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Pete Hill's side-by-side/split junk catamaran 'Oryx'/Tabernacles

  • 11 Jan 2013 14:17
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    Reply # 1177404 on 1160890
    Anonymous member

    Hi Brian,

    Thanks for the link to the drawing. I'm sure the large swell would have been reported in the press, so I feel it must be a distorted photo. The reason I ask is that the battens look dostorted and the rig looks 'bent'. A picture can say a thousand words, but they may not be the intended words. The real question is, " what is the best way to build a split rig?"

    Cheers, Slieve
  • 11 Jan 2013 13:27
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    Reply # 1177344 on 1160890
    Anonymous member

    It looks like the photos are all from Plymouth Sound, so if that is a giant swell, I wonder why we have not heared of the Devon Tsunami! 

    My point is that Pete would not have had much time to fiddle with the rig by that stage, so unfair to judge.

    I also recieved a quick note from Gran Canaria, he says that he very pleased with Oryx, which itself is somewhat of an experiment. 

    Mark

    Last modified: 11 Jan 2013 13:29 | Anonymous member
  • 11 Jan 2013 00:34
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    Reply # 1177021 on 1176261
    Deleted user
    Slieve McGalliard wrote:

    What was the basis for calculating the position of the masts? Does anyone have a side elevation drawing of the original design with its original rig? It would be interesting to compare it with the photos. 

     

    In photo 19 the horizon isn’t level, so are we to assume that this is a number of photos stitched together?

    Hi Slieve. There's a side elevation drawing here - seems to be the one. Re photo 19 (which is now photo 20), I dunno. I took it to be a huge swell :-)
  • 10 Jan 2013 17:53
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    Reply # 1176397 on 1160890
    Anonymous member
    Received from Pete this morning by email:

     
    "We are intending to set off for the Cape Verde islands on Saturday.
    The self steering gear is an OTG I. 
    All the sailing photographs were taken by members of the Duval-Hall family.
    Weather helm: thanks for your comments, when we get to Brazil I will try putting a stiff batten at the aft 1/2 end  of the sails. I have a piece of garden hose in a pocket with a bit of plastic water pipe at the aft 1/2 (to reduce flogging), but the plastic tube is not very stiff. This seems to be the easiest way to try and reduce the weather helm. If that doesn't work then I will have to try something more complicated."
  • 10 Jan 2013 16:18
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    Reply # 1176322 on 1175506
    Anonymous member
    David Tyler wrote:Pete says that there is a lot of weather helm. I put it down to having the draft in the sail too far aft. [...] I don't know what can be done to improve this. 

    How about tapered flexible battens, like in a Bermudan fully-battened mainsail?  Tapered because they need to be more flexible towards the luff.  The only alternative I can think of is the rigid flipping batten, like Nils Myklebust had in his sail, and I in my model sail.  They would also impose a profile on the sail.

    I can't think of anything else.  As I understand it, the broadseaming used in Bermudan sails wouldn't work because it depends on tension along luff and leach that you neither have nor want in a junk rig.   As far as I can see, if you want to control the profile without vertical tension, you need to attach to the sail something going from luff to leach that gives you the profile you want.

    Regards

    Robert Biegler
  • 10 Jan 2013 15:33
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    Reply # 1176261 on 1160890
    Anonymous member

    It’s interesting that there are sailors who are interested in the split junk concept, and want to use it as the basis for experimentation. Poppy’s rig was built not only to see if there was potential in the idea of the split cambered sail, but to include other features such as yard angle, curved luffs and camber shape control. Pete has approached these points from a completely different angle, so his rigs are quite different from the ones that I have been drawing up and therefore may have quite different sailing characteristics and performance. It will be very interesting to see how Oryx performs and how his ideas work out in practice.

     

    What was the basis for calculating the position of the masts? Does anyone have a side elevation drawing of the original design with its original rig? It would be interesting to compare it with the photos. With my rigs I have done a lot of head scratching regarding mast position and seem to be settling on a very simple solution, but am waiting for some more reports before writing it up.

     

    In photo 19 the horizon isn’t level, so are we to assume that this is a number of photos stitched together?

    Cheers,  Slieve.
  • 09 Jan 2013 18:04
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    Reply # 1175506 on 1175231
    Anonymous member
    Arne Kverneland wrote:

    PS: I notice one possible problem with this half-wishbone rig: As the shadow pattern shows on photo 22, the camber in the main part of the sail is just an even arc with plenty of curve close to the leech. This may be powerful, but I am not so sure that it makes a close-winded rig..

    Pete says that there is a lot of weather helm. I put it down to having the draft in the sail too far aft. On one tack, the wishbone would support the sail, if it were straighter near the leech, but on the other tack, the sail is unsupported, and will tend to have its draft too far back anyway. I don't know what can be done to improve this. 
  • 09 Jan 2013 14:35
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    Reply # 1175231 on 1160890
    Anonymous member (Administrator)

                                                                  Stavanger, Wednesday

    An interesting (..and surprisingly small...) rig on a beautiful craft. I notice that the sail sets perfectly when running before on photo 22. On photo 23 the sail is close-hauled and quite distorted from the hard down-haul of the sheets. Could it be an idea to add a second halyard, a peak halyard to the yard, and to beef up the leech of the upper panel with a stitched-on Dyneema line? Hopefully that would keep the yard and subsequently the battens below it from drooping.

    Arne

    PS: I notice one possible problem with this half-wishbone rig: As the shadow pattern shows on photo 22, the camber in the main part of the sail is just an even arc with plenty of curve close to the leech. This may be powerful, but I am not so sure that it makes a close-winded rig..

    PPS: Typically me; now I go in sail analysing mode right away! I'm sorry; I bet the rig will work and will anyway be much better than if the sails were flat...

    Last modified: 09 Jan 2013 15:34 | Anonymous member (Administrator)
  • 08 Jan 2013 23:13
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    Reply # 1174665 on 1160890
    Deleted user
    Pete Hill has just sent 21 images of Oryx, some of her sailing, and some of her interior. There are also 3 of her tabernacle. David is working these up for the February issue of the JRA magazine, but if you can't wait for that, take a look now. They're in our Photo Gallery (in 'Public Pages' on the site's Home page),numbers 1 to 24, but will shift along as other images are added. Once you're in the Gallery, double-click an image to enlarge it. There's a caption beneath each. As David just said in an email to Pete, "By 'eck, you've fitted a lot into a 10 meter boat!"

    Pete says, "Oryx is a modified Bernt Kohler KD860. The main alterations I made to the design was to lengthen her from 8.6 metres to 10.0 metres and, of course, change the rig to a junk. There were many other modifications so that the completed boat is very different from the standard design. Her dimensions are:

    LOA           10.0m          (33’)
    Beam            5.6m          (19’)
    Draught        0.6m          (2’)
    Sail area      51.5 sq.m    (544 sq ‘)

    The rig is a side by side split junk sail."
    Last modified: 08 Jan 2013 23:35 | Deleted user
  • 16 Dec 2012 15:10
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    Reply # 1161007 on 1160890
    Deleted user
    Hi Peter. By no means have we forgotten Pete Hill's Oryx. We've been waiting for a good picture of her sailing, which hasn't arrived yet. I'll drop Pete an email and see what he says. Thanks for the reminder.
       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

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