High Performance MPX Foil/Self-righting Trimaran-The Test Model

WOLF daughter of Fire Arrow -- I just had a business meeting that lasted most of the day. The results look very encouraging(spectacular) for the WOLF Project.

 

WOLF daughter of fire arrow
Specifications
Latest Update 3/15/19
==================
A) WOLF specs(tentative) :
LOA 15' 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 below for max pressure comparison with an F18.
RM-max righting moment=4460ft.lb.(not including downforce from mainfoil)

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B) Advantages:
1-Singlehander- Excellent upwind and downwind performance with 220lb crew. Minimum crew weight 120lb. Two people for daysailing-max about 340lb.
--
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 , Macif jr(24'Diam tri) 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. UptiP foils stay down-no adjustment when tacking or gybing.
(see #16 below)
--
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- Automatic Foiling: no foil adjustments required after shoving off the beach and lowering the foils.
--
16- Adjustable crossarm dihedral for prototype to facilitate testing.


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C) ---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"

D) ---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.

================
E) --- 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)*
=======================================================
F) Max pressure for F18 before depowering or reefing :

1) The max pressure for an F18 based on 227 sq.ft. upwind SA, CE at 16.75', 2-180lb crew on trapezes and 5827.25 ft.lb. RM is 1.53 lb/sq.ft..
---
2) Max pressure for WOLF with 167 sq.ft. upwind SA, CE at 14.92', one 220lb crew sitting in a comfortable sliding seat, and 4460 ft.lb RM* is 1.79 lb/sq.ft..
*not including downforce automatically generated by the wand controlled main foil.

===========================================================
G) *The Two Stage Ama Design offers a lot both Statically and Dynamically:
1-Statically- the boat is sitting still and hit by a hand of God gust. It is theoretically possible that the boat could be knocked over with the mast horizontal but the two stage ama offers reserve buoyancy after the the ama hull itself is immersed by the immersion of Stage Two("curved piece") and yet it is not enough to fly the main hull. It is enough, however, to right the boat.
2-Dynamically-The ama hull has two levels of dynamic vertical force:
a. first and foremost the ama lifting foil that works from very low speed on up,
b. Second, and a sort of back up at speed, is the planing hull design of the ama. To start with on Fire Arrow/WOLF, the planing surface only comes into contact with the surface at very low speed with the ama starting to fly before the main hull does. And when the boat is flying the ama performs as reserve lift during incidental surface contact at speed.
*Also see page 191, post 2865 for more on the Two Stage Ama theory.


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UptiP Ama Altitude Control-pictures A & B----
Note that the ama is flying before main hull-note ama flight altitude:


Now that the 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:

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

 

Gitana 17 Flying on the Most Advanced Trimaran Foiling System Ever:


Fire Arrow Doing Exactly the Same Thing:

 

Wand Controlled Mainfoil--- There are several possible wand system options going forward with the WOLF:
1) The Bradfield System- currently used on the F3 and Fire Arrow Test Model, and Rave, Osprey and SKAT fullsize trimaran foilers. The Bradfield Wand System allows the flight altitude of the boat it is mounted on to be adjustable by moving the whole foil/wand assembly up or down and adjusting wand length accordingly,
--
2) The Ron Price designed wand system is integrated into the mainfoil currently used on the Whisper Cat and F101 trimaran. The Price System does not allow the flight altitude to be adjustable except a small amount by adjusting wand length.
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3) A new type wand system installed in a hull recess that works ,in principle, like a Bradfield system. This system would be recessed in the main hull forward of the daggerboard and would require only one wand. Further, the wand would work at, at least, two retracted positions with the foil as close as 6" to the bottom of the boat which the Price system won't do. The disadvantage is getting access to the wand pivot position and a slight concern over the effect the recess will have when the boat is seahugging. Would probably have to move the wand a bit to one side to prevent interference with the daggerboard.
=========
At this point, the Price System looks ok as does the Bradfield system using two wands(operating as one) similar to the Fire Arrow System:

Price System with wand integrated with foil:


Price System on an F101 trimaran. Note that wand will not work if main foil is retracted:

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The Bradfield System used on fullsize boats allows the foil to be able to be retracted and still work at different foil settings, which changes the flight altitude of the boat and the angle of heel on WOLF:
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Modified Bradfield Wand System on Fire Arrow--see page 191, post 2862 for more:


Slightly modified Bradfield Wand System used on the F3:


Bradfield System used on full size 18' LOA X 22' wide Osprey trimaran foiler:

 

We interrupt your regularly scheduled program to bring you this fantastic picture of the Star:

This is one boat I regret not having had the chance to race! I built a fairly sophisticated RC model of the boat with all the controls of the fullsize Star--- and the bendy mast and took it to the Coral Reef Yacht Club years ago during the Bacardi Cup--I think. Lots of top sailors sailed the model. Lots of fun!

 

WOLF daughter of fire arrow--- I read articles on a regular basis about people wanting an "easy to fly, comfortable" small foiler. WOLF's design ,as of right now, fills the bill and has no competition under 20' LOA.
The List of Advantages of the WOLF design from the spec sheet dwarf any other currently manufactured small foiler under 2o' :

Advantages:
1-Singlehander- Excellent upwind and downwind performance with 220lb crew. Minimum crew weight 120lb. Two people for daysailing-max about 340lb.
--
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 , Macif jr(24'Diam tri) 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.
(see #16 below)
--
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.
Uses Two-Stage Amas-see pictures in post 2882 above-the Spec sheet. 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 sealed to deck.
--
15- Automatic Foiling: no foil adjustments required after shoving off the beach and lowering the foils.
--
16- 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 Spec sheet above-post 2882- for Two-Stage Ama pictures)
4) the first trimaran foiler in history to use two different altitude control systems simultaneously.

 

Proven attributes of the Fire Arrow Foil System(Basic system used on Maserati, Gitana 17, Macif jr, Macif and Banque Populaire and possibly on the new Sodebo after initial testing.) :

1) allows an oversquare trimaran to foil in very light air and be stable in heavier air,
--
2) allows full foiling upwind and downwind completely automatically without any adjustments by the crew,
--
3) allows for retractable foils controlled from the cockpit, B
--
4) allows the lee UptiP ama foil daggerboard portion, with an AOI of +3 degrees, to unload the main hull daggerboard(AOI zero degrees) for reduced drag and enhanced leeway coupling. The ama foils do not require constant rake adjustment-basically set it and forget it. B
--
5) allows considerably greater pitch authority than any conventional trimaran, B
--
6) allows automatic control of the angle of heel of the whole boat, B (manual on Ultims for now)
--
7) allows automatic control of the ride angle of the lee ama UptiP foil, B (manual on Ultims for now)
--
8) allows mainfoil to automatically unload as the main hull flies ,dramatically reducing drag,
--
9) allows automatic gust response with instantaneous increases in righting moment automatically ,as required, through mainfoil downforce. B -manually on large tri's for the time being.
--
10) allows a "Two Stage" ama that provides back up buoyancy if needed but allows the part of the ama that would normally make incidental contact with the water to be as small as practical. Allows the knockdown righting moment to be as great as possible by moving the center of buoyancy of the ama assembly(ama hull+ "curved piece") vertically in combination with an oversquare beam.
--
11) allows the use of UptiP ama foils without the requirement to retract/deploy a foil with each tack or gybe-a requirement on every other multihull using uptip foils. Foils can stay in their deployed position without retracting except for shallow water/beaching.
--
12) allows use of two different types of altitude control simultaneously. B
=================

 

WOLF daughter of fire arrow-- I've done some tweaking of the WOLF design to improve its ability to carry up to 340lb-two people. While the boat is conceived of as a singlehander the changes allow the performance of the boat throughout the weight range above to be excellent.
The main (tentative) difference is that the singlehanded boat will fly in a 5 knot breeze(or less) and the doublehanded version will require about 5.75 knots of wind for takeoff-which is perfect.
Boat weight is targeted at between 175lb and 190lb.
Sail area will be increased a little from the upwind 167sq.ft. in the spec sheet to around 180 sq.ft with the downwind area going to 300sq.ft.
Sail loading will be(tentative) :
1-220lb singlehanded--2.27lb/sq.ft upwind at a boat weight of 190+crew and 1.4lb/sq.ft downwind.
2-340lb doublehanded--2.9lb/sq.ft upwind at a boat weight of 190+ crew and 1.77lb/sq.ft downwind.
Sail Area/wetted surface(tentative) :
--Non-foiling: Upwind =3.1/1 Downwind = 5.1/1
--Foiling: Upwind = 19.2/1 Downwind = 32/1
==============================================
The figures above reflect a sail area based on an oversquare beam with a sliding seat to increase the RM provided by the crew. What isn't integrated in these figures is the enormous increase in RM possible with downforce from the main foil-it could easily exceed an extra 30% of the current RM as listed in the Spec Sheet above(post 2882). That could allow more sail area, less crew weight or a mix. As is, it automatically adds instantaneous extra RM in response to gusts.
Deciding exactly how to make the most of this capability is one of the most fun challenges of designing a boat using this kind of foil system and is why so much of the above is "tentative"!!

 

Thinking about Dr. Sam today- a friend and foiler pioneer:
Whats left of the Hydrosail website: HydroSail https://sites.google.com/site/hydrosail/

Here's a video of Dr. Sam Bradfields NF3 -one of many foilers he designed:


And a short video of Dr. Bradfields last foiler, Osprey--Loa 18', Beam 22'(according to Dr. Sam) with wand based altitude control system:


A longer Osprey video:

 

WOLF daughter of fire arrow This is a concept mock-up of a "W" foil (Welbourn foil) as it might be used on WOLF and/or Fire Arrow. Has many of the same advantages of an UptiP foil except that the uptip foil might work better in rough water and possibly fly a bit higher. Biggest advantage of a W foil is a substantial increase in righting moment due to the outboard movement of the foils' center of lift. Has the same automatic altitude control as does the UptiP foil but is susceptible to altitude change with speed changes- more so than the UptiP foil.
Increases the Righting Moment developed automatically by downforce from the main foil which means for the same RM as with the uptip foil there will be less drag from the mainfoil due to the increased distance between the main foil and ama "W" foil.
W foils add 46% more RM for nearly zero gain in weight.

May slightly increase the structural requirements . Can be tested on Fire Arrow and on the full size WOLF.

"W" foil mock -up on WOLF concept model:


"Q" (Quant/Welbourn) foil(DSS2) on the Quant 23:

 

WOLF daughter of fire arrow --- UptiP foils in the bottom picture have a bit more span than they would on the actual boat-compare with W foils to see how far outboard the center of lift moves:
"W" Foils:


UptiP Foils:

 

Take a Moment on April Fools Day to ponder this gem from EuroSail News:
The Last Word
A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools. -- Douglas Adams

 

WOLF daughter of fire arrow-- Interesting to note that using UptiP foils WOLF has a 16' beam, but using "W"(Welbourn) foils the beam is 22'-same as Dr. Sams 18' Osprey. Plus 46% more RM(not including the downforce possible from the main foil).
UptiP ama foils:

 

WOLF daughter of fire arrow------ "from the stern, for instance" :

 

Fire Arrow Experimental---- Thinking of converting the D4Z catamaran into two approximately 52" LOA smaller RC speed boats using the Fire Arrow Foil System. The D4Z hulls are ultra light Kevlar/Carbon and I no longer have the hull molds. The finished boats should weigh between 4 and 5lb each. They will have a beam somewhere around 60" and use a wand controlled main foil and either UptiP ama foils or Welbourn foils or both interchangeably on the amas.
Hopefully, I'll be able to finish the WOLF fullsize foiler and the D2 before doing these.