Re: Chinese gaff rig
--- Inbolger@yahoogroups.com, "Bruce Hallman" <brucehallman@y...>
wrote:
I see the batten
gaff" has nowhere to go when under compression other then to take the
path of least resistance,bending to relieve the compressive forces.
did indeed have to be fussed with for a certain wind strength but
that as wind and waves changed so to did the battens relative
stiffness.For example,how about a case where you have light winds
(soft batten required?) but left over chop/waves which would like to
have a stiffer batten to maintain foil shape?
Chinese Gaff.It does appear to be something a handy fellow like
yourself can build :-).However, I know that on a 30 footer that I
once had our Hero draw up for me,with the Chinese Gaff,the multiple
components required to realise the rig added up to beaucoup de $$$
especially with the Harken gear specified.The custom design was
eventually called off for a number of unrelated reasons but I did
feel somewhat uncomfortable at that time about having build an entire
rig that once completed would,in fact,require much fussing and
tweeking to get it to function per specs. Perhaps I am just spoiled
by more conventional rigs that you just build-n-sail or,better
yet,too lazy to "do the work".
At any rate, I am guilty of thinking about the bigger sizes and not
focussing on the simpler realities that a smaller application of this
rig suggests.
build.Not that many of us could keep up with your pace :-)
I look forward to seeing more pictures of your Navigator progress
and,of course, a full report(Arrgh matey,with pictures!) of this
potentially very promising rig :-)
Sincerely,
Peter Lenihan,in the rain..........
wrote:
I see the batten
> in strong bending, but I don't see much compressionWith a sheet on the outboard end and jaws on the inboard end ,the"
> stress.
gaff" has nowhere to go when under compression other then to take the
path of least resistance,bending to relieve the compressive forces.
>hmmmmmm....interesting,I was under the impression that the battens
> No 'constant fussing', once the batten stiffness
> is determined during the intital tryouts, the
> do not change. In the case of Yonder, they speculate
> that a boom sheet and a gaff sheet might be all that
> is needed, with the intermediate sheet a 'maybe'
> based on experience.
did indeed have to be fussed with for a certain wind strength but
that as wind and waves changed so to did the battens relative
stiffness.For example,how about a case where you have light winds
(soft batten required?) but left over chop/waves which would like to
have a stiffer batten to maintain foil shape?
> I intend to use the specified homebuiltI wasn't aware of the specifics for the smaller versions of the
> plywood 'jaws', and polytarp while I proto-type
> the sail, and maybe later a cloth sail
> copied from the proto-type. The sheeting
> halyards and reefing lines, I already have
> bought on EBay for less than $100 total, so in
> my case at least, this seems like a cheap
> rig.
Chinese Gaff.It does appear to be something a handy fellow like
yourself can build :-).However, I know that on a 30 footer that I
once had our Hero draw up for me,with the Chinese Gaff,the multiple
components required to realise the rig added up to beaucoup de $$$
especially with the Harken gear specified.The custom design was
eventually called off for a number of unrelated reasons but I did
feel somewhat uncomfortable at that time about having build an entire
rig that once completed would,in fact,require much fussing and
tweeking to get it to function per specs. Perhaps I am just spoiled
by more conventional rigs that you just build-n-sail or,better
yet,too lazy to "do the work".
At any rate, I am guilty of thinking about the bigger sizes and not
focussing on the simpler realities that a smaller application of this
rig suggests.
> > But who am I to stop the fun, ... perhapsIndeed!! You inspire many side benchers to get out there and
> > the Chinese gaff rig will suit the compulsive
> > whittler :-)
>
> That is me!
build.Not that many of us could keep up with your pace :-)
I look forward to seeing more pictures of your Navigator progress
and,of course, a full report(Arrgh matey,with pictures!) of this
potentially very promising rig :-)
Sincerely,
Peter Lenihan,in the rain..........
--- Inbolger@yahoogroups.com, "Derek Waters" <dgw@d...> wrote:
It must be driving you nuts to have launched your boat but
not have the rig yet! Can't wait to see pictures of your pride and
joy all rigged up......hey!......even unrigged would be nice to see:-)
Continued success on her as you finish up the rigging
details!!
Sincerely,
Peter Lenihan,doing some serious housework(ha!) while the rain
continues to fall and fall and fall some more,along the banks of the
St.Lawrence.........
> Since we're building a 'Navigator' rig for our Micro [hull got wetlast
> week, at long last, floats right side up :)Congrats Derek!!!
It must be driving you nuts to have launched your boat but
not have the rig yet! Can't wait to see pictures of your pride and
joy all rigged up......hey!......even unrigged would be nice to see:-)
Continued success on her as you finish up the rigging
details!!
Sincerely,
Peter Lenihan,doing some serious housework(ha!) while the rain
continues to fall and fall and fall some more,along the banks of the
St.Lawrence.........
> No doubt in light winds the top of the sail willThis is a problem with long battens in the usual Bermudan sail as
> not have 'perfect' foil shape.
well.
Peter
--- "Peter Lenihan" <ellengaest@b...> posed:
No doubt in light winds the top of the sail will
not have 'perfect' foil shape. I see the batten
in strong bending, but I don't see much compression
stress.
is determined during the intital tryouts, the
do not change. In the case of Yonder, they speculate
that a boom sheet and a gaff sheet might be all that
is needed, with the intermediate sheet a 'maybe'
based on experience.
plywood 'jaws', and polytarp while I proto-type
the sail, and maybe later a cloth sail
copied from the proto-type. The sheeting
halyards and reefing lines, I already have
bought on EBay for less than $100 total, so in
my case at least, this seems like a cheap
rig.
> The ... "top" batten comes under greater loadsNot engineered, but rather sized by trial and error.
> and needs to be engineered for such loads.
No doubt in light winds the top of the sail will
not have 'perfect' foil shape. I see the batten
in strong bending, but I don't see much compression
stress.
> I cannot see any practical means of havingThe PB&F design does not either.
> a variable stiffness batten...
> In the end, one may discover that allNo 'constant fussing', once the batten stiffness
> the constant fussing and gigging around
> with this rig simply is not worth the effort
is determined during the intital tryouts, the
do not change. In the case of Yonder, they speculate
that a boom sheet and a gaff sheet might be all that
is needed, with the intermediate sheet a 'maybe'
based on experience.
> an expensive rig ... deep pocketsI intend to use the specified homebuilt
plywood 'jaws', and polytarp while I proto-type
the sail, and maybe later a cloth sail
copied from the proto-type. The sheeting
halyards and reefing lines, I already have
bought on EBay for less than $100 total, so in
my case at least, this seems like a cheap
rig.
> But who am I to stop the fun, ... perhapsThat is me!
> the Chinese gaff rig will suit the compulsive
> whittler :-)
>All the things that have been said about Chinese Gaffer battens areThis is not a new rig. Commodore Munroe used full-battened short gaff
>also true of junk rig battens. I suppose that the junk rig battens
>are not subject to the same compressive force, though, now that think
>about it. Still, I would have thought that the gaff itself would have
>been protective.
>
>Remember, too, that sailmakers haven't had many chances to get the
>bugs out from a sail design perspective.
>
>Peter
sails, and I have a photo of Nat Herreshoff's CLARA, ca 1888 I think,
with full battens and some extra sail above the gaff. Munroe combined
his with sprit booms that used a jaw, snotter = outhaul.
What's new is the multiple sheet arrangement.
--
Craig O'Donnell
Sinepuxent Ancestors & Boats
<http://freepages.genealogy.rootsweb.com/~fassitt/>
The Proa FAQ <http://boat-links.com/proafaq.html>
The Cheap Pages <http://www2.friend.ly.net/~dadadata/>
Sailing Canoes, Polytarp Sails, Bamboo, Chinese Junks,
American Proas, the Bolger Boat Honor Roll,
Plywood Boats, Bamboo Rafts, &c.
_________________________________
-- Professor of Boatology -- Junkomologist
-- Macintosh kinda guy
Friend of Wanda the Wonder Cat, 1991-1997.
_________________________________
---
[This E-mail scanned for viruses by friend.ly.net.]
All the things that have been said about Chinese Gaffer battens are
also true of junk rig battens. I suppose that the junk rig battens
are not subject to the same compressive force, though, now that think
about it. Still, I would have thought that the gaff itself would have
been protective.
Remember, too, that sailmakers haven't had many chances to get the
bugs out from a sail design perspective.
Peter
also true of junk rig battens. I suppose that the junk rig battens
are not subject to the same compressive force, though, now that think
about it. Still, I would have thought that the gaff itself would have
been protective.
Remember, too, that sailmakers haven't had many chances to get the
bugs out from a sail design perspective.
Peter
Since we're building a 'Navigator' rig for our Micro [hull got wet last
week, at long last, floats right side up :) ] the batten question is of
considerable interest...
Clearly, Jim Melcher is seriously unhappy with the incarnation of the
'Chinese Gaff' rig on Alert. I haven't been able to locate any pictures so
there's little point in my speculating on the forces involved. I can imagine
a batten being 'whipcracked' and broken near the jaws, but IIRC Jim
mentioned compression forces breaking battens.
Peter wrote...
good foil shaping.However,as the sail is reefed down, that same "top" batten
comes under greater loads and needs to be engineered for such loads.<<
It seems that Bolger's battens do a number of things - they support roach,
they carry the jaws to control the luff, they carry sheetlets for leech
control etc etc but it seems to me unlikely that they need to carry much
compression load beyond the fairly static load applied to stretch the sail.
I suspect a too rigid batten may be more trouble than a too flexible one. My
theorising is based on the fact that the sail would hoist as a gaff sail
sans battens and sheetlets, albeit requiring a 'roachectomy' - gaff and boom
jaws should carry the load to the mast.
Reefed down, the upper span [top batten to gaff] on the Micro Navigator rig
would be sheeted pretty well horizontally; it appears the sheet will be able
to offer good support. Time will tell :)
cheers
Derek
week, at long last, floats right side up :) ] the batten question is of
considerable interest...
Clearly, Jim Melcher is seriously unhappy with the incarnation of the
'Chinese Gaff' rig on Alert. I haven't been able to locate any pictures so
there's little point in my speculating on the forces involved. I can imagine
a batten being 'whipcracked' and broken near the jaws, but IIRC Jim
mentioned compression forces breaking battens.
Peter wrote...
>> The "top" batten IS used in light winds when one wants to get allavailable sail area up there while remaining flexible enough to encourage
good foil shaping.However,as the sail is reefed down, that same "top" batten
comes under greater loads and needs to be engineered for such loads.<<
It seems that Bolger's battens do a number of things - they support roach,
they carry the jaws to control the luff, they carry sheetlets for leech
control etc etc but it seems to me unlikely that they need to carry much
compression load beyond the fairly static load applied to stretch the sail.
I suspect a too rigid batten may be more trouble than a too flexible one. My
theorising is based on the fact that the sail would hoist as a gaff sail
sans battens and sheetlets, albeit requiring a 'roachectomy' - gaff and boom
jaws should carry the load to the mast.
Reefed down, the upper span [top batten to gaff] on the Micro Navigator rig
would be sheeted pretty well horizontally; it appears the sheet will be able
to offer good support. Time will tell :)
cheers
Derek
--- Inbolger@yahoogroups.com, "Bruce Hallman" <brucehallman@y...>
wrote:
I think that is where the problem is with this rig and why it
hasn't exactly caught on like a house on fire despite much earlier
theoretical promise.
The "top" batten IS used in light winds when one wants to get all
available sail area up there while remaining flexible enough to
encourage good foil shaping.However,as the sail is reefed down, that
same "top" batten comes under greater loads and needs to be
engineered for such loads. I cannot see any practical means of having
a variable stiffness batten short of some very complicated internally
controlled stiffening mechanisms.
In the end, one may discover that all the constant fussing and
gigging around with this rig simply is not worth the effort for the
relatively small performance gain extracted/expected from the
exercise and that it is far more fruitfull to simply accept the
apparent degraded performance of a straight junk rig or gaff rig and
all the romance that they imply.
And as if that wasn't enough,in boats the size of Melchers,this
is an expensive rig with fancy(expensive) Harken cars needed on the
forward end of each batten,the track to run the cars on,the hundreds
of feet of line to properly control the sail and,of course,the
expense of having one un-common sail custom made for you.
For real performance/speed,we all need deep pockets while taking
a close look at the pure-bread machines out there to see how it is
achieved.
But who am I to stop the fun,for just as so called traditional
rigs are deamed appropriate for those who are compulsive line
pullers,then perhaps the Chinese gaff rig will suit the compulsive
whittler :-)
Sincerely,
Peter Lenihan
wrote:
> > as none can be alike in stiffnessBruce,
>
> Thinking about this, I figure the
> top batten, used in higher winds
> will need to be stiffer than the lower
> battens, that which are only used
> in light and lighter winds.
I think that is where the problem is with this rig and why it
hasn't exactly caught on like a house on fire despite much earlier
theoretical promise.
The "top" batten IS used in light winds when one wants to get all
available sail area up there while remaining flexible enough to
encourage good foil shaping.However,as the sail is reefed down, that
same "top" batten comes under greater loads and needs to be
engineered for such loads. I cannot see any practical means of having
a variable stiffness batten short of some very complicated internally
controlled stiffening mechanisms.
In the end, one may discover that all the constant fussing and
gigging around with this rig simply is not worth the effort for the
relatively small performance gain extracted/expected from the
exercise and that it is far more fruitfull to simply accept the
apparent degraded performance of a straight junk rig or gaff rig and
all the romance that they imply.
And as if that wasn't enough,in boats the size of Melchers,this
is an expensive rig with fancy(expensive) Harken cars needed on the
forward end of each batten,the track to run the cars on,the hundreds
of feet of line to properly control the sail and,of course,the
expense of having one un-common sail custom made for you.
For real performance/speed,we all need deep pockets while taking
a close look at the pure-bread machines out there to see how it is
achieved.
But who am I to stop the fun,for just as so called traditional
rigs are deamed appropriate for those who are compulsive line
pullers,then perhaps the Chinese gaff rig will suit the compulsive
whittler :-)
Sincerely,
Peter Lenihan
> as none can be alike in stiffnessThinking about this, I figure the
top batten, used in higher winds
will need to be stiffer than the lower
battens, that which are only used
in light and lighter winds.
--- craig o'donnell <dadadata@f...> wrote:
I will keep y'all informed
over the next few months.
The PB&F instructions advise that
the sizing and the tapering of the
batttens is to be by trial and error,
based on observations of their bendiness
and performance in a variety of wind
conditions over time.
Quoting:
"The issue remaining on each version of this geometry is the relative
stiffness of the battens along their length, as none can be alike in
stiffness and all have to work together to produce a reasonable
sailshape - I.E. some draft forward and flatter near the trailing
edge. With NAVIGATOR's proposed 176 sf main and shortish smallish
battens that task would not be overwhelming. Starting out with too
much stiffness, you'd observe the cloth's shape under various
conditions, to then unbolt and pull the battens, and taking the
planer/belt-sander to each batten in respective locations 'softening'
it where it needs it; errors in removal could be corrected by adding
a layer of glasstape or put back strips of veneer."
> He reported problems with battensI am building one now, and
I will keep y'all informed
over the next few months.
The PB&F instructions advise that
the sizing and the tapering of the
batttens is to be by trial and error,
based on observations of their bendiness
and performance in a variety of wind
conditions over time.
Quoting:
"The issue remaining on each version of this geometry is the relative
stiffness of the battens along their length, as none can be alike in
stiffness and all have to work together to produce a reasonable
sailshape - I.E. some draft forward and flatter near the trailing
edge. With NAVIGATOR's proposed 176 sf main and shortish smallish
battens that task would not be overwhelming. Starting out with too
much stiffness, you'd observe the cloth's shape under various
conditions, to then unbolt and pull the battens, and taking the
planer/belt-sander to each batten in respective locations 'softening'
it where it needs it; errors in removal could be corrected by adding
a layer of glasstape or put back strips of veneer."
>I've seen a number of Bolger designs with what he has developed as hisAt least one has been built and used, I believe Jim Melcher used it.
>"Chinese gaff rig" or "Chinese gaff yawl", at least on paper. I like
>the looks of it, and it seems to my untrained eye that it should work,
>however I can't recall seeing a photo of a built boat with this rig...
>Nor any first hand reports from someone using the rig.
>
>Am I missing something? Has this rig been built and used? Any links to
>photos or reports?
>
>Rick
He reported problems with battens snapping at sea as they are under
high compressive loads. It may be that the rig is a good idea with
the caveat that you've got to have speial carbon-fiber battens made.
There is a Junk Rig Yahoo Group where Jim has contributed a few
comments from time to time. You can join that group, search the
archives, perhaps contact him directly.
The last message from him I remember was one in which he said he was
switching to the traditional Chinese lugsail.
--
Craig O'Donnell
Sinepuxent Ancestors & Boats
<http://freepages.genealogy.rootsweb.com/~fassitt/>
The Proa FAQ <http://boat-links.com/proafaq.html>
The Cheap Pages <http://www2.friend.ly.net/~dadadata/>
Sailing Canoes, Polytarp Sails, Bamboo, Chinese Junks,
American Proas, the Bolger Boat Honor Roll,
Plywood Boats, Bamboo Rafts, &c.
_________________________________
-- Professor of Boatology -- Junkomologist
-- Macintosh kinda guy
Friend of Wanda the Wonder Cat, 1991-1997.
_________________________________
---
[This E-mail scanned for viruses by friend.ly.net.]
I've seen a number of Bolger designs with what he has developed as his
"Chinese gaff rig" or "Chinese gaff yawl", at least on paper. I like
the looks of it, and it seems to my untrained eye that it should work,
however I can't recall seeing a photo of a built boat with this rig...
Nor any first hand reports from someone using the rig.
Am I missing something? Has this rig been built and used? Any links to
photos or reports?
Rick
"Chinese gaff rig" or "Chinese gaff yawl", at least on paper. I like
the looks of it, and it seems to my untrained eye that it should work,
however I can't recall seeing a photo of a built boat with this rig...
Nor any first hand reports from someone using the rig.
Am I missing something? Has this rig been built and used? Any links to
photos or reports?
Rick