Design Challenge: Trapwing-"on-deck" ballast-12'-22'

Well, time to abandon another interesting thread, I guess. I stop subscribing to threads that I find offensive or seem to have run out of direction.

This time, though, I am leaving due to the frustration resulting from all the BS which is swamping the data. This happens on Doug's threads more than most, and it's not always Doug's fault IMHO. I certainly do not blame him for responding angrily to the abuse that always seems to take over his threads.

I have to wonder why those of you who find his ideas or whatever so repugnant bother to peruse one of his threads in the first place. Yes, I know the argument that others must be protected from his baleful influence, but those of us who were interested in the topic did not request or require folk to leap in to protect our sensitive souls from exposure to Doug’s ideas.

We consider ourselves to be adult and able to take care of ourselves, thank you very much. An adult is able to sort out the chaff from the wheat, even if it takes some of us a little longer than others. Similarly, an adult should be able to respond with constructive criticism and quit the thread if that criticism fails to achieve its end. Exercise self-control: you don't have to keep pecking at the white hen.

Doug: you must realise they'll never leave you alone until you build something, probably not even then. Responding to insults in kind merely gives them something else to answer, that is human nature. Since the concept is too advanced for me to be able to make constructive suggestions, I can only wish you well. You owe us a description of how it turns out, or an explanation if you decide not to pursue the idea; that is the other side of the “fairness coin” after all.

Just to cut off childish attempts to twist my words, I will spell it out: I am not quitting the thread because of Doug.

 

Trapwing Prototype

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Thanks, Terry-your participation here is valued and welcome always. Remember the old saying: "Don't let the ******** get you down!" I sure don't.
You might quit for a while ,Terry but there is likely to be some exciting news before long-or not. Either way you'll be interested in the story-I guarantee it!
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Terry, this is a little thing I wrote about ridicule:

"Nobody should be afraid of ridicule and let that stop them from trying any experiment or experiments. For the most part ridicule emanates from those who don't understand what you are trying to achieve or the degree to which something that appears not to have worked did work. There is an element of criticism that is well founded ,well reasoned and very constructive; there is another element of criticism-ridicule- that emanates from uninformed small minded people whose opinion is not worth the cyber space it
uses. No one should be afraid of a cyber MOB and hold back on ideas they think are worthwhile-that goes for discussing them and doing them and showing others what you've done. One bit of constructive criticism is worth a hundred bits of trash from useless snipers on the sidelines.I made many mistakes on my first full size foiler design/construction but I also did a lot right including the weight, learning about manual foil altitude control systems(on foils), a square topped jib, the Swift solo(Bram Daly)sheeting system and many other things. I'm glad I did it and a damn proud I had the guts to try. The next one will be much,much better."

 

Doug, I've definitely "looked at the boats", including years of sailing at two clubs that raced or shared courses with Skates and owning an IC. To my eye, the Trapwing as modelled appears to have much less clearance than the Skate - compared the attached pic (or the one you posted) and the clearance in the . Would it not be a good idea for someone who has asked for constructive criticism to scale some dimensions off the Skate and IC to ensure that the new design is in the same ballpark, rather than just going by eye, especially when the eyeball estimate of one person differs from the eyeball estimate of one of those who has been asked for feedback?

I note that the extension of the Unit's plank was much shorter than the Skate/IC plank or the Trapwing wing. Experience in ICs etc demonstrates that the distance of the plank/wing/rack extension is a vital factor when working out clearance, because of course the vertical movement of the end of the wing when the boat heels is proportional to the extension of the wing. The great beam of the Trapwing would therefore require a great deal of clearance off the water. I assume that the Trapwing may have to sail quite flat to avoid the lee float dragging in the water, whereas an IC can be sailed quite heeled at times to give greater wing clearance.

You say that the self-righting capacity of the boat "is augmented by the sealed wing which has a great deal of buoyancy." I note that when a Canoe's buoyant sliding seat is jammed under a capsized Canoe, it creates in the region of 40-50 kg of positive buoyancy, which is a great deal for a boat of (IIRC) 85kg. The Canoe also has "ballast" consisting of about 200lb of sailor - and yet I have found that I cannot right a Canoe with the seat jammed under the boat, because the leeway of the boat. Therefore, perhaps more detailed calcs of the effect of the wing are in order? Why not do the calcs as a ballpark figure instead of building the beam and finding it's not big enough?

One wonders whether the 2.5 times the moment of the rig is the correct measure for re-righting, since Canoe cannot be re-righted with more ballast counteracting a smaller rig. Similarly, the 16 can require 7 times the Trapwing's ballast for re-righting yet it has a rig only about 1.25 times the area of the Trapwing. Therefore it appears that the 2.5 figure may be a distinct under-estimate.

Finally, you are of course correct when you point out the difference in dimensions between the Trapwing and the Challenger. One still wonders how one is going to reduce the weight by 140lb while introducing batteries, ballast and a sliding beam, and then bring in a boat lighter than a 49er and not much heavier than an IC. Having seen some of the modern ICs under construction, one wonders how easy it will be to build a bigger boat with its batteries, bigger sliding beam (which is of course subject to bigger loads in proportion to its length), buoyancy floats, ballast track system, foot steering system etc and fit all that into a package just 60lb heavier.

Anyways, having said that I'll drop out of the thread. If I come back, someone please remind me that I said I'd not return.

 

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Thanks for the comments:
1& 2) measurements would be great but the measurement that counts the most, in my opinion, is how high the wing is right at the side of the boat. My opinion is that the Trapwing is about 50% higher. A critical thing to note, though, is that the Trapwing pivots athwartship-making the outboard end adjustable thru a large range.(see pictures below) UPDATE 5/13: CT, the distance from the bottom of the WING(level) to the water on the Trapwing(at the side of the boat) is 1.75'(.53m) which I'd guess is substantially more than the Skate( scaled from picture: 10"-11"/.25-.33m) and over twice that of an IC.
3) This,again, comes back to the pivoting of the wing: at 90 degrees the wing is pivoted max with the lee side wing CB substantially away from the hull toward the masthead. The separation adds to the RM. This will have to be proven in testing.

4) Be careful here: when comparing weights the hull only or hull plus rig weights are compared to see if the boat could be called "light" or "heavy"-ballast is not included. When comparing to the Challenger keel ballast is not included because the boat would not need it at the same SA as the Challenger. When comparing all up weight, say with an IC it must be kept in mind that the Trapwing is a singlehander with a ballast system equivalent to a "normal" doublehander w/trapeze.
There is a difference in the prototype compared to,say, the Trapwing 15 detailed earlier: this boat is being built on an existing hull-the Proto is NOT being designed for a specific SA or ballast or limited to a specific length of WING because we want to test the limits so that the info discovered can be used to refine a production design be it the Trapwing 15, Turbo or another version. The boat is probably big enough to go with 180lb. of wing ballast and 200 sq.ft. of upwind sail with an approx. wing of up to 16-18'. Wing buoyancy at the tip will be variable. The buoyancy pod/endplate at the mast tip will also be variable. Starting SA will be about 100sq.ft.
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Notes on the pictures: the Melges model is an illustration of the athwartship pivot as is the Trapwing picture with the WING deployed to port. That picture shows that, adjusted as it is, the boat could heel to stb substantially w/o contact of the WING and water on the lee side. The adjustable pivot is KEY to this system. I think if you look at the pictures closely you can see that the WING(at the side of the boat) is higher than it is on the Skate:

Click on image wait for new image to open in window then click on that image for biggest picture:

 

I'm not sure but for me (able-bodied) I think I would prefer a continuous rope and tack system for moving the wing from side to side as I think I would be able to move it quicker and be more precise with where I have it but thats just me.

 

Looks like it wants to be a tri to me . If you are going to go for it make the keel max out for the water depth you have and cant it 45 degees. Am working on a 40 foot canting keel boat 1500# disp 2 foot beam on water with racks. maybe 12 knots up wind not planing 1000# ballast

 

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That sounds like an exciting boat, Dan!

 

Contender Racing video

We interupt this program to show a great racing video of the singlehanded trapeze boat:

http://www.youtube.com/watch?v=Pzrb-HYrxPM

 

In the course of this thread and a couple of others various incarnations of this concept were considered. The final "incarnation" came down to the Trapwing 15 for which you can find sketches and numbers earlier in this thread. Due to some fortuitous events I was able to get my original 16' foiler hull back and then made the decision to go with it as the prototype for developing this project. The 15 remains the ideal version of the planing version of this concept(so far) and will likely be built after the Prototype is thoroughly tested and explored. The Prototype hull based on the 16 is a bit narrower than ideal but it is an all carbon hull and ideal for a relatively quick conversion to a sailing prototype. So, that's whats next-sooner or later and here are more details that reflect the modifications to the topsides and bow that change the 16 into the Trapwing Prototype. The prototype is shown with weight and sail area ranges that reflect the potential capability of the modified hull as well as the tests that need to be made. The suitability of the concept to disabled sailing will be determined by sailors involved in disabled sailing. Engineering, as required, will be done by a Naval Architect and Marine Engineer with electronics expertise as required. Performance testing will be exhaustive with help from one of the top marine testing laboratories in the US.
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The following is a detailed look at the characteristics of the new Prototype, as well as the design elements it will encompass and test:
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Trapwing Prototype:
LOA 17' 8"
Beam hull-3.25' overall 12'(subject to testing)
Weight- hull 155lb
ballast-wing 80-180lb(variable and subject to testing)
keel 0-80(subject to testing)
SA-upwind 100-180sq.ft. variable
downwind 200-360sq.ft. (variable and subject to testing)
crew-singlehanded-120lb-220lb (variable and equalized under class rules-
subject to testing)
crew position for racing on the centerline inside boat, fixed
athwhartships, variable fore and aft
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1) Sail area to be between 100 and 180 sq.ft
a-different rigs
b-different amounts of ballast
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2) Ballast wing to be supported by trapeze wires and unique retention system that allows wing and ballast to slide simultaneously, allows athwhartship pivoting and fore and aft movement.
a-version one will use two aluminum tubes with sliding external tray- the tubes and tray move simultaneously:
-attachment system allows wing- with weight centered-to be levered up and then pivoted from a position 90 degrees to the CL to a position parallel to the centerline for transport and stowage.
-weight can be added or removed in small increments.
-fore and aft pivot/sliding tube is mounted to the boat slightly offset from the CL to allow room to retract board/keel.
-aluminum tubes terminate at outboard ends in buoyancy pods-pods will be changeable as determined in testing.
-sliding ballast tray and structural design of wing to be capable of 180lb max ballast @9' from CL; ballast completely adjustable in the range of 80 to 180lb.
b-version two is a slightly curved(athwhartship), molded and sealed(with sealable access to ballast tray) wing with an internal sliding ballast tray. This version will be the final version and incorporates all the features of version one with significantly increased sealed buoyancy.
c-Wing movement by manual or electric means. Minimum electrical movement full out to full out: 4.5 sec. Minimum electrical "stamina" on single battery-12 hours at a rate equivalent to a approximately 60 (full track)tacks per hour. Manual back-up.
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3) Crew Position:
a-version one-racing position-allows crew to sit in an extremely comfortable seat that is fixed athwhartship and slides fore and aft adjustably while sailing.
-extremely wide crew weight range:for racing lower tray attached to seat may contain ballast used to equalize crew weight in the range of 120 to 220 lb.
-seat may be moved manually or electrically.
b-version two-center seat is removed and two fixed carbon seats with backrests are "plugged-in" to each side deck.
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4) Rigs to be tested are main and jib, main alone, with and without an asymetrical spinnaker.
a-asymetrical will be tested as permanently mounted off a bowsprit(a la Weta tri) or retracted into a trough with roller(a la Viper) and a retractable pole.
b-mast to be sealed with masthead floatation in an endplate configuration. Some buoyancy possible in head of sail.
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5)-Daggerboard/ keel/rudder
a -boat will be tested with and without a retractable "lifting keel"
which would essentially be a carbon daggerboard with the minimum ballast required(determined in testing) to right the boat from a pitchpole(where the wing buoyancy may not significantly help).
b-self-righting from a knockdown or pitchpole is a required design element for any version of the boat used for disabled sailing.

c-a turbo version of the boat will not use a ballasted keel and may not be suitable for disabled sailing but this will be determined in testing.
d- the daggerboard may include as standard a lifting hydrofoil designed to provide "foil-assist" to reduce wetted surface and in conjunction with the rudder hydrofoil improve the pitch and planing characteristics of the
boat.
e-a fully flying hydrofoil system will be tested as will a fully flying system that allows the boat to fly downwind only(requiring less upwind SA and less ballast).
f-rudder will be retractable with a t-foil.
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6)-On the Beach
a-the boat will be able to be easily beach sailed with a dolly incorporated into the trailer design to make it very simple to go from trailer to water. A "power assist" dolly may be available. Disabled sailors/coach(s) will assist in the design of systems to allow launching and use of the boat with the minimum outside assistance possible.
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7)-Performance
a- the goal is to develop a high performance planing sailboat that can be safely sailed from a center crew position by disabled or able-bodied sailors. I am hoping to be able to achieve an SCP/total weight of 30% or slightly better though that is just a target and a less powerful version with numbers and performance more like a Windmill or Tasar may be perfectly acceptable. The use of foil-assist technology will help to achieve the performance goals. Full flying foiling is possible in a selfrighting boat-particularly one with the righting assist this boat has from version two of THE Wing.
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The concept has extraordinary potential and it will be a blast finding out just what she'll do.

 

If you are using that sort of sailing as an indication of the required movement of your ballast you will run into very big problems, I have never seen conditions that stable before (wind and sea), requiring almost trim changes at all.

 

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Actually, I was "using that sort of sailing" to enjoy a good video.......

 

Trapwing Power Ballast System

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Contender- http://www.youtube.com/watch?v=Pzrb-HYrxPM

By the way: 7 seconds full out to full out in good weather for the movable ballast system on the Contender vs 4.5 sec for Trapwing in any weather*...
*absolute minimum speed for wing +ballast movement. May be a bit faster but it will not, under any circumstances, be slower (within design framework with constant full out to full out tacking every few seconds for 8 hours+)
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Flying Dutchman- http://www.youtube.com/watch?v=dHsa0bUdFOM
6-8 seconds for the trapeze movable ballast system from full out to full out

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505- http://www.youtube.com/watch?v=YqEhYl8X2Pc&feature=related
6-7 seconds for the trapeze movable ballast system from full out to full out

 

Pure speculation, not fact.

Tell us.... Did Rick W. plug-in a reduced performance coefficient for the typical dorky maintenance schedules practiced by most sailors?...and how does that factor into a predictable failure process, since you're already guessing about things?

 

Personally I think you are way under estiamting the speed at which you will have to move your ballast and consequntly the forces and power consuption.

Now you are using full out to full out as your referance, if you look at any of the videos the in and then to new windward side movement is fast, the slow bit is tacking/sheeting the jib. Have a look at some of the R-class video or 12ft etc (with self tacking jibs) the full out to windward weight is much faster than your times above. In fact you can probably find a foiling jibe that is faster than your times above.

http://www.youtube.com/watch?v=nJEd...AC103911&playnext_from=PL&playnext=1&index=12

 

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The crew wasn't full out on any gybe that I saw completed and even so it was about 5-6 secs across.
Might as well stick with tacking-I'm open to any video showing people on a trapeze going full out to full out-find me one under 6 secs-maybe -but I'll bet you won't find any as fast as the designed speed of the Trapwing......