Re: [bolger] Re: Sinkers v. Swimmers
dbaldnz wrote:
older lasers (mine was around 37400 or so). I saw the same
thing on a couple of other hulls at my club. I fixed it by
gouging out a channel in the join with a blade and filling
with epoxy. Plus, of course, all the other opportunities for
damage around the dagger board, mast step, pintles etc.
Lasers are sailed pretty hard and the flexing of the hull
will suck a surprising amount of water through a very small
hole.
Bruce Fountain
Senior Software Engineer
Union Switch & Signal
Perth, Western Australia
> I raced a laser for 3 years, and it never wracked or leaked. Your oneSmall leaks at the hull/deck join are pretty common on
> must have been a real dunger!
older lasers (mine was around 37400 or so). I saw the same
thing on a couple of other hulls at my club. I fixed it by
gouging out a channel in the join with a blade and filling
with epoxy. Plus, of course, all the other opportunities for
damage around the dagger board, mast step, pintles etc.
Lasers are sailed pretty hard and the flexing of the hull
will suck a surprising amount of water through a very small
hole.
Bruce Fountain
Senior Software Engineer
Union Switch & Signal
Perth, Western Australia
I guess the Laser must not have the vent built into the Sunfish? On the
Sunfish, high up on the forward side of the footwell, hidden under the deck
overhang, is a small hole, smaller than 1/8" which serves to prevent
"pumping." One has to really look to find it.
It didn't prevent the leaks which resulted from:
1) slamming the (old style) rudder down with leeway on so that it missed
the catch and poked a hole in the transom, and
2) running full speed into a gravel beach with the dagger board all the way
down (then's when it got the bumper someone else mentioned earlier).
Roger
derbyrm at starband.net
http://derbyrm.mystarband.net
Sunfish, high up on the forward side of the footwell, hidden under the deck
overhang, is a small hole, smaller than 1/8" which serves to prevent
"pumping." One has to really look to find it.
It didn't prevent the leaks which resulted from:
1) slamming the (old style) rudder down with leeway on so that it missed
the catch and poked a hole in the transom, and
2) running full speed into a gravel beach with the dagger board all the way
down (then's when it got the bumper someone else mentioned earlier).
Roger
derbyrm at starband.net
http://derbyrm.mystarband.net
----- Original Message -----
From: "dbaldnz" <oink@...>
To: <bolger@yahoogroups.com>
Sent: Tuesday, February 03, 2004 2:22 PM
Subject: [bolger] Re: Sinkers v. Swimmers
> I beg to disagree Bruce.
> I raced a laser for 3 years, and it never wracked or leaked. Your one
> must have been a real dunger!
> Also I built an Elegant Punt. I glued ply sides to the full length
> thwart, down to the bottom to form a permanent air chamber. Until it
> was stolen after 8 years, always outside uncovered, it never leaked
> or showed any signs of unwanted activity.
> Providing the inner space is epoxy sealed, and joins are taped, there
> need be no problem.
> DonB
>
> > I used to sail a laser, and that would suck water through the
> > tiniest holes (usually the join between the hull and deck) as
> > the hull flexed. Mind you, the enclosed space on a laser is
> > very large (the entire 14ft hull) and subject to continuous
> > stress.
> >
> > I tend to be pessimistic about these things - any enclosed
> > space will eventually leak, and you will wish you had installed
> > an access port.
> > Bruce Fountain
> > Senior Software Engineer
> > Union Switch & Signal
> > Perth, Western Australia
>
>
> Bolger rules!!!
> - no cursing, flaming, trolling, spamming, or flogging dead horses
> - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
> - Pls add your comments at the TOP, SIGN your posts, and snip away
> - Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax:
(978) 282-1349
> - Unsubscribe:bolger-unsubscribe@yahoogroups.com
> - Open discussion:bolger_coffee_lounge-subscribe@yahoogroups.com
>
> Yahoo! Groups Links
>
> To visit your group on the web, go to:
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>
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>
I beg to disagree Bruce.
I raced a laser for 3 years, and it never wracked or leaked. Your one
must have been a real dunger!
Also I built an Elegant Punt. I glued ply sides to the full length
thwart, down to the bottom to form a permanent air chamber. Until it
was stolen after 8 years, always outside uncovered, it never leaked
or showed any signs of unwanted activity.
Providing the inner space is epoxy sealed, and joins are taped, there
need be no problem.
DonB
I raced a laser for 3 years, and it never wracked or leaked. Your one
must have been a real dunger!
Also I built an Elegant Punt. I glued ply sides to the full length
thwart, down to the bottom to form a permanent air chamber. Until it
was stolen after 8 years, always outside uncovered, it never leaked
or showed any signs of unwanted activity.
Providing the inner space is epoxy sealed, and joins are taped, there
need be no problem.
DonB
> I used to sail a laser, and that would suck water through the
> tiniest holes (usually the join between the hull and deck) as
> the hull flexed. Mind you, the enclosed space on a laser is
> very large (the entire 14ft hull) and subject to continuous
> stress.
>
> I tend to be pessimistic about these things - any enclosed
> space will eventually leak, and you will wish you had installed
> an access port.
> Bruce Fountain
> Senior Software Engineer
> Union Switch & Signal
> Perth, Western Australia
--- Inbolger@yahoogroups.com, fountainb@s... wrote:
I know of only one canoe that leaked water into a floatation
compartment and that was an aluminum model, owned by a friend. You
would soon know once you start on a long portage if one leaked as the
weight of the water in either end would soon become intolerable.
(Which is what happened to the aluminum one.)
One could easily test a block of foam for expansion by measuring it
and then putting it into an over at whatever temperature you consider
to be hot. My guess is the air expands inside and compresses the cell
walls around it and the outer volume hardly changes. This of course
would not be the case with a plastic bottle or something that doesn't
enclose the air in small compressable chambers. An empty tank would
build up more pressure than one filled with foam I would think. So
therefore an empty chamber should have a relief valve of some kind
perhaps. I don't consider an empty sealed chamber to be that safe
myself. Better than nothing perhaps.
Nels
> I tend to be pessimistic about these things - any enclosedCan't blame you for being pessimistic based on your experience.
> space will eventually leak, and you will wish you had installed
> an access port.
>
> I think that your spaces must have leaked to some extent, or your
> canoe would have looked like a blimp on a hot day. Or maybe the
> walls were very rigid.
I know of only one canoe that leaked water into a floatation
compartment and that was an aluminum model, owned by a friend. You
would soon know once you start on a long portage if one leaked as the
weight of the water in either end would soon become intolerable.
(Which is what happened to the aluminum one.)
One could easily test a block of foam for expansion by measuring it
and then putting it into an over at whatever temperature you consider
to be hot. My guess is the air expands inside and compresses the cell
walls around it and the outer volume hardly changes. This of course
would not be the case with a plastic bottle or something that doesn't
enclose the air in small compressable chambers. An empty tank would
build up more pressure than one filled with foam I would think. So
therefore an empty chamber should have a relief valve of some kind
perhaps. I don't consider an empty sealed chamber to be that safe
myself. Better than nothing perhaps.
Nels
Nels wrote:
tiniest holes (usually the join between the hull and deck) as
the hull flexed. Mind you, the enclosed space on a laser is
very large (the entire 14ft hull) and subject to continuous
stress.
I tend to be pessimistic about these things - any enclosed
space will eventually leak, and you will wish you had installed
an access port.
I think that your spaces must have leaked to some extent, or your
canoe would have looked like a blimp on a hot day. Or maybe the
walls were very rigid.
Bruce Fountain
Senior Software Engineer
Union Switch & Signal
Perth, Western Australia
> I have owned about 15 diferent canoes over the years and almost allI used to sail a laser, and that would suck water through the
> of them had sealed floatation tanks at both ends. Never had one crack
> and that includes dumping in rapids many times.
tiniest holes (usually the join between the hull and deck) as
the hull flexed. Mind you, the enclosed space on a laser is
very large (the entire 14ft hull) and subject to continuous
stress.
I tend to be pessimistic about these things - any enclosed
space will eventually leak, and you will wish you had installed
an access port.
> They have been left outside in tmeperatures ranging from 40 below toOh, 100F. I was talking about HOT weather :-)
> 100 above. Closed cell foam doesn's seem to change too much but the
> inserts are just snug and not expanded foam.
I think that your spaces must have leaked to some extent, or your
canoe would have looked like a blimp on a hot day. Or maybe the
walls were very rigid.
Bruce Fountain
Senior Software Engineer
Union Switch & Signal
Perth, Western Australia
Well, thanks, Nels. Thanks good to know. I was attracted to this dory
because it could be constructed inexpensively, quickly, and when finished weighs 45
lbs. (which
was particularly attractive as I needed to carry it over a dune to get to the
beach),
and because its is such a beautiful boat. I need to get busy and finish it.
Maybe this
spring will be the year.
Best wishes,
boblynn
frboblynn@...
just outside Chicago
because it could be constructed inexpensively, quickly, and when finished weighs 45
lbs. (which
was particularly attractive as I needed to carry it over a dune to get to the
beach),
and because its is such a beautiful boat. I need to get busy and finish it.
Maybe this
spring will be the year.
Best wishes,
boblynn
frboblynn@...
just outside Chicago
--- Inbolger@yahoogroups.com, frboblynn@a... wrote:
of them had sealed floatation tanks at both ends. Never had one crack
and that includes dumping in rapids many times.
They have been left outside in tmeperatures ranging from 40 below to
100 above. Closed cell foam doesn's seem to change too much but the
inserts are just snug and not expanded foam.
Cheers, Nels
> Thanks for your response, Grant. By "rock on" I hope you don'tmean that I
> am going to be "rocking" up and down in my little dory. I aminterested in
> your idea about a drainI have owned about 15 diferent canoes over the years and almost all
> plug for my fore and aft tanks.
of them had sealed floatation tanks at both ends. Never had one crack
and that includes dumping in rapids many times.
They have been left outside in tmeperatures ranging from 40 below to
100 above. Closed cell foam doesn's seem to change too much but the
inserts are just snug and not expanded foam.
Cheers, Nels
Thanks for your response, Grant. By "rock on" I hope you don't mean that I
am going to be "rocking" up and down in my little dory. I am interested in
your idea about a drain
plug for my fore and aft tanks. In part, my interest comes from a concerned
expressed by Bruce Fountain about the tanks developing cracks that leaks due
to sun
and their being sealed. So good idea. Thanks.
best wishes,
boblynn
frboblynn@...
living just outside Chicago
am going to be "rocking" up and down in my little dory. I am interested in
your idea about a drain
plug for my fore and aft tanks. In part, my interest comes from a concerned
expressed by Bruce Fountain about the tanks developing cracks that leaks due
to sun
and their being sealed. So good idea. Thanks.
best wishes,
boblynn
frboblynn@...
living just outside Chicago
By comparison, the Jochems schooner is about the same size and the
displacement is given as 5000lbs. I don't know about the amount of
water.
As the thead on water ballast has amply demonstrated, it's not an
easy topic to understand. The bottom line, however, is that water
ballast works best in a fairly light boat with a flat or nearly flat
bottom. St. Valery, Jochems and Martha Jane are all examples, and
together sugggest that PCB would agree. In addition, due to it's
bulk, it works best with a ballast/displacement ratio that is low to
moderate, say about 25% tops. With metal ballast, a hull like this
might go as high as 50%, e.g. the LFH Meadowlark.
Peter
displacement is given as 5000lbs. I don't know about the amount of
water.
As the thead on water ballast has amply demonstrated, it's not an
easy topic to understand. The bottom line, however, is that water
ballast works best in a fairly light boat with a flat or nearly flat
bottom. St. Valery, Jochems and Martha Jane are all examples, and
together sugggest that PCB would agree. In addition, due to it's
bulk, it works best with a ballast/displacement ratio that is low to
moderate, say about 25% tops. With metal ballast, a hull like this
might go as high as 50%, e.g. the LFH Meadowlark.
Peter
Nels,
I think you're right, and I'm wrong. St. Valery is drawn to metric
measurements. The profile view in BDQ shows "C.B." next to a bulls-
eye type symbol then "2.1 m3," then below it "(c.4700 LBS.)" All
those numbers and symbols are within the confines of the water
ballast tanks, which led to my quick assumption that he was referring
to the ballast.
But you're right, that assumption makes no sense; it's too big. Taken
with the fact that there are other numbers showing 4700lbs
displacement(how did I not notice that!) it's clear 4700 is total.
The article also shows 1000 lbs trailer weight (which seems low to
me...) That's a min. 3700 lbs ballast, but a lot of that (1700 lbs?)
is probably assumed to be folks and gear. Maybe 2000 lbs ballast?
That's more reasonable. 31+ ft3 of tanks. The tanks shown extend
about 7' fore and aft.
Thank for pointing it out...
By the way, the drawings show a flotation fore and aft in the wells.
John O'Neill
I think you're right, and I'm wrong. St. Valery is drawn to metric
measurements. The profile view in BDQ shows "C.B." next to a bulls-
eye type symbol then "2.1 m3," then below it "(c.4700 LBS.)" All
those numbers and symbols are within the confines of the water
ballast tanks, which led to my quick assumption that he was referring
to the ballast.
But you're right, that assumption makes no sense; it's too big. Taken
with the fact that there are other numbers showing 4700lbs
displacement(how did I not notice that!) it's clear 4700 is total.
The article also shows 1000 lbs trailer weight (which seems low to
me...) That's a min. 3700 lbs ballast, but a lot of that (1700 lbs?)
is probably assumed to be folks and gear. Maybe 2000 lbs ballast?
That's more reasonable. 31+ ft3 of tanks. The tanks shown extend
about 7' fore and aft.
Thank for pointing it out...
By the way, the drawings show a flotation fore and aft in the wells.
John O'Neill
--- Inbolger@yahoogroups.com, "Nels" <arvent@h...> wrote:
> Are you sure the figures you are using above are correct? The
reason
> I ask is that 74 cubic feet of water is a pretty large tank. For
> example if the tank was 15 feet long by 5 feet wide by 1 foot high
it
> would contain 75 cubic feet, and would indeed hold 4700 pounds of
> water if your weight per cubic figure is correct. That is almost
21/2
> tons of water to pump in and out of the boat every time you want to
> go sailing. How is this accomplished I am wondering?
>
> I really admire the looks of the design, but feel there must be a
> glitch in the ballest figures somewhere. 470 pounds on each side
> would make more sense to me, as you would need more because I don't
> think you would have the same righting leverage as lead installed
in
> a salient keel like LONG MICRO. (With 520 pounds)
>
> I would consider locating the closed cell foam as insulation in
> between the roof beams and upper hull sides above the dressers.
This
> would add comfort, (preventing condensation) as well as safety.
>
> Nels
--- Inbolger@yahoogroups.com, "oneillparker" <jboatguy@c...> wrote:
Are you sure the figures you are using above are correct? The reason
I ask is that 74 cubic feet of water is a pretty large tank. For
example if the tank was 15 feet long by 5 feet wide by 1 foot high it
would contain 75 cubic feet, and would indeed hold 4700 pounds of
water if your weight per cubic figure is correct. That is almost 21/2
tons of water to pump in and out of the boat every time you want to
go sailing. How is this accomplished I am wondering?
I really admire the looks of the design, but feel there must be a
glitch in the ballest figures somewhere. 470 pounds on each side
would make more sense to me, as you would need more because I don't
think you would have the same righting leverage as lead installed in
a salient keel like LONG MICRO. (With 520 pounds)
I would consider locating the closed cell foam as insulation in
between the roof beams and upper hull sides above the dressers. This
would add comfort, (preventing condensation) as well as safety.
Nels
> Continuing from my last post (34128), I worked out the numbers forDesign
> St. Valery, (25' overall) based on the drawings of her in Boat
> Quarterly (#10) as for water vs. lead ballast.Hi John,
>
> Bolger shows 2.1 m3 (74.2 ft3) of water ballast, about 4700 pounds,
> stuck in the bilge. From what I can tell it seems to be distributed
> outboard port and starboard, mostly under dressers and berths, and
> doesn't seem to impact centerline headroom at all.
>
Are you sure the figures you are using above are correct? The reason
I ask is that 74 cubic feet of water is a pretty large tank. For
example if the tank was 15 feet long by 5 feet wide by 1 foot high it
would contain 75 cubic feet, and would indeed hold 4700 pounds of
water if your weight per cubic figure is correct. That is almost 21/2
tons of water to pump in and out of the boat every time you want to
go sailing. How is this accomplished I am wondering?
I really admire the looks of the design, but feel there must be a
glitch in the ballest figures somewhere. 470 pounds on each side
would make more sense to me, as you would need more because I don't
think you would have the same righting leverage as lead installed in
a salient keel like LONG MICRO. (With 520 pounds)
I would consider locating the closed cell foam as insulation in
between the roof beams and upper hull sides above the dressers. This
would add comfort, (preventing condensation) as well as safety.
Nels
on 2/2/04 1:04 AM,frboblynn@...atfrboblynn@...wrote:
What you have done is made your boat more seaworthy by adding the styrofoam,
hopefully of the closed cell variety. You could have achieved the same
effect or better by sealing the "tanks" and having simply dead air in them
with a drain plug should they develop a leak over time, rock on!!!
Grant
I am wondering if my putting Styrofoam fore and aft was a good
What you have done is made your boat more seaworthy by adding the styrofoam,
hopefully of the closed cell variety. You could have achieved the same
effect or better by sealing the "tanks" and having simply dead air in them
with a drain plug should they develop a leak over time, rock on!!!
Grant
I am wondering if my putting Styrofoam fore and aft was a good
> idea or a bad
> one; it's all glassed in either way as I sealed these spaces with
> fiberglass. Any advice about this? I'd appreciate knowing if I should go on
> with the
> project or if my
> little addition of "positive flotation" will be a problem of some sort? I
> hope this is
> all clear.
>
> Thanks and best wishes to all,
> boblynn
>frboblynn@...
>
> Bolger rules!!!
> - no cursing, flaming, trolling, spamming, or flogging dead horses
> - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
> - Pls add your comments at the TOP, SIGN your posts, and snip away
> - Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax:
> (978) 282-1349
> - Unsubscribe:bolger-unsubscribe@yahoogroups.com
> - Open discussion:bolger_coffee_lounge-subscribe@yahoogroups.com
>
> Yahoo! Groups Links
>
> To visit your group on the web, go to:
>http://groups.yahoo.com/group/bolger/
>
> To unsubscribe from this group, send an email to:
>bolger-unsubscribe@yahoogroups.com
>
> Your use of Yahoo! Groups is subject to:
>http://docs.yahoo.com/info/terms/
>
>
Thanks, Bruce, for sharing your opinion and for your encouragement. Phoenix
would be
a great name for this boat. I hadn't planned to name it. But I hadn't
planned not to name it either. Just haven't thought about it. But great idea, and
I thank you for the
suggestion. Also, there would have been another tank at the thwart but I
decided I
need passage ways for water to run back to the back so I could bail it out.
I feel sure
if I sailed it, it will take on water through the centerboard case and
possibly over the sides at times when wave action is high. I plan to put plastic
bottles in that area.
Thanks again. Hope you are sailing. It has been below zero here lately (was
warmer
today but still way too cold to put a boat in the water.
Fair winds,
boblynn
frboblynn@...
Just outside Chicago in Park Forest, IL, USA
would be
a great name for this boat. I hadn't planned to name it. But I hadn't
planned not to name it either. Just haven't thought about it. But great idea, and
I thank you for the
suggestion. Also, there would have been another tank at the thwart but I
decided I
need passage ways for water to run back to the back so I could bail it out.
I feel sure
if I sailed it, it will take on water through the centerboard case and
possibly over the sides at times when wave action is high. I plan to put plastic
bottles in that area.
Thanks again. Hope you are sailing. It has been below zero here lately (was
warmer
today but still way too cold to put a boat in the water.
Fair winds,
boblynn
frboblynn@...
Just outside Chicago in Park Forest, IL, USA
frboblynn wrote:
is perhaps redundant, but it can't do any harm. It also ensures
that the spaces remain bouyant even if the hull is breached.
Personally I don't like completely sealed spaces - expanding
air can blow the joints as the boat heats up in the sun. And
if there is even a hairline crack it will suck water as the
boat flexes. I prefer to install inspection hatches, and I
usually use removably bouyancy (aka plastic milk bottles)
rather than foam to make it easier to access the space for
repairs. But that is just my personal preference.
The ballast/floatation discussions don't really apply to
your dory, since the only ballast in your dory is your
good self.
Don't stress over cutting a hole for the daggerboard.
I know exactly how you feel, but it is really a very
straighforward exercise. Make your centreboard case a
little oversize, so that it pokes through the bottom.
After glueing it in place from the inside, flip and trim
the case down to the hull. Saves fiddling about working
out the angle of the hull.
Good to hear that the boat survived the fire. Maybe you
should call her "Phoenix" :-)
Bruce Fountain
Senior Software Engineer
Union Switch & Signal
Perth, Western Australia
> I am wondering if my putting Styrofoam fore and aft was a goodIf your fore and aft spaces are completely sealed then the foam
> idea or a bad one; it's all glassed in either way as I sealed
> these spaces with fiberglass
is perhaps redundant, but it can't do any harm. It also ensures
that the spaces remain bouyant even if the hull is breached.
Personally I don't like completely sealed spaces - expanding
air can blow the joints as the boat heats up in the sun. And
if there is even a hairline crack it will suck water as the
boat flexes. I prefer to install inspection hatches, and I
usually use removably bouyancy (aka plastic milk bottles)
rather than foam to make it easier to access the space for
repairs. But that is just my personal preference.
The ballast/floatation discussions don't really apply to
your dory, since the only ballast in your dory is your
good self.
Don't stress over cutting a hole for the daggerboard.
I know exactly how you feel, but it is really a very
straighforward exercise. Make your centreboard case a
little oversize, so that it pokes through the bottom.
After glueing it in place from the inside, flip and trim
the case down to the hull. Saves fiddling about working
out the angle of the hull.
Good to hear that the boat survived the fire. Maybe you
should call her "Phoenix" :-)
Bruce Fountain
Senior Software Engineer
Union Switch & Signal
Perth, Western Australia
In a message dated 2/1/04 10:00:42 PM,jboatguy@...writes:
<< the day
will come when a blue-water sailboat bum can ask a sailboat dealer if
the dreamboat he or she is eyeing has positive flotation, and not be
laughed out the door... >>
OK, I don't understand this. While the discussion of ballast and flotation
has been interesting, it really has been pretty impossible to be sure of
anything except that things change. Now maybe someone can tell me something I need
to know in addition to this truism. I have built a beautiful little dory I
came across in the SBJ. It is not completely finished as I have not been able
to bring myself to putting a hole in the bottom for a daggerboard and make
other modification for a mast. It is said to be a "9 foot dory" but it is really
6' along the bottom, and I believe that makes it a 6 foot dory. It has a tank
at the stern and another at the bow. I filled both with Styrofoam thinking
that I would be improving its safety. I never built a boat before. The bottom
has been glassed--needs more sanding--and I thought I would glass the sides.
It holds water. I know that because it was in the basement when my house
burned and
water from the fire department's hoses flooded it. But it has never been in
the water. I am wondering if my putting Styrofoam fore and aft was a good
idea or a bad
one; it's all glassed in either way as I sealed these spaces with
fiberglass. Any advice about this? I'd appreciate knowing if I should go on with the
project or if my
little addition of "positive flotation" will be a problem of some sort? I
hope this is
all clear.
Thanks and best wishes to all,
boblynn
frboblynn@...
<< the day
will come when a blue-water sailboat bum can ask a sailboat dealer if
the dreamboat he or she is eyeing has positive flotation, and not be
laughed out the door... >>
OK, I don't understand this. While the discussion of ballast and flotation
has been interesting, it really has been pretty impossible to be sure of
anything except that things change. Now maybe someone can tell me something I need
to know in addition to this truism. I have built a beautiful little dory I
came across in the SBJ. It is not completely finished as I have not been able
to bring myself to putting a hole in the bottom for a daggerboard and make
other modification for a mast. It is said to be a "9 foot dory" but it is really
6' along the bottom, and I believe that makes it a 6 foot dory. It has a tank
at the stern and another at the bow. I filled both with Styrofoam thinking
that I would be improving its safety. I never built a boat before. The bottom
has been glassed--needs more sanding--and I thought I would glass the sides.
It holds water. I know that because it was in the basement when my house
burned and
water from the fire department's hoses flooded it. But it has never been in
the water. I am wondering if my putting Styrofoam fore and aft was a good
idea or a bad
one; it's all glassed in either way as I sealed these spaces with
fiberglass. Any advice about this? I'd appreciate knowing if I should go on with the
project or if my
little addition of "positive flotation" will be a problem of some sort? I
hope this is
all clear.
Thanks and best wishes to all,
boblynn
frboblynn@...
Oh yea, lets here it for TRADITION.
TRADITION once told us we should sling the rudder on the 'steerboard'
side because "99%, give or take, of sailboats since man climbed off a
floating log have been steered with oars"
TRADITION once told us sails should be hung athwartships
because "99%, give or take, of sailboats since man climbed off a
floating log - with the exception of a few outlandish Mediterrian
rigs, and that ain't but a pond next to the big wide oceans - have
had athwartships sails"
TRADITION tells us the underwater shape should look like a mackeral.
TRAIDITON tells us sailboats should have low freeboard.
TRADITION tell us booms should sweep the deck.
TRADITION tells us there should be long overhangs fore and aft.
TRADITION tells us that catboat rudders should be shallow and long
and hang off the stern, and sharpie rudders should be shallow and
long and balanced and hang underneath.
TRADITION tells us marconi rigs are inherently superior and gaff rigs
have too much weight aloft, sag off to leeward and are prone to break.
TRADITION tells us all sailboats worthy of attention need high
tension rigs.
Now TRADITION tells us that, as you say, "99%, give or take, of
ballasted sailboats since man climbed off a floating log have been
sinkers."
I say, what TRADITION really tells us is that things change, uses
change, technology changes, priorities change, values change. And
here we are in the 21st century with traditional design procedures,
of all disciplines, being SWEPT out the door by computer aided
design. Using it, it's possible to predict vessel behavior and
stability over a wide range of conditions, and the era of the SINKER
is at an end. It won't happen tomorrow, or next week. But the day
will come when a blue-water sailboat bum can ask a sailboat dealer if
the dreamboat he or she is eyeing has positive flotation, and not be
laughed out the door...
The only real TRADITION is called CHANGE.
John O'Neill
TRADITION once told us we should sling the rudder on the 'steerboard'
side because "99%, give or take, of sailboats since man climbed off a
floating log have been steered with oars"
TRADITION once told us sails should be hung athwartships
because "99%, give or take, of sailboats since man climbed off a
floating log - with the exception of a few outlandish Mediterrian
rigs, and that ain't but a pond next to the big wide oceans - have
had athwartships sails"
TRADITION tells us the underwater shape should look like a mackeral.
TRAIDITON tells us sailboats should have low freeboard.
TRADITION tell us booms should sweep the deck.
TRADITION tells us there should be long overhangs fore and aft.
TRADITION tells us that catboat rudders should be shallow and long
and hang off the stern, and sharpie rudders should be shallow and
long and balanced and hang underneath.
TRADITION tells us marconi rigs are inherently superior and gaff rigs
have too much weight aloft, sag off to leeward and are prone to break.
TRADITION tells us all sailboats worthy of attention need high
tension rigs.
Now TRADITION tells us that, as you say, "99%, give or take, of
ballasted sailboats since man climbed off a floating log have been
sinkers."
I say, what TRADITION really tells us is that things change, uses
change, technology changes, priorities change, values change. And
here we are in the 21st century with traditional design procedures,
of all disciplines, being SWEPT out the door by computer aided
design. Using it, it's possible to predict vessel behavior and
stability over a wide range of conditions, and the era of the SINKER
is at an end. It won't happen tomorrow, or next week. But the day
will come when a blue-water sailboat bum can ask a sailboat dealer if
the dreamboat he or she is eyeing has positive flotation, and not be
laughed out the door...
The only real TRADITION is called CHANGE.
John O'Neill
--- Inbolger@yahoogroups.com, "dbaldnz" <oink@w...> wrote:
> 99%, give or take, of ballasted sailboats since man climbed off a
> floating log have been sinkers.
> I like your chances of not sinking.
> DonB
>
>
> > But, if disaster struck and she filled with water, she's now a
> SINKER
> > and down she goes.
> > John O'Neill
99%, give or take, of ballasted sailboats since man climbed off a
floating log have been sinkers.
I like your chances of not sinking.
DonB
floating log have been sinkers.
I like your chances of not sinking.
DonB
> But, if disaster struck and she filled with water, she's now aSINKER
> and down she goes.
> John O'Neill
Saint Valery is clinker planked, but she's almost a slab-sided boat
with high, vertical sides, wide, flat plywood bottom and hard bilges,
reminescent of a tanker viewed head on. She's also has a nearly 7'
beam.
She draws less then a foot fully ballasted, cat schooner rigged but
with balanced lug sails, far forward centerboard and huge, kick-up
rudder (in profile she could almost be mistaken for a big Cartopper
with less rocker). She has an inboard outboard, rigged to swing up
backwards through a remarkably small hole in the motor well,
tabernacled masts, and wells forward and aft outside the people
envelope. PCB has drawn a dingy on her deck. She'll fit a legal
trailer, and has a lovely, almost frigate-like transom, with big
holes cut in it (above deck level) kind of like stern windows.
With her high bulwarks she looks like a traditional French fishing
trawler, after which she was inspired. If wanted she can carry
topsl's, and a jib on a bowsprit run-out through a hole in the
bulwarks beside the tall stem.
I would LOVE to build this craft. I have drooled over her since the
moment I first saw her. The bilges are so hard it strikes me I could
build her right side up, saving the hull sides until the major
interior pieces were done.
"This will be a stiff boat, and a very fast and weatherly boat, when
she is keenly sailed."
PCB
Oh how I want to 'keenly sail' this boat!!!
John O'Neill
with high, vertical sides, wide, flat plywood bottom and hard bilges,
reminescent of a tanker viewed head on. She's also has a nearly 7'
beam.
She draws less then a foot fully ballasted, cat schooner rigged but
with balanced lug sails, far forward centerboard and huge, kick-up
rudder (in profile she could almost be mistaken for a big Cartopper
with less rocker). She has an inboard outboard, rigged to swing up
backwards through a remarkably small hole in the motor well,
tabernacled masts, and wells forward and aft outside the people
envelope. PCB has drawn a dingy on her deck. She'll fit a legal
trailer, and has a lovely, almost frigate-like transom, with big
holes cut in it (above deck level) kind of like stern windows.
With her high bulwarks she looks like a traditional French fishing
trawler, after which she was inspired. If wanted she can carry
topsl's, and a jib on a bowsprit run-out through a hole in the
bulwarks beside the tall stem.
I would LOVE to build this craft. I have drooled over her since the
moment I first saw her. The bilges are so hard it strikes me I could
build her right side up, saving the hull sides until the major
interior pieces were done.
"This will be a stiff boat, and a very fast and weatherly boat, when
she is keenly sailed."
PCB
Oh how I want to 'keenly sail' this boat!!!
John O'Neill
--- Inbolger@yahoogroups.com, "Nels" <arvent@h...> wrote:
> --- Inbolger@yahoogroups.com, "oneillparker" <jboatguy@c...> wrote:
> > Continuing from my last post (34128), I worked out the numbers
for
> > St. Valery, (25' overall) based on the drawings of her in Boat
> Design
> > Quarterly (#10) as for water vs. lead ballast.
> >
> > Bolger shows 2.1 m3 (74.2 ft3) of water ballast, about 4700
pounds,
> > stuck in the bilge. From what I can tell it seems to be
distributed
> > outboard port and starboard, mostly under dressers and berths,
and
> > doesn't seem to impact centerline headroom at all.
>
> 4700 pounds sure sounds like a lot of ballest on a boat that small!
>
> LONG MICRO is almost as big and only requires 520 pounds of lead to
> keep her self-righting. So St. Valery requires over over 8 times
the
> ballest to keep it from tipping over it seems.
>
> Nels
--- Inbolger@yahoogroups.com, "oneillparker" <jboatguy@c...> wrote:
LONG MICRO is almost as big and only requires 520 pounds of lead to
keep her self-righting. So St. Valery requires over over 8 times the
ballest to keep it from tipping over it seems.
Nels
> Continuing from my last post (34128), I worked out the numbers forDesign
> St. Valery, (25' overall) based on the drawings of her in Boat
> Quarterly (#10) as for water vs. lead ballast.4700 pounds sure sounds like a lot of ballest on a boat that small!
>
> Bolger shows 2.1 m3 (74.2 ft3) of water ballast, about 4700 pounds,
> stuck in the bilge. From what I can tell it seems to be distributed
> outboard port and starboard, mostly under dressers and berths, and
> doesn't seem to impact centerline headroom at all.
LONG MICRO is almost as big and only requires 520 pounds of lead to
keep her self-righting. So St. Valery requires over over 8 times the
ballest to keep it from tipping over it seems.
Nels
> From what I can tell it seems to be distributedIn a flat (or nearly) bottomed boat, there are advantages to dividing
> outboard port and starboard, ...
inside ballast in two and pushing it to the sides. First, obviously,
it gets it out of the middle of the cabin. Second, it increases the
rotational moment of inertia so the boat won't react as quickly when
hit by a gust. It can make a substantial difference to the feel of
the vessel underay, similar to the difference in a sailboat boat hull
between having the mast stepped and not.
Peter
No, Bolger already has flotation designed in, I just calculated the
amount of extra foam that would be needed to 'float' the lead in a
version that substituted lead for water with no other changes.
John O'Neill
--- Inbolger@yahoogroups.com, "John Bell" <smallboatdesigner@m...>
wrote:
amount of extra foam that would be needed to 'float' the lead in a
version that substituted lead for water with no other changes.
John O'Neill
--- Inbolger@yahoogroups.com, "John Bell" <smallboatdesigner@m...>
wrote:
> Have you figured in the positive buoyancy of all the woodenstructure in
> your calculations for foam?Design
>
>
> ----- Original Message -----
> From: "oneillparker" <jboatguy@c...>
> To: <bolger@yahoogroups.com>
> Sent: Sunday, February 01, 2004 4:54 PM
> Subject: [bolger] Sinkers v. Swimmers
>
>
> | Continuing from my last post (34128), I worked out the numbers for
> | St. Valery, (25' overall) based on the drawings of her in Boat
> | Quarterly (#10) as for water vs. lead ballast.....
Have you figured in the positive buoyancy of all the wooden structure in
your calculations for foam?
your calculations for foam?
----- Original Message -----
From: "oneillparker" <jboatguy@...>
To: <bolger@yahoogroups.com>
Sent: Sunday, February 01, 2004 4:54 PM
Subject: [bolger] Sinkers v. Swimmers
| Continuing from my last post (34128), I worked out the numbers for
| St. Valery, (25' overall) based on the drawings of her in Boat Design
| Quarterly (#10) as for water vs. lead ballast.
|
| Bolger shows 2.1 m3 (74.2 ft3) of water ballast, about 4700 pounds,
| stuck in the bilge. From what I can tell it seems to be distributed
| outboard port and starboard, mostly under dressers and berths, and
| doesn't seem to impact centerline headroom at all.
|
| Now, if instead of water, lead was put in the bilge, all else being
| equal she'd only need about 6.6 ft3 of lead to equal that weight in
| water. Because the lead could be placed more advantageously she
| probably wouldn't need as much, say 6 ft3. In St.Valery that would
| buy a few extra sock drawers (the ballast tanks seem to be about 8"
| high off the flat-floored bilge), at the expense of her trailering
| capability. (BDQ lists her empty weight as 1000 lbs.)
|
| But, if disaster struck and she filled with water, she's now a SINKER
| and down she goes.
|
| To offset that lead and keep her swimming - and taking into account
| that lead in the water weighs less than lead not in the water - she'd
| need about 70 ft3 of flotation somewhere in the boat just to offset
| the weight of that lead.
|
| That means, in total, if lead ballast is used and positive flotation
| was wanted, a minimum of around 76 ft3 of space would have to be
| found to stuff all the lead and foam into - more space than was used
| for water ballast alone. Flotation doesn't necessarily fill nooks and
| crannies as handily as water does, so it might take more than that.
| Also, if the bulk of the flotation is placed down low, say under the
| berths and out of the way where Bolger put the water ballast, in an
| inverted boat filled with water that flotation is now acting as hard
| as it can to keep her inverted...
|
| Now, obviously if PCB had designed St. Valery from the start to use
| lead it would not be the St. Valery it is now, but an entirely
| different boat: probably deeper draft, probably not as much ballast
| but still not easily trailerable, not as beachable - and on and on.
|
| The point is, if in a given boat lead is used to save the space
| otherwise devoted to water ballast, it only works if you're willing
| to have a boat that abandons you for the deep blue just at the time
| you need her most...
|
| Numbers:
| Lbs./Ft3
| Lead 710
| Water, pure 62.4
| Water, sea 64.08
|
| 1 ft3 styrofoam floats 55 lbs (according to buoyancyfoam.com)
|
| John O'Neill
|
|
|
| Bolger rules!!!
| - no cursing, flaming, trolling, spamming, or flogging dead horses
| - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
| - Pls add your comments at the TOP, SIGN your posts, and snip away
| - Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax:
(978) 282-1349
| - Unsubscribe:bolger-unsubscribe@yahoogroups.com
| - Open discussion:bolger_coffee_lounge-subscribe@yahoogroups.com
|
| Yahoo! Groups Links
|
| To visit your group on the web, go to:
|http://groups.yahoo.com/group/bolger/
|
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|bolger-unsubscribe@yahoogroups.com
|
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|http://docs.yahoo.com/info/terms/
|
|
Continuing from my last post (34128), I worked out the numbers for
St. Valery, (25' overall) based on the drawings of her in Boat Design
Quarterly (#10) as for water vs. lead ballast.
Bolger shows 2.1 m3 (74.2 ft3) of water ballast, about 4700 pounds,
stuck in the bilge. From what I can tell it seems to be distributed
outboard port and starboard, mostly under dressers and berths, and
doesn't seem to impact centerline headroom at all.
Now, if instead of water, lead was put in the bilge, all else being
equal she'd only need about 6.6 ft3 of lead to equal that weight in
water. Because the lead could be placed more advantageously she
probably wouldn't need as much, say 6 ft3. In St.Valery that would
buy a few extra sock drawers (the ballast tanks seem to be about 8"
high off the flat-floored bilge), at the expense of her trailering
capability. (BDQ lists her empty weight as 1000 lbs.)
But, if disaster struck and she filled with water, she's now a SINKER
and down she goes.
To offset that lead and keep her swimming - and taking into account
that lead in the water weighs less than lead not in the water - she'd
need about 70 ft3 of flotation somewhere in the boat just to offset
the weight of that lead.
That means, in total, if lead ballast is used and positive flotation
was wanted, a minimum of around 76 ft3 of space would have to be
found to stuff all the lead and foam into - more space than was used
for water ballast alone. Flotation doesn't necessarily fill nooks and
crannies as handily as water does, so it might take more than that.
Also, if the bulk of the flotation is placed down low, say under the
berths and out of the way where Bolger put the water ballast, in an
inverted boat filled with water that flotation is now acting as hard
as it can to keep her inverted...
Now, obviously if PCB had designed St. Valery from the start to use
lead it would not be the St. Valery it is now, but an entirely
different boat: probably deeper draft, probably not as much ballast
but still not easily trailerable, not as beachable - and on and on.
The point is, if in a given boat lead is used to save the space
otherwise devoted to water ballast, it only works if you're willing
to have a boat that abandons you for the deep blue just at the time
you need her most...
Numbers:
Lbs./Ft3
Lead 710
Water, pure 62.4
Water, sea 64.08
1 ft3 styrofoam floats 55 lbs (according to buoyancyfoam.com)
John O'Neill
St. Valery, (25' overall) based on the drawings of her in Boat Design
Quarterly (#10) as for water vs. lead ballast.
Bolger shows 2.1 m3 (74.2 ft3) of water ballast, about 4700 pounds,
stuck in the bilge. From what I can tell it seems to be distributed
outboard port and starboard, mostly under dressers and berths, and
doesn't seem to impact centerline headroom at all.
Now, if instead of water, lead was put in the bilge, all else being
equal she'd only need about 6.6 ft3 of lead to equal that weight in
water. Because the lead could be placed more advantageously she
probably wouldn't need as much, say 6 ft3. In St.Valery that would
buy a few extra sock drawers (the ballast tanks seem to be about 8"
high off the flat-floored bilge), at the expense of her trailering
capability. (BDQ lists her empty weight as 1000 lbs.)
But, if disaster struck and she filled with water, she's now a SINKER
and down she goes.
To offset that lead and keep her swimming - and taking into account
that lead in the water weighs less than lead not in the water - she'd
need about 70 ft3 of flotation somewhere in the boat just to offset
the weight of that lead.
That means, in total, if lead ballast is used and positive flotation
was wanted, a minimum of around 76 ft3 of space would have to be
found to stuff all the lead and foam into - more space than was used
for water ballast alone. Flotation doesn't necessarily fill nooks and
crannies as handily as water does, so it might take more than that.
Also, if the bulk of the flotation is placed down low, say under the
berths and out of the way where Bolger put the water ballast, in an
inverted boat filled with water that flotation is now acting as hard
as it can to keep her inverted...
Now, obviously if PCB had designed St. Valery from the start to use
lead it would not be the St. Valery it is now, but an entirely
different boat: probably deeper draft, probably not as much ballast
but still not easily trailerable, not as beachable - and on and on.
The point is, if in a given boat lead is used to save the space
otherwise devoted to water ballast, it only works if you're willing
to have a boat that abandons you for the deep blue just at the time
you need her most...
Numbers:
Lbs./Ft3
Lead 710
Water, pure 62.4
Water, sea 64.08
1 ft3 styrofoam floats 55 lbs (according to buoyancyfoam.com)
John O'Neill