Foiling Keelboat: 30'

Discussion in 'Sailboats' started by Doug Lord, Jun 8, 2011.

  1. Doug Lord
    Joined: May 2009
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    Doug Lord Flight Ready

    Recently I was contacted to help take a look at the potential of this fairly basic statement of requirements. The project is being supervised by a well known naval architecture and marine engineering company. The names are omitted for the time being to protect the guilty. This has been both fun and enlightening and I have permission to post this material.
    The SOR:

    Basically what we would like to do is make a 30ft keel boat on foils.

    The hull is 30ft long and 5ft 8 wide and weighs 260kg with reverse bow. Carbon kevlar construction over new type of honeycomb core suitable for high speed impact. We are also planning to use a new carbon infused resin.
    The keel strut will be 10ft long with 200kg on the end and able to cant to 85Deg.

    Ideally we would like to be taking off at say 6-7kts of boatspeed with the boat fully loaded at say 1000 kgs



    It is manufactured using Eglass and foam core. We will be using carbon/kevlar over a nomex core. It also has a fixed keel where we will be using a canting keel with just 200kgs off ballast not the 700kgs below.[/COLOR][/I]

    Specifications of the "base" boat from which the new boat will be developed
    if possible.

    LOA -29' 11" 900 cm

    LWL 27' 11" 851 cm

    Beam 5' 8" 173 cm

    Draft (keel down) 7' 2" 220 cm

    Draft (keel up) 2' 4" 71 cm

    Displacement 2,425 lbs 1,100 kg

    Ballast 1,543 lbs 700 kg

    Sail Area, upwind 430 sf
    40 sm

    Spinnaker Area 612 sf 53 sm

    SA/DSPL 30.63

    ====================================

    Version One--canting keel plus sliding on-deck waterballast*:

    Modifications in red--

    1) Beam 16'--5.17' racks on each side and designed to ensure that the boat is regarded as a monohull and can meet other rule parameters.
    --
    2) Displacement:

    --a. hull + rig= 882lb

    --b. canting keel(110 degree) 440lb. 10' canting keel strut.

    --c. max. sliding on-deck water ballast(not used at earliest takeoff) 809lb

    --d. takeoff displacement(min) 1847lb( 3-crew-no waterballast-min.)

    --e. crew-3@ 175lb 525lb

    --f. Max displ. 2656 lb.( 3 crew + waterballast)

    3) SA 680 sq.ft( @ 21' with designed max pressure at approx. 15-30 degrees veal heel= 1.8lb. sq.ft.)

    4) SA/D ((w/o water ballast) 72 (Moth 78, 60' Moth 66 )

    5) Mainfoil area(supports 80% of total weight)- 8.11 sq. ft

    --a. 83.8 sq.ft. SA per sq. ft main foil (Moth 78.2, 60' Moth 83, Mirabaud 91)

    6) HM(est Heeling Moment) :

    --a. SA= 680 sq.ft at 21'
    --b. est. design wind pressure before depowering: 1.8lb. per sq.ft.
    --c. TOTAL HM--[680 X 1.8] X 21 = 25704 ft. lbs.

    7) RM (est Righting Moment) Note: Veal Heel moves hull CG(and everything else) to weather about 4'

    --a. hull-882 X 4= 3528 ft. lb.

    --b. canting keel-(10+ 4) X 440= 6160 ft. lb.

    --c. 3 crew-( 8+4) X 525 = 6300 ft.lb.

    --d. waterballast (8+4) X 809 = 9708 ft. lb.

    --e. TOTAL RM= 25696ft.lb(essentially equal to HM) NOTE: 41.3% of RM is due to Veal Heel.

    8) Takeoff at 8 knots boat speed, approx 6-7 knots wind speed. Uses bi-foiler configuration-one foil on daggerboard, one foil on rudder. Uses mechanical(wand), electronic and/or manual altitude control. Much discussion of foil configuration since the owner had his own ideas about foils. Wanted to use double mainfoils with adjustable dihedral tips. Essentially, a semi-surface-piercing ladder configuration that would ,he hoped, enhance RM. Discarded after illustration of the extra drag such a system would engender(and the poor performance of such systems in the past) and after showing the impractical nature(both hydrodynamicly and engineering wise) of using adjustable tips for righting moment.

    * A system similar to the one on Hydroptere will also be looked at. That system requires no pumps and water comes in thru an intake on the rudder. The biggest question with this kind of system is how fast can the ballast be moved(in or out) and how does that compare with a sliding tank.
    =================
    Version 2 and much more to come......
     
    Last edited: Jun 15, 2011
  2. Stumble
    Joined: Oct 2008
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    Stumble Senior Member

    Doug,

    It sounds like an interesting project. Strangely reminiscent of a boat here in New Orleans named Danger Zone. All up weight is 1800lbs with 900 in the keel. It is a radically fast boat (rates -27 in GYA PHRF) at 30 foot. But of course without foils.

    If you need any crew for test rides I might be willing to take a trip to Coco....
     
  3. Doug Lord
    Joined: May 2009
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    Doug Lord Flight Ready

    ------------------------
    Thanks! I only wish it was going to be here-unfortunately, a long way away.
    I hope the guy follows thru with it-it will be spectacular! Every indication is that he will......
    You know when I was a kid I raced several times in Naleans at the Southern Yacht Club. Are Click Schreck and Buddy Fredricks still around--and John Dane? Clicks brother Paul was my mentor for racing-good times back then.
    Any pictures of the boat you mention above? Do they do anything special for righting moment-canting keel, racks etc?
     
  4. Cheesy
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    Cheesy Senior Member

    Is that Admiralty yachts in Singapore? Your post is a bit confusing, but I assume you are saying that they are basing a foiler off the production production boat which is glass-foam and the foiler will be carbon-nomex
     
  5. Doug Lord
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    Doug Lord Flight Ready

    ==============
    I'm not sure-as I understand it these dimensions were something the owner was familiar with and wanted them to serve as a general basis for the new boat. Whether that is possible or not is still being determined and if the design requires starting from scratch then so be it.
    What made you think it was Admiralty? I don't know the company at all....
    PS- the original rendering he sent was of a 2007 Doug Schickler design.
     
  6. Cheesy
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    Cheesy Senior Member

    This bit was the unclear comment
    "It is manufactured using Eglass and foam core. We will be using carbon/kevlar over a nomex core"
     
  7. Doug Lord
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    Doug Lord Flight Ready

    =================
    This is the rendering that was sent. You have to understand this is wide open
    no hull has been 100% decided upon by the design team.
    A hull that is not designed as a foiler from scratch may have issues that are unacceptable-so we'll see.

    click on image:

    Schickler(SYDE) copyright 2007
     

    Attached Files:

  8. Cheesy
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    Cheesy Senior Member

    All well and good but why are you talking about a glass-foam build and a carbon-nomex build unless you are comparing it to something.....
    Also why would a 30fter have twin wheels with such a narrow beam, maybe I should post a picture of a boat that looks almost exactly like the specs you have up there
     
  9. CT 249
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    CT 249 Senior Member

    That rendering is labelled as an AC90 on Doug Schickler's site, so no wonder it has room for twin wheels and twin grinders.....they're sorta rare on 30 footers.

    http://styacht.com/category/racing/

    Scroll down and you'll see the pic and copy, reproduced below


    AMERICA'S CUP 90

    The overall length and draft have been chosen; evidence that the concept that the next AC90 rule will be a box rule. The intent is to speed the boats up considerably, therefore an improved DLR has been targeted. The hull form itself has been totally parametrically generated and improved through several iterations toward a balance between easily driven planing off the wind and ultra-high pointing. The bow profile is the result of pushing to the maximum dimension of box rule length, while eliminating all extraneous material.



    The minimum drag appendage package has been established based on the idea that the race course and boats will be altered to make downwind performance of far greater importance. The possibility of two rudders has been accounted for in the preliminary design. With extensive experience designing state-of-the-art lifting keel systems, Schickler Tagliapietra are poised to apply highly evolved engineering concepts and techniques to the highest level of inshore racing in the yachting world.
     
  10. Doug Lord
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    Doug Lord Flight Ready

    Interesting-I never checked Shicklers site. The guy liked the shape I guess-easily achievable in 30'. Details like the twin wheels were not part of his SOR to me-just that it foiled. The idea was to come as close to the supplied dimensions as possible with the foiling consideration above all else.
    Heres a 27 footer designed as a training boat for the AC:
     

    Attached Files:

  11. Doug Lord
    Joined: May 2009
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    Doug Lord Flight Ready

    ===========================
    I wasn't comparing it to anything-the owner sent the dimensions and his thoughts on construction as a basic frame of reference-it doesn't matter to me what they're for--- I and the rest of those involved have a blank sheet of paper......a 30' foiling keelboat.

    UPDATE: The design specs-frame of reference numbers are from the "Admiralty 30" http://jsyachtsusa.com/designspecs.asp (which I think used to be called the JS9000). The Admiralty company is not involved with this project.
     
  12. Gary Baigent
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    Gary Baigent Senior Member

    Interesting; I started to reply about the canting keel/foiler/oxymoron and suggested they get rid of the bulb, make it a hollow, fattened T foil instead and pump water in or out - and turn the deign into a sort of enlarged Moth... but then decided that was too way out crazy and deleted it.
     
  13. Doug Lord
    Joined: May 2009
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    Location: Melbourne, Florida

    Doug Lord Flight Ready

    ======
    Hah! Those conservative impulses spring to life when you say the words: "keelboat foiler"......At least you were on the right track before you "wisened" up....
     
  14. Doug Lord
    Joined: May 2009
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    Location: Melbourne, Florida

    Doug Lord Flight Ready

    Foiling Keelboat: 30' / self-righting

    Version 2- This version is still being looked at. It may offer significant advantages because it eliminates the canting keel 100%. It incorporates ballast at the juncture of the daggerboard and main foil whose primary purpose is to assist in righting the boat-it provides NONE of the RM while the boat is on foils. Foiling RM is provided 100% by the crew and sliding on-deck(or Hydroptere-style) waterballast. The beam will be increased a bit-just the "racks".

    Advantages:
    --a. no canting keel
    --b. if the Hydroptere system can be made to work then no system of pumping or sliding ballast will be required,
    --c. self-righting w/o crew intervention(target)
    --d. Same light air takeoff capability
    ======
    Disadvantages:
    --a. heavier all up weight at max ballast,
    --b. possibly slower at max ballast-but not by much.

    More detail to follow....

    Pictures,L to R: 1 & 2 Mirabaud* bulb-the bulb system here will be similar only larger. Bulb system is used on Mirabaud to facillitate quick changes of foils-not for
    ballast, 3 & 4 KFoil designed and patented by me for use on a canting keel instead of a separate forward foil. May have some applications in the new foil assist or full flying keelboat foilers:

    * 27'(hull) foiler with three crew on racks + trapezes

    -click on image-
     

    Attached Files:


  15. CutOnce

    CutOnce Previous Member

    Question of terminology.

    At what point does this project stop being labeled as a foiling keelboat? With the Version 2 being outlined, ballast (if any) is being used for righting purposes only when capsized. At some point it becomes a very large dinghy-ish boat.

    Perhaps this type of boat should get a new label the can encompass open-style speed oriented performance boats that may combine attributes of dinghies (capsize and unaided recovery are expected, normal events) and keelboats (long waterlines, righting moment augmentation via water ballast etc.).

    With the appearance of Mr. Oatley's Q and other boats that do not fit established definitions, perhaps the definitions need to change.

    --
    CutOnce
     
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