Re: [bolger] Re: Bolger keel
Mark
I am with you on some of this. When I am talking of a Bolger box keel , I mean the
sneakeasy 2 type or the one on the 48' steel boat that has been talked about lately. In
several other articles on these keels, he has mentioned the plan , profile matching. But
you are also right , I believe in saying that he has said the same thing in reference to
straight sided sharpies. I guess back to the books is called for.
HJ
Mark Albanese wrote:
_ _ _ _ _
% Harrywelshman@...
I am with you on some of this. When I am talking of a Bolger box keel , I mean the
sneakeasy 2 type or the one on the 48' steel boat that has been talked about lately. In
several other articles on these keels, he has mentioned the plan , profile matching. But
you are also right , I believe in saying that he has said the same thing in reference to
straight sided sharpies. I guess back to the books is called for.
HJ
Mark Albanese wrote:
> There's a semantic unclarity in talking about these keels ( at least to--
> me ). The keels for Oldshoe and Micro are plywood boxes containing
> lead, thus arguably, "Box Keels." But I've always thought of the box
> keels as the hollow box cutwater / step for Microtrawler, Sneakeasy v.2,
> or the Fast Motorsailor and its derivatives. Like the box deadwood in a
> Seabright Skiff.
>
> The lead containers are slab sided aren't they, so won't match their shapes
> in plan and profile, but I'll gladly call them boxes if that's what
> everybody's doing. I don't think the empty ones match those lines either.
> The more we have a planing boat, the less they should have to. But they
> might, and I'd like to find this out.
>
> I wish I could remember about which flat sharpie I first read from PCB
> about matching those lines. It's in one of the books. Guess I suffer the
> effects of too much youthful fun myself. Either that or 53 is farther gone
> than I expected.
>
> I looked tonight at all the pictures I could find of Microtrawler et al.
> All I can tell is that, contrary to what I may have thought at first, the
> narrower the beam the easier those lines would be to draw matched up.
>
> Happy Sails,
>
> Mark
>
_ _ _ _ _
% Harrywelshman@...
Mark Albanese wrote:
provide a means of minimizing the pounding that an otherwise flat bottom inclined to the
flow might suffer and to improve handling characteristics during hard turns at speed. It
accomplishes those goals.
The structure, however, has another effect which is quite remarkable. Most, nearly all in
fact, of the vessel's displacement is carried by the keel. Thus most of the wavemaking
associated with its motion is caused by the box keel. The waves normally associated with
dragging a hull through the water are then damped by the lightly immersed flat outward
extensions of the upper hull. With less of their propulsive energy converted to waves,
the boats move more rapidly and more easily to a point where they are planing on the
bottom of the box. And, without waves to climb, the boats run flatter.
The box deadwood of the Seabright and the planked and framed deadwood of the Nova Scotia
Cape Island model had basically the purpose of achieving lightness while retaining
strength and a good run aft. They were both notably successful and both somewhat labor
intensive. The Cape Island boat's wide flat frames were an awful source of rot too. Other
designers have used box keels to gain headroom or to lower engines or as a nice location
for tankage. Bolger's purpose is different.
I think that Phil's invention should be tested on a much heavier vessel, perhaps a tug,
to see if the wave quelling phenomenon holds true.
These observations are mine, not made by PCB. He makes no claim to what I honestly
believe is something of a genius level marine invention.
Jim Pope
> There's a semantic unclarity in talking about these keels ( at least toPCB, when discussing the box keel structure, is very modest. The box keel's purpose is to
> me ). The keels for Oldshoe and Micro are plywood boxes containing
> lead, thus arguably, "Box Keels." But I've always thought of the box
> keels as the hollow box cutwater / step for Microtrawler, Sneakeasy v.2,
> or the Fast Motorsailor and its derivatives. Like the box deadwood in a
> Seabright Skiff.
>
> Hi Mark & Group
provide a means of minimizing the pounding that an otherwise flat bottom inclined to the
flow might suffer and to improve handling characteristics during hard turns at speed. It
accomplishes those goals.
The structure, however, has another effect which is quite remarkable. Most, nearly all in
fact, of the vessel's displacement is carried by the keel. Thus most of the wavemaking
associated with its motion is caused by the box keel. The waves normally associated with
dragging a hull through the water are then damped by the lightly immersed flat outward
extensions of the upper hull. With less of their propulsive energy converted to waves,
the boats move more rapidly and more easily to a point where they are planing on the
bottom of the box. And, without waves to climb, the boats run flatter.
The box deadwood of the Seabright and the planked and framed deadwood of the Nova Scotia
Cape Island model had basically the purpose of achieving lightness while retaining
strength and a good run aft. They were both notably successful and both somewhat labor
intensive. The Cape Island boat's wide flat frames were an awful source of rot too. Other
designers have used box keels to gain headroom or to lower engines or as a nice location
for tankage. Bolger's purpose is different.
I think that Phil's invention should be tested on a much heavier vessel, perhaps a tug,
to see if the wave quelling phenomenon holds true.
These observations are mine, not made by PCB. He makes no claim to what I honestly
believe is something of a genius level marine invention.
Jim Pope
>
>
> Bolger rules!!!
> - no cursing
> - stay on topic
> - use punctuation
> - add your comments at the TOP and SIGN your posts
> - add some content: send "thanks!" and "ditto!" posts off-list.
Harry,
Thanks for the help with this.
Merrill's Private Postings has a PDF of part 2 of that article
with more on the rig, but doesn't mention the keels.
http://members.nbci.com/_XMCM/merrellc1/Files/navigator1.pdf
I've sent for the back issue.
There's a semantic unclarity in talking about these keels ( at least to
me ). The keels for Oldshoe and Micro are plywood boxes containing
lead, thus arguably, "Box Keels." But I've always thought of the box
keels as the hollow box cutwater / step for Microtrawler, Sneakeasy v.2,
or the Fast Motorsailor and its derivatives. Like the box deadwood in a
Seabright Skiff.
The lead containers are slab sided aren't they, so won't match their shapes
in plan and profile, but I'll gladly call them boxes if that's what
everybody's doing. I don't think the empty ones match those lines either.
The more we have a planing boat, the less they should have to. But they
might, and I'd like to find this out.
I wish I could remember about which flat sharpie I first read from PCB
about matching those lines. It's in one of the books. Guess I suffer the
effects of too much youthful fun myself. Either that or 53 is farther gone
than I expected.
I looked tonight at all the pictures I could find of Microtrawler et al.
All I can tell is that, contrary to what I may have thought at first, the
narrower the beam the easier those lines would be to draw matched up.
Happy Sails,
Mark
"Harry W. James" wrote:
Thanks for the help with this.
Merrill's Private Postings has a PDF of part 2 of that article
with more on the rig, but doesn't mention the keels.
http://members.nbci.com/_XMCM/merrellc1/Files/navigator1.pdf
I've sent for the back issue.
There's a semantic unclarity in talking about these keels ( at least to
me ). The keels for Oldshoe and Micro are plywood boxes containing
lead, thus arguably, "Box Keels." But I've always thought of the box
keels as the hollow box cutwater / step for Microtrawler, Sneakeasy v.2,
or the Fast Motorsailor and its derivatives. Like the box deadwood in a
Seabright Skiff.
The lead containers are slab sided aren't they, so won't match their shapes
in plan and profile, but I'll gladly call them boxes if that's what
everybody's doing. I don't think the empty ones match those lines either.
The more we have a planing boat, the less they should have to. But they
might, and I'd like to find this out.
I wish I could remember about which flat sharpie I first read from PCB
about matching those lines. It's in one of the books. Guess I suffer the
effects of too much youthful fun myself. Either that or 53 is farther gone
than I expected.
I looked tonight at all the pictures I could find of Microtrawler et al.
All I can tell is that, contrary to what I may have thought at first, the
narrower the beam the easier those lines would be to draw matched up.
Happy Sails,
Mark
"Harry W. James" wrote:
>
> I was just looking at an article in MAIB on the Micro Navigator (1 Jan 99) which I
> had copied out because of the chinese rig. He is talking about the box keel in the
> plan and profile discussion in this article. This keel is interesting as the
> difference between it and the ones for power are marked. I am hoping to get back up
> to Nome soon, so I can take a look at Ramon's "Seven Stars" with a little more
> educated eye.
> HJ
> Mark Albanese wrote:
>
> > I don't believe Philip Bolger was actually writing about those keel steps
> > when he mentioned matching up the chine curves in plan and profile. He was
> > actually writing about sharpies built on beam length ratios of 3 or 4 to
> > 1.
> >
> > I guess it could be done on any beam / length ratio, but that maybe the
> > narrowness is your problem. In fact, I cannot tell myself if the Sneakeasy
> > drawing does it or not. It's close, I think.
> > Mark
> >
I was just looking at an article in MAIB on the Micro Navigator (1 Jan 99) which I
had copied out because of the chinese rig. He is talking about the box keel in the
plan and profile discussion in this article. This keel is interesting as the
difference between it and the ones for power are marked. I am hoping to get back up
to Nome soon, so I can take a look at Ramon's "Seven Stars" with a little more
educated eye.
HJ
Mark Albanese wrote:
_ _ _ _ _
% Harrywelshman@...
had copied out because of the chinese rig. He is talking about the box keel in the
plan and profile discussion in this article. This keel is interesting as the
difference between it and the ones for power are marked. I am hoping to get back up
to Nome soon, so I can take a look at Ramon's "Seven Stars" with a little more
educated eye.
HJ
Mark Albanese wrote:
> I don't believe Philip Bolger was actually writing about those keel steps--
> when he mentioned matching up the chine curves in plan and profile. He was
> actually writing about sharpies built on beam length ratios of 3 or 4 to
> 1.
>
> I guess it could be done on any beam / length ratio, but that maybe the
> narrowness is your problem. In fact, I cannot tell myself if the Sneakeasy
> drawing does it or not. It's close, I think.
> Mark
>
> Bolger rules!!!
> - no cursing
> - stay on topic
> - use punctuation
> - add your comments at the TOP and SIGN your posts
> - add some content: send "thanks!" and "ditto!" posts off-list.
_ _ _ _ _
% Harrywelshman@...
Here's a link to Greg Carlson's boat project page, which has a link to
his design program Hulls.
Jeffrey,
http://www.carlsondesign.com/projects.html
Here is Gavin Atkin's tutorial for the program, which is also very
helpful.
http://home.clara.net/gmatkin/hullstut.htm
One (or more?) of the designs included with the software uses the
"bolger keel." Could be a starting point.
I recall Jim Michalak reflecting on the theory of the keel - equal
pressures etc. - and commented that when you view lines bow on, the
chine lines will bisect the angle between the bottom and the sides. This
indicates equal curvature of the panels. Greg's program also "develops"
the panels and lets you test position them on ply sheets and outputs dxf
files to import into Turbo Cad or what have you. It's the best boat
design gift on the internet. Check into it.
david beede
freedem@...wrote:
SOME CLICKS THAT COUNT!!
Feed someone.
http://www.thehungersite.com/
Save a little rain forest.
http://rainforest.care2.com/front.html/player12296
Simplicity Boats (& mirror sites)
http://members.tripod.com/simplicityboats/index.html
http://members.xoom.com/simpleboats/index.html
Here's my latest boat:
http://members.tripod.com/simplicityboats/summerbreeze.html
http://members.xoom.com/simpleboats/summerbreeze.html
Quasi esoteric musical instruments
http://unicornstrings.com
his design program Hulls.
Jeffrey,
http://www.carlsondesign.com/projects.html
Here is Gavin Atkin's tutorial for the program, which is also very
helpful.
http://home.clara.net/gmatkin/hullstut.htm
One (or more?) of the designs included with the software uses the
"bolger keel." Could be a starting point.
I recall Jim Michalak reflecting on the theory of the keel - equal
pressures etc. - and commented that when you view lines bow on, the
chine lines will bisect the angle between the bottom and the sides. This
indicates equal curvature of the panels. Greg's program also "develops"
the panels and lets you test position them on ply sheets and outputs dxf
files to import into Turbo Cad or what have you. It's the best boat
design gift on the internet. Check into it.
david beede
freedem@...wrote:
>--
>
> Mark
> Thankyou
> What is " gregs hulls"?
>
> Jeffery
>
> --- Inbolger@egroups.com, Mark Albanese <marka@o...> wrote:
> > freedem@e... wrote:
> > Jeff:
> >
> > You are asking about the Box / Step keel aren't you? These are
> mostly on
> > the order of about 5:1 length / beam ratio.
> > In all the motorboats they seem quite deep at the bow, and run out
> to about
> > half the depth or less behind.
> >
> > In addition to PCB's published drawings, there are a couple of
> these
> to
> > look at in Greg's Hulls. "Don't design a boat to leave your home
> without it."
> >
> > Mark
> > >
> > > Don't know if this is quite kosher to ask but how does one design
> a
> > > bolger keel what are the paramiters of the width of keel to beam
> ect
> > > In Homage to Mr Bolger
> > > Jeffery W Bybee
> > >
> > > Bolger rules!!!
> > > - no cursing
> > > - stay on topic
> > > - use punctuation
> > > - add your comments at the TOP and SIGN your posts
> > > - add some content: send "thanks!" and "ditto!" posts off
>
> Bolger rules!!!
> - no cursing
> - stay on topic
> - use punctuation
> - add your comments at the TOP and SIGN your posts
> - add some content: send "thanks!" and "ditto!" posts off-list.
SOME CLICKS THAT COUNT!!
Feed someone.
http://www.thehungersite.com/
Save a little rain forest.
http://rainforest.care2.com/front.html/player12296
Simplicity Boats (& mirror sites)
http://members.tripod.com/simplicityboats/index.html
http://members.xoom.com/simpleboats/index.html
Here's my latest boat:
http://members.tripod.com/simplicityboats/summerbreeze.html
http://members.xoom.com/simpleboats/summerbreeze.html
Quasi esoteric musical instruments
http://unicornstrings.com
Jeffrey,
Look for the free hull design software posted the by our moderator, Greg at:
http://www.egroups.com/files/bolger/%22%2A.hul%22+Design+Files+%26+Hull+Designer/
In the samples that come with it, see the Sneakeasy file. There are also a
couple of Bees and an AquaCasa hull that have the box cutwater too.
I don't believe Philip Bolger was actually writing about those keel steps
when he mentioned matching up the chine curves in plan and profile. He was
actually writing about sharpies built on beam length ratios of 3 or 4 to
1.
I guess it could be done on any beam / length ratio, but that maybe the
narrowness is your problem. In fact, I cannot tell myself if the Sneakeasy
drawing does it or not. It's close, I think.
Someone help us out here, please.
Mark
Look for the free hull design software posted the by our moderator, Greg at:
http://www.egroups.com/files/bolger/%22%2A.hul%22+Design+Files+%26+Hull+Designer/
In the samples that come with it, see the Sneakeasy file. There are also a
couple of Bees and an AquaCasa hull that have the box cutwater too.
I don't believe Philip Bolger was actually writing about those keel steps
when he mentioned matching up the chine curves in plan and profile. He was
actually writing about sharpies built on beam length ratios of 3 or 4 to
1.
I guess it could be done on any beam / length ratio, but that maybe the
narrowness is your problem. In fact, I cannot tell myself if the Sneakeasy
drawing does it or not. It's close, I think.
Someone help us out here, please.
Mark
Pippo
I guess That I focused so much on power boats that the unique "Bolger
Keel is the one he used on the modified sneekeasy or the microtrawler
and Hawkeye.
Best wishes and admeration sir to oall who is building insteed of
dreaming like my self
jeffery
--- Inbolger@egroups.com, "Giuseppe Bianco" <giuseppe.bianco@a...>
wrote:
I guess That I focused so much on power boats that the unique "Bolger
Keel is the one he used on the modified sneekeasy or the microtrawler
and Hawkeye.
Best wishes and admeration sir to oall who is building insteed of
dreaming like my self
jeffery
--- Inbolger@egroups.com, "Giuseppe Bianco" <giuseppe.bianco@a...>
wrote:
> What's a Bolger keel? Best, Pippoa
> --- Inbolger@egroups.com, freedem@e... wrote:
> > Don't know if this is quite kosher to ask but how does one design
> > bolger keel what are the paramiters of the width of keel to beamect
> > In Homage to Mr Bolger
> > Jeffery W
Thankyou sir I did meen the power keel likw on hawkeye and micro
trawler its just as I draw the curves of the side then take the same
curve to draw the bottom it changes the curve of the side becayse as
thee sides are bent around the bottton they 'shorten or do you think
close is good enoughsince sharpness if rather the point.?
thankyou
Jeffery
trawler its just as I draw the curves of the side then take the same
curve to draw the bottom it changes the curve of the side becayse as
thee sides are bent around the bottton they 'shorten or do you think
close is good enoughsince sharpness if rather the point.?
thankyou
Jeffery
--- Inbolger@egroups.com, "peter lenihan" <ellengaest@b...> wrote:
> Jeffery,
> Not exactly sure of what your idea is of a Bolger keel.Are you
> refering to the box-keels he sometimes puts on His sharpies or the
> full-lenght ones He has used on his
SHOEBOX,MICRO,LONG-MICRO,SEA-BIRD
> II etc...?The only literature I have come across from the designer
> explains somewhat the"science"of the box-keel by stating the rocker
> of the bottom must match the curve of the sides to reduce the
> generation of unequal pressures hence turbulence.As for the MICRO
> type keel;despite the apparent novelty of its construction,it is
just
> a question of creating a(old fashioned?)balanced form of lateral
> resistance.For a concise explanation of how or why these keels hold
> on to the hull without just breaking away,read the chapter on STORM
> PETREL in DIFFERENT BOATS(I think!).Ultimately,the best way to
design
> a"Bolger"keel may be to simply contact the designer.
> Sincerely,
> Peter Lenihan
> Micro"LESTAT"
>
>
>
>
>
>
> -- Inbolger@egroups.com, freedem@e... wrote:
> > Don't know if this is quite kosher to ask but how does one design
a
> > bolger keel what are the paramiters of the width of keel to beam
ect
> > In Homage to Mr Bolger
> > Jeffer
Jeffery,
Not exactly sure of what your idea is of a Bolger keel.Are you
refering to the box-keels he sometimes puts on His sharpies or the
full-lenght ones He has used on his SHOEBOX,MICRO,LONG-MICRO,SEA-BIRD
II etc...?The only literature I have come across from the designer
explains somewhat the"science"of the box-keel by stating the rocker
of the bottom must match the curve of the sides to reduce the
generation of unequal pressures hence turbulence.As for the MICRO
type keel;despite the apparent novelty of its construction,it is just
a question of creating a(old fashioned?)balanced form of lateral
resistance.For a concise explanation of how or why these keels hold
on to the hull without just breaking away,read the chapter on STORM
PETREL in DIFFERENT BOATS(I think!).Ultimately,the best way to design
a"Bolger"keel may be to simply contact the designer.
Sincerely,
Peter Lenihan
Micro"LESTAT"
-- Inbolger@egroups.com, freedem@e... wrote:
Not exactly sure of what your idea is of a Bolger keel.Are you
refering to the box-keels he sometimes puts on His sharpies or the
full-lenght ones He has used on his SHOEBOX,MICRO,LONG-MICRO,SEA-BIRD
II etc...?The only literature I have come across from the designer
explains somewhat the"science"of the box-keel by stating the rocker
of the bottom must match the curve of the sides to reduce the
generation of unequal pressures hence turbulence.As for the MICRO
type keel;despite the apparent novelty of its construction,it is just
a question of creating a(old fashioned?)balanced form of lateral
resistance.For a concise explanation of how or why these keels hold
on to the hull without just breaking away,read the chapter on STORM
PETREL in DIFFERENT BOATS(I think!).Ultimately,the best way to design
a"Bolger"keel may be to simply contact the designer.
Sincerely,
Peter Lenihan
Micro"LESTAT"
-- Inbolger@egroups.com, freedem@e... wrote:
> Don't know if this is quite kosher to ask but how does one design a
> bolger keel what are the paramiters of the width of keel to beam ect
> In Homage to Mr Bolger
> Jeffery W Bybee
I am dealing with this problem right now.
Micro has a small keel that is built to the dimensional thickness of
a
2X4 on edge; that is, 1 and half inches. It is shallow so as to
allow for shoal draft (about 1 foot thick, and 6 feet long), it
weights 375 lbs. this is short of the designed weight of 410 lbs.
It is actually a slug that ends up being encased, glued, and nailed
to
a plywood (and for some of us, glass and epoxy) container. The
inherent resistance to heeling is from the keel structural members,
not the actual lead keel itself. It is simply a counterweight and
not
through bolted to the bottom of the boat. In order for the keel to
drop off the boat (which used to happen to some older O'Day
sailboats)
The entire bottom of the boat would need to go first.
Boy, I hope I am correct on this, or I will be doing a lot of
swimming in the near future. Hopefully, Nantucket Sound and not the
Gulf of Maine!
Micro has a small keel that is built to the dimensional thickness of
a
2X4 on edge; that is, 1 and half inches. It is shallow so as to
allow for shoal draft (about 1 foot thick, and 6 feet long), it
weights 375 lbs. this is short of the designed weight of 410 lbs.
It is actually a slug that ends up being encased, glued, and nailed
to
a plywood (and for some of us, glass and epoxy) container. The
inherent resistance to heeling is from the keel structural members,
not the actual lead keel itself. It is simply a counterweight and
not
through bolted to the bottom of the boat. In order for the keel to
drop off the boat (which used to happen to some older O'Day
sailboats)
The entire bottom of the boat would need to go first.
Boy, I hope I am correct on this, or I will be doing a lot of
swimming in the near future. Hopefully, Nantucket Sound and not the
Gulf of Maine!
> What's a Bolger keel? Best, PippoI assumed he meant a Micro-type keel, hollow with free-flooding
spaces.
PHV
What's a Bolger keel? Best, Pippo
--- Inbolger@egroups.com, freedem@e... wrote:
> Don't know if this is quite kosher to ask but how does one design a
> bolger keel what are the paramiters of the width of keel to beam ect
> In Homage to Mr Bolger
> Jeffery W Bybee
> Don't know if this is quite kosher to ask but how does one design aIf anyone chooses to answer this question, please include an
> bolger keel what are the paramiters of the width of keel to beam ect
explanation of what holds it together and what holds it perpendicular
to the hull when the boat heels. I'm don't completely understand the
engineering.
Peter
Don't know if this is quite kosher to ask but how does one design a
bolger keel what are the paramiters of the width of keel to beam ect
In Homage to Mr Bolger
Jeffery W Bybee
bolger keel what are the paramiters of the width of keel to beam ect
In Homage to Mr Bolger
Jeffery W Bybee