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

Discussion in 'Sailboats' started by Doug Lord, Oct 7, 2009.

  1. Doug Lord
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    Doug Lord Flight Ready

    This concept is much broader than the Prototype-which will be built to test the system.
    See post # 6, page 1 with the story of Charles Herreshoff and Sons successful race boats using sliding on-deck ballast.

    See post# 11,page one for Julian Bethwaites comment on the Trapwing System as well as his experience with Paul Cayard and Russell Coutts who requested that such a design concept be explored.

    See this thread, post #1 for a detailed exploration of how a 60' monohull bi-foiler can use this system to be as fast or faster than an ORMA tri using foil assist.

    The concept can be used on very small "beach boats" to provide kids and others a whole new way to sail fast simply and inexpensively.( Shifter X)

    The concept can be incorporated into sportboat design allowing more RM with less crew-even working in conjunction with Hugh Wellbourns DSS for a very powered up self-righting boat.

    Whether its shifting water or lead the system has the potential to offer exciting high speed sailing in a way not seen currently on any full size boats anywhere.

    Advantages and Features in small boats:
    1) tremendous increase in RM while retaining a self-righting characteristic, if desired.
    2) Probable significant reduction in aerodynamic drag compared to two-handed boats with a single trapeze.
    3) Exciting sailing with a drastic reduction in workload.
    4) Very low drag, very high power Turbo versions possible.
    5) Power to weight ratio will allow full-flying bi-foiler versions.
    6) Foil assist standard on every version. Other dinghies using foil assist like the I-14 and National 12 using a single rudder foil whereas the Trapwing system will use two foils tested and proven to increase speed and enhance pitch control.
    7) Most versions will have two seating options: "sit-in" inside single seat or plug-in rail seats. Seating arrangement can be changed at will.
    8) Wing Tip Rig(tm) with upper buoyancy and Square topped main AND jib will be standard pending extensive testing and development. Una rigs with upper buoyancy, peaked up squareheads AND adjustable upper outhauls to be tested extensively. Rig variations already prototyped in models and fullsize over 30+ years.
    Details of the Trapwing Prototype currently under development in post 205 of this thread.....
    To enhance this summary and overview, I've included this study of the tacking speed of various well known dinghies with the Design Speed for the Trapwing system:

    Tacking Speed Summary:


    7 seconds full out to full out in good weather for the trapeze movable ballast system on the Contender
    Flying Dutchman-
    6-8 seconds for the trapeze movable ballast system from full out to full out*

    6-7 seconds for the trapeze movable ballast system from full out to full out

    12' skiff- (toward end of video)
    7-8 seconds for the trapeze movable ballast from full out to full out

    International Sailing Canoe-
    5 sec 50% out to 50% out;estimate 7 seconds full out to full out (very hard to find IC videos that show a boat tacking!)

    * full out to full out= max outboard movable ballast CG on one tack to the same position on the other tack.

    Trapwing Design Speed-4.5 sec for Trapwing in any weather full out to full out**...
    **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 minutes for 8 hours+)

    Attached Files:

  2. Chris Ostlind

    Chris Ostlind Previous Member

    What do you want to bet that there are, literally, thousands of readers of this forum out there who have bosses who do the same thing that you do to make themselves look important?

    That being the endless stream of redundant, self-important posturing through the email, office paper distribution and droning oral comments in the staff room sessions. The points do not get better with more redundant expressions, Doug. They just get more redundant.

    What do you say you answer the points I made from your previous form letter and show the gang that you are responsive to strongly presented arguments in opposition?
  3. Paul B

    Paul B Previous Member

    If this stuff has been prototyped for 30+ years already why isn't it perfected?

    It seems to be easier to write nonsense for years than actually do even one technical drawing to work out the details.
  4. Doug Lord
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    Doug Lord Flight Ready

    Trapwing Prototype-development 6/14 /10

    Next step will be to build the prototype using the 16' aeroSKIFF hull. The length will be extended, the bow modified and the topsides extended. Target weight for these mods is 38lb. Details of the prototype have been described earlier.
    --In the meantime I'll try to answer any questions not already answered and, if I get the chance, discuss some of the larger variations of the Trapwing concept.

    Click on image then click again for larger size,depending on photo:

    Attached Files:

  5. Paul B

    Paul B Previous Member

    What is the schedule for this "next step"?

    As I mentioned earlier in this thread, a model can be useful if it is used to work out mechanics or other details. The model you built did not, so the "next step" should have started already instead of the time wasted on the model.
  6. Doug Lord
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    Doug Lord Flight Ready

    This post and post 226 above give a detailed technical look at the Prototype(which will be built as soon as possible) and elements of the proposed technology. The Prototype will serve as a test bed for the Trapwing sliding on-deck ballast system and several variations possible within the system.

    A Summary for those who don't want to read the whole thread:

    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- 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.
    The following is a detailed look at the characteristics of the new Prototype, as well as the design elements it will encompass and test:
    Trapwing Prototype:
    LOA 17' 8"
    Beam hull-3.25' overall 12'(subject to testing)
    Weight- hull 138+38=176(corrected from original post mistake)
    ballast-wing 80-180lb(variable and subject to testing)
    keel 0-80(subject to testing)
    SA-upwind 100-182 sq.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
    1) Sail area to be between 100 and 182 sq.ft
    a-different rigs
    b-different amounts of ballast
    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.
    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.
    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.
    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
    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.
    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.
    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.
    The concept has extraordinary potential and it will be a blast finding out just what she'll do.


    DESIGN RATIOS(Trapwing prototype in its most powerful initial configuration)
    LOA 17.7
    LWL 17.7
    Sailing weight 653lb w/keel, 573 w/o keel
    Displ./ Length Ratio: 52.7
    Sail Area to Displ. Ratio: 38.66
    Sail Area/Wetted Surface: 4.23/1 w/o foil assist
    5.87/1 with foil assist
    S number: 9.61

    Thanks to Eric Sponberg for introducing me to the "S number" and for publishing an excellent series on all these ratios.(see pdf below)

    Attached Files:

    Last edited: Jun 23, 2010
  7. Gary Baigent
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    Gary Baigent Senior Member

    Enough endless talk and repetition and general "will-be possible" BS Doug .... start building the bloody thing.
  8. Doug Lord
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    Doug Lord Flight Ready

    Thanks ,Gary!
  9. Paul B

    Paul B Previous Member

    Well, one early IOR boat was built in 21 days in order to make it to the SORC on time, where it won overall...

    So, ASAP means your wing-ding-thing should be sailing easily by end of July.

    By the way, in my business life I never accept ASAP as an answer as to when a task will be completed. ASAP means nothing when you are working a schedule.
  10. Doug Lord
    Joined: May 2009
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    Doug Lord Flight Ready

    Trapwing Proto from aeroSKIFF 16

    Since the Proto will be built using the original aeroSKIFF 16 foiler hull, here are the original specs for the 16:

    aeroSKIFF™ Specifications

    1) LOA: 16 feet (4.87 meters)

    2) Beam: Overall: 8 feet (2.44 meters); Hull: 3 feet (.91 meter)

    3) Displacement:
    --Hull weight: 150 lb (68 kg)-includes racks, seats and traveler(138lb those items removed)
    --ready to sail:190 lb (86 kg) ;
    --crew:2 -320 lb (145 kg.);
    --minimum crew weight: 250 lb (113.6 kg).(requires trapeze over 15k wind)
    --all up sailing weight with two crew: 510 lb (231.8 kg.)
    --all up sailing weight with minimum crew:440 lb. (200 kg.)

    4) Sail Area: upwind:182 sq. ft. (16.9sq. meters); downwind: 332 sq. ft. (30.8sq.meters) including 150 sq. ft. (13.9 sq. meter) spinnaker.

    5) W/SA*
    -- with two crew,upwind: 2.8 (same as Moth with Gulari sailing)
    -- with minimum crew weight: 2.42 (better than Moth with Veal sailing)
    * W/SA=weight in pounds divided by SA in sq.ft.(metric doesn't work). Over the years the range of effective foiling has been shown to be under 3.1. The range of 2.4-2.5 is the Moth range for best light air takeoff and performance. 2.8 in the Moth class has shown excellent moderate to heavy air performance. W/SA has been shown to be an excellent first comparison for foilers from 11' to 26'.

    6) Foils: two: one on daggerboard; one on rudder-foils specifically engineered
    for safe jumping. Designed by DL, engineered thru Fastacraft, built by John Ilett.

    7) Draft: foils down: position one: 2 feet (.6 meter); position two: 3 feet (.91 meter). Foils are retractable.

    More on the aeroSKIFF 16-many of these same features will be tested on the Trapwing prototype:

    This boat was designed by me at about the time the first Moth foiled(1999). It was built( mostly by me) over a three year period at a cost of around $17,000.And it was a blast to pull it all together. Among the things tried on this thing for the first time(as far as I know-at least in the US) were:
    1) square top jib.
    2) reefable camber induced main.
    3) manual control of the main foil.
    4) angled up foil tips(lots of dihedral)-as a hunch to allow crash free jumping.
    5) angled up extension tiller ends to allow physical leverage for manual hydrofoil control.
    6) virtually no hull-just a scaled up windsurfer. I had two designs-one with a high beam to length ratio hull and buoyancy pods,one like this. My thinking at the time was to try to find a solution to the rollovers and difficulty common to the Moth at that time in initial startup. I chose the wrong design-this hull was a ***** in the short chop of the intercoastal and actually delayed takeoff in marginal conditions. Big mistake because ,for me, light air take off is the whole ball game.
    7) retractable foils controlled from the cockpit.
    8) partial span mainfoil and rudder foil flaps( foils built to my design by John Ilett. Johns company engineered the foil laminate to be strong enough to jump the boat).
    9) tapered mainfoil planform.
    10) fully adjustable angle of incidence of both foils while sailing(main foil system disabled initially). I was in a hurry so sailed without this IMPORTANT system-and I would not have tried to foil if I had realized how much easier it was with this system active.
    11) trailerable with foils retracted.
    12) all carbon/foam
    The boat foiled rather poorly because of the hull design(no light air takeoff) in intracoastal chop. One problem in addition to the hull was the fact that the forward cross beam was two low: if the boat rolled any waves would impact it slowing it down a bit. The biggest problem with foiling was that the mainfoil manual control system( no wand) had slack in it making it very difficult to control. But it did foil and no there are no pictures foiling-I was on my own. I consider the boat a success for many reasons including the fact that even though it was difficult to control it did foil and never once crashed. It taught me that there was a huge potential in further developing manual altitude control and adding a new feature to the new boat(under development now): simultaneous control of main and rudder foil. The extension tiller with the turned up ends worked real well, the reefable main worked ok and the square top jib has great potential. The retractable foil system worked perfectly.
    The first aeroSKIFF was a great learning experience and as far as I know the first monofoiler scratch built and designed in the US. It will not be the last....

    Attached Files:

    Last edited: Jun 23, 2010
  11. Chris Ostlind

    Chris Ostlind Previous Member

    Douglas.... PLEASE!

    Could you please stop posting the same stuff over and over and over again, along with the same photos we have all seen now, some hundreds of times?
  12. Doug Lord
    Joined: May 2009
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    Doug Lord Flight Ready

    Jeez, Ostlind-there is no repetition whatsoever in the last post-all new stuff! Except the pictures which serve to contrast the before and after. That technical stuff all looks the same,huh? Maybe if you read it.....
  13. Paul B

    Paul B Previous Member

    As I mentioned earlier, I believe this "build" came to an end with the fixing of the brass plate.

    If you are crazy enough to actually read some of this stuff you'll see it isn't even realistic. For example, if the red paddleboard currently weighs 150 pounds, and the mods are estimated at 38 pounds, how can the finished hull be estimated at 155 pounds?

    Why is there now a claim that there are no photos of the "foiler" foiling, when there were claims in the past that photos do exist? Not very good photos, but good enough to show the foiling. What happened to those photos, and why were they never posted as promised?

    Why are there multiple posts about the boat not foiling, no posts about the boat foiling when it was supposed to have foiled, but claims at a later date that it did foil?

    Why is it impossible for the foiling guru to give any information about the foiling?

    Why is it impossible for the builder to give a timeline for the launch of the wing-ding-thing?

    I think we all know why. Perhaps he doesn't have a garden like you do.

    Attached Files:

  14. Munter
    Joined: Jul 2007
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    Munter Amateur

    Doug - now that you've got access to the old hull you could put all the "your boat never foiled" sceptics in their place by simply reassembling the aerofoiler, going sailing and taking a few photos. Wouldn't that shut them up!

  15. Paul B

    Paul B Previous Member

    I suggested that weeks ago. I suspect that is not going to happen, for obvious reasons.
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