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69075Xmas-Tree Rig again (was, some time ago, Re: Isometric, 19ft6in 'Minimum Proa')

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  • c.ruzer
    Nov 22, 2012
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      I thought the Bolger proas were sorted in the group designs list database.

      I'm sure I entered one or two myself some years ago. I went to that cupboard and let me tell ya it's pretty bare, and it's - Arrrggghhhh! - it's confusion all over again. There's so much confusion and confounding of things to do with the Bolger proa effort out there on the intertubes. I'll have a go at straightening it out a bit. I don't have all the reference material I'd like to have, and it's somewhat patchy, for example, page number determinations but not the publication issue. So if you'll bear with me, lengthy post, and please correct any errors...

      I've clipped that Catalyst photo of Joe Norwood minimum proa sailing ( http://www.ayrs.org/Catalyst_N03_Jan_2001.pdf it's also a BoD article illustration) and will later stick it in the Photos section, and I'll add some entries to the designs database later. But first to somehow get it better sorted, at least in my mind, a bit of background...

      And a bit of note taking.

      Bolger Proa 20 Design #664, 19'6" x 10'0" x 147sf (MAIB V21N06 pp27-31): [The Concept Study was Proa 19'6" x 10'5" x 95sf BWAOM Chapter 24 (aka Minimum Proa - AYRS Xmas-tree sail - two independent kick-up rudders mounted toward midships and cantilevered to windward of the vaka), 95sf rig tested prior to MiniP on Canard Design #440 (was prior SBJ#70 Cartoon "South Seas Proa", see http://hallman.org/bolger/isometrics and especially http://hallman.org/sbj/70/ {NB. SBJ media pdf<=65, gif<=68?})]

      #664 Proa 20 now has the rudders [robust aluminium those, plus stout leeboard (off the lee of a proa!) 360 degree articulated amidships - 170 degrees of that a clr fine adjustment from tiller] moved to the very bows, one at each end of the vaka (main hull) with, wait for it, a single tiller. Ah-ha! Recall, from Canard Chapter 23 BWAOM page 112, for example, "If I design another bow-steerer, I will arrange the two fins to be independently steerable for balance adjustment, but interconnected for sharp turns in such a way that the ends of the boat both swing around the center of gravity. An America's Cup boat with such a layout was astonishingly competitive, considering how radical the concept was. (I had nothing to do with her design except to admire its boldness.)" But wait again, no, here the rudders free in two planes are always either one kicked up (the current bow) or both up - freed as it were by the leeboard control. Rudder steering response is also adjustable by gearing. It may sound like these controls, linkage routing, endless loops are a busy worried complex thing, but it seems to be all simplicated in a remarkable way at the almost common tiller and mast axis - the cable routing becomes cleverly very direct, so much so I think I may call the tiller what it seems to be - a joy stick! Improved mast staying, bigger sail of lower aspect, 2HP Honda, two 'bridges' for trimming crew weight aft - and a volunteer promising to build in Noumea.

      Plans price for #664 isn't mentioned in that MAIB BoD article (there will be a number of plans sheets). Also, the preceeding issue had a 2 page BoD article, "Proa Background" (MAIB V21N05), covering Micronesia, rig issues, Anson's drawing, Munroe, LFH, Minimum Proa study concept, steering, Xmas-tree, Joe Norwood (Minimum Proa sailing photo... his previous proa publications), the Netherlands Minimum Proa speed experience of Vincent de Bode with a windsurfer adapted rig but limited by aft rocker (it looks to me from the MAIB illustrations that #664 has finer hulls and flatter rocker towards the bows); and so on to the design of an improved version for a committed New Caledonian volunteer builder, and the subject of the subsequent issue covered already above.

      Then later (MAIB V24N01 pp.26-28 Bolger Proa-60 Pt 1 5/15/2005 - I am only sure of the page numbers for this reference) there's the concept study of a large cruising "Bolger Proa-60", 60'0" x 25'6" x 1'6" x 1600/2sf, with tabernacled lowereing two masted refined Xmas-tree rig, partially lateral plane loaded rudders mounted within articulating bows of the vaka, two centreboards in the ama, capsize mitigating self-correcting geometry, asymetric reserve bouyancy, sail panels of differentially weighted cloth, differentially cambered sail panels according to height with additionally electrically actuated differential sail panel camber adjustment, a third sail flown from the mastheads brace...

      The next MAIB BoD article MAIB V24N02 Bolger Proa-60 Pt 2, and another later still, MAIB V24 N06 Proa 60 Pt 3, have more detail on handling this Proa-60 rig, dicussion of the hull structures, the ergonomics... and sundries such as dinghies and auxiliary propulsion. Bruce Hallman has given us an index at http://groups.yahoo.com/group/bolger/message/61756 From that we may be better able to check what's been published on the proas as concepts and designs, and maybe what has been built....

      Now the business:

      Connected in some way with Bolger proa design there is published and/or built:

      1. Proa, Design #217, 39'6" x 19'6"; The Folding Schooner, Chapter 15, p91. (I'm not so sure this was built)

      2. South Seas Proa, aka Minimum Proa, aka AYRS or Xmas-tree or Christmas tree proa, 19'6" x 10'5" x 95sf; both as Cartoon in SBJ#70 and Concept Study in BWAOM, Chapter 24, p116. (2 boats known - associated by most with Joseph Norwood's boat) http://hallman.org/sbj/70/ http://www.ayrs.org/Catalyst_N03_Jan_2001.pdf page 42

      3. Proa 20, Design #664, 19'6" x 10'0" x 147sf; MAIB V21N06, pp27-31. (MAIB V21 N06 Bolger Proa 20 Pg 1 A boat built in Noumea?)

      4. James Wharram Designs designed and built a 30ft proa with, allegedly, a Bolger proa rig. They certainly built a proa.

      5. Michael Schacht (proafile.com) built a proa with a test Bolger Proa Rig

      6. John Dalziel (AS29 skipper, Yahoo proafile group owner, and member of this group) built a proa with a test Bolger Proa Rig

      And further, in literature only there is:

      7. Proa Background Pg 1 MAIB V21N05

      8. Bolger Proa-60, Concept Study, 60'0" x 25'6" x 1'6" x 1600/2sf; Bolger on Design Pt 1 (5/15/2005) MAIB V24N01, pp.26-28.

      9. Bolger Proa-60 Pt 2 MAIB V24N02

      10. Bolger Proa-60 Pt 3 MAIB V24N06

      Looks like 3 boats to enter in the design databse. It's a start anyway. Gotta getta sleep.

      --- In bolger@yahoogroups.com, "c.ruzer" <c.ruzer@...> wrote:
      > Joe Norwood's _Practical Proas_ report to the AYRS on the Minimum Proa and that rig is at page 42 here http://www.ayrs.org/Catalyst_N03_Jan_2001.pdf (He found the steering to be good, indeed the boat appears to have given him much pleasure.)
      > To refresh, others found the rig problematic http://proafile.com/archive/article/rig_options_bolger
      > however the fascination http://proafile.com/archive/article/the_zen_of_proa continues with further developments under way in search of the well mannered quick bidirectional cambered shunting sail
      > http://proafile.com/forums/viewthread/124/
      > Perhaps, as is suggested there, in the earlier trial excessive roach was a problem?
      > ~
      > ~ ^ ~
      > / \
      > / | \
      > <___________>
      > --- In bolger@yahoogroups.com, "Susanne@" <philbolger@> wrote:
      > > Very interesting test-report on the 'Chistmas-Tree' rig.
      > > I believe the only proa-based report we ever saw was Joe Norwood's piece on his scaled-up (10%?) Bolger-Proa-20. Phil of course tried it on his CANARD, if memory serves correctly.
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