping the flange to the rocker might be troublesome. Bolger has
done this on several of his designs. See for example "Fin Keel Sharpie
Schooner"/Design 165 in MAIB June 1 2004.
Wood-epoxy bilge keels could be made but if you plan on hitting stuff they
will have to be strong. Carbon cloth or kevlar cloth qiuckly adds $$$ to
the project.
3. Might be less weatherly.
4. Isn't the junk-rigged "Badger" a flat-bottom bilge keeler?
I believe Skene's Elements of Yacht Design gives a formula for bilge keels
in terms of area, but I am not certain about this. Don't quote me.
--
Craig O'Donnell
Sinepuxent Ancestors & Boats
<http://freepages.genealogy.rootsweb.com/~fassitt/>
The Proa FAQ <http://boat-links.com/proafaq.html>
The Cheap Pages <http://www.friend.ly.net/~dadadata/>
Sailing Canoes, Polytarp Sails, Bamboo, Chinese Junks,
American Proas, the Bolger Boat Honor Roll,
Plywood Boats, Bamboo Rafts, &c.
_________________________________
-- Professor of Boatology -- Junkomologist
-- Macintosh kinda guy
Friend of Wanda the Wonder Cat, 1991-1997.
_________________________________
On Sat, 18 Sep 2004 17:51:31 -0000, daveydimwit
<david@...> wrote:
Plywood $400
Epoxy $500
Sails $1000
Polycarbonate $500
Misc. $500
<david@...> wrote:
>A quick wild guess:
> I may be nuts but I am thinking of building a Birdwatcher. Anyone
> want to hazard a guess of costs using good materials?
Plywood $400
Epoxy $500
Sails $1000
Polycarbonate $500
Misc. $500
I may be nuts but I am thinking of building a Birdwatcher. Anyone
want to hazard a guess of costs using good materials?
want to hazard a guess of costs using good materials?