The Flying Apple Crate
Hi Proa-types,
I really want one of John Harris’ Madness style proas. First of all, its gorgeous, and beauty counts in a boat. I love that he took the principles of Russell Brown’s boats and created a stitch and glue kayak kit out of them. Did I mention its gorgeous?
But as I enter year 2 of my 16” Wa’apa build, I’m confident that I do not have the time to complete such a project without it seriously interfering with my family life, financial situation or both. And having it built is expensive. Very expensive.
So while I’m figuring out where I’m going to scrape together the money to have one built for me, I started doodling a minimum proa for sailing on San Francisco Bay. Coincidentally, the size I came up with is about the depth of my garage—24 feet. At that length, I trade in accommodation for a cozy, high sided cockpit that is self draining in the main hull. Maybe you could cover it and roll out some air mattresses, but this is a daysailer!
The plywood main hull is single chined. In profile, the topsides of the hull rise up to form a hump in the middle of the boat, to hang the lee pod off of, in the classic Newick/Brown style. In early drawings I had a pod shaped bit on the windward side too, but it seemed like a lot of work to build a cockpit inside the pod. So to save weight and time, I left the windward pod out. So the single sided cockpit just hangs off the windward side, like an apple crate. Outboard of that is a beam to spread mast compression loads out to the akas.
The akas are plywood box beams that taper fit into sockets in the vaka and ama. Then I’d have a couple bolts or lashings to keep them seated in their tapers.
The ama is based on Harmen Hielkema’s, described in this reposting of Russell’s Proa File International posting.
http://www.wingo.com/proa/brown/observations_on_pacific_proas.html
...that’s a good enough recommendation for me.
The rudders would also be Russ Brown/Newick inspired—with the clever foam crash box and easier to fabricate rectangular cases.
I’ve drawn it with a James Brett inspired cambered junk rig (even thought it looks flat in the rendering). That would be an amazing rig if it works up wind. James says it does! I sized it at about 250 sq feet on a 24’ mast. I could add a jib for light air.
But what I’d really like to try is the twist control gaff rig that Paul Bieker developed for the PT 15 dinghy. There is a great article about this in Wooden Boat #193. The gaff rotates with the mast to control twist! Plus, the bendy top of the sail goes down when you reef, so the top of the sail acts the same whether you are reefed or not. Super cool. I’d pair that with hanked on jibs and the jib catching nets used on Pacific Bee.
Anyway, when I get a minute I’m going to work on further Dierking-izing the design; take more away and focus on increased simplicity.
Let me know if you have any thoughts.
All the best,
Chris
Chris, That’s a great start to a design, I think. I’ve been musing on 24’ being about right for me too - 3 sheets of ply, small enough to trailer nicely, large enough to camp cruise the San Juans, 1 or 2 people. Thanks for the header to the PT 15 rig, what a cool idea (though I like the junk a lot, too).
I keep drawing something like this, then removing the pod, then adding it back. Unlike Madness, the pod is too small for a bunk and shouldn’t be loaded up with storage, and it looks a bit “yachty” for a proa of the type I’m visualizing through a lens darkly. So off it comes, and then I think about how much I really want a self-righting proa, and on it goes again. have you seen the pod on Lazarus (ex-Jzero)? I like that one quit a bit. Sometimes I think to just mount a small kayak over there to work as the “pod”, and it would be fun and useful as a landing craft/dinghy. It could also be removed for racing…
Skip’s Nomad design is right in this ballpark as well, he’s using a dory section hull (no pod) which I am guessing would offer some extra righting moment at extreme angles of heel?
Skip’s Nomad design is right in this ballpark as well, he’s using a dory section hull (no pod) which I am guessing would offer some extra righting moment at extreme angles of heel?
Not nearly enough to qualify for offshore work 😉 I am currently thinking about flaring out the cabin structure to make a lee pod, The positives; there’s a lot of extra volume in the right place for very little extra material, an additional right angle helps stiffen things up. Not so positive; it’s still extra material.
I like the direction some of the threads are taking, to look at the zen of the thing. One of my other bucket activities is expedition canoeing in Big Bend, less is more. I’ve whittled down gear to a comfortable to me minimum (juries still out on chair).
Nomad is an outgrowth of experiences with P52, a coastal cruiser. Dory section was selected for ease of build and toughness pulled up on an oyster reef or rocky shore, both of which are within easy trailering distance. Turned out to be a very good all around section and I no longer sweat the extra wetted surface, anathema to canoe design which operates in a different set of minimums. Flaring out structure originally wasn’t an option since P52 started life with a crab claw which needed to slide along the lee side on shunts. Current thinking with a biaxial cambered junk puts the range of motion of tack shuttle within the bounds of cabin area so a little more cogitation is in order.
Great fun,
Skip
Hey Michael,
That twist control gaff might just be the missing bit from your Manu Kai design.
To lee pod or not to lee pod? To me, at 24’, the pod has little or no accommodation or storage utility. The whole thing is about keeping the ama low, where it can do its job. It needs to put the boat back on its feet rather actively as the ama rises. Sven gave an awesome account of the work the lee pod does here:
http://proafile.com/forums/viewthread/25/
go to post #9, Clarifying the dynamic heeling.
Lazarus’s big comfy looking cockpit was a big influence on the Flying Apple Cart. I also dig Lazarus’ pod geometry, which looks to me like a page out of the Cheers book—it curves gunwale to gunwale in plan view, instead of being more wing like, as on Jzerro. The flying saucer-ness of it is sweet looking. But does the lee pod want to have more waterline when it immerses?
I LOVE the idea of a kayak or something like that as a lee pod for a 24’er. My Wa’apa has an (embarrassingly) oversized safety ama. So I’ll have some real world experience to work from. But I have a feeling that the lee pods on Russell’s boats act like hydroplanes more than kayaks. That is to say, there’s more than just displacement going on—there’s dynamic lift going on. This may be my overactive imagination, but I bet that there’s a tunnel hull sort of effect at high enough speeds and angles of heel. Sven, any thoughts?
So that got me riffing on the idea of a little pram as a lee pod. What if you hung an 8’ pram off the lee side of the vaka? It could be attached hung off of the akas—leaving your vaka a simple canoe! Maybe you’d want to put some kind of a shaped gasket on the lee gunwale of the vaka to keep a geyser from shooting out of there when you put the lee pod down.
Could a canvas cover for the pram be made watertight, like a kayak skirt? Maybe the pram is partially decked with a big elliptical combing like a kayak! That would look sweet, if complicated to build.
Then I started looking at bolger prams etc, and came upon this:
http://webspace.webring.com/people/wt/trond_are/LatThinking.html
go down to October 2004
He’s talking about using a bolger pram as a windward cockpit, but the idea is basically there. (Make sure you check out his version of a roller furling Gibbons/Dierking rig!)
So that’s my next version. Simple, flat bottomed dory/Wa’apa shape with a springy sheer and tall bows. Akas lashed onto the deck of the vaka that extend off of the lee side far enough to lash the nose of a pram to them. And an 8’ double ended pram that can be removed and rowed around. I love it.
I could leave it anchored out in Richardson Bay, and use my little 8’ pram to row out to it, and then lash it on for cruising around. The pram would come in handy up in the Delta as well!
Skip, I think Nomad looks fantastic. What are your thoughts on dory shape flare? Gary Dierking is not a fan—he says it slows you down in chop. But it might also provide some dynamic lift as well. You mention that its a great open water boat—I’d love to hear about your experiences.
Best,
Chris
Skip, I think Nomad looks fantastic. What are your thoughts on dory shape flare? Gary Dierking is not a fan—he says it slows you down in chop. But it might also provide some dynamic lift as well. You mention that its a great open water boat—I’d love to hear about your experiences.Best,
Chris
Hi Chris,
My experience is fairly limited, a third of an Everglades challenge, half of a Texas 200
http://www.texas200.com/2009/stories/johnson/index.htm
Then a finished Texas 200.
The dory flare seemed to have worked well for me, a lot is pure serendipity based on length and loading. I’m positive that adding some extra weight can always make things worse, effect proportional to distance from center of buoyancy. My only yardsticks are Kevin’s green proa and Laurant’s speed machine. Both are fast wet boats. P52 never got more than a teacup of splash in the cockpit.
Not sure that dynamic lift is involved, it’s more a matter of being balanced with as little force as possible.
Cheers,
Skip
That twist control gaff might just be the missing bit from your Manu Kai design.
Yea, it’s very cool. Interestingly, the rest of the PT15 fleet was built with a standard sloop rig. Maybe they had a sail off between no. 1 (gaff) and no. 2 (sloop) and the sloop won? Or maybe the sloop is just less trouble to build. Here’s Paul Bieker’s page: PT Dinghy
Using a Bolger pram for the lee pod would be brilliant and also excellent karma. I’m still leaning toward a long, slender canoe shape - something like Teal or if I want to get fancy a skin-on-frame type thing.
Skip: based on your experience with P52 I’m drawing a dory hull. I’d like to experiment with some hull asymmetry (there will be a model test this time!).
Skip: based on your experience with P52 I’m drawing a dory hull. I’d like to experiment with some hull asymmetry (there will be a model test this time!).
I’m not that big a fan of asymmetry thinking a little bit goes a long way and I don’t know enough yet to delve into it. My first couple of generations of double blade paddles were strongly symmetrical, Current model is subtly tweaked on several axis and is a gem (IMHO).
As long as I’m being contrarian (easy at my age) not that big a fan of models either, preferring to play with minimalist solo boats to try out ideas. That being said I’m contemplating building a model of Nomad at least 3’-4’ long to check out static hydrodynamics of design with and without a lee pod. Contemplation comes from the messy calculations that require several guesstimations to find out what happens when you flip up to leeward, easier to build a model and tack on a shaped foam pod. Watching the video of Jim Brown interacting with the model of Madness didn’t hurt either. I do usually build some quick and dirty cardboard models to see how things look in 3D and play with sheet leads and the like.
Chris wrote:
That is to say, there’s more than just displacement going on—there’s dynamic lift going on. This may be my overactive imagination, but I bet that there’s a tunnel hull sort of effect at high enough speeds and angles of heel. Sven, any thoughts?
Well , one thing springs to mind, is the smaller you get ,the more dependent you are with your own weight. Logical, but also the quicker heeling of the smaller sizes proa will likely send you regularly on that pod, a properly designed wing(could IMHO be model tested) could dynamical lift that pod.
Now I would not compare it too much with Russell designs, as we NEVER sail like that, nor does the pod go in the water as a habit, its more very seldom .( I managed 35 degrees only ones in 4 years, because I didn’t pay attention ,to a near hillside )
But it is interesting, I let my though go over it a bit more ......
Cheers Sven
The pod issue is indeed a deep subject. I like the idea of getting some video footage of the pod at work. That’s maybe something that I could do once I get the waterproof camera going.
I do think that having leading edges on the pod (not semi-circular like Cheers) is important. Getting the leading edges as high as possible also seems good to make the pod act like a toboggan. The method I suggested to John Harris is my favorite; to run the crossbeams above the deck and have the crossbeams become the leading and trailing edges of the pod or pods. This involves making fairings for the crossbeams, but also makes for much more interior volume in the cabin. It looks pretty good too.
My friend Paul Bieker is planning to design and build a 26” proa for racing. Paul is an absolutely brilliant designer and if he indeed builds this boat it will be something to study. Paul went through a 50 knot gale with me on Jzerro and sailed on the boat quite a bit in New Zealand as well. He really likes proa’s.
All the best,
Russell
The apple rate concept is largely what I’ve been trying to do. The rig shown is exactly where I’m at. Only difference is I’m going for more enclosed accomodation because I’m in the pacific NW.
I’ve also gone back and forth on the pod issue, wanting the storage/accomodation/safety, but then again it makes the whole boat signigicantly wide for trailer or slip.
Going down my box keel road, here’s what I came up with. the “pod” is narrower, but extends much farther from end to end, and at full displacement probably engages sooner. I’m hoping I have a fine enough entry and a small enough total “flat” that pounding won’t be an issue.
I’m thinking of painting the “cheeks” to look like a WW2 submarine complete with torpedo tubes….
Tom.
Hey Russell,
Thanks for chiming in on the subject of pods!
It makes perfect sense that the leading edge of a pod should be high to act like a toboggan. On Jzerro it looks like that leading edge is above where the sheer of the canoe body would be. On Madness, that edge is at deck level. Does that make it more likely to bury, or is the gunwale high enough?
I noticed that Madness’ pod looks to be about 1/4 of the overall length, where Jzerro’s looks to be about 1/3 of LOA. Longer feels less likely to stop the boat. Or is it more a question of volume?
I LOVE the way the faired crossbeams look on Madness. I was wondering your thoughts about bolting crossbeams to a bulkhead, as opposed to supporting those bolts on both sides, with two bulkheads, as you do in your designs (I think…).
Finally, what do you think about the suitability of the gaff rig from the PT 15 dinghy for larger craft. Is it better just to get on with a rotating, square headed main? Or are there benefits to be gained from that configuration?
Again, thanks for your thoughts!
I can’t wait to see Paul Bieker’s proa. I’m a huge fan of his work. As soon as there are relevant details, I’m sure a lot of us would love to hear more.
Best,
Chris
Tom said: Going down my box keel road, here’s what I came up with. the “pod” is narrower, but extends much farther from end to end, and at full displacement probably engages sooner. I’m hoping I have a fine enough entry and a small enough total “flat” that pounding won’t be an issue.
You’ve certainly achieved a sort of Bolger geometrical efficiency here! I also like the submarine idea, you could paint it yellow for additional whimsy. I think these, narrow, vertical-sided hulls tend to “freight train” through waves at speed. This may cause your low horizontal flats to get hit pretty hard and pretty often. I know why they are down there, though. You want sitting headroom inside.
Going down my box keel road, here’s what I came up with. the “pod” is narrower, but extends much farther from end to end, and at full displacement probably engages sooner. I’m hoping I have a fine enough entry and a small enough total “flat” that pounding won’t be an issue.
I’m thinking of painting the “cheeks” to look like a WW2 submarine complete with torpedo tubes….
Tom.
I was doodling something similar this morning in Dr’s office. I think the idea has great merit. Only comment I’d have is I’m not sure that Bolger’s concept of matching curves is altogether applicable at these L/B ratios. But who knows? I’ll have a little better handle on what’s what after fiddling with my Bionic Broomstick.
Cheers,
Skip
“You’ve certainly achieved a sort of Bolger geometrical efficiency here! I also like the submarine idea, you could paint it yellow for additional whimsy. I think these, narrow, vertical-sided hulls tend to “freight train” through waves at speed. This may cause your low horizontal flats to get hit pretty hard and pretty often. I know why they are down there, though. You want sitting headroom inside.”
That was a nice by-product, But the big reason was to get a nice berth with plenty of head room. It’s @ 48” wide at the head, making it a tight double if I don’t bring a heavy displacement woman. batteries, water jugs, a holding tank from a head with good sitting headroom in the other end all go low in the keel (leaving a central footwell), well corralled for final stability. The main danger of pounding would be when the boat is bolt upright, and it’s the main reason I made such a long lean entry for the “anti-ballast” tanks. I suppose if it was an issue I could glue in/glass large foam fillets to ease the entry and reduce the flat area. Talk about an easy layout and build though…..
Tom
The flying apple crate has become dinghy on a stick…
Here are some views of the same 24’er with a 10’ pram as a lee pod.
From some angles it almost makes sense. From others, it just looks silly. Looks ok without the pram on it….
But there might be a there here. The question is how much can the design constraints of a lee pod and the design constraints of a pram overlap. In dinghy mode, this would probably hobby horse like mad. And the flat top looks bad. The idea was that you’d be able to make it on a bench top, but it needs more shape.
Back to work!
Chris
How about a dinghy the folds on a longitudinal seam? Akas ccould be 50% recessed into the deck of each half. could even be a “cat” dinghy.
Tom