Crossbow fl

Discussion in 'Sailboats' started by Doug Lord, Jun 21, 2012.

  1. Doug Lord
    Joined: May 2009
    Posts: 16,651
    Likes: 322, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    =====
    Thanks, Raps. The amazing thing to me is that there isn't any high performance, rightable, singlehander for disabled or physically restricted people already. I hope that I can complete,test and refine this concept for my sake and the sake of the sailors it could benefit.
     
  2. Doug Lord
    Joined: May 2009
    Posts: 16,651
    Likes: 322, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Summary of features and specs:
    --------------------------
    Features:

    1) Self-bailing cockpit
    2) Boat rightable from 90+ degree knockdown by crew w/o crew movement using the wing regardless of the position of the sliding ballast.
    a. ballast wing is sealed and has buoyancy much greater than that required to float the ballast sliding inside.
    b. ballast+ wing can be moved manually or electrically faster than a crew on a trapeze could move.
    3) Rig utilizes modified rotating, A Class wing mast, sealed with masthead buoyancy to prevent turtling,
    4) Ballast wing pivots:
    a. to allow trailering
    b. to move ballast aft when required with wing extension.
    5) Ballast is adjustable in 10lb increments,
    6) Boat can be sailed off a beach,
    7) Boat features an asymetrical spinnaker, an underdeck spinnaker chute and retractable bow pole,
    8) Skipper sits in a sliding seat that can also tilt 10 degrees each side so the the skipper sits upright at the designed angle of heel.Seat can be fixed in center so it won't tilt while still retaining the capability of sliding fore and aft.
    9) Large, buoyant "spray rails" act to help provide a dry ride and knockdown recovery,
    10) Self-tending jib with variation of Swift solo single sheet system.
    11) Boat uses removable, "plug-in" DSS foils for greatly increased power to carry sail with speed.
    12) Boat can be "turboed" to be capable of upwind planing with addition of a maximum of 62lb ballast and a 150 sq.ft. rig.
    13) Boat has extremely wide crew weight range: approx 100lb to 250lb for normal sailing. All ratios are based on 250lb crew and would drastically improve with lighter crew weight. For class racing, it would be my desire to see a class adopt the maximum crew weight as standard with lighter crew carrying weight under the seat-or perhaps two "weight classes"-whatever it takes to encourage the widest participation.

    -------------

    Specifications: (changes are to be expected)
    LOA-14.6'
    Beam- 4.75'
    ---at waterline-3.75'
    Sail Area-(boat will use a carbon A Class wing mast from Matt McDonald/ Falcon Marine LLC, laid up specifically for this boat).
    --upwind- 120 sq.ft.
    -- downwind- 240 sq.ft.
    Weight-sailing weight w/o crew- 223lb which includes:
    --hull, rig, foils-124lb
    --Trapwing Ballast System:
    --wing-21lb. @ 12' length overall, pivots for transport, and moving weight aft.
    -- max ballast 78lb(8 pieces of lead-removable-.25" X 8" X 12"-about 9.72lb each)
    Max Crew weight: 250lb(crew weight range is exceptionally wide on this type of boat since the crew contributes very little to righting moment)
    All up sailing weight including crew-473lb
    DSS Foils: each 1.63 sq.ft.( 6" X 39") 6.5/1 aspect ratio, Welbourn section.
    -------
    Ratios-
    DLR=67
    SA/D=
    --upwind-31.6/1
    --downwind- 63.3/1
    SCP/Total weight= .2
    Note 1: a ratio of at least .3 is required for upwind planing and could be achieved on this boat by adding 62 lb. to the ballast tray in the wing. Nice "turbo" idea for sometime as long as the buoyancy of the wing is enough for righting.
    Note 2: an interesting side note to the application of Bethwaites ratio to this boat is that it is not clear to me that proper "credit" is given to the lift potential of the DSS foils. For the upwind RM calculation the lift from the foil was calculated based on a speed of slightly over 5 knots. If the upwind speed were, say, 8 knots the ratio would increase to .27+. A speed of 10 knots with the 250lb crew changes the ratio to .295 and with a 180lb crew that ratio changes to .35.
    That adds a very interesting twist to testing in that it appears that reaching off a bit to increase speed may pay much larger than normal benefits on this boat. Speed increases the lift on the DSS foil expoentially and therefore increases RM dramatically. Sounds like fun to me.....
    ===========
    See post #1 for rough working plans (the actual plans won't be complete until the boat is built and tested) and,
    Picture of scale model of an 18 foot singlehander using the same sliding ballast wing.
    See model pictures in posts 2 & 3.
     
  3. sharpii2
    Joined: May 2004
    Posts: 1,912
    Likes: 111, Points: 63, Legacy Rep: 611
    Location: Michigan, USA

    sharpii2 Senior Member

    Good to see you're finally getting to try some of your ideas in full scale.

    I'm just wondering how much of this is going to be automated (driven by some kind of motor) and how much is going to be hand cranked.

    You intend to put a fearsome amount of sail on your creation. 240 sf is a lot of sail area for a 500 lb, 14.5 ft boat, even down wind.

    Just how much control is the presumably handicapped lone sailor going to have on all this canvass?

    And isn't he going to be busy with other stuff? Such as cranking out or in the DSS foil and/or the trapwing?

    I think the best way to make this all work is to not only automate the extension/retraction of both anti heeling devises, but to computerize them as well, so they extend/contract automatically, leaving the skipper to tend the sails and steer the boat.

    The 20 ft single outrigger I have in mind would have all that, except it would need no motors, no cranks, and the sail would go up or come down in individual panels, eliminating the messy job of slab reefing. It would have 200 lbs at the end of its crossbeam (which becomes at least 400 lbs of buoyancy on the other tack). Yeah, it could flip, but the grizzled sailor is presumed to have wisdom and knowledge, based on decades of sailing, that more than makes up for his lack of youthful agility. It is also modestly canvased (120 sf or less), and it's VCA is kept reasonably low, for its righting moment. And, no, it won't plane. But it may very well get into the mid teens in knots, while the skipper just sits there, with all the sail handling lines leading to his cockpit, and smiles. Even if a trapwing/DSS machine blasts past it.

    You have gone out and gotten some very good talent to make your dream real. And I really hope you manage to pull it off.

    I wish you the best of luck.
     
  4. Doug Lord
    Joined: May 2009
    Posts: 16,651
    Likes: 322, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    ---------------
    Thanks, Sharpii. I tried to point out that the DSS foils are plugged into trunks in the side of the boat and retained there before going out. These foils do not retract. If the boat is sailed at a nominal 10 degree angle of heel the windward foil is always clear of the water. Everything in boat design is a compromise and so it is with the plug-in foils. At speeds less than say 2.5 knots the foil is mainly drag-but I don't care about that because if you know its going to stay that light-don't use the foils. I personally won't sail without them but I also won't sail in drifting conditions if I can avoid it.
    On the Trapwing system, keep in mind that as the wing is extended the load is mostly on the trapeze wires supporting the ends of the wing. I think I have a system that will allow moving this weight quickly side to side manually since, with the boat mostly level, there is little to no load. But my preferred system is to use an electrical system controlled by a joystick-exacly the same system I used on numerous test models. Both systems should be very fast with the electrical system guaranteed to be faster than a crew on a trapeze from full out to full out and with enough battery power for an 8-12 hour day of sailing, tacking or gybing max out to max out every 6 seconds!
     
  5. Doug Lord
    Joined: May 2009
    Posts: 16,651
    Likes: 322, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    ===================
    I've thought about this some more-and I thank you for bringing it up. For me part of the fun of sailing this boat will be handling the Trapwing and learning how to keep the boat at a 10 degree angle of heel using the joystick, inclinometer and sheet(s) as necessary. I imagine it will become second nature after a short while.
    But you have a good point : there may be some who are interested in sailing a boat like this who would find the movable ballast too much of a challenge.
    So I think, as time permits, it would be a good idea to develop an "auto wing" that would move the ballast as required to keep the boat at a 10 degree angle of heel from tack to tack,gybe to gybe regardless of how the sails are set with the least crew input possible. I'm 100% sure that some of the guys I used to deal with when designing and flying videopiloted rc heli's could help with this.
    Good idea!
     
  6. Doug Lord
    Joined: May 2009
    Posts: 16,651
    Likes: 322, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Crossbow fl- DSS Foils

    Here is DSS foil #1 laid up and vacuum bagged last night:
     

    Attached Files:

  7. Doug Lord
    Joined: May 2009
    Posts: 16,651
    Likes: 322, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Crossbow fl -DSS foils

    Both foils carbonated -now finish work and clear coating -and shipping!

    click:
     

    Attached Files:

  8. daiquiri
    Joined: May 2004
    Posts: 5,372
    Likes: 246, Points: 73, Legacy Rep: 3380
    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    Should something go wrong, you can always start up a new business - foil, rudder or keel fabrication. Those foils look great. ;)
     
  9. Doug Lord
    Joined: May 2009
    Posts: 16,651
    Likes: 322, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Thanks! The foils are being made by Rick Loheed-he does good work..... The section is from Hugh Welbourn, the planform, area, location on the hull and installation by me( with a lot of consultation).
    Accumulating a lot of boat parts and toys here-hope it will all come together... Slavi, any thoughts on the design/concept of the boat?
     
  10. ancient kayaker
    Joined: Aug 2006
    Posts: 3,497
    Likes: 146, Points: 0, Legacy Rep: 2291
    Location: Alliston, Ontario, Canada

    ancient kayaker aka Terry Haines

    Looking good Doug; hope everything turns out well. You have quite a dream team in post #1 . . .
     
  11. Doug Lord
    Joined: May 2009
    Posts: 16,651
    Likes: 322, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Crossbowfl

    =====
    Thanks, Terry! Good people that have helped me a lot thru a difficult time.
    Terry, what do you think of the boat?
     
  12. ancient kayaker
    Joined: Aug 2006
    Posts: 3,497
    Likes: 146, Points: 0, Legacy Rep: 2291
    Location: Alliston, Ontario, Canada

    ancient kayaker aka Terry Haines

    Extreme - just what I would have expected from you! There'll be a multiple learning curve on this one, I'm thinking: construction, sail rig tuning, handling, keeping the crowds away . . .

    Please keep us updated on the construction technique, as you probably know I am particularly interested in that aspect of boatbuilding . . .
     
  13. Doug Lord
    Joined: May 2009
    Posts: 16,651
    Likes: 322, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Thanks, Terry. Here are some pictures of the model just prior to final sanding. I screwed the deck up by getting some Duratec on the thing that held the boat so I created more sanding and probably more filling on the deck. Nothing more sure to mess up a job than getting in too much of a hurry!
    That's the carbon wing mast next to the boat...
    click:
     

    Attached Files:

  14. Doug Lord
    Joined: May 2009
    Posts: 16,651
    Likes: 322, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    The boat has sanded thru my fingers and is down to 320. Now I'll add the trunks/ mounts for the two DSS foils, daggerboard and rudder. I'll also add the spinnaker pole launch tube, the fascimille "trough"(no actual hole in the model-at this point, a mount and retainer for the deck, chainplates for the shroud bridle, and a mast tang and forestay attachment.
    The wing is shown mocked up and will change quite a bit as it is finished. It will allow the crew to right the boat no matter where the ballast is. As well as make it extremely difficult to capsize in the first place along with the sealed wingmast and masthead flotation.

    click:
     

    Attached Files:


  15. Silver Raven
    Joined: Oct 2011
    Posts: 437
    Likes: 11, Points: 0, Legacy Rep: 67
    Location: Far North Queensland, Australia

    Silver Raven Senior Member

    Gooday - Geezzzze my friend - I AM VERY BLINKEN IMPRESSED. W O W

    Keep it up guy - 'all's-good' as we say in OZ.
    Gotta keep those pic comming though. They are like 'life-blood' to lots of us.

    Ciao & thanks, james
     
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.