16-18' "Sit-in" Planing Monohull ("Trapwing")

just to be clear, are you proposing to move the wing and ballast independantly?

 

Yes, he is. His calculations are based upon the ballast moving 18' (@5.5 meters!) from side to side during a tack or gybe. This requires the 12' wing to move completely across, and the ballast to move to the end of the 12' wing. Doug's numbers count on the 160 pounds moving 9' from the center of the boat.

I guess Doug is planning to rid the world of mobility-challenged people. Perhaps the "trap" part of the name is appropriate.

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Bill

 

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No, they move simultaneously-the ballast and the wing move together:the wing moves and "pulls" the ballast-very simple. There are numerous versions of this boat that are possible from low-key ,nice and easy to the turbo version which will push the limits of this concept to the max.

 

Sounds like fun. If you time it, you don't need much energy, if any, to move it. And, its location could be controlled by a wand, or a paddle wheel.

 

Steve Clark criticism from SA:

From a man I respect a great deal:
"My guess is that anyone who has tried to build model boats that feature "real life" performance has had ideas along these lines. Almost half of the models I built as a kid had some sort of movable ballast systems to make them sail faster in the typically windy place I lived. Because RC gear was beyond my means, I never tried to make a remote controlled shifting ballast system until I was over 45 years old. But I do have to admit that I had canting keels and racks that held ballast packages well out to windward, and sometimes these models went stupidly fast.
Could this be scaled up, probably but I am pretty unhappy with the so called "trapwing" concept that is being promoted. At least as portrayed in the images of model boats shown and from Doug's descriptions. I think it is awkward and that the difficulties outweigh the potential benefits.
Many people have come to me with versions of this over the years, and I haven't seen one I liked.
It is also worth noting that there were ballast carts on many cruising boats around Narragansett Bay in the mid 1800's. (Herreshoff"s Clara for one) This feature was not maintained as time wore on, I suspect because the kinetic risk of having a rail car full of a few thousand pounds of lead helt to the high side by a a pawl or equvalent mechanism was pretty disquieting. I know of no record of disasters, but I would have been pretty careful around these things. Talk about lose cannons!
However it is also fairly obvious to me that a faster version of the Martin 16 is possible. One has merely to refine away some of the compromises and make the obvious improvements to specifications to achieve that.
One important parameter is how much body shifting is acceptable within the notion of "sitting inside." Just being able to shift your bum or roll your shoulders to windward could be a significant increase in sail carrying power. So mobility within the constraint of "sit inside" needs further examination.
So while I don't see any reason why there can't be sit inside boats that sail very very well, I don't like the above deck shifting ballast system as proposed."
SHC
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and disagree with sometimes......
pix is the Melges24RC prototype I designed and built with help(!)from Reichel-Pugh using a Trapeze Power Ballast System-a very rough version of the Trapwing:

 

I agree with you, Bill. The old geezer who chooses, willingly, to ride in this thing should be getting a pre-paid by the manufacturer, life insurance policy, assigned to be paid-out to the little woman from day one of ownership.

 

From the first post for those who don't read too well:
A well designed, tested and proven version of this boat(that was self-righting) COULD offer disabled sailors(and/or grumpy old men like me) a high performance single-handed alternative to the 2.4 meter. BUT,and this is important: to be viable this boat does not have to be suitable for disabled sailors! Don't view this concept ONLY thru the lens of what might be suitable for disabled sailors.
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Its striking to see the "level" some will go to in criticism of a concept they prove time and again they don't understand. At least Steve is honest as well as being informed of the history behind this concept even if he doesn't feel happy about the history in front of the concept.

 

There is no physical way a 12' plank can provide 9' of lever arm for 160 pounds of ballast unless the ballast moves across the plank and the plank moves across the boat. Period. The plank and the ballast move independently Q.E.D. They may move at the same time, but do not confuse this with a static ballast fixed on a plank.

You can't have a 9' lever arm for righting moment without moving ballast on a moving plank. There would have to be a carriage for the plank to travel in, and a separate track for the ballast to travel in.

Your design, not mine.

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Bill

My point is that this is not a simple concept.

 

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You don't understand this: "No, they move simultaneously-the ballast and the wing move together:the wing moves and "pulls" the ballast-very simple. There are numerous versions of this boat that are possible from low-key ,nice and easy to the turbo version which will push the limits of this concept to the max."
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I'll get around to some sketches in a while.
Its slightly more complicated* than this to keep the wing watertight,but:
1) the ballast inside the wing is attached via something like waterproof turning blocks*(just a figure of speech) to the centerline of the boat.
2) a line from each end of the wing is attached via turning blocks to a motor or to a hand or foot driven sheave.
3) when the line from each end of the wing moves(by electric or human power), the wing moves. When the wing moves the ballast moves. They move simultaneously. Simple and proven with hundreds of hours of model testing.
4) the weight of the wing+ ballast is supported by trapeze wires as it moves outboard.

*a small shaft with a miniature waterproof stuffing box(brass tube) with two correctly sized sheaves(one inside the wing,one outside the wing) is inserted in a molded area at each end of the wing: a line is wound around the inside sheave and goes to the ballast; a line is wound around the outside sheave on each side and goes to the same attachment point at the center line of the boat. Simple and effective at keeping the wing 100% watertight.
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There is more to it than this but you should understand the general concept.

 

Doug, if you don't know this by now, you should. When you indicate that any component element of a design is on the table, you have to design to that metric... or take it off the table. Since you have not done so, it remains an unfulfilled element and is ultimately dangerous for those for whom it is intended.

I'm so surprised at the lengths that some will go to defend that which they already indicated was a part of the design. Not one whiff of an apology for being the one to suggest this design component (the disabled sailor routine) and then trying to indignantly yank it off the table when getting roughed-up for poor design considerations.

 

There you go again-nothing is yanked off any table-the point was to reiterate that this concept AND/OR the Turbo version should not be exclusively viewed as for disabled sailors though the concept should prove ideal for all sailors-with proper consideration for their abilities and limitations.
It will be a flat out blast that is not available in ANY currently available monohull dinghy anywhere.

 

Simple and effective at keeping the wing watertight then becomes Exhibit A for maintenance driven failure. Maintenance failure then confines the use of the boat to pretty much not at all. No dependable use means no more sales. No more sales means no profits for investors. No investors in your scheme means your name is mud for future dreamschemes.

This is just another of your "ideas" to overly complicate every single boat in sight in order to worship at the altar of technology.

Could you give us a list of overly technical marvels that have become notable commercial success stories in the world of boating?

Canting keels... nope
Foilers (any).... nope
Horizontal foils. nope
Rotating amas.. nope

Nope, Nope, Nope

The same will be true for this bit of exuberance. The trick is for the idea to have substantive merit. Otherwise, what's the point? Pulling combinations of stuff from the dark halls of the parts department is not from that kind of discipline.

 

Doug:

I DO understand the concept. Clearly, I can see how the idea works mechanically. Understanding the concept and agreeing it is viable is another thing. I do not agree this is an appropriate solution for mobility-challenged sailing.

As an engineer, I can also see many problems with the concept, not the least of which is that the more complex the solution to a problem, the less reliable it is. This idea., like many others you propose is complicated and complex.

Sailing high performance skiffs, I understand and accept the fact that I swim frequently, that crashes can be (and are) often violent. Things break, including the guy sailing the boat. I can't remember a single time I sailed my Laser 5000 in breeze last year that I didn't leave some blood in the boat. Upwind planing, huge asymmetrical kites and high speed increases the potential for getting hurt. These are not informed choices I could make as a professional engineer designing a product for the mobility challenged. Nor could I design complex failure-prone systems for this venue.

You have a history of applying overly complex solutions to problems in an attempt to "break the rules" and make a breakthrough that others have failed to achieve.

In thirty five years of product development I've learned that almost all real progress is accomplished via small increments building upon the efforts the have preceded me. Small steps making incremental progress forward. Dealing with technical risks one at a time had worked well for me.

Every time I've witnessed efforts (and I've seen lots) to combine several radical concepts together to achieve a "breakthrough" it has resulted in failure. You make the equation so complex, with so many variables that it becomes quickly unsolvable.

Never mind the issue that you never bother to clearly research & define your product concept to validate if it answers a question anyone else is asking, or if it is something anyone else would be willing to buy. Real product development starts and ends with a market need, and a market willing to pay for it.

Your ideas fall into the "Field of Dreams" school - based on "gut instinct" and blind faith that "if you build it, they will come". That just isn't good enough for the mobility challenged.

--
Bill

 

The Turbo version is but one of many possible versions of this concept yet you indict the whole concept because you can't figure out how it could work.
I think you are dead wrong and that you really haven't looked at this thing closely enough to make the judgement you make. Whether or not the turbo version is suitable for disabled sailors is something that will have to be proved on the water with lots of testing by ablebodied sailors-I think it will be with the ballast keel so that it is self righting.
The Turbo- version with or without the keel- is suitable for a broad range of people that would want a completely unique and exciting sailing experience that is NOT available now.

 

I reject the concept because it is inappropriate and potentially dangerous - not because I fail to understand it. I completely understand your hollow wing concept and how you propose to move it and the internal ballast. By the way, how much do you think a 12' hollow wing capable of supporting 160 pounds at nine feet will weigh? And the systems necessary to make it work? How big is 160 pounds of lead? How big does the hollow core need to be? What kind of positive positioning control do you propose to implement inside the hollow plank to make sure the ballast doesn't move at the wrong time? How can you meet that criteria and also make sure it does move when it is supposed to? This weight could be sitting up at a 45 degree angle in a gust, how does it lock in place?

Your lack of understanding of basic engineering concepts is highlighted by your idea that testing by able bodied people can be used as validation that mobility challenged folks would be safe. Never have I heard a more completely wrong concept.

How about Product Development 101: Talk to disabled sailors and ask THEM what they want, and what risks they are willing to take. As them how fast they want to go, and what complexity they can cope with. Your thoughts are worthless. Their thoughts on the subject are gold. Maybe they are happy with their current options.

The only thing that matters is the real world. Build the damned thing and prove your case. Arguing the concept ad nauseum here waiting for someone to tell it is a great idea is a waste of time. You've already had feedback from one of North America's most successful dinghy builders gently tell you the concept needs a major re-think, rejecting the "trapwing" concept.

You prolong these ideas forever in your threads and fail to execute, making the whole endless exercise a waste of everyone's time. The other problem I have with these endless threads is that (giving you more credit than you've earned) you already have your 20' foiler to build and make functional, so this discussion is already taking place one to two years before it should. Finish your current build and prove to everybody you can make it from drafting table successfully to the water.

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Bill