Taking Off the Training Wheels (Sailing a Hydrofoil Trimaran Without the Amas)

Discussion in 'Multihulls' started by Doug Halsey, Jul 10, 2008.

  1. Busman1965
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    Busman1965 Junior Member

    If my memory serves me right, the rudder foil was 4ft, when fully extended for flight. The rudder foil was made of some old Harken Sailboard Foil Extrusion.
    It was not a kick up rudder, but rather a dagger type, that retracted vertically. A pin was inserted when fully extended, to lock it in position.

    Since the rudder foil was a fairly thin foil section, it was easy to stall at low speed. The flap on the foil was controlled by a small push pull cable, in the cockpit.

    The rudder foil was deeper than the main foils by about 6". In practice, it worked out well, as it did not ventilate. We had a bright orange stripe on the main foils, which was the danger zone. If you could see the stripe above the water, you were about to ventilate. That usually ment giving the rudder foil some more lift, to change the angle of attack downward on the main foils, decreasing the lift. Also, we found that falling off the wind a couple of degrees would cause the boat to settle lower on the foils,which was handy in puffy conditions.

    The fountain off the foil was something we saw at times,also some great roostertails,at times. Alot of it was the rudder to foil joint, and the foil ends.
    Both areas need careful fairing and smoothing.

    I still have 2 sets of J-foils from NF3,in my warehouse. I will dig them out and post some pictures of them.
     
  2. Doug Lord
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    Doug Lord Flight Ready

    ======================
    Don, I've been thinking about this since you posted it for possible application on a couple of my boats down the line. If your rig had broken what was your "quick way out" plan? Any thoughts on your system would be much appreciated...
     
  3. Busman1965
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    Busman1965 Junior Member

    Doug,

    Since NF3 was operated from a seated position, with foot steering, I was able to utilize a lap belt bolted to the floor. I sewed 2 loops in some 1" nylon webbing and used a harken snap-shackle as the buckle.

    I had a large, orange monkeys fist knot on the release,to make it easy to find underwater.

    I left the belt slightly loose fitting, as its only function was to keep me from flying out, during a pitchpole.

    As a final exit strategy, I had a Swedish "Mora" sheathknife velcored on the belt. The "Mora" is the sharpest rigging/survival knife I have found......it has saved my hide on a number of occasions!!! And they are CHEAP!

    The belt did work, as I pitchpoled with it, and I DID NOT fly into the wingsail.
     
  4. Doug Lord
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    Doug Lord Flight Ready

    Thanks, Don. Would you use it again?
     
  5. Busman1965
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    Busman1965 Junior Member

    I would! There are so many variables in foil boats which can cause a crash,
    a little safety is a good thing. I am a walking monument to various crashes
    sustained while foiling.

    All of the foilers after NF3 were trampoline type boats, which precluded using a safety harness or belt.

    I received some serious thrashings on these boats.
    Wrenched neck, broken ribs, puncture wounds on my legs,were just some of the fun adventures.
     
  6. Doug Halsey
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    Doug Halsey Senior Member

    Don,

    I'm more worried about safety then I was the first couple of years with Broomstick. Last summer, I got thrown off the trampoline twice & turtled both times. In the photo shown (when I broke a foil), I didn't hit anything on the way over the forward crossbeam, but the other time I gashed my hand pretty badly on something (probably the stay).

    I've thought about some sort of strap to help keep me in place, but so far have shied away from that for fear of getting tangled.
     

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  7. Gary Baigent
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    Gary Baigent Senior Member

    I've done my share of crashes and juddering stops but have never been catapulted off ... and that is because my tiller is well aft, and gripping that helps stop you flying forward, but most importantly, I'm also gripping the main or traveller sheet which is behind me, ALL the time ... and that's a good safety harness.
    Years ago on Supplejack cat, coming back singlehanded from Kawau in a strong north easterly, again using only the wing mast (and travelling bloody fast passing numbers of fully crewed keelers running for home) we all got into a wind against tide waves over a deep shoal out from A Buoy ... and the half dozen keelers beside me all broached on a large and ugly shaped, breaking wave - while Supplejack went up to what seemed almost vertical on her side, completely burying her leeward hull under white water, me with the helm hard up trying to turn downwave and my other hand gripping a bit of hatch cover rope ... which without I would have been to leeward in a flash with the boat going over on top of me. So a bit of rope in one hand could probably save you guys with foot or wheel steering. I don't like the idea of tethering yourself to a multihull.
     
  8. Doug Lord
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    Doug Lord Flight Ready

    I don't like the idea of being "tethered" but maybe it's worth thinking about. On boats like the Moth with shrouds some guys have been really hurt flying into the wires. Dons experience is enlightening but I'm still not convinced-on my boat one will sit on a seat with feet down in the cockpit(or in a single seat in the center)-and the flying version will have shrouds.....
     
  9. Busman1965
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    Busman1965 Junior Member

    I agree that it is not good to be teathered to a multihull, in principal. But when dealing with the excessive speeds and rapid stops a foiler can generate, it may be the lesser of the evils? My personal feeling was it was right for NF3, however, on other foilers I have sailed, it was not possible or desireable to do.

    The idea of holding the tiller and mainsheet is very valid, it will keep you from flying, but on NF3 the rudder was foot controlled, and the main sheet was ahead of the helm position, so that was of no use.

    I remember thinking during the first pitchpole, as I flew out of the cockpit into the rigid wing...I should of had a seat belt.

    On soft sail foilers, the potential damage is about the same as a fast catamaran, so it is an acceptable risk, but there is the issue of hitting the foils themselves. I calved a good hunk off my shin, on the rudder foil of Mosquito when a strut failed, and the leeward foil folded (don't ask me how it happened, it was a blur...).

    The single best safety device was a good thick wetsuit, and knee pads. I know this saved me from many injuries during crashes. But, it will not prevent broken ribs......I know this first hand!!

    It's funny, I still have little chunks of glass and carbon fiber come to the surface of my scars, from my first pitchpole. Every now and then, I will see a little black fleck in one, and have to dig it out. Amazing,as it happened almost 20 years ago!!!
     
  10. Tom.151
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    Tom.151 Senior Member

    This _old_ thread is so exciting and interesting I just had to give it a bump.
     
  11. Baltic Bandit

    Baltic Bandit Previous Member

    Well one of the things about being thrown is that and advantage of being on the wire is that often you can make sure you are thrown clear. particularly simpler if you are out on an ama and hiking but not trapping.

    Buckling in, particularly in a mid-seat position strikes me as borderline suicidal. Look just go buy a cheap tackling dummy and strap it into the boat ahead of you so that you crash into that.

    But one of the things that US Navy/AF learned about even the fittest pilots is that once you are no longer "right side up" - its very very hard to get your bearings and access your safety releases. Hence the training with the inversion dunk seats


    Now particularly if the reason you are sitting inside the boat is because you are not fully mobile in some way (disabled, injured etc ) basically you are ******.

    Mothies do get hurt on the shrouds - in part because of how they crash (cartwheels) and that's why a lot of skiff sailors where wet suits even in the summer
     
  12. Busman1965
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    Busman1965 Junior Member

    There was one aspect I had forgot to mention in my old posts regarding the use of a safety belt on NF3.

    Since NF3 was a hard wing sail rig, it was impossible for the boat to capsize beyond 90 degrees in any direction. The reason for this is that the wing sail was hollow and very buoyant. The leading edge of the wing was a carbon fiber spar, that acted as the mast, and was sealed and buoyant, even if the fabric of the wing was pierced.

    If you pitchpoled or broke an ama and capsized the boat (I did both!) it would only go over till the wing hit the water. Being strapped in the centerline of the cockpit, it would have been virtually impossible to be trapped underwater while strapped in.

    The biggest danger on that particular boat was pitchpoling, which would launch the helmsman out of the cockpit, like a trebuchet, and lob him right into the mast.

    I will say that a seat belt was never even thought of on the other 4 hydrofoil boats we had during my time with Dr. Bradfield (they were more conventional triamaran style with netting decks).
     
  13. Baltic Bandit

    Baltic Bandit Previous Member

    Nothing is impossible Busman. Solid wings can and do break off.
     
  14. Busman1965
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    Busman1965 Junior Member

    That is true, however I had several crashes in NF3 before adding the seatbelt.
    The non-seatbelt crashes resulted in lacerating my leg, breaking ribs. loosing all the
    skin on both palms, wrenching my neck and various other injuries.

    After adding the seatbelt, I sustained no injuries, so it was an acceptable risk to my mind. In theory the belt is a bad idea, but in the real world, it was a form of damage mitigation that far outweighed the dangers inherent to being belted to the boat.

    Trust me on this, when you are faced with slamming into a huge, solid wing sail at high speed, you would be very happy to risk the danger the belt adds to the unlikely event the wing is broken off the hull (which on NF3 was virtually impossible to do, the boat would have to disintegrate for the wing to break free).
     

  15. Doug Halsey
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    Doug Halsey Senior Member

    Another Advantage to Sailing Without Amas

    Since this is a thread about sailing without amas, I was a little surprised to see the photo I attached in Post #36 (almost 4 years ago), showing me doing a dive over the crossbeam midway between the main hull & the windward ama. So, what is the explanation for how that photo is relevant to this thread ? It's this :

    Right after that photo was shot, the boat turtled. Even though the amas are very small, they still have too much buoyancy for me to sink them & start trying to right the boat. But Broomstick's amas are attached to the crossbeams with loops of bungee-cord, so I was able to remove the ama on the side which still had a usable foil. I then righted the boat & sailed it to shore with an ama on one side & a foil on the other, towing the other ama behind.

    With the amas attached, the boat is very stable up-side-down & practically impossible to right, even with help; without the amas, it's much easier.
     
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