New High Performance Monofoilers

not quite

that was a PM? looked like a reply in a quote, the horn he is talking about is where the control lines for moving the rudder attach on each side

 

Foiling 49er

Here you go,Sigurd. You can see the lines coming off the foil shaped horns; click on the image to make it a bit larger:

 

Foiling 49er

From Gulari post on SA:
"Not sure I quite believe it but the Velocitek said 28.6 knts max speed.

Wind was between 10-13 knts. Big difference was the big fat ******* at the front hauled the main sheet on bloody hard as we came out, much tighter sails, just check out the forestay sag.

Longer more sustained flights, more in control, main foil was letting go occasional as we came right out.

Very quite, quite amazing feeling as it was wound up, and the deceleration was amazing, more so than Trilogy sticking its nose in.



Julian "

 

High Performance Monofoiler Design

Interesting to note that there are now three twin trapeze foilers, three triple trapeze foilers, and two single trapeze foilers in various stages of development! Pretty impressive-and those are only the ones known about.....

 

R Class Foiler

Heres a little tidbit published by permission of Paul Roe:
--
Foiling L3 does Horizon Job
--------------------------
On Saturday 24th of January, the foiling R Class completed its first official race distance and did a horizon job on the rest of the fleet. Sean Milner and Dan Leech easily won the 2 lap Parsons Rock harbour race. Paul Roe and Jess Hix on TheVirtual were a comfortable second, but well over ten minutes behind. If it hadn't been for a couple of dramas on L3 the margin would have been much greater: they lost quite a bit of time rethreading the mainsheet on the first run when it went out through the blocks, and even more on the second beat when Sean had to swim 50m back to the capsized boat after falling overboard.

TheVirtual crew had a clean race and pushed the whole way, but the conventional R was totally outclassed by Sean and Dan on foils. After one lap L3 was just dropping its kite at the bottom mark as TheVirtual gybed at the Cashin Quay breakwater. We're now really starting to see the potential of the foils.

 

Doug!
I am not totally convinced about the 49'er with foils. There is no flat water under it, in the photo above. Pehaps they have to incorporate a horn in the design. This may have the possibility to satisfy the Weber conditions. And put the knuckle in the Cd-Froude diagram further to the right. One have to be carful, though, to not trigger the Strouhal frequencies with the horn. Reynold, on the other hand should be no problem. A slight modification to the sail-plan is probably needed at this speed. To fully benefit from the Kutta second-order vortices.
Regards,
Booster

 

Foiling 49er

Well, booster, they've apparently done over twice the wind speed and are close to the highest peak speed ever recorded for a Moth. Not too shabby.... And you've got one of the best development teams in dinghy design looking at this thing. Early days-but very impressive so far.

 

There's nothing impressive about this report at all.

One would expect that a boat with significant reduced wetted surface would seriously outpace the standard boats in the same class.

This is like a 40 hp 4 cylinder VW engined* sports car racing against a 160 hp 4cylinder Porsche engined** car with the same body. Both engines from the same basic design, but one having been breathed-on in a more than significant fashion.

Of course the Porsche powered car is going to kick butt on the VW version.

Want to know if these guys have it all going on....? Put another foiler in the same race and class them both differently from the standard boats as they exist. Allow the drivers to switch boats between races and let's see if the mentioned boat is still raging fast. My bet is that it is not when comparing apples to apples.

Yes, I get that this is a development class and stuff will happen that may make the boats faster. Is that the whole, simplistic reason why all of us go sailing? Can the rest of us afford to install foils on our boats at a USD$5-8K clip just to go faster? Want the answer to that, then look at the hotrod culture of cars....

The stuff to go faster has been out there for several decades, now and it still only appeals to a slim percentage of car enthusiasts. Everyone in the car world knows that a turbine engine equipped auto will absolutely shred a conventional piston powered machine, yet there are precious few turbines running around embarrassing the V8 crowd of car nuts.

So, why is that? Is going faster not all its cracked up to be? Has the cost/benefit quotient seen its better days? Is the hassle of maintaining the more exotic machine just too much for the average guy? Has the expense issue driven most of the followers away in favor of less costly, more driveable vehicles?

This is a non-issue that seems to be pushed by those who think it matters.

It doesn't


* one barrel carburetor, vacuum advance distributor, single stock cam, moderate cylinder compression, stock valves and openings, mild valve springs and stock intake and exhaust manifolds, with slightly enlarged and flow modulated exhaust and muffler.

** twin, two barrel carbs, mechanical advance distributor, aggressive cam shaft timing, high compression pistons, cylinders and heads, heavy duty valve springs, larger valves and openings, ported and relieved intake and exhaust manifolds, coupled with large diameter exhaust pipes and mufflers.

 

Foily Niner

Just for objectvity:

I believe that Frank Bethwaite is more than capable of making serious breakthroughs in foiler performance, especially if aided by his son Julian (and grandson Harry). These people were at the center of similar performance gains in skiff classes, and have both the engineering and physics skills to get the job done.

If the initial reports of speed are credible (and I think they are), getting 28 knots out of the new 49er rig is amazing on the test foiler platform. With a purpose built low drag rig, I would expect serious improvements perhaps on the order of 10-15%.

I would not be surprised in the least to see this team reach 30 knots within a year or less.

Again, for objectivities sake, I don't think this would be a serious candidate for a production boat. Julian's reports of massive deceleration problems make it a less than general-public safe ride.

--
Bill

 

Foiling 49er

The "deceleration" referred to is directly related to the altitude control system which will improve dramatically (as it has on the Moth) as time goes by. An interesting thing about the Foiling 49er is that with an upwind SA of 215 and approx. all up weight of 588lb gives a W/SA which is higher than almost every other current foiler except the R class.(lower is better in light air) The Moth,RS600FF,and Mirabaud are all about 2.5 or less. More than anything this speaks to light wind takeoff but watching the R and 49er in under 10 knots of wind will be enlightening.
I think(and hope) that the Bethwaites will do a second foiling 49er soon to help them make dramatic gains. Thats about to happen in the R class and they will sure learn a lot-and hopefully we'll all gain as a result.

 

So the wannabe is posting an months-old article about someone else's project, yet still can't post the drawings or photos of his project that has been "in build" for years.

Can't get anyone else to do the engineering and drawings for you?

 

Maybe I'm losing my mind, but I posted a response to you regarding the right word to describe our friend .. and that word was "sycophant". It looks like the invisible editing police are out, removing posts. I sure hope this site isn't getting all Dick Cheney / media control about what is posted.

If a post is removed, I would expect the courtesy of notification and provision of a reason. If this site is being manipulated and content being altered without poster's permission, I'll leave or start a competitive site without editorial oversight.

 

Doug, Paul B, bistros et al
The Bethwaits are doing good work on the 49'er. Doug's and Ernest's posts have qualities. Information is spread.
Regards,
Booster

 

Booster:

Along with some valuable information, much mis-information is spread by Doug Lord. His "work" lacks objectivity and balance.

Doug is controversial and his provocative, confrontational approach generates strong response from people - causing lots of page reads and clicks as people slow down to watch the car wrecks. Unfortunately, Doug makes up for his lack of real experience and ability with VOLUME, drowning out people like SimonN, Bgulari and other real experts who actually have serious experience at performance sailing.

I completely understand how many folks may come to believe Doug's posts - but with actual time and real experience on the water sailing performance boats much of what he says starts to look .... unbalanced. Doug's true value is that he does a lot of information consolidation from all over the Internet - saving some people the effort of doing their own research. The problem is that Doug's research only provides one side of the case - pro-foiling.

If you make the effort to check out Doug's sources, you will often find that things are very different than Doug presents - he edits and shapes his posts carefully.

Do the exercise yourself - and form your own opinions. Let the forum know your results.

Now watch how fast Doug complains about my suggestion to form your own opinion.

--
Bill

 

Bistros!
As I recall Doug and Ernest were early with there critics of the canting-keels of the Volvo Ocean Race last time. Some of the designers had assumed the hull to be infinitely stiff. This assumption imposed bending to the hydraulic pistons. Since some bearings only were designed to rotate around one axis. Moreover, Doug and Ernest pointed out that the base of the hydraulic system shall be as wide as possible. But as you say we cannot have desinformation. This is a difficult line to be drawn here.
Regards,
Booster