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The mainfoil retracts into a recess in the bottom so that it is flush which makes beaching(and trailering) easy. The upturned tips have some hydrodynamic value but their primary purpose on this boat is to prevent the tips from digging into sand or mud.
The ama uptip foils retract above the waterline as does the rudder foil.
The boat folds for trailering in about 4 minutes.
The Fire Arrow Foil System is a unique system first tested in 2014 and published then on boatdesign.net. From then several full size trimarans adopted virtually identical versions of the foil system:
WOLF daughter of fire arrow
Latest Update 1/30/19
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WOLF specs(tentative) :
LOA 14.8'
Max Beam 16'
CL ama hull to CL ama hull-14'
Target weight 175-190lb
SA-(mast length 24' all carbon wing mast)
--upwind: 167 sq.ft
--downwind: 267 sq.ft
--max pressure before depowering/reefing: 1.79lb/sq.ft
* NOTE-see bottom of this page for max pressure comparison with an F18.
RM-max righting moment=4460ft.lb..
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Advantages:
1-Singlehander- Excellent upwind and downwind performance with 220lb crew. Minimum crew weight 120lb.
2- Will foil in 5 knots of wind with 220lb crew .
3-Carbon rotating wing mast, carbon cross arms and carbon foils.
4-Retractable foils(from cockpit). Mainfoil retracts flush with bottom and tips are designed to not dig into sand. Rudder foil retracts above bottom. Ama foils retract above waterline when boat is level.
5-Extremely comfortable sliding seat on each side. Allows crew to move 1.75' outboard very quickly.
6-Uses the Fire Arrow Foil System(like Fire Arrow, Gitana 17, Banque Pop, Macif and Maserati)-- the same as the original system first used on the Test Model- except the larger boats use two rudder t-foils on each tack. WOLF has two UptiP ama foils-one used at a time-and one wand controlled mainfoil for very early takeoff and capable of substantial downforce- all working with a single rudder T-foil. Downforce can be virtually instantaneous adding RM in response to gusts.
7-Foiling throughout the wind range -including very light air-the essence of 3D SAILING!
8- Assy Spin/Screecher retracted under the front deck.
9- Boat folds from max beam to trailerable width in about 4 minutes. No waterstays.
10-Mid (wish)boom mainsheet so sheet is always in forward hand and extension tiller always in aft hand.
11-Quickly self-draining cockpit-large scuppers with backflow flap.
12- Planing ama hulls designed for incidental contact with water at speed and for inadvertent contact at slow speed.
Adjustable angle of incidence of planing surface of each ama simultaneously. Angle of incidence of ama foil has to be changed when this is done. Planing surface starts at +4 degrees.
Uses Two-Stage Amas-see attachments below. They consist of a planing ama hull(Stage One) coupled to a "curved piece"(Stage Two) that provides extra buoyancy in the event of a knockdown. Curved piece facilitates high dihedral crossarms which keep the crossarms clear of the water.
13-Planing main hull.
14- Aerodynamic surfaces added to forward and aft crossarms. Adjustable flaps added on rear cross each side. Jib foot and forward part of main foot to be sealed to deck.
15- Adjustable crossarm dihedral for prototype to facilitate testing.
[IMG]
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---Memorable quote from JG Baker, Designer and Builder of the Monitor foiler in the 1950's: " The main need is to lower the wind velocities required for flying in order to increase the opportunities for high speed travel"
---VPLP on the daggerboard main foil:
" On these big boats, when you ease a sail, it is a pain because it takes so long to grind it back in. But here you press a button and the angles of incidence change. And with the foil on the daggerboard you can use it to alter the flight according to the wind*. If it builds, rather than easing the sheet you increase the righting moment by increasing the angle and conversely, as it eases you can reduce it and let it fly more." * done 100% automatically on Fire Arrow/ WOLF with wand controlled main foil.
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--- Fire Arrow Foil System-first of its kind on any trimaran. Elements developed first by Fire Arrow include:
1) the first trimaran in history to use UptiP ama foils,
2) the first trimaran in history to use a single wand controlled main foil capable of downforce,
3) the first trimaran in history to use Two Stage Amas.(see below for Two-Stage Ama pictures)
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Note that ama is flying before main hull-note ama flight altitude:
[IMG]
Now that main hull is flying and speed and load are significantly greater than in "A" above, note that ama flight altitude is the same! And that's due to the ama UptiP foil design:
[IMG]
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Gitana 17 has won the Brest Atlantique using a revolutionary foil system! Fire Arrow was the first trimaran anywhere to utilize this basic foil system which will be incorporated in the new WOLF. http://www.pressure-drop.us/forums/c...-For-Gitana-17
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