Doug Lord

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About Doug Lord

  • Rank
    Super Anarchist
  • Birthday 06/17/1949

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  • Location
    Cocoa Beach, FL
  • Interests
    Foiler design and development,.........sailing fast,
    movable ballast systems and..... justice.

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  1. Tell me, gbs: what version do you use when you talk to people about the foil: up-tip, UptiP or uptip?! One things for sure : you don't use any version when you write about it........
  2. Facts on Monitor-Hanno Smits-about 1995: Monitor videos:
  3. Doug Lord


    What you ,apparently don't get, is that foil design depends to a large extent on the operational RE for the foils and on the way they are intended to be used. So foils for the Moth and for the Fire Arrow Model are bound to be different. Further, the Fire Arrow foils are designed for very low speed takeoff as a priority not top end speed and are very experimental. For instance, the iFLAP allows the UptiP ama foil to work almost like a wand controlled foil(with no moving parts) with high lift at low speed and low drag at high speed. The small endplates being tried on the partial span flap of the Fire Arrow main foil are experimental and based on an endplate installation on an airplane. They may not work beneficially at all because the characteristic of a partial span flap is that the change in lift can extend past the end of the flap and the endplate may prohibit that causing more drag ,not less. Then again because this partial span flap is longer than the adjacent foil chord that may not happen. Experimental!
  4. Doug Lord


    As I said the SLR is "somewhat relevant" when designing for low takeoff speed but the relevance depends on the L/B ratio of the hull or hulls contacting the water before takeoff and the size of the boat. Moths are 10-11/1 L/B ratio, many other multihulls are 15-20/1. The L/B ratio of the main hull of Fire Arrow is 6.6/1. The test model and full size version(19.5') are designed to take off in a 5 mph(model) or 5 knot(full size) breeze. Boat speed at take off for the model is about 4-5 mph-the SLR for the model is 3.5mph using Velinga's formula. The SLR for the fullsize version is 6.62mph which is about what her projected takeoff speed would be in a 5 knot wind(5.75mph). The SLR for the 15.5' WOLF is 5.59mph with an L/B ratio of 6.65/1 which corresponds to her estimated takeoff speed in a 5 knot wind. The SLR is never more than somewhat relevant, even less so on models but an interesting reference for fullsize hulls with less than an about 8/1 L/B ratio for earliest takeoff target. The relatively wide planing hull on Fire Arrow/WOLF keeps the main hull rocker small for clearance when flying and provides reserve buoyancy forward and planing area forward for incidental contact with the water at speed. Note difference in rocker between Rave and Fire Arrow: Rave pix from Hydrosail website/Dr.Bradfield-- Fire Arrow pix DL and Dan Burke---
  5. Note that Monitor was able to tack and gybe on foils..........
  6. Doug Lord


    What an uninformed idiot you are............
  7. Wrong to the point of being utter nonsense! UptiP foils have been used for ama foils on two of the state of the art maxi trimarans designed from scratch to use a version of the foil configuration pioneered on the Fire Arrow test model. You can't get more high performance than Gitana and Banque Populaire! They use UptiP foils because they can be designed to have automatic altitude control. Guillaume Verdier specifically referenced the TNZ foils from 34 in explaining his choice of ama foil. A llittle over half way through he mentions TNZ's discovery of an auto stable foil--click on the sound icon: Gitana UptiP ama foil pictures by Fred Monsennec--
  8. Doug Lord


    SLR is somewhat relevant when you are designing for a specific takeoff speed-particularly low speed ,light air takeoff. Show me a picture of a later development by the Decavitator team instead of just running your poorly informed mouth!!!!!
  9. Thats just not true-its used by the inventors of the foil. And by anybody that has the common decency to give them credit for the invention of the foil and the name they chose! Part 1, paragraph 4
  10. Doug Lord

    Whisper Foiling Catamaran Sailors

    Great, Martin-thanks! Did you go after the Weta?
  11. Doug Lord

    Sailors Powerboat

    My Dads motorsailer.He started out with a Larchmont "O" boat and then decided to take the family on a cruise. So he found a good deal on this Hand designed motorsailer and had it completely refurbished at Higgins in New Orleans and we took off for Miami, the Isle of Pines, Havana, Nova Scotia and ,finally Brazil......
  12. Doug Lord


    why I waste my time with a complete ass like you beats the hell out of me... I don't -generally- use Froude #'s in design work. I use the old "speed-length ratio"(1.34 X square root of the wl length) or as modified in Vellingas book- 1.5 instead of 1.34 for monohulls. Of course, if for any reason I needed a Froude number I would just multiply the SLR X .30........
  13. Doug Lord


    And I was thinking good riddance! Don't let the door hit you in the ass......
  14. Doug Lord


    Latest development of decavitator foils(record setting) : Decavitator rudder foil showing offset.pdf
  15. Doug Lord


    Well, you weren't gone long!! For water: speed in mph X Chord in ft.X 121,000 or for quick reference, table p35 vellinga's book