Alternative catamaran rigs for self build? Becoming more self sufficient

Discussion in 'Multihulls' started by Mark Stevens, Aug 30, 2019.

  1. Mark Stevens
    Joined: Aug 2019
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    Mark Stevens Junior Member

    Hello,
    I have just acquired an old Prout ranger. The rig is old and the sails knackered. I have previously converted 2 yachts to junk rig, making everything from the mast to the sail. I understand that junk rig is not favoured for cats but I would like to make my own rig and maybe take elements from the junk. I really enjoy making everything and not having to outsource the work. Does anyone have experience of self built rigs that sail efficiently?
    Thanks
     
  2. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    Mark. Cats with junk rigs are not uncommon if you look at the JRA pages and Poppy (35 foot mono) has a very efficient junk rig. Look up PHA and Grand PHA catamarans for there versions of junk rigs and Pete hill Oryx (?) and China Moon catamarans. I am not suggesting 2 masts but all the boats mentioned have all crossed oceans with the rigs that were all home built. Good luck.
     
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  3. Eric ruttan
    Joined: Jul 2018
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    Eric ruttan Junior Member

    I second the JRA. An electronic membership is ~7$? Well worth it.

    They have literal masters who have built and sailed hand made junk rigs 10's of thousands of miles over decades. And they keep moving this simple technology forward in a kind of Open Source way.
     
  4. Mark Stevens
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    Mark Stevens Junior Member

    Thanks for the reply. If I was to go down the route of batten lug main I would use a high peaked sail like Bertie so that I could use stays and a jib. This would allow for a shorter mast that could be lowered on tabernacle.
     
  5. guzzis3
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    guzzis3 Senior Member

    I'm probably beating my drum here but fwiw...

    A crabclaw/oceanic lateen on an A frame would have to be one of the easiest rigs to make for a cat.

    The A frame replaces the shrouds, the upper spar leads forward to replace the forestay forming a tripod. Because you don't douse the sail you don't need sail tracks or halyards. A luff pocket is also acceptable because again no dousing. You can use either a traveler or a double mainsheet, then 2 more blocks to hoist the lower spar to reduce sail. That's it. The A frame doesn't need special mounts either, just fixed to the side decks.

    If your prout is an older cat with the aft stepped mast then it's already designed for a fairly aft center of area of sail.

    Just a thought. Junks are ok for cruising but I bet a crabclaw is just as good.
     
  6. Mark Stevens
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    Mark Stevens Junior Member

    I use a crab claw on my Wharram melanesia. It is a very simple sail. My reservations would be reducing sail. I am looking for alternative to the junk, something that I can make myself. I dont feel the junk rig I what I want for the cat. Do many people use a Wharram style soft wing on non Wharram cata?
     
  7. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    Mark. Yes there have been some boats that have used a Wharram soft wing on a non Wharram cat with reasonable success. I cannot find the photo's on the web but it was about 30 foot full bridge deck cat and sailed successfully for a few years. Also if you want a real wing mast plan (stressform 6 PDF's) with full details go to Multihull Structure Thoughts thread on boat design net Page 5. The wing mast was designed for a 26 foot tri that would have a similar righting moment to a Prout Ranger. There are a few other ideas attached including a tri under the VPLP banner.
     

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  8. Mark Stevens
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    Mark Stevens Junior Member

    Thanks for the info. Will check out these designs.
     
  9. Rumars
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    Rumars Senior Member

    You could convert to some form of junk but it would require unstayed masts, and that means biplane rig on a cat. That modification will be expensive since the hulls were not set up for it. Then you still have to make the masts and sails.
    It's better to reuse what you have. I suppose the mast is still sound, maybe some cosmetic work needed. The standing rigging you can do yourself using dyneema and some deadeys that you carve out of hardwood. Blocks can be refurbished, second hand or you can build them if you like. That sails are the big item and you either get them used or you build them yourself. You will need to learn about "normal" sailmaking, and in the beginning your sails will not be as good as profesional ones, but they will probably match junk rig performance. The big expense on new sails is not the sailcloth but the work and expertise of the sailmaker. Eliminate that and you are self sufficient. I don't see any reason to go to "alternative" rigs, you can make everything yourself if you desire. Buy some books about rigging and sailmaking and keep going. A cheap source of sailcloth are used sails, you take them apart on their seams and recut the panel to match your design. A good sewing machine is a big help but sails were made by hand in the past, so you can do it also.
     
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  10. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    Mark and Rumars. If you are prepared to do a little reinforcing of the cabin roof and wing deck area a single free standing mast on a cat is very possible as indicated by the photo's below. I am not suggesting an aerorig but a junk rig etc could be done on the free standing mast. I have limited information on the Hirondelle reinforcing structure. Also a comparison of a split junk versus a conventional rig is available at Bermudan rig vs Junk rig - Practical Boat Owner https://www.pbo.co.uk/seamanship/bermudan-rig-vs-junk-rig-17481
     

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  11. rwatson
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    rwatson Senior Member

    I agree with all your points except the last one.
    Unless you have a team of strong fingered, skilled sewers, making sails by hand is the worst option.
    A decent sewing machine can cost as low as $300, for say, used semi-commercial machines.
    Just hand sewing the corners of the bolt ropes is a real pain.
     
  12. Rumars
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    Rumars Senior Member

    Yes I know it's a pain, I only mentioned it as a last resort. Just as I don't actually recommend taking apart used sails instead of new sailcloth. I just have the impression the OP wants it cheap so I mention the alternatives.
    Depending on location buying some decent sails that fit could be cheaper then the sewing machine and thread. Used sails are often from monos and are cut fuller then a multi needs, but his is not a high performance boat anyway.
     
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  13. Rumars
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    Rumars Senior Member

    Oldmulti, yes it's possible to put a unstayed mast on a cat. It is more involved then biplane not only because of the reinforcing that needs to be done, but because he wants junk. Matching the CE of the original sailplan with a jibless rig like the junk means moving the mast forward and he might run out of cabin for adequate burry to support the mast. Then he will have the problem of weight distribution, all the reinforcement and bigger mast and battens will be up forward (this is also a problem with biplane). All this can be solved of course, but it's not a walk in the park.
    The obvious option, using a stayed junk rig with a jib (a la Colvin) is possible but gains him little over the existing rig and adds weight up high. The only benefit I see is beeing able to use lesser quality sailcloth for the mainsail and some quicker reefing. The jib would still have to be made of good cloth, with broadseaming and all. And if he can make a conventional jib he can make a bermudan main.
     
  14. Mark Stevens
    Joined: Aug 2019
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    Mark Stevens Junior Member

    Thanks for your reply. I said that I have converted 2 boats to junk, not that I wanted to pit a junk on my cat. I had considered taking elements from the junk. I definitely dont want unstayed masts or mast. More wingsail on stayed mast. It's not about the money, I certainly dont do things because they are 'cheap' that is someone else's assumption. It is not the cheaper option to replace the whole rig and make your own sail from scratch as opposed to getting new sails made for existing rig.
    The reason I am thinking about going down this route is to experiment with a self build rig on a smaller cat as I want to build a much bigger one later in life. I feel it would be prudent to work out design problems on a smaller scale before implementing it on a large scale project. It's not about the money it's about being able to service every aspect of the rig and replace when needed. Maybe I should just put a wharram style soft wing on as it has been proven many times.
     

  15. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    Mark. Tiki 30 masts are 9.5 meters high with build options of 140 mm outside diameter with 25 mm timber walls or a 140 mm diameter aluminum tube 3.5 or 4 mm walls with 700 mm long internal sleeves in the top and bottom. An alternate timber mast is a box mast of 170 x 170 mm with 25 mm walls and 40 x 40 mm triangles in each corner. The mast is then rounded. If you want to go high tech there was a guy who had a carbon fibre mast made of 125 mm inside diameter with 3 mm walls. Hope this helps
     
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