The "Sib-Lim" Challenge

  • 30 Nov 2014 22:02
    Reply # 3160029 on 3158909
    Graham Cox wrote:
    Jim Hall wrote:

    I'm a new-ish member and you've just tempted me out for a 1st post  with this very interesting thread.

    For the last 6 years I've sailed a Paradox - Matt Layden's radical shoal draft Micro cruiser and I'm convinced that a larger junk version would work well. 

    The Paradox is a very interesting micro-cruiser.  A 28 ft version would be fascinating.  Have you spoken to Matt Layden about it?
    Very interesting, not in the least because there several built and sailing with obviously happy owners.  And I think that, if not pretty, she is certainly 'cute' and would be at twice the size.  And absolutely crying out for junk rig!  Now we're shaping.  I love these mircorcruisers, but alas, am too hedonistic to think of living on one full time.
  • 27 Nov 2014 21:22
    Reply # 3159161 on 3158909
    Deleted user
    Graham Cox wrote:
    Jim Hall wrote:

    I'm a new-ish member and you've just tempted me out for a 1st post  with this very interesting thread.

    For the last 6 years I've sailed a Paradox - Matt Layden's radical shoal draft Micro cruiser and I'm convinced that a larger junk version would work well. 

    The Paradox is a very interesting micro-cruiser.  A 28 ft version would be fascinating.  Have you spoken to Matt Layden about it?

    No I haven't. I don't have that much cheek, unfortunately. I'm not sure how much interest he has in this design now. I understand that he's involved in the design of expensive 'luxury'  yachts for a day job, and stays away from online discussions. Someone else sells the Paradox plans without involving him  and I don't know if he gets any income from the design now.

    Best

    Jim

    ..
  • 27 Nov 2014 21:10
    Reply # 3159159 on 3144241
    Deleted user


    Paradox Rudder

    The deep rudder does partly act as a centre board in addition to its steering duties and this works well because the centre of effort of the rig is far aft due to the rectangular sail plan and long boom.

    In some respects the boat would be improved if the foot of the sail wasn't as long as it is. (softer gybing, less rolling?)    But then I would expect that you'd need to alter the underwater profile to compensate.

    Best

    Jim

  • 27 Nov 2014 19:26
    Reply # 3159119 on 3158745
    Deleted user
    Jim Hall wrote:

    For the last 6 years I've sailed a Paradox - Matt Layden's radical shoal draft Micro cruiser and I'm convinced that a larger junk version would work well. 

    Lot's going for it. No centre board or lee boards required, as the chine runners and the hull shape in conjunction with the big rudder take care of lee way.

    Matt Layden is keen to stress that it is the hull shape which was responsible for resisting leeway. Having a heavily rockered flat bottom and very flat side, the underwater effect when heeled is said to be that of a hydrofoil - flat to leeward and curved to windward, giving hydrodynamic lift to windward. The chine runner is there to act like a plate on the end of the keel to reduce leakage from the high to the low pressure side.

    I wonder. The fishing junks of north China also had flat rockered bottoms, but not flat sides. Without the aid of leeboards or centreboards/daggerboards, they also seem to have been capable of resisting leeway. This is deducible from the fact that many of them (e.g. #1 in the China National Offshore Fishing Atlas) fished the southern Bohai Sea and all round the Shandong peninsula to Haizhou Bay but mostly sold their catch in Shanghai. They could not have made this trip regularly if they could not get to windward on occasion.

    It is always said that the deep rudder acted as some kind of keel, but it is too far aft to effectively keep the head up to wind. There seems to be something else going on here. Any ideas?

    Last modified: 27 Nov 2014 20:41 | Deleted user
  • 27 Nov 2014 14:03
    Reply # 3158990 on 3144241

    JUNK CATAMARAN

    Just for fun I sketched over Petes Oryx to look more like a Badger and with a single fanned junk rig.  Better looking?

    Of course the Gary Lepac Dragon Wings had a very Chinese look, if that is what is desired.

    Posted in Technical Forum / Illustrations

  • 27 Nov 2014 09:06
    Reply # 3158909 on 3158745
    Jim Hall wrote:

    I'm a new-ish member and you've just tempted me out for a 1st post  with this very interesting thread.

    For the last 6 years I've sailed a Paradox - Matt Layden's radical shoal draft Micro cruiser and I'm convinced that a larger junk version would work well. 

    The Paradox is a very interesting micro-cruiser.  A 28 ft version would be fascinating.  Have you spoken to Matt Layden about it?
  • 26 Nov 2014 22:51
    Reply # 3158745 on 3144241
    Deleted user

    I'm a new-ish member and you've just tempted me out for a 1st post  with this very interesting thread.

    For the last 6 years I've sailed a Paradox - Matt Layden's radical shoal draft Micro cruiser and I'm convinced that a larger junk version would work well. 

    Lot's going for it. No centre board or lee boards required, as the chine runners and the hull shape in conjunction with the big rudder take care of lee way. No complications. Self righting due to inside ballast and the free board and the buoyancy given by the cabin top.

    I can assure you that cleaning the flat bottom isn't an issue. As you scrape along, up rivers and creeks in the shallows, the bottom cleans itself.  So you only have to scrub the sides which are easy of access.

    My boat is only 14 foot long and about 4 feet beam but the interior is so well thought out that it's not cramped for one person. I could almost house a 6ft  lodger too.

    One twice the size - 27 ft by 8ft would give me 8 times the volume I have now. I'd keep the proportions the same as they are now. The mast is already in the right place for a junk. The only thing that would take some working out is how to mount an outboard engine as having it hanging on the transom isn't the best plan.

    Best

    Jim







  • 26 Nov 2014 21:16
    Reply # 3158697 on 3158409
    Mark Thomasson wrote:

    JUNK RIGGED CATAMARANS

    Well sailing across the Atlantic in a wee Wharram would put an but the hardiest soul off cats for life!

    No, that wasn't the issue.  I am still rather fond of Wharram's designs, but I don't like such a big footprint for such minimal accommodation

    To try an keep the, albeit rather small, flag for junk rigged catamarans flying, a few more comments:

    A)  Build time.  I would question whether it is much different, it would be enlightening to hear Pete's view.  You are working with lighter components that can be manhandled, at least until joined together.  Take a look at  http://www.thecoastalpassage.com/cheapcat.html  A 30ft cat for $21k  £12k (though not sure when)  Built in 900hrs by an Ozzie in his 70s,  designed on the back of a beer mat after a few stubbies  (Annie: a youngster like yourself, inspired by a few glasses of the red stuff could produce a really elegant design!!)

    I don't need Pete's view: I was there for 2 of the 3 years w/he took to build China Moon :-(  A simple chine ply hull has x slabs of wood to make the hull and deck.  A catamaran needs 2x for the hull and deck.  It's joining the bits together that takes the time, IMHO.

    B)  I have contacted Bernd Kholer, he says a single junk rig may be ok on the KD860 (Orynx is an extended KD860).

    Yes, I can see no reason why it shouldn't work in a bridgedeck cat and seems to me the logical way to go.  Much less complexity.

    C) The interior of a bridge-deck cat is a very pleasant and social space,  good views out on at least 3 sides.   There is good contact between galley and sitting area.  If you spend much time at anchor, where there could be any swell, a cat is going to be so much more comfortable.  You can also squeeze up little creeks, without too much worry about being stuck. I would admit, not so good in a rocky harbour, full of steel fishing boat (as around E Scotland).

    As someone who very much enjoys cooking for my friends on board, I'm afraid I'd have to dispute that 'good contact between galley and sitting area'.  Indeed, it's one of the things that puts me off a bridgedeck cat - you can't actually see who you're talking too.  But I can see the attractiveness of the saloon-with-a-view.

    D) Heating, yes considerably more than a Mono, but if you are building lots of insulation can be added, so should be cosy enough.

    Heating could possibly be arranged, but moving the air around so that you don't get condensation in the ends is more of an issue.  Even insulation isn't enough to prevent this.

    E) The more I look at the KD860, the more I think what a good looking cat.  Probably about as small as you can go and not look ungainly.  http://ikarus342000.com/KD860page.htm

    No, sorry - not the sort of boat I find at all attractive.  Cat or mono, it has to have sheer, or at least be cute.  I'm afraid this one does nothing for me :-(

    Whether I get the time and energy to start my own build, who knows?

    Cheers Mark

    I don't know whether I will get the money or the energy, either!  I haven't completely dismissed cats, but I think a small mono is a more likely proposition, not in the least for the 'row-away factor'.  I like to smile when I look at my boat!  But keep posting - you may see something that would suit even me!

  • 26 Nov 2014 20:49
    Reply # 3158688 on 3156880
    Peter Manning wrote:

    Annie, I put a home made epoxy with copper antifouling on Malliemac. It appeared to work quite well last year but since she spent more time in the marina than out at sea it was not really a good test. Since then I have been told about another commercial copper antifouling made by Reactive Resins here in the UK called Synergy. This uses a water based epoxy and does not need to be abraded once applied. I am thinking of applying it to Mallie. I am not sure if it is availble outside the UK. It may be worth a look.


    Peter, this sounds very interesting - especially if it avoids some of the nasty chemicals that go with applying epoxy.  It's one thing mixing up a batch of glue, quite another rolling the stuff on over a period of several hours.  This product should be included in the Links, I think.
  • 26 Nov 2014 20:07
    Reply # 3158658 on 3144241

    Coppercoat can be great, but only if the preparation is right and the application even better. Get ts slightly wrong and it is a total waste of money. You cannot trust a south coast boatyard to do the job, and really have to do it yourself in ideal weather condition to be sure of the result. You must follow the instructions exactly.

    Guess how I know?

    Cheers,  Slieve.

       " ...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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