A little Moxie for the modular idea
Bruce Hector wrote:
group of sailmakers in Australia have apparently come up with a way to
make a controllable powerful spinnaker/kite that will even go to
windward at least as well if not better than the old time square riggers
did. They did it for a real racing machine project but the finished item
works much better than they had hoped and is for sure useful for
cruising sailors.
Their sail sheets from the deck level. No heeling and it can pull like
the devil. www.kiteship.com/
is the web site which has descriptive information. And the AYRS had an
article on it.
Three or four of those things pulling her and the TIMS might get up and
plane - safely.
Jim Pope
[Non-text portions of this message have been removed]
>This relates more for the TIMS I guess than it does for the canoe. A
> A few concept, building, launch and first paddle photos are now up at:
>http://photos.groups.yahoo.com/group/bolger4photos/lst
>
> She behaved well, and no water came on board.
>
> Looks like I need to increase the aft rocker, as she drags her tail a
> bit with a load like me in it. Still, a few easy stokes drove her
> easily. Hmmmm.
>
> Enjoy.
>
> Bruce Hector
>http://photos.groups.yahoo.com/group/bolger4photos
>
>
>
>
>
>
group of sailmakers in Australia have apparently come up with a way to
make a controllable powerful spinnaker/kite that will even go to
windward at least as well if not better than the old time square riggers
did. They did it for a real racing machine project but the finished item
works much better than they had hoped and is for sure useful for
cruising sailors.
Their sail sheets from the deck level. No heeling and it can pull like
the devil. www.kiteship.com/
is the web site which has descriptive information. And the AYRS had an
article on it.
Three or four of those things pulling her and the TIMS might get up and
plane - safely.
Jim Pope
[Non-text portions of this message have been removed]
Bruce Hector wrote:
"Econ_MS30". Is there any more information on that boat? That looks just
like the arrangement that I onetime had a talk with PCB about. ( Soon
after I went bust so no more talk seemed useful but it looks as though
someone else had about the same idea too.)
Any word on her would be appreciated.
Jim Pope
[Non-text portions of this message have been removed]
>The Bolger 4 photo site has a picture of a boat referenced as
> A few concept, building, launch and first paddle photos are now up at:
>http://photos.groups.yahoo.com/group/bolger4photos/lst
>
>
"Econ_MS30". Is there any more information on that boat? That looks just
like the arrangement that I onetime had a talk with PCB about. ( Soon
after I went bust so no more talk seemed useful but it looks as though
someone else had about the same idea too.)
Any word on her would be appreciated.
Jim Pope
[Non-text portions of this message have been removed]
--- Inbolger@yahoogroups.com, "Bruce Hector" <bruce_hector@h...> wrote:
Bruce,
Interesting boat, beautiful damsel, but who's that Old Guy so
prominently featured? It's rainy & 50's here in Oregon. Those photos
make me long for Spring. How do you transport that entire boat shop to
Florida?
Cheers,
David Graybeal
Portland, OR.
"Youth is the gift of nature-but age is a work of art" - Stanislaw Lec
>************
> A few concept, building, launch and first paddle photos are now up at:
>http://photos.groups.yahoo.com/group/bolger4photos/lst
>
> She behaved well, and no water came on board.
>
> Looks like I need to increase the aft rocker, as she drags her tail a
> bit with a load like me in it. Still, a few easy stokes drove her
> easily. Hmmmm.
>
> Enjoy.
>
> Bruce Hector
>http://photos.groups.yahoo.com/group/bolger4photos
Bruce,
Interesting boat, beautiful damsel, but who's that Old Guy so
prominently featured? It's rainy & 50's here in Oregon. Those photos
make me long for Spring. How do you transport that entire boat shop to
Florida?
Cheers,
David Graybeal
Portland, OR.
"Youth is the gift of nature-but age is a work of art" - Stanislaw Lec
A few concept, building, launch and first paddle photos are now up at:
http://photos.groups.yahoo.com/group/bolger4photos/lst
She behaved well, and no water came on board.
Looks like I need to increase the aft rocker, as she drags her tail a
bit with a load like me in it. Still, a few easy stokes drove her
easily. Hmmmm.
Enjoy.
Bruce Hector
http://photos.groups.yahoo.com/group/bolger4photos
http://photos.groups.yahoo.com/group/bolger4photos/lst
She behaved well, and no water came on board.
Looks like I need to increase the aft rocker, as she drags her tail a
bit with a load like me in it. Still, a few easy stokes drove her
easily. Hmmmm.
Enjoy.
Bruce Hector
http://photos.groups.yahoo.com/group/bolger4photos
Just got back from a 1 mile paddle with Elaine in Wing Nut.
She worked great. Smooth, easy motion, fast, sleek, fine paddler, and
the boat wasn't too bad either.
With a load of 450 pounds the little 2 foot beam canoe was fast and
stable, as long as we sat on the floor. Kneeling, I found it fine,
but Eaine didn't feel comfortable.
She paddled light and easy. I has a sense she was easily faster than
our 16' fibreglass Peterbourough Canoe. Far more stable and forgiving
that our Payson Piroque,
All wing nuts were as tight as can be. She bridged 1 to 1/2 foot
power boat wakes with ease, and no elasticity. The Intra-Coastal here
is 100 to 200 yards wide, and a nice Sunday like today brings the
plastic palaces out in droves.
Taking a foot wake on the beam rolled her a bit, but she never
shipped any water. We were drawing about 4 inches with that load,
I've been forbidden to say how much of the weight was Elaine, but i'm
250 pounds.
Taking them bow on or at a slight oblique was fine, no pitch or yaw.
About a dozen of our cell mates. er fellow snow birds came for the
launch, and she was duly christened Wing-Nut, and a short prayer
ofered to God and Poseidin, ya' can't be too careful now.
Pictures later, I'll take the camera chip and have a CD made this
afternoon.
Bruce "Who are you calling a Wing-Nut buddy?" Hector
She worked great. Smooth, easy motion, fast, sleek, fine paddler, and
the boat wasn't too bad either.
With a load of 450 pounds the little 2 foot beam canoe was fast and
stable, as long as we sat on the floor. Kneeling, I found it fine,
but Eaine didn't feel comfortable.
She paddled light and easy. I has a sense she was easily faster than
our 16' fibreglass Peterbourough Canoe. Far more stable and forgiving
that our Payson Piroque,
All wing nuts were as tight as can be. She bridged 1 to 1/2 foot
power boat wakes with ease, and no elasticity. The Intra-Coastal here
is 100 to 200 yards wide, and a nice Sunday like today brings the
plastic palaces out in droves.
Taking a foot wake on the beam rolled her a bit, but she never
shipped any water. We were drawing about 4 inches with that load,
I've been forbidden to say how much of the weight was Elaine, but i'm
250 pounds.
Taking them bow on or at a slight oblique was fine, no pitch or yaw.
About a dozen of our cell mates. er fellow snow birds came for the
launch, and she was duly christened Wing-Nut, and a short prayer
ofered to God and Poseidin, ya' can't be too careful now.
Pictures later, I'll take the camera chip and have a CD made this
afternoon.
Bruce "Who are you calling a Wing-Nut buddy?" Hector
--- wmrpage@a... wrote:
downwards bending.
fairly flimsy boxes so that they can stand some chop without breaking
up.
Instead of adding a lot of material to get it stiff, I am thinking to
allow it some flexibility.
for longitudinal stress and tension (along the fibres). When mounted
with some gaps, the bottom chine logs are loaded for bending. This
might make a difference.
hydrostatic reasons the plywood can be fairly thin.
the bending of the chine logs between the modules. Everything else
would be stiff.
I am not so much worried about the connection logs themselves, but
the connections to the hull, i.e. the screws. They might split the
logs when loaded for tension.
As said: I am considering options. Not claiming that this is the best
way. The problem with the flexible chine logs is, that assembly will
be difficult without getting wet. Better would probably be to mount
the modules via a connection log at the sheerline or rubrails.
Assuming quasi sine shaped waves, then parts of the bottom would
leave the water once the height of the waves get more than twice the
draft, no?
I always imagine, that the some/one module would be firmly sitting on
sawhorses (or on top of some stairs), while one module is completely
suspended, and loaded with 100 to 200 kg (200 to 400 lbs).
Would the connection hold that?
Have a nice evening,
Stefan
> I think there might be some merit in clamping the modules togetherSure, the gaps make only sense when deliberately allowing upwards and
> with both a chine log and a heavy sheer strake or rubbing rail,
> but even in that case I see no merit in leaving gaps
> between the modules.
downwards bending.
> The notion that flexibility in a boat's hull is somehow conduciveI am not looking for increased speed, but only to join a number of
> to seaworthiness and/or speed is a pretty venerable one.
fairly flimsy boxes so that they can stand some chop without breaking
up.
> Deflection of aircraft wings is readily visible, but it doesn'tAnd those are basically the reasons why I am considering it.
> occur because designers see flexibility as a virtue in itself -
> quite the contrary - instead they are forced to trade off large
> (but not too large!) deflections against structural weight)
Instead of adding a lot of material to get it stiff, I am thinking to
allow it some flexibility.
> the ultimate strength of the assembly will be no greater than thatWhen mounted "closely together", the chine and sheer logs are loaded
> of the chine logs themselves.
for longitudinal stress and tension (along the fibres). When mounted
with some gaps, the bottom chine logs are loaded for bending. This
might make a difference.
> Assuming the chine logs to be of reasonable dimensions,The modules are max. 4 feet wide, with a few inches draft only. For
> their ultimate strength would be much less that of the plywood
> sides of the module, (assuming no buckling of the panel).
hydrostatic reasons the plywood can be fairly thin.
> So, while this scheme would certainly make the structure???
> more flexible, it would also make it much weaker.
> If the chine log is secured by mechanical fasteners,I don't understand what you mean. The flexibility would only be in
> the working of the flexible hull would further degrade
> the strength of the system over time.
the bending of the chine logs between the modules. Everything else
would be stiff.
> If a chine log was used in connection with a sheer strakeThe connection logs would be in any case one or two modules long.
> or rubbing rail, one would have a structure analogous to an
> I-beam - the side panels of the modules would function
> as sheer webs, while the chine and sheer strake would bear
> most of the tension and compression loads. (This assumes
> that the chine log and strake are continuous members for
> their lengths, not butted pieces.)
I am not so much worried about the connection logs themselves, but
the connections to the hull, i.e. the screws. They might split the
logs when loaded for tension.
As said: I am considering options. Not claiming that this is the best
way. The problem with the flexible chine logs is, that assembly will
be difficult without getting wet. Better would probably be to mount
the modules via a connection log at the sheerline or rubrails.
Assuming quasi sine shaped waves, then parts of the bottom would
leave the water once the height of the waves get more than twice the
draft, no?
I always imagine, that the some/one module would be firmly sitting on
sawhorses (or on top of some stairs), while one module is completely
suspended, and loaded with 100 to 200 kg (200 to 400 lbs).
Would the connection hold that?
Have a nice evening,
Stefan
wmrpage@...wrote:
I think you're right. I seem to recall some drawings of a ship built
back in the nineteenth century in segments which were designed to allow
her to conform to waves rather than to fight them.
Again, as I recall, she failed ignominiously, at a cost to her crew. The
world's lifeboat services, coast guards, etc. seem to favor brute
unyielding strength and, in fact, make a case of it.
Jim
> The notion that flexibility in a boat's hull is somehow conducive toHi Bill,
> seaworthiness and/or speed is a pretty venerable one. IMHO, one could
> right a
> history of naval construction as a progression toward less, not more,
> flexibility in the structure of hulls.
>
>
I think you're right. I seem to recall some drawings of a ship built
back in the nineteenth century in segments which were designed to allow
her to conform to waves rather than to fight them.
Again, as I recall, she failed ignominiously, at a cost to her crew. The
world's lifeboat services, coast guards, etc. seem to favor brute
unyielding strength and, in fact, make a case of it.
Jim
In a message dated 3/19/05 7:20:14 AM Central Standard Time,
stefan.probst@opticom.v-nam.net writes:
I'm no engineer, but I don't think this sounds like a very sound idea.
I think there might be some merit in clamping the modules together with both
a chine log and a heavy sheer strake or rubbing rail, but even in that case I
see no merit in leaving gaps between the modules.
The notion that flexibility in a boat's hull is somehow conducive to
seaworthiness and/or speed is a pretty venerable one. IMHO, one could right a
history of naval construction as a progression toward less, not more,
flexibility in the structure of hulls.
I occasionally see claims in histories that Viking ships owed
something of their seaworthiness to the flexibility of their hulls. I think that this
is pure balderdash, wherein a chain of historians, ignorant of technical
nautical matters, unthinkingly repeat the claims of previous historians, no more
learned than they, repeating notions that, if they could be traced, probably
lead back to a conversation someone with his elbows on a yacht club bar at Cowes.
The keels of longships got deeper over time, but the effect of this was to
increase their structural stiffness as least as much and probably more than any
gain in hydrodynamic efficiency. In the late nineteenth century when composite
construction was introduced, the metal frames were sometimes joined with
threaded rods or otherwise adjustable stays. I've read that when one of the tea
clippers of the era out ran another, the crew of the slower vessel would declare
that the faster had "let its stays out." Given the difficulty of even getting
at the stays in a loaded cargo vessel, this sounds like just a tale to me. A
perusal of plans of American clipper ships provides a rather dismaying picture
of heroic, but inept and largely unsuccessful, efforts to prevent their hulls
from hogging. Possibly the earliest effort at using reasoned engineering
principles in the construction of ships was Sepping's introduction of diagonal
bracing in Royal Navy warships in the second half of the 19th century. This was
definitely an effort to reduce, not increase the flexibility of the structures.
There is nothing special about the fact that tree trucks bend under
wind loads. A tree is basically a cantilevered beam, like an unstayed mast. All
beams deflect in proportion with the load imposed, the stiffness of the
material, its size and geometry, until either equilibrium is reached or the beam
fails. (You should not detect the deflection of floor joists when you walk over
them, but theory says they have to deflect by some finite amount to support
your weight. Deflection of aircraft wings is readily visible, but it doesn't
occur because designers see flexibility as a virtue in itself - quite the contrary
- instead they are forced to trade off large (but not too large!) deflections
against structural weight)
Ignoring what happens when the top edges of the spaced modules come in
contact with one another as the chine logs bend upward at the bow and stern,
the ultimate strength of the assembly will be no greater than that of the
chine logs themselves. Assuming the chine logs to be of reasonable dimensions,
their ultimate strength would be much less that of the plywood sides of the
module, (assuming no buckling of the panel). So, while this scheme would certainly
make the structure more flexible, it would also make it much weaker. If the
chine log is secured by mechanical fasteners, the working of the flexible hull
would further degrade the strength of the system over time.
If a chine log was used in connection with a sheer strake or rubbing
rail, one would have a structure analogous to an I-beam - the side panels of
the modules would function would function as sheer webs, while the chine and
sheer strake would bear most of the tension and compression loads. (This assumes
that the chine log and strake are continuous members for their lengths, not
butted pieces.) However, in this scheme, spacing the modules would either
accomplish nothing, except for creating the hydrodynamic drag and waterproofing
problems you noted, or else replicate the weakness noted above or, probably, some
combination of the two vices.
Or so I think. I'm open to reeducation if anyone really knows this
stuff!
Ciao for Niao,
Bill in MN
[Non-text portions of this message have been removed]
stefan.probst@opticom.v-nam.net writes:
> In nature, slightly flexible structures can often stand more stressHi!
> than completely stiff ones. See how a tree bends a bit under high
> wind load.
>
> What about joining the modules not via some bolts through the
> bulkheads, but by two chine logs at the bottom.
I'm no engineer, but I don't think this sounds like a very sound idea.
I think there might be some merit in clamping the modules together with both
a chine log and a heavy sheer strake or rubbing rail, but even in that case I
see no merit in leaving gaps between the modules.
The notion that flexibility in a boat's hull is somehow conducive to
seaworthiness and/or speed is a pretty venerable one. IMHO, one could right a
history of naval construction as a progression toward less, not more,
flexibility in the structure of hulls.
I occasionally see claims in histories that Viking ships owed
something of their seaworthiness to the flexibility of their hulls. I think that this
is pure balderdash, wherein a chain of historians, ignorant of technical
nautical matters, unthinkingly repeat the claims of previous historians, no more
learned than they, repeating notions that, if they could be traced, probably
lead back to a conversation someone with his elbows on a yacht club bar at Cowes.
The keels of longships got deeper over time, but the effect of this was to
increase their structural stiffness as least as much and probably more than any
gain in hydrodynamic efficiency. In the late nineteenth century when composite
construction was introduced, the metal frames were sometimes joined with
threaded rods or otherwise adjustable stays. I've read that when one of the tea
clippers of the era out ran another, the crew of the slower vessel would declare
that the faster had "let its stays out." Given the difficulty of even getting
at the stays in a loaded cargo vessel, this sounds like just a tale to me. A
perusal of plans of American clipper ships provides a rather dismaying picture
of heroic, but inept and largely unsuccessful, efforts to prevent their hulls
from hogging. Possibly the earliest effort at using reasoned engineering
principles in the construction of ships was Sepping's introduction of diagonal
bracing in Royal Navy warships in the second half of the 19th century. This was
definitely an effort to reduce, not increase the flexibility of the structures.
There is nothing special about the fact that tree trucks bend under
wind loads. A tree is basically a cantilevered beam, like an unstayed mast. All
beams deflect in proportion with the load imposed, the stiffness of the
material, its size and geometry, until either equilibrium is reached or the beam
fails. (You should not detect the deflection of floor joists when you walk over
them, but theory says they have to deflect by some finite amount to support
your weight. Deflection of aircraft wings is readily visible, but it doesn't
occur because designers see flexibility as a virtue in itself - quite the contrary
- instead they are forced to trade off large (but not too large!) deflections
against structural weight)
Ignoring what happens when the top edges of the spaced modules come in
contact with one another as the chine logs bend upward at the bow and stern,
the ultimate strength of the assembly will be no greater than that of the
chine logs themselves. Assuming the chine logs to be of reasonable dimensions,
their ultimate strength would be much less that of the plywood sides of the
module, (assuming no buckling of the panel). So, while this scheme would certainly
make the structure more flexible, it would also make it much weaker. If the
chine log is secured by mechanical fasteners, the working of the flexible hull
would further degrade the strength of the system over time.
If a chine log was used in connection with a sheer strake or rubbing
rail, one would have a structure analogous to an I-beam - the side panels of
the modules would function would function as sheer webs, while the chine and
sheer strake would bear most of the tension and compression loads. (This assumes
that the chine log and strake are continuous members for their lengths, not
butted pieces.) However, in this scheme, spacing the modules would either
accomplish nothing, except for creating the hydrodynamic drag and waterproofing
problems you noted, or else replicate the weakness noted above or, probably, some
combination of the two vices.
Or so I think. I'm open to reeducation if anyone really knows this
stuff!
Ciao for Niao,
Bill in MN
[Non-text portions of this message have been removed]
--- "Bruce Hector" <bruce_hector@h...> wrote:
Length? Load (i.e. empty, or people sitting in the unsupported/less
supported module)?
there would be only some forces to bend it. I am more worried that
the bulkhead break away from the sides.
This would allow to use horizontally mounted machine screws with
bolts. No need to screw into wood....
load on the connecting logs, which can be made as thick as desired.
And of course there would be the load on the bolt connections. But
they too can be made thick, and multiple....
not as much.
around it. It is a mix between Bolger's Brick, the Puddle Racer
(which is based on the Brick) and a TIMS module: 8 feet long, 4 feet
wide, 2 feet high. The rocker of the bow is taken from the Puddle
Racer. The stern is not only a small "walk-through" break-out like in
a TIMS module, but it is only 10" high over the whole beam. The chine
logs, sheer logs, skeg, are extra strong.
When finished, I can mount a trolling motor (I have meanwhile one), a
small outboard, or another module. Two modules like that can be
mounted "back to back" - giving a rocker at both ends. No need for a
joiner module like with the brick.
Status right now: hull structure finished - except the stern transom.
Will probably in a few weeks - when the weather gets a bit more
comfortable - continue with sanding (there are dark spots on the
plywood due to some months storage in wet outdoor conditions), epoxy
and gf, doubling the chines, painting ....
I don't dare to give lauch dates anymore ;)
Cheers,
Stefan
> <snip> that one issue is the stress on the joints in case ofThat sounds promising. Would be interesting to know a bit more:
> larger waves....leave bow and/or stern unsupported).
>
> :Hasn't been a problem so far. I've had TIMS out at varying lengths
> and condition, up to about a fot and a half chop.
Length? Load (i.e. empty, or people sitting in the unsupported/less
supported module)?
> <snip> slightly flexible structures can often stand more stressI guess, only time will tell. I am not much worried about the bottom.
> than completely stiff ones.
>
> :Quite possibly that's wht TIMS survives. Bolted, lashed or
> clamped, it still flexes. Especially at the longer lengths,
> 1/2" ply for bottoms and sides are pretty thin scantlings.
> I gues it works because its really just a bunch of 8 footers,
> for which 1/2" is way overbuilt.
there would be only some forces to bend it. I am more worried that
the bulkhead break away from the sides.
> <snip> What about joining the modules by two chine logsPut the connecting log not below the existing log, but besides it.
> at the bottom?
>
> I've thought of that, or maybe it was John Bell's idea.
> The original TIMS idea was to screw them together with drywall
> nails on an chine doubler.
> The reason I don't do it, is I want to be able to frequently
> assemble and dissassemble, and I'm afraid of repeatedly
> screwing into the same little log.
This would allow to use horizontally mounted machine screws with
bolts. No need to screw into wood....
> <snip> If one leaves a bit of space between the modules,It would quite completely relieve the bulkheads, and put all bending
>
> :I think that would be a bad idea, wouldn't it give a space for the
> units to lever themselves apart, and snap the logs?
load on the connecting logs, which can be made as thick as desired.
And of course there would be the load on the bolt connections. But
they too can be made thick, and multiple....
> <snip> Question is, with what to fill the gap,I was thinking at a soft foam, but don't know which one.
>
> :If I were to leave a space, I think I'd like it tightened down
> on a flexible rubber gasket. Perhaps the quintessential Canadian
> solution, bolt through drilled hockey pucks.
> Solid, but with a bit of flex.
> Bolger says in several of his articles on the slim power sharpies,Good Point. The smooting effect would probably still be there, but
> is that they bridge over several wave troughs, and this smooths
> the ride. I wonder if making is flex would be good, or bad?
not as much.
> BTW, have you seen the pictures Jeff Blunck took at the 2003Yes I saw them. A good "proof of concept".
> Kingston Messabout?
> Are you building a modular boat yet, or still designing it?I am building a boat "with modular features" - but still designing
around it. It is a mix between Bolger's Brick, the Puddle Racer
(which is based on the Brick) and a TIMS module: 8 feet long, 4 feet
wide, 2 feet high. The rocker of the bow is taken from the Puddle
Racer. The stern is not only a small "walk-through" break-out like in
a TIMS module, but it is only 10" high over the whole beam. The chine
logs, sheer logs, skeg, are extra strong.
When finished, I can mount a trolling motor (I have meanwhile one), a
small outboard, or another module. Two modules like that can be
mounted "back to back" - giving a rocker at both ends. No need for a
joiner module like with the brick.
Status right now: hull structure finished - except the stern transom.
Will probably in a few weeks - when the weather gets a bit more
comfortable - continue with sanding (there are dark spots on the
plywood due to some months storage in wet outdoor conditions), epoxy
and gf, doubling the chines, painting ....
I don't dare to give lauch dates anymore ;)
Cheers,
Stefan
--- Inbolger@yahoogroups.com, stefan.probst@o... wrote:"
Hi Stefan,
<snip> "Not sure whether this list is the right place,"
:Sure it is, as you say, many Bolger designs are modular (Folding
Schooner, Breakdown Schooner, Insolent 60, etc). And many are capable
of being built that way, such as Jeff Blunck's (sorry, re spelling
Jeff) 50 foot Wyoming. Anyway, mine included or not, there's a LOT
more modular boats here than in Woodenboats.
<snip> that one issue is the stress on the joints in case of larger
waves....leave bow and/or stern unsupported).
:Hasn't been a problem so far. I've had TIMS out at varying lengths
and condition, up to about a fot and a half chop.
<snip> slightly flexible structures can often stand more stress than
completely stiff ones.
:Quite possibly that's wht TIMS survives. Bolted, lashed or clamped,
it still flexes. Especially at the longer lengths, 1/2" ply for
bottoms and sides are pretty thin scantlings. I gues it works because
its really just a bunch of 8 footers, for which 1/2" is way overbuilt.
<snip> What about joining the modules by two chine logs at the bottom?
I've thought of that, or maybe it was John Bell's idea. The original
TIMS idea was to screw them together with drywall nails on an chine
doubler. The first Tims idea was for a publicity stunt, with no
longevity considered. The reason I don't do it, is I want to be able
to frequently assemble and dissassemble, and I'm afraid of repeatedly
screwing into the same little log. It would work though, just stagger
the locations for subsequent assemblies.
<snip> If one leaves a bit of space between the modules,
:I think that would be a bad idea, wouldn't it give a space for the
units to lever themselves apart, and snap the logs?
<snip> Question is, with what to fill the gap,
:If I were to leave a space, I think I'd like it tightened down on a
flexible rubber gasket. Perhaps the quintessential Canadian solution,
bolt through drilled hockey pucks. Solid, but with a bit of flex.
Bolger says in several of his articles on the slim power sharpies, is
that they bridge over several wave troughs, and this smooths the
ride. I wonder if making is flex would be good, or bad?
BTW, have you seen the pictures Jeff Blunck took at the 2003 Kingston
Messabout? If not there's a link on the Messabout page of my site to
them. Might inspire you some more.
Are you building a modular boat yet, or still designing it?
Bruce Hector
http://www.brucesboats.com
Hi Stefan,
<snip> "Not sure whether this list is the right place,"
:Sure it is, as you say, many Bolger designs are modular (Folding
Schooner, Breakdown Schooner, Insolent 60, etc). And many are capable
of being built that way, such as Jeff Blunck's (sorry, re spelling
Jeff) 50 foot Wyoming. Anyway, mine included or not, there's a LOT
more modular boats here than in Woodenboats.
<snip> that one issue is the stress on the joints in case of larger
waves....leave bow and/or stern unsupported).
:Hasn't been a problem so far. I've had TIMS out at varying lengths
and condition, up to about a fot and a half chop.
<snip> slightly flexible structures can often stand more stress than
completely stiff ones.
:Quite possibly that's wht TIMS survives. Bolted, lashed or clamped,
it still flexes. Especially at the longer lengths, 1/2" ply for
bottoms and sides are pretty thin scantlings. I gues it works because
its really just a bunch of 8 footers, for which 1/2" is way overbuilt.
<snip> What about joining the modules by two chine logs at the bottom?
I've thought of that, or maybe it was John Bell's idea. The original
TIMS idea was to screw them together with drywall nails on an chine
doubler. The first Tims idea was for a publicity stunt, with no
longevity considered. The reason I don't do it, is I want to be able
to frequently assemble and dissassemble, and I'm afraid of repeatedly
screwing into the same little log. It would work though, just stagger
the locations for subsequent assemblies.
<snip> If one leaves a bit of space between the modules,
:I think that would be a bad idea, wouldn't it give a space for the
units to lever themselves apart, and snap the logs?
<snip> Question is, with what to fill the gap,
:If I were to leave a space, I think I'd like it tightened down on a
flexible rubber gasket. Perhaps the quintessential Canadian solution,
bolt through drilled hockey pucks. Solid, but with a bit of flex.
Bolger says in several of his articles on the slim power sharpies, is
that they bridge over several wave troughs, and this smooths the
ride. I wonder if making is flex would be good, or bad?
BTW, have you seen the pictures Jeff Blunck took at the 2003 Kingston
Messabout? If not there's a link on the Messabout page of my site to
them. Might inspire you some more.
Are you building a modular boat yet, or still designing it?
Bruce Hector
http://www.brucesboats.com
Hi Bruce,
you know that I am VERY interested in the modular design philosophy,
partly because of the same reasons like you (limited space to build,
transport, store). Besides that, it allows to get onto the water
quickly, with limited budget, and then continue to build at an ever
bigger boat.
I'd like to discuss some more issues. Not sure whether this list is
the right place, or better WoodenPowerboats, or ...
We had it some time before in one of the lists, that one issue is the
stress on the joints in case of larger waves that either lift bow
and/or stern (and leave the middle sections unsupported), or lift the
centre section(s) (and leave bow and/or stern unsupported).
In nature, slightly flexible structures can often stand more stress
than completely stiff ones. See how a tree bends a bit under high
wind load.
What about joining the modules not via some bolts through the
bulkheads, but by two chine logs at the bottom. They could be screwed
onto existing chine logs at the bottom, i.e. no risk for leaks due to
screw wholes, and the forces would be much better distributed over
the whole module, i.e. no risk to get cracks at the bulkheads like
with the "conventional" modular bolt joints. If one leaves a bit of
space between the modules, then the whole assembly can bend a bit up
and down at the joints, depending on the stiffness of the connection
logs. Question is, with what to fill the gap, and how drag would be
affected, if the gap is left open. I don't know whether there are
rules of thumb regarding such gaps (e.g. for barge convoys), or
whether there is SW where it can be similated, or somebody has
experiences, or ...
Actually, you could even test the effect of such gaps by inserting
some distance holders (pieces of pipe) onto the connection bolts in
your construction.
A number of Bolger "boxes" seem to be fairly easy broken into
modules, or special designs (e.g. rocker only in the forward and aft
modules) can be built with Bolger inspiration.
BTW: I like also your outrigger. Put a board onto the connection
beams and you get a boat with large space (e.g. for camping) that can
be stored in the living room ;)
Cheers,
Stefan
you know that I am VERY interested in the modular design philosophy,
partly because of the same reasons like you (limited space to build,
transport, store). Besides that, it allows to get onto the water
quickly, with limited budget, and then continue to build at an ever
bigger boat.
I'd like to discuss some more issues. Not sure whether this list is
the right place, or better WoodenPowerboats, or ...
We had it some time before in one of the lists, that one issue is the
stress on the joints in case of larger waves that either lift bow
and/or stern (and leave the middle sections unsupported), or lift the
centre section(s) (and leave bow and/or stern unsupported).
In nature, slightly flexible structures can often stand more stress
than completely stiff ones. See how a tree bends a bit under high
wind load.
What about joining the modules not via some bolts through the
bulkheads, but by two chine logs at the bottom. They could be screwed
onto existing chine logs at the bottom, i.e. no risk for leaks due to
screw wholes, and the forces would be much better distributed over
the whole module, i.e. no risk to get cracks at the bulkheads like
with the "conventional" modular bolt joints. If one leaves a bit of
space between the modules, then the whole assembly can bend a bit up
and down at the joints, depending on the stiffness of the connection
logs. Question is, with what to fill the gap, and how drag would be
affected, if the gap is left open. I don't know whether there are
rules of thumb regarding such gaps (e.g. for barge convoys), or
whether there is SW where it can be similated, or somebody has
experiences, or ...
Actually, you could even test the effect of such gaps by inserting
some distance holders (pieces of pipe) onto the connection bolts in
your construction.
A number of Bolger "boxes" seem to be fairly easy broken into
modules, or special designs (e.g. rocker only in the forward and aft
modules) can be built with Bolger inspiration.
BTW: I like also your outrigger. Put a board onto the connection
beams and you get a boat with large space (e.g. for camping) that can
be stored in the living room ;)
Cheers,
Stefan
http://groups.yahoo.com/group/bolger4photos/
I put it up as the home page photo. To see the earlier pic you had to
be a member of the Yahoo group Boatdesign.
I put it up as the home page photo. To see the earlier pic you had to
be a member of the Yahoo group Boatdesign.