Made for a Junk Rig (Harry Proa)

  • 30 May 2021 12:01
    Reply # 10574414 on 10563218

    Insistence on the use of a balanced lug or junk sail could be practical if a boom were to extend far enough out to function mainly as a sheet point for the block/blocks receiving the sheet parts from the batten bridles. First proa that I built and sailed had a free standing mast stepped midships, so had  a basic configuration that might be likened to a 'harryproa', except that this was back in the 1980's ( before Rob Denny had christened or made known the craft he promotes as a Harry). Sheeting on my craft ran from the Bermudan type boom to a block on a wire traveller that was stretched on the lee side gunnel of the lee hull. Sheet tail was picked up at the after end of this traveller after a shunt, before hardening to bring in the boom. Since a wooden paddle served as a steer er, it was simply a matter of moving self aft of the mast to deploy the paddle and grab the sheet, but which is not so easily done on a cruiser sized canoe.Still, it might be possible to have a car on the traveller that permits the sheet to be led to a winch at midships, makin   g the boom part of the Junk-like reefing system, other than being much like a quasi ballestron, to be controlled by a separate sheet.

    Stepping the mast with wedges at the partners is of course an advantage over a bearing system and having the boom extending forward of the mast can be tied in with a luffspar and rotating masthead that takes care of twisting that the halyard must  otherwise cope with.This is a concept that has previously been discussed on this forum and is as much dependant on carbon composites as is the Harry design above. In order to entertain any such ideas, it is unavoidable to  begin without being able to lay up carbon tubes or spars.  

  • 29 May 2021 01:57
    Reply # 10571083 on 10565670
    Anonymous wrote:

    Let me see if a reply to this post works out OK and then I might be lucky enough to post an image or two that adds to proa possibilities. Fact that a free standing mast is the primary feature of a 'Harryproa' is an apparently good reason to consider the Rob Denny design as a potential junk rig candidate.Then,  you need to be aware that a boom of  sortss (probably a balestron) is needed to carry the sheet point from end to end, and a junk sail has battens that make the weight of such a boom excessive, besides unnecessary. Certainly a free standing mast can make a proa configuration seem promising, however, a tacker is going to suit battens and junk sheeting way more. Creating a facility to produce carbon composites tubes(for mast, battens and boom) is pretty much the starting point for any junk or wingsail rigged multi with a single mast that is lightweight, so the shunting over tacking configuration is hardly of great importance, except that a tacker is so much less complicated.


     I would think a fixed mast (no bearings) with a junk rig and ordinary junk rig boom would work fine, and that changing the sheeting from one end to the other would be a matter of  having double sheets... Perhaps a line to the front of the boom to help drag the boom around, as it will be swinging outboard as it's on the leeward hull.  A bearing mounted mast doesn't make sense to me in a marine environment.  The Ballestron rig does not strike me as a low maintenance rig.  A conventional camber panel junk rig with it's fairly small balance percentage would have very little over the deck... ever... on a Harry Proa... most of the sail flying outboard or aft unlike a biplane rig where on many tacks one sail will be flying over the deck, and one outboard.

         It is a whole set of problems we are not used to looking at, and there are multiple ways of addressing them.  

         How lucky we are to live in a time when we have the means to learn about the innovations & innovators at the fringes of our sport / passion.... And we can connect and interact with them half a world away........ a true golden age.  I'm of an age where when growing up, the pursuit of knowledge and ideas required "real effort".   I laugh remembering  the telephone company advertising long distance at a 3 minutes for a dollar!   As a child in 1967, I was programming in basic on a computer 200 miles away that took up 3 floors in a university at a cost of $20 per minute of processor time using a teletype with punch tape and an accoustic coupler on a telephone....... Never in my wildest dreams did I imagine where we would be today.   Community is no longer a "place" and the people in it, it can span the entire world......... It won't last.  Humanities capacity to screw up a good thing is without limit ;-) ..... enjoy it while we can.


                                                                        H.W.

  • 28 May 2021 01:03
    Reply # 10565670 on 10563218

    Let me see if a reply to this post works out OK and then I might be lucky enough to post an image or two that adds to proa possibilities. Fact that a free standing mast is the primary feature of a 'Harryproa' is an apparently good reason to consider the Rob Denny design as a potential junk rig candidate.Then,  you need to be aware that a boom of  sortss (probably a balestron) is needed to carry the sheet point from end to end, and a junk sail has battens that make the weight of such a boom excessive, besides unnecessary. Certainly a free standing mast can make a proa configuration seem promising, however, a tacker is going to suit battens and junk sheeting way more. Creating a facility to produce carbon composites tubes(for mast, battens and boom) is pretty much the starting point for any junk or wingsail rigged multi with a single mast that is lightweight, so the shunting over tacking configuration is hardly of great importance, except that a tacker is so much less complicated.

  • 27 May 2021 16:01
    Message # 10563218

    I'm a sucker for original outside the box thinkers.... and Rob Denny fills the bill in that respect with his Harry Proa series.   The boats are like most multihulls other than condomarans, focused on "performance", but it is a very narrow definition of "performance" ....... meaning speed.   I have a far broader definition.  What good for example is speed if you have to be uncomfortable?  What good is speed if you can't carry  anything (motorcycles for example), and what good is speed if the cost of operation and maintenance eats you alive?    My definition of performance has far more to do with functionality and practicality.   The Harry Proas do not fit anywhere within my parameters, but they are fun and innovative.

         This older 40 footer built with strip plank construction is for sale in NZ for $30K (kiwi I assume).


    40 ft harryproa catamaran 2004

    The HP has always struck me as made for a junk rig.

    20868 USD

    17981 EUR

    15482 GBP

    5466750  YER  (If you happen to live in Yemen  ;-)



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