redesigning Atkins' "Joan" for strip planking

Discussion in 'Boat Design' started by vjt, Dec 31, 2008.

  1. vjt
    Joined: Dec 2008
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    vjt New Member

    I have poured over designs for minimalist offshore cruisers for a singlehander and Joan seems to fit the bill as the most able little ship under 20'. I really love this design in many ways but the plans are only available in traditional wood construction. I am on a mission to redesign the boat to be set up for modern sheathed strip construction, much like the MacNaughton Coin collection I plan on keeping the dimension and weight the same of course but I am partial to the junk rig instead of the knockabout rig originally designed. I am looking for resource advice and also some fellow designers who could be a second set of eyes to evaluate the scantlings and mast placement and rig dimensions, etc. All assistance is appreciated.
    VJT

    Here's a link to the designer's page. You might need to click on "Designs by Name" and find little "Joan" there to see what I am looking at.
    http://www.atkinboatplans.com/
     
  2. Tcubed
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    Tcubed Boat Designer

    <<<minimalist offshore cruisers>>> could well be my middle name, so i am very intrigued by your post.

    I see no reason why this design cannot be adapted to strip planked with glass both sides type of construction which offers many advantages over classic carvel. Although i would recommend heavy floors to spread the load of this rather heavily ballasted little boat.

    The junk rig adaptation is also interesting . I would be inclined to give it a bit more canvas as a junk due to the flatness of the sails and their extreme ease of reefing. It may be necessary to design in a bumpkin to get a good lead for all the sheets and assure lack of entanglement. The main downside to just one sail is it won't heave to as well as with the jib/main arrangement.

    If it were me i would eliminate the auxiliary (I mean common 18 feet ! you can sail that anywhere ) and reap a substantial increase in performance and handling as well as extra cargo capacity/ living room/storage space. I would also eliminate the cockpit to massively increase living space without increasing windage and no cockpit is always safer in extreme conditions. But that ' s just me.
     
  3. Tad
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    Tad Boat Designer

    Some pics of Joan at Brentwood Bay in September of 08. This boat is currently owned by the Cowichan Bay Maritime Center. Note she is seriously tiny inside! In my mind adding a foot of beam would make the boat far more worth building/owning/investing all that work and effort in.
    Sorry for the misty effect....
    joan01.JPG

    joan02.JPG

    joan03.JPG

    joan04.JPG

    As the interior was too small for me....I just held the camera in the hatch and snapped away.
     
  4. timothy22
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    timothy22 Junior Member

    Nice boat. There is a lot to be said for the heavy displacement pocket cruiser, but economy isn't one of them, but then you know that already. If you can find one, a copy of Skene's Elements of Yacht Design by Francis Kinney will give you three different scantling rules to choose from, as well as a rather complete exposition of the state of the art ca. 1960 or so. A set of McNaughton's Shilling plans might also be money well spent. Paul Gartside, Selway-Fisher and others have designs in this range, as well as extensive advice on modern planking methods.
    As mentioned above, Joan is a little narrow by modern American standards. More beam will also make her significantly easier to strip.
     
  5. PAR
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    PAR Yacht Designer/Builder

    I disagree, in that more beam would make this an easier boat to strip. Quite the contrary, more beam would make tucking in the ends, more difficult. As she's currently designed, she'd be very easy to strip up.

    The value of a design like this is questionable in modern times. In your area, where draft issues aren't as much of a concern, these "channel" boats do well. Of course accommodations are slight, but all this has been mentioned.

    Personally VJT, I'd be looking for a more up to date design. Yes, it could be converted, but I would strongly recommend you seek a designer for this task, which shouldn't be taken lightly. If going this route, you might as well make other major revisions to the design. Now that you've invested all this money into a 70 year old design you still have the remnants of some pretty old technology and design concepts.

    It's hard to compete with $50 plans packages, but you'll find you get what you pay for. No instructions, no way to call the designer, just a table of offsets, BML, construction plan, sail plan and deck plan, plus a wish of good luck.

    With most modern design, there's no need for a conversion. If you have a problem, you can call or email the actual designer and get a response, at least all the ones I know will (except Bolger). Most often you'll get building instructions, tips and tricks, photos of the process, etc., plus a more complete plans set.

    It's your choice, Joan is a fine little ship, but somewhat lacking in a number of areas compared to modern variants on the same theme.
     
  6. timothy22
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    timothy22 Junior Member

    Right you are, sir, I meant to say easier to sell.
     
  7. PAR
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    PAR Yacht Designer/Builder

    Most folks looking to build aren't considering the resale value (yet) of the project. All boats, like most things in life, are commodities, meant to be bought and sold. Of course they get used and enjoyed too, but this is a given. Designers place a lot of effort on features and styling just for this reason. No one will buy an ugly boat, even if built masterfully (which makes it hard to understand some of Bolger's offerings).

    I think that reparability and resale value are two of the most under looked issues in home built craft and ones that shouldn't be slighted. Having a white elephant in the backyard has ruined many a marriage or nixed a real-estate deal. I even got an uncompleted project free once, from a home owner trying to sell his house, but the boat had to go first, before the sale could go through.
     
  8. Ulysse_31
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    Ulysse_31 New Member

  9. pat60
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    pat60 Junior Member

    Hello All

    Just joined the forums and this thread caught my eye. While I agree that modern designs offer improved performance and greater interior volume (width), I know of none that offer comparable headroom and comfortable motion. If any of you do please let us know.

    My thrill seeking days are behind me and as my wife is now disabled we are searching for a comfortable little cruiser in the size range of Joan. Our sailing is in and around SF bay, day sails and the odd overnighter. Previously, we had among others, a bear boat (loa 23',B 6'9",D 3'6" displ 5600) a good little boat but too little headroom for comfortable overnighting for us.

    I'm well aware of the flicka's and compac's available just looking to do something different because we can.

    Thanks for any replies.
     
  10. chabrenas
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    chabrenas Mike K-H

    For comparison, it would be worth trying to get hold of plans for Sopranino, one of the original UK Junior Offshore Group designs. See http://www.jog.org.uk/history.htm for a photo of her. Here, you will find info about how to contact Laurent Giles, and mention of the later, beamier, Barchetta class. And look here http://easternyachts.com/minim/comments.htm for a good photo as well as more history.

    PS it's a long time since I've heard anyone insist on calling Joan's rig 'knockabout' rather than 'sloop'. Takes me back to my childhood.
     
  11. pat60
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    pat60 Junior Member

    Nice boat, even with the reverse sheer. However it is a profoundly different beasty than Joan. around 1800# displacement and the pictures show great fun on the trapeze. But my days on the trapeze are behind me. Here in SF bay I'm afraid its motion would simply be to lively and again short of headroom. I don't need standing but as my wife is 5'1", for her Joan"s designed 5' would be most comfortable. Width below adds room for storage but in this size boat that can sometimes be too much of a good thing. A bit of care in the layout should take full advantage of whats available on Joan's 5'6" beam. Of course neatness in small quarters is always a desirable trait.

    Joan is of a type that seems to have been forgotten. The design brief was for a boat far removed from the basic trailer sailer we see in this size range these days. Steady friend , trustworthy reguardless of conditions, and a snug comfortable place to hole up waiting for the next breeze. Not the fastest, nor the biggest, but for one or two, enough to enjoy.

    But back to the original question, what about strip planking THIS design. The lines for the hull appear to lend itself easily to strip constuction. Or strip overlayed with double diagonal veneer, now we are getting high tech! To be certain of retaining the positive aspects of the original design, having a competent NA make the changes would be money well spent. At the same time redesigning the rig to increase the performance range of the boat would be wise. Along those lines any idea what such services would cost? Say rig redesign, scantllings, and ballast calc. for lead to replace the iron?

    Suzan at Cowachin Bay kindly sent me additional pictures of Sweet Pea, the modified Joan design they own. She has modified rigging (bowsprit and bumkin)and an outboard to replace the original inboard. While the increased sail area is surely an improvement the outboard appears to have dropped the stern underway.

    I'm thinking a Strip/composite Joan with modern rig design should give respectable perfomance over a fair range of conditions. As to the argument for a modern underbody with traditional topsides a clean bottom is sometimes better than a fin keel when all is considered, in my experience anyway.

    It seems many of use have learned to think of displacment in a small sailboat as something to be avoided at all costs. Displacement has benefits also, as each design is a compromise why not look to maximise this design's strengths rather that simply suggest to discard her and go with a caricture based on "modern" ideals or whats popular.
     
  12. chabrenas
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    chabrenas Mike K-H

    The trapeze was a joke - not legal for offshore racing! And the fin keel layout and minimalist, self-draining cockpit make no concessions to comfort. So let's get back to Joan.

    I presume you are looking for recommendations about skin thickness, etc? Setting up moulds for fibreglass-sheathed cedar strip would not need any different drawings from those intended for carvel construction - just mark out each frame and take off the thickness of the cedar plus the outer fibreglass skin. But you would need guidance from a professional about where and how much to thicken up the fibreglass sheath on the inside, how to attach the deck, and what to do about frames or ribs to enable the hull to carry that keel and the junk mast. I suppose there's no way of getting hold of a used set of MacNaughton plans for guidance?
     
  13. PAR
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    PAR Yacht Designer/Builder

    You're correct in that most modern thinking in regard to hull shapes are that of minimal wetted surface and hull volume placed where bearing area is necessary. This makes for light, fast boats, but also makes for a rough ride in a boat with little real accommodations.

    Not all designs are like this. I have several that use higher D/L's then would be typical, in an effort to increase ride comfort and provide interior accommodation. They're not racers, just wholesome cruisers that can carry what you need and survive storms without towing assistance. Several designers specialize in this sort of design (which is much more difficult to plan out). Look for those who focus on cruising designs. Payne and Benford come to mind
     

  14. pat60
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    pat60 Junior Member

    Thanks for the input Par.

    Payne's designs offer good variety however the only one that appears to come close is a hard chine design which for me is ruled out simply for looks. I am aware of the simpler build and good performance characteristics of such construction, just not my style.

    Benford's Puffin is close though, as a sloop rig might be a consideration.

    I checked out your online images, which are quite nice by the way, but could not locate your website, if you have one please let me know.

    In the past I have found builders quite willing to do new construction based on older designs but haven't checked with designers such as yourself as to the relative merits of updating one such as Joan as opposed to starting with a blank sheet.

    Leaving out the costs for a moment, say we keep the hull form as designed and focus on the desired construction method and possible rig changes. Is it your opinion that this type of boat is simply inferior for the aforementioned use?

    I admit to having my own biases but I have learned to respect the opinions of professionals. So if Joan, modified to be built of strip construction, is not a reasonable choice these days for a comfortable stable pocket cruiser for an older couple of limited mobility please explain why you believe so.

    Thanks
     
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