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

WOLF---daughter of fire arrow / Concept Model / Two Level Seating

I've been studying the mock-up of the two level seating and I may have a better idea for the upper level.
The whole point is to allow me to move further outboard in conditions where an initial increase in RM is necessary to get started-not necessarily to use on a regular basis since after the boat is flying the extra RM won't be necessary most of the time and to the extent it is mainfoil downforce can do the job.
So the idea is to install a tramp from the back of the lower seat to the ama "curved piece" and to add a foldable -and perhaps slidable-back between the two crossarms so that if I use the tramp I'll have some back support. Seems better and lighter than two additional "hard" seats that will be used relatively infrequently.
Going to tentatively go with this initially.

 

Fire Arrow Foil System / Ama foil

Fire Arrow planing ama: (STB UptiP foil still has iFlap-removed from port ama foil)

 

Fire Arrow Foil System

One of the wildest things that has happened in a while took place a few months ago when it was discovered that Maserati was the FIRST fullsize trimaran to use a lifting foil on the daggerboard in combination with an UptiP foil on the stb ama!!!!!
Very similar to the Fire Arrow configuration conceived of 6 years ago and tested successfully in light air two years ago!
And Maserati is about to race with this complete configuration for the first time in the Transpac in July. She had a collision with a ufo that destroyed her stb rudder t-foil just before the Malta race. She got lucky and won that when Phaedo made a mistake. Her next race was the Carribean 600 where she raced with a third of her foil system non-functional again and finished within 12 minutes of Phaedo even with that monumental handicap.
Thats why the Transpac is so important: she has a real chance to finally beat Phaedo outright!
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Here's what the Maserati guys say about the basic Fire Arrow system-it may sound familiar to anyone that has read this thread:

First* trimaran in the world to fly with effortless stability on the horizontal loading-bearing surface of her centerboard, Maserati Multi70 brilliantly puts into practice Guillaume Vernier and his Team’s idea of flying on three resting points using a load-bearing centerboard, L-foil and a rudder instead of the two rudders and single foil adopted on America’s Cup cats.
Giovanni Soldini and his Team are engaged in a new challenge as they endeavour to turn Maserati Multi70 into the first ocean-going flying trimaran. An ambitious project that spans not just Guillaume Vernier’s excellent work (he worked on the modifications to her appendages) but also over 4.000 nautical miles of sailing clocked up by the Team this summer.
The straight central daggerboard plays a revolutionary role in this new flying trim as the horizontal load bearing surface at its end generates lift, raising the boat out of the water. “When Maserati Multi70 rises up on her lateral foil and rudder, the daggerboard wing acts as a third resting point – the central and largest one”.
Tests in wind of 40 knots have demonstrated that Maserati Multi70 is now much more stabilized and able to fly in conditions unthinkable before. Safely tackling also big seas.

* Fire Arrow was the first trimaran to use this configuration!








Maserati

 

WOLF---daughter of fire arrow / Concept Model / Two Level Seating

Here are a couple shots of the upper level seating changed to (mostly) a tramp on each side. See the top of this page to see the change. The adjustable seat back is not shown:

 

WOLF---daughter of fire arrow / Concept Model / Two Level Seating

Another view of the tramp/upper seating. I'm pretty well sold on this because it allows the ultimate comfort that I want as well as the ability to sit outboard when required comfortably and quickly:

15.5' LOA(minus rudder)
18.75' Beam (folds to 8')

 

WOLF---daughter of fire arrow / Foils

One thing that was learned in testing the model is that in waves it would be ideal to be able to lower the ama foils from their standard position. Out of the question on the Test Model because of the extra weight and radio complication.
But on Wolf it should be a simple thing to do, so the Concept Model will reflect UptiP ama foils that can be lowered around a foot(.3m). The rake of the ama foils will be adjustable but probably not the cant. I want the foils to be simple to sail with with the fewest regular adjustments possible. One thing that is unique about the ama UptiP foils on the Test Model and on Wolf is that they don't have to be retracted/deployed every tack or gybe like the UptiP foils on the AC cats, Flying Phantom, GC32, NACRA FCS 20 and others.
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I'm still thinking about having a recess in the main hull to allow the daggerboard foil to be retracted above the bottom. That will leave a hole in the bottom which may be able to be dealt with using foam or? So it fills in automatically as the foil is lowered. The daggerboard foil will use a flap adjusted by a wand-either one like the Whisper* or similar to the dual wand set-up on the Test Model(below).
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The rudder T-foil will pull straight up and clear the transom/bottom intersection.

*See the Whisper wand system on page 165, post 2463


Fire Arrow Test Model Dual Wand System:

 

WOLF---daughter of fire arrow / angle of heel

These illustrate two angles of heel for Wolf:
UPDATE: made a mistake on Sketch C-will redo correctly at some point. Sorry.


Sketch A-13 degrees angle of heel-illustrates boat with mainhull flying 5 inches above the water with the ama planing surface aft end flat on the water:






Sketch B-10 degrees-illustrates mainhull floating and the aft end of the ama planing surface just touching the water. See Sketch C for a better illustration of this:

 

WOLF---daughter of fire arrow / Angle of heel /Altitude

These three pictures illustrate angle of heel and, in two, flight altitude:


Sketch C shows main hull floating and ama just touching with the boat not moving:




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Sketch D shows the nominal flight altitude and angle of heel for relatively smooth conditions starting from takeoff in 5 knots of wind:





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Sketch E shows the nominal flight altitude and angle of heel for rougher conditions:

 

Fire Arrow Test Model Testing and Development / WOLF

The dihedral of the crossarms on the concept model is about 1/3rd more than on the Fire Arrow Test Model and I'm considering reducing it.No decision yet but I have the model set up so I can study it carefully. I'm looking at the numbers for initial RM and max RM and other considerations including capsize/knockdown response and more.
UPDATE: Definitely decided to reduce the dihedral but haven't decided how much yet. Greatest benefit is getting moving easier in stronger wind......

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This picture shows the dihedral on Fire Arrow which occurs with the main hull static at a bit less than a 10 degree angle of heel. The important part is that the foil on the high ama is nearly clear of the water when the boat is not moving. The Wolf may have a bit more dihedral because it has movable ballast(crew) whereas the Test Model does not:

 

Manta (daggerboard) Foil on Maserati

First pictures of this foil: http://www.boatdesign.net/forums/multihulls/maserati-70-ocean-racing-foiler-57254-2.html#post803332 Fire Arrow and Maserati are the only trimarans in the world now using a foil on the daggerboard in combination with ama foils that work like UptiP foils(automatic altitude control) and rudder t-foil (2 on Maserati).

 

Test: Fire Arrow flying:

 

3D SAILING
About 16 years ago when I was building the production version of the F3 foiler-(the worlds first production RC sailing foiler)-I came up with a trademark- "3D Sailing"-
to describe hydrofoil sailing. I applied for and was granted the trademark. Shortly after that I was contacted by an agent for a major boat company who offered me $1000 for the mark . I wouldn't sell. They finally upped the offer to $8500(!) and I did sell it. I just discovered that they let it expire in 2010!

 

The top picture is the surface piercing foil from the new Quant 23, the middle picture is the new UptiP foil from the new DNA G4. The bottom picture is the UptiP ama foil from the Fire Arrow.
Now consider these tips breaching the surface. From an article I read by Hugh Welbourn he mentioned that one of the reasons his production foil is shaped like it is is to make the angle at which the tip breaches the surface more vertical to reduce the tip drag which, when compared to the original, much flatter foil, makes noticeably less disturbance in the water when it breaches.
The droop in the Fire Arrow foil is there to allow more vertical lift from the foil tip but when it breaches the surface the flatter angle at the surface is almost parallel to the water at a 10 degree angle of heel and makes a lot of disturbance. But it rarely breaches
so it may be ok-or not.
The G4 foil when it breaches may make a lot of disturbance when the horizontal portion is close to the surface-will have to pay attention to pictures of the foil flying and see.
At any rate, thanks to Hugh for calling my attention to this....

 

somebody beat you to it Doug - this vid from 2013, quite stable too;

 

Thanks, Groper. Well, I think I know that guy and he did a really good job! But his boat is entirely different than the Fire Arrow-no main foil, no two stage amas, no UptiP foils -one used at a time. His boat is a surface piercing foiler with altitude controlled by speed ,whereas the Fire Arrow uses fully submerged foils and dual, independent altitude control systems. And the Fire Arrow is an exact scale model of a 19.5' fullsize foiler.
For the record(again) I built the worlds first production RC sailing foiler in 2001....the F3 which tacked and gybed on foils. See the Model Yachting cover above.