Foiler vulnerability to trash in the water

1) Lets see: Groupama, using lifting hydrofoils 100% of the time, just set the round the world record, the worlds fastest sailboat set her record using hydrofoils, Banque Populaire set a new Atlantic record using lifting hydrofoils.
And two Nigel Irens designs: Sodebo and IDEC are right now being converted to use lifting hydrofoils. Are they the exception or the rule? In fact it is highly likely that EVERY major record from now on will be set using lifting hydrofoils!
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2) This is the comment of an individual who has never sailed a boat with retractable lifting hydrofoils! The RS600FF uses retractable hydrofoils, Hydroptere and the 40' Spitfire foiler use retractable hydrofoils. The 26' Mirabaud uses retractable foils. And the 16' Rave foiler(which I have over 70 hours sailing) uses retractable hydrofoils with two operational settings! Same with the new all carbon Osprey... I personally used retractable hydrofoils on my first foiler with absolutely NO "complications" or "calibration" problems.They will be used on my new boats as well. The National 12 uses a partially retractable t-foil rudder for light air sailing. This statement,and the voice behind it, is just plain wrong and does not reflect the real common sense of foiler design!

Andy Paterson/Bloodaxe-retractable IC rudder t-foil-http://home.freeuk.com/bloodaxe/ic.htm (see pix)

 

Doug:

By your definition, an I-14 with a T-foil rudder that is capable of retracting meets your standard, therefore I HAVE sailed a boat with retractable lifting hydrofoils. I don't know how your omniscient Internet spy cameras at all sailing clubs worldwide missed that!

People here have tried and have rejected "retractable" lifting T-foil rudders as they are overcomplicated and fail frequently compared to fixed position T-foils that are simpler and do not have adjustment issues. Single (vertical) position rudders on gantries are the rule, not the exception on International 14s. The benefit of "retracting" the T-foil rudder is overshadowed by the simplicity of having a fixed location. It isn't that hard to install and remove a fixed T-foil rudder at the dock, and as all I-14s here are dry sailed from dollies, there is no advantage to a retractable one. In addition, most all the I-14s here rigged on grass with boats tipped over to install sails while tied to their dollies. A T-foil attached during rigging would be damaged as the boat is rolled on to it's side.

I know things cost no money in your workshop (a major benefit of virtual reality), but here foils are a very expensive part of performance boat sailing. A T-foil rudder with gantry and pitch adjustment capability represents a big investment of time and money. No one here risks their vulnerable and somewhat fragile foil investments for a little convenience when trailer launching. Just floating a dinghy backwards off a dolly would expose the fragile foil edges to hitting the rear bunks of the dolly. If I sailed a fully foiling dinghy I'd just tip the boat at the dock with someone holding the mast and have another person in the water installing or removing the T-foil - no risk, no exposure to the ramps or gravel. If you are afraid of getting wet, you picked the wrong sport.

Performance boats here tend to use hand-done masthead halyard locks (avoiding mast compression) and tuff-luff jibs - which are rigged rolled down on the dry using dollies - since dry rigging is the standard, car trailer-launched retractable T-foils like your aeroSKIFF(tm) gain no benefit.

I fully understand your "user-friendly quest" for retractable T-foils, but the reality of the performance boat sailing scene here today is that it isn't a benefit given how the boats are sailed or shore rigged.

Doug, go spend some time at active performance dinghy sailing clubs where people sail on water instead of on the Internet. You will quickly see how things are done and why. I haven't seen a dinghy launched off a car trailer for years. Many are just carried in the water, many are dolly launched and some of the very heavy ones are dropped in by hoist.

I knew my reality-based response would result in more ignorant abuse from you. How about a picture of you helming your aeroSKIFF while foiling to substantiate your claim? If you are good with Photoshop you may be able to come up with one.

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Bill

 

Practicality and common sense probably doesn't include skiffs, A-cats, IC's and a bunch of other cool boats too. Certainly not a Volvo 70, or G3.

A while ago I ran across a S. Hemisphere discussion of handicaps. One boat that ranked higher than I would have expected, especially considering the fact that it gets so much bad press on the forums, was the Laser. Still, one of the first recent videos of a foiling Moth I saw had a Laser race in the background. The comparison of speed was, well, stunning. The Lasers were poking around and the Moth was flying - in a couple senses. The Moth wasn't sagging on the foils, but was pretty effortlessly zipping along.

At most venues weeds are probably the least of the impracticalities of a Moth, since there are just so many impraticallities, but it still leaves them a worthwhile niche boat.

There are different types of sports. In every sport there are big differences in skill between the best and the worst, but it's more obvious in some sports than in others. In sailing typically you could have 20% of the skill of the best and still have 80% of the performance. It seems like in a Moth it's flipped. If you have 20% of the skill, you'll have trouble just getting around the course. I can't say if that's good or bad. In a sense it moves the sport towards a different kind of audience. Maybe to about where ski racing, skiffs and windsurfers are and a little past where the A-cats and Contenders are. We'll have to see. Maybe people who learn to sail a foiling Moth at an early age will be able to enjoy sailing one to a ripe old age. It does seem like it's a skill question, not a brute strength question.

Now, to get completely off thread, I just figured out what we need. We need a junior foiler, so that kids can start learning at an early age. If you look at what kids can do on ice skates, why not foilers? Small and light, strict one-design, very simple sail controls, robust wand and floats under the wings that are more like amas.

 

I live in the land of skating, and hockey is a serious religious topic to my French Canadian-schooled son. Nursery and Kindergarten school children skate at school for physical education on outside rinks, and hockey players too small to seriously ride a bike skate better than I do.

Starting very young make seemingly impossible tasks like learning languages and skating crossover turns backwards at speed easy. My son speaks English and French with equal ease - and he did not have to "learn" how to do so. It just painlessly came with the environment.

There is a lot of merit in your idea - and a lot of challenges. Light and robust concurrently generally equals expensive. We've had a fair amount of resistance to "hot" kids boats like the O'pen Bic here - mostly from the rabid Opti cult who have behaved like universal health care opponents in the United States.

Perhaps in the UK, with it's far more adventurous dinghy culture and higher "bar" of recreational sailing.

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Bill

 

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Offtopic for sure but AMAC is working on just such a boat....

 

The racing cat in the example above is itself at a "clear disadvantage" when compared to a boat with a weed knife system. Does that matter? Is it relevant to the cat when racing?

The time whether shorter or longer to clear the foils of other craft isn't really relevant as as the Moths in the worlds are just racing other Moths, so they all have pretty much the same problem and solutions available. A lowrider Moth may well be able to get stuff of its foils quicker, but there may be other less desirable tradeoffs that come with that.

Picking up something on the foils is not necessarily catastrophic, nor does it necessarily make foiling impossible. I'm sure Cheesy will agree that in Lyttelton where most of the R foilers sail there's plenty of weed and other hazards. It isn't more of an issue that its ever been, and at the recent Nationals the non foilers complained more about it than the foilers.

The increased height when sailing downwind makes it easier to see things in the water, so being on foils has some advantages when it comes to avoiding the visible stuff.

Yep it did seem to be discussed, pumping and the tricky and light conditions seemed to get a fair bit of discussion as well. I'm not sure anyone bemoaning issues with trash in the water was suggesting that foils were the problem.

Trash and other random events add some noise to an individual competitors signal, but thats the same in any class and hardly surprising.

The whole point of the International Moth (and the R) is to get around the course first, using whatever means are within the rules. At the moment hydrofoils seem to be the best way of consistently achieving that aim. They seem happy with the tradeoffs they're making, but who knows what the future may hold. Do you have any suggestions as to how the Moth and other craft could reduce the vulnerability and get round the course at least as quickly?

Whether or not its an increased vulnerability doesn't really matter because the speed vulnerability of the alternative options is way more significant.

There may well be no free lunch, but using foils is currently the quickest way round the course even if occasionally you pick up stuff and have to deal with it.

Apart from yes stuff affects foils, it'd be nice to sail where the waters clean, I'm not sure what you're trying to achieve with this thread.

 

Im pretty sure that you got what I was getting at. Thinking about it a bit more, coming back from Pigeon bay on Sunday we had a night mare of a time getting a bit of weed off BadonkaDonks keel, in relative terms I think you could clear any weed off the R's foils with less of a penalty than we could on the Shaw, it isnt easy trimming the gennaker (and steering Im guessing) to get just enough heel on so you can hook something off the keel, the boat speed is too high to just poke something down there.

Even on the Shaw one of those leafy bits of kelp will knock off more than 0.5kt of boat speed

 

Yep, the weed around is a pain, there was certainly plenty after the Tsunami surges. Getting stuff off the R's isn't too bad. Just judging the relative options is the difficult bit.

Like any craft, dealing with non catastrophic foil draggers is a choice between putting up with the performance loss and how quickly any losses made resolving the issue can be regained.

For the Moths, although a capsize may appear to be a slow way of dealing with it, it's probably more efficient than fooling around coming of foils, backing out of a tack and starting again.
The controlled capsize and righting of a moth is pretty quick, plus its guaranteed to clear the problem. On a skiff Moth you'd be lucky to stop, pull up the plate (which will no doubt stick), not capsize (now that you've cunningly reduced the stability), shove it down again and then get going significantly more quickly. You'll certainly loose places in a tight fleet, which is what seems to be the issue.

The R, being larger with more crew, isn't as quick to right. So capsizing to remove stuff by choice would be a last resort. No one I asked has actually had to do it. The R's seem to mainly get stuff on the plates, rather than the wings, which is pretty easy to fix. Most bits come off doing a slow tack by backing the jib and allowing the boat to drift a bit sideways. If it looks like it's wrapped well enough then you'd decide to back it out of the tack rather than just drop speed. If the option chosen doesn't work then the weed will have floated up near the hull. On takeoff it stays high on the foil and once out of the water, flaps and bounces around a bit till it falls off.

 

Regarding retractable T-foils - from someone with actual experience

Since our local "virtual reality" foiling guru maintains his position that retractable T-foils are both simple and necessary, here is a dissenting opinion from someone who foils on water using full size boats.

See the linked post on SA by Phil S.

 

Retractable Foils

Phil's prognostications in the past are notoriously incorrect, for instance, he said that no boat bigger than a Moth could foil upwind! His comments on retractable foils may be appropo to the Moth where there is very little initial stability but are not applicable when applied to my 16 foot foiler, the RS600FF, the Rave, and others including a properly designed system for the "foiling Laser". Note that the fastest sailboat in the world uses retractable foils..... Whether retractable foils work for any particular application is a matter of design not voodoo.....

 

Whether retractable foils actually work for any particular application is a matter of building, testing and proof, not "design" and day dreaming they will.

The Bladerider "design" predicted functional, retractable T-foils. Upon testing by buyers who actually regularly sail, the concept did not work as expected, therefore the design prediction was proved wrong.

There is a huge difference between the drawing board and out on the water.

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Bill

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What was shown with the Bladerider is that their retractable system design was faulty not that the concept of retractable foils was faulty as proven by the numerous boats that use retractable foils successfully.

 

I can understand how lifting a daggerboard will cause stuff entangled on it to slide off the tip allowing the boat to continue. In the case of a retractable foil and strut, I am not so clear on the principle. Merely lifting it in some kind of slot like a daggerboard trunk will result in the foil blades meeting the bottom of the hull where they will stop. No reason to suppose the weed, rope, net or plastic bag will do anything except get trapped between the hull bottom and the foil blades. So the arrangement has to be somewhat more complicated so it can be raised to where the skipper can get to it. Any pictures of how this is to be done?

 

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I don't think you would, necessarily, retract the foils to clear them of weed-it would probably be easier and quicker to use a tool or back down. But it's nice to know you could. The advantage of a properly designed retractable system is in launching or leaving-makes that process as simple as any other dinghy rather than the convoluted process of having to walk the boat in or out -on its side-to launch or leave.
In years of sailing a Rave, my boat and numerous models in this area I have never gotten weed or trash on hydrofoils. There have been just a couple of instances of weed on the vertical fins since most of the grass/weed floats on the surface not as low down as the lifting foils.

 

That isn't the reason our local foiling guru feels retracting foils are critical. His criteria is to be able to launch and retrieve the boat from a trailer without having to play with manual foil insertion or removal. Long ago his People's Foiler concept was based on the premise that a foiler need not be more complicated to sail than a "normal" dinghy.

The problem is that ANY play in the foil mounting and there are handling and maneuvering problems. This led early Moth foiler development to tighter and tighter foil trunks till insertion and removal got hard. When there is ANY load on the foil, it has trouble moving vertically in the trunk. This is one of those compromise situations encountered in product development where two opposing needs are head to head. For a easily retracting foil, you need a trunk that allows movement on the water so you can lift foils before they encounter the bottom. For handling precision you need tight foil to trunk contact.

People that sail the boats have opted clearly to choose tight trunks and to minimize control linkage slop. That is why Moth people walk their boats out "capsized" to deep enough water to right the boat and start sailing with the foils fully inserted.

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Bill

<awaiting the predictable onslaught from our resident expert>