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If the VOR configuration didn't have min crew rules, on a foiling IMOCA 3 folks hot bunking it on a beanbag and bunk will probably not require too much modification. Prob strike balance re not having too much extra gear that slows boat down (figuring each leg is about ~20 days) - consumables weight for 3 + personal gear + crew weight would be in the neighborhood of a IMOCA leaving for a trip around the globe. 

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^^^ AP and crashing along versus hand steering but more loaded up/more body weight to windward probably go close to cancelling each other out in the break shit department.

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1 hour ago, jack_sparrow said:

^^^ AP and crashing along versus hand steering but more loaded up/more body weight to windward probably go close to cancelling each other out in the break shit department.

Yeah you'd think human steering would be a huge advantage over the AP. 

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1 hour ago, terrafirma said:

Yeah you'd think human steering would be a huge advantage over the AP. 

Not.

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7 hours ago, Varan said:

Not.

Well that all depends on how good the helmsman is. Also, the fully crewed AP will only get I do from compass, so will be shit.

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15 minutes ago, Chimp too said:

Well that all depends on how good the helmsman is. Also, the fully crewed AP will only get I do from compass, so will be shit.

Not that shit, Mich Desj lost wind data to his pilot 5 days into his Vendee Globe win... 

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With fresh people driving the loads on the boat and rig will be considerably larger then anything the AP will ever produce. And the wipeouts even more so.

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On ‎10‎/‎5‎/‎2018 at 4:10 PM, Chimp too said:

The problem with T rudders in these is that the skippers all like the kick up systems for if they hit something. Kick up a T rudder and the tip would come off. Only solution is to retract the windward one vertically. But hit something and your race is over as you then turn back into a hobby horse.

 I am also not suggesting that IMOCA turn multi, only that foiling monohulls is not a natural progression. If you want to foil a multi is the obvious starting platform. The same goes for the new AC75.

I doubt the T's would come off if kicked up. They tend to rotate up until they are skimming the surface, yes a bit of load in the transition, but not foil breaking. And if you do lose a T your back to where things are now on that tack. Given the ingenuity of these guys I would not be surprised if they can change one out when doing 30 knots all without a harness on. 

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2 hours ago, Rawhide said:

I doubt the T's would come off if kicked up. They tend to rotate up until they are skimming the surface, yes a bit of load in the transition, but not foil breaking. And if you do lose a T your back to where things are now on that tack. Given the ingenuity of these guys I would not be surprised if they can change one out when doing 30 knots all without a harness on. 

They would clearly need to be in vertical cassettes like on the ultims, if rotating up, except if totally out of the water it would break

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4 hours ago, Rawhide said:

I doubt the T's would come off if kicked up. They tend to rotate up until they are skimming the surface, yes a bit of load in the transition, but not foil breaking. And if you do lose a T your back to where things are now on that tack. Given the ingenuity of these guys I would not be surprised if they can change one out when doing 30 knots all without a harness on. 

 

2 hours ago, yl75 said:

They would clearly need to be in vertical cassettes like on the ultims, if rotating up, except if totally out of the water it would break

Not necessarily the case. The foil is strong enough to support a significant proportion of the vessel's mass (10-20%) plus a margin, and the stall load of the foil when perpendicular to the flow is high, but only of the same order. The key is that the normally compressive joint with the rudder must take this load in tension, but this is required anyway as the rudder foil must be capable of pulling down as well as lifting.

However, if the rotational pivot point is made well aft of the lifting foil, then in the event of a rotation, the flow across the foil will cause it to flip out of the water very rapidly, and remember that when it is flipping up due to impact with a near stationary object, the relative speed of flow across the lifting foil is near zero as it flips up.

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Hugo Boss spotted testing in the Solent today. Looks like they have a bit on!

Photo taken by John Green Cowes

77E6826D-B9A7-448F-8144-E63DC3854C91.thumb.jpeg.f35f5320f8fa1e42e3618bef4271213d.jpeg

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17 hours ago, JL92S said:

Hugo Boss spotted testing in the Solent today. Looks like they have a bit on!

Photo taken by John Green Cowes

77E6826D-B9A7-448F-8144-E63DC3854C91.thumb.jpeg.f35f5320f8fa1e42e3618bef4271213d.jpeg

Maybe a touch more keel cant required. :P

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What seems absolutely bonkers to me is Hugo Boss has never raced in a long event on Mk 2 foils. They failed when they were testing before the VG and we've only gotten a glimpse during Middlesea and Fastnet. 

Sure AT is going to be pushing to win it - would be a great boat sale highlight that the boat is still available and immediately makes you a contender. 

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8 hours ago, Miffy said:

What seems absolutely bonkers to me is Hugo Boss has never raced in a long event on Mk 2 foils. They failed when they were testing before the VG and we've only gotten a glimpse during Middlesea and Fastnet. 

Sure AT is going to be pushing to win it - would be a great boat sale highlight that the boat is still available and immediately makes you a contender. 

I could be wrong but I believe they still sail the boat on the MK1 foils. 

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4 hours ago, JL92S said:

I could be wrong but I believe they still sail the boat on the MK1 foils. 

I thought he only has one of those left, never having built a new pair or replacement for the one sitting at bottom of the Sth Atlantic?

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5 hours ago, jack_sparrow said:

I thought he only has one of those left, never having built a new pair or replacement for the one sitting at bottom of the Sth Atlantic?

I think the VG foils were Mk2, not sure what they are using now. Heard somewhere that Mk1 barely made it past a few hours Sailing... Can't remember where I heard that, so could be complete bollocks :rolleyes:

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Complete bollocks:)   They designed a Mk2, and it lasted less than a couple of hours so stayed with the Mk1.  And then sued the builder of the foil - dunno what happened finally but they were also busy suing Green Marine and GM went out of business.   Wouldn't have been time to build any more as these things are extremely costly in time to build as well as $$$$$$$$$$$$$$$$$$$

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2 hours ago, GBH said:

Complete bollocks:)   They designed a Mk2, and it lasted less than a couple of hours so stayed with the Mk1.  

We all know that for the VG..question is what is bolted on now?

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I think Persico built them a replacement for the one that broke in the VG and then built them a replacement for the other one at a later date.

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6 hours ago, GBH said:

Complete bollocks:)   They designed a Mk2, and it lasted less than a couple of hours so stayed with the Mk1.  And then sued the builder of the foil - dunno what happened finally but they were also busy suing Green Marine and GM went out of business.   Wouldn't have been time to build any more as these things are extremely costly in time to build as well as $$$$$$$$$$$$$$$$$$$

Have they resolved the court case(s) yet? 

As I believe, the foil builder wasn’t responsible for the engineering of the foils, just the build. 

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2 hours ago, mad said:

Have they resolved the court case(s) yet? 

As I believe, the foil builder wasn’t responsible for the engineering of the foils, just the build. 

Correct, but they sued him anyway, ditto for GM too when it was really a design config FU seeing as all the others had similar issues.

The foils in the pic look very much like the originals, and would make sense to stick with those to get a better idea of how they work against the latest generation to take that knowledge into the new boat and configuration.

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2 minutes ago, GBH said:

Correct, but they sued him anyway, ditto for GM too when it was really a design config FU seeing as all the others had similar issues.

The foils in the pic look very much like the originals, and would make sense to stick with those to get a better idea of how they work against the latest generation to take that knowledge into the new boat and configuration.

Nothing like fostering good relationships with suppliers. :blink:

Anybody else willing to step up and supply the next generation foil package? 

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how much metal as opposed to carbon do most of these foils rely on for their structural integrity? given the loads and how dainty they look, it's impressive they don't just break, especially at the bends.

the people who build those things are true artists.

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1 hour ago, 3to1 said:

how much metal as opposed to carbon do most of these foils rely on for their structural integrity? given the loads and how dainty they look, it's impressive they don't just break, especially at the bends.

the people who build those things are true artists.

Pretty sure most are all composite, though some might have played with different tips like the AC boats. 

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2 hours ago, GBH said:

Correct, but they sued him anyway, ditto for GM too when it was really a design config FU seeing as all the others had similar issues.

The foils in the pic look very much like the originals, and would make sense to stick with those to get a better idea of how they work against the latest generation to take that knowledge into the new boat and configuration.

Unless you're privvy to the specific claims in the suit, rather presumptive to say it was due to foil breaking as opposed to say failure to meet schedule/spec weight/balance metrics. 

 

1 hour ago, 3to1 said:

how much metal as opposed to carbon do most of these foils rely on for their structural integrity? given the loads and how dainty they look, it's impressive they don't just break, especially at the bends.

the people who build those things are true artists.

Initial designs were all over the place and some foils had titanium trailing edge inserts/skeleton sheathed in carbon so you could have finer edges. 

It really depends on the boat design and intended use. These are more complicated than aircraft wings because you have moving mounts and also bearings that interact with the foil. Get it wrong? Foil fails. The dali foils had more issues because the loads changed depending on boat/water interaction a lot more and a small shark hitting the vertical edge of the foil could shatter the horizontal part. 

The mk2 foils on the French boats generally moved away from having aggressive titanium inserts and opted for more one piece composite structures. 1/3 of a million euros a pair. Ouch. 

 

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2 hours ago, 3to1 said:

how much metal as opposed to carbon do most of these foils rely on for their structural integrity? given the loads and how dainty they look, it's impressive they don't just break, especially at the bends.

the people who build those things are true artists.

I talked to a guy in Persico last month (currently building an Imoca) and he told me on that boat the board is mostly solid carbon, with some core material in the thickest part of the section. No metal stuff. Everything prepeg and cooked in autoclave , with very different fabric charactetistics (modulus, direction, etc) in the different parts of the foils, depending on the loads.

Last AC boats had definitely some metal in, instead, at least to my knowledge.

 

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Also largest country of origin of high performance antitwist rope for furlers. From a country where there is like one marina by the national opera house. 

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1 hour ago, 17mika said:

 

Last AC boats had definitely some metal in, instead, at least to my knowledge.

 

AC rules had allowances for swapping tip etc.  a lot easier to do this with a metal tang/socket.

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15 hours ago, Miffy said:

 1/3 of a million euros a pair. Ouch. 

 

And the rest! Not even half way there if you add tooling. Then think about housings, bearings etc. 

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On 10/14/2018 at 10:06 AM, GBH said:

Complete bollocks:)   

Yeah, I knew one pair had failed. Thanks for the info. 

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15 hours ago, jack_sparrow said:

Everytime foil design/construction comes up I can't help thinking of these carbon composite things. They are made by a world ortho device leader based in Iceland of all places.

https://www.ossur.com/corporate/about-ossur

Alan-Oliveira.jpg

Compared to IMOCA foils this is fairly straight forward technology. Known loads with predictable offaxis loading. Awesome to watch the athletes at work but no where near as complex as a dali foil.

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On 10/14/2018 at 5:06 AM, GBH said:

Complete bollocks:)   They designed a Mk2, and it lasted less than a couple of hours so stayed with the Mk1.  And then sued the builder of the foil - dunno what happened finally but they were also busy suing Green Marine and GM went out of business.   Wouldn't have been time to build any more as these things are extremely costly in time to build as well as $$$$$$$$$$$$$$$$$$$

Are English court filings available on the internet?  Would be pretty interesting to read.

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10 hours ago, Chimp too said:

And what about the DSS patent?

It's on the PTO website and google patents like almost every other US patent (national security exception).  

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Have read it, and the international patents. My question is why Hugo Boss haven’t paid it when the foils clearly meet the requirements of the patent.

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1 hour ago, Chimp too said:

Have read it, and the international patents. My question is why Hugo Boss haven’t paid it when the foils clearly meet the requirements of the patent.

The foils are prototypes not something you can buy.

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I thought the DSS claims were only related to a single, transverse mounted, sliding foil a la Infinity and CQS. There's scads of prior art on dual lifting daggerboards.

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Just because a patent exists doesn't mean it is valid. 

Reasonable minds at read the patent, weigh the risk that a patent litigation would find that prior art existed or it is obvious, and quietly ignore it. 

DSS's own lawyers could review the other designs and conclude it isn't worth the risk of having their patent invalidated. 

There are only so many naval architects and would be boat buyers and thus far, DSS hasn't exactly lit the world on fire. 

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As I say, I have read the various patents on DSS and understand that Hugo Boss have refused to pay even though they clearly infringe (read the patents if you want to know why). The one DSS boat that was designed to use it it Maverick, the 46 that seems to do pretty well

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Sighhhhh again - just because a patent exists does not mean it is valid. 

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On 10/12/2018 at 3:22 PM, mad said:

Maybe a touch more keel cant required. :P

At the beginning of the last VOR, Dongfeng was training against Mapfre and realized that you don't have to put your canting Keel at the maximum, specially upwind. Sorry for my bad English but you don't get much gain for the list of the vessel ( a little bit but not that much) and putin your keel 5-10° before the maximum makes your rig more "stiff?" (in French we say "Raide", not sure about the translation). We will say Stronger. DF Team discovered that during the trainings on the VO65 (and after every team copied that), could be the same for Imoca's.

Or Mb i'm wrong ! Who knows

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1 hour ago, Baguette du Fromage said:

At the beginning of the last VOR, Dongfeng was training against Mapfre and realized that you don't have to put your canting Keel at the maximum, specially upwind. Sorry for my bad English but you don't get much gain for the list of the vessel ( a little bit but not that much) and putin your keel 5-10° before the maximum makes your rig more "stiff?" (in French we say "Raide", not sure about the translation). We will say Stronger. DF Team discovered that during the trainings on the VO65 (and after every team copied that), could be the same for Imoca's.

Or Mb i'm wrong ! Who knows

For the IMOCA's, there is a speed at which the vertical lift from the fully canted keel starts to counter act the ballast in the bulb, and that's when the de-cant it a bit and press on the foil more.  I think it's around 20 kts.  Someone here will know better than me though.

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4 minutes ago, r.finn said:
1 hour ago, Baguette du Fromage said:

At the beginning of the last VOR, Dongfeng was training against Mapfre and realized that you don't have to put your canting Keel at the maximum, specially upwind. Sorry for my bad English but you don't get much gain for the list of the vessel ( a little bit but not that much) and putin your keel 5-10° before the maximum makes your rig more "stiff?" (in French we say "Raide", not sure about the translation). We will say Stronger. DF Team discovered that during the trainings on the VO65 (and after every team copied that), could be the same for Imoca's.

Or Mb i'm wrong ! Who knows

For the IMOCA's, there is a speed at which the vertical lift from the fully canted keel starts to counter act the ballast in the bulb, and that's when the de-cant it a bit and press on the foil more.  I think it's around 20 kts.  Someone here will know better than me though.

Makes sense, but in that picture HB does look slightly overpowered. Could just be a picture taken in an extra puff wind  as well. 

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6 minutes ago, r.finn said:

For the IMOCA's, there is a speed at which the vertical lift from the fully canted keel starts to counter act the ballast in the bulb, and that's when the de-cant it a bit and press on the foil more.  I think it's around 20 kts.  Someone here will know better than me though.

Didn't know about that on Imoca's. Ty for the tip (i won't use this one, don't have any plans to sail on ;)

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4 minutes ago, mad said:

Makes sense, but in that picture HB does look slightly overpowered. Could just be a picture taken in an extra puff wind  as well. 

Alex is famous for sailing overpowered, at the contrary the French guys will always take reef in mainsail in order to keep the boat safe (CF : last VG), diferent sailing styles !

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31 minutes ago, mad said:

Makes sense, but in that picture HB does look slightly overpowered. Could just be a picture taken in an extra puff wind  as well. 

He probably was, but they make exciting social media photos.  The IMOCA's often look overpowered these days as the optimum heel angle with the foil is more than with classic boards.  Shockingly over 25 degrees.  Again, someone here will know more than me, but I wasn't surprised to see the elevations on Charal's foil tips when the boat was launched.  

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on youtube- 'Charal, le film'. better than average 7 minute video in french.

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For reasons of procrastination I was looking at the Welbourn/DSS Patent 7,664,672. And in so googling I did find people have been debating if the Imoca foils infringe since Safran well before the last VG and evidently DSS has never perused any actions. When you look at claim 1 of the '672 patent there does seem to be quite a bit in common with the Imocas but throughout the sub claims and the following claims at least as far as I read, the "foil" is referred to in the singular. Also fairly far up in claim 1 there is the notion that the foil is angled such that it is substantially flat when the boat is heeled appropriately. This suggests they've restricted themselves a bit, or the examiner restricted them, to not talking about two separate foils and not J-foils that have a constantly changing angle. One could still be partially infringing on the substantially horizontal extension and retraction of a foil but there might be a lot of prior art around involving ship stabilizers and the like that the DSS patent already can't cover, so two foils puts you home free. Anyway, I have to go work, but remember, when you talk about patents, always go look at the claims and see the claims as a series of circles in a Venn diagram with Claim 1 being the largest, so that's what you have to focus on. 

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4 hours ago, 3to1 said:

on youtube- 'Charal, le film'. better than average 7 minute video in french.

Thanks 3to1, nice find. 

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13 minutes ago, shaggybaxter said:

Thanks 3to1, nice find. 

anytime.

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15 hours ago, mad said:

Makes sense, but in that picture HB does look slightly overpowered. Could just be a picture taken in an extra puff wind  as well. 

Exactly - Context is everything. Still shots have been used way too much to prove or disprove whatever argument you support. Dare we remember the fLordia fucKwit?

The Dongfeng trick was leaked accidentally/on purpose and created quite some controversy as a result. Team DF played a classy hand and didn't let it derail them.

It is based on the inclined hinge pin being set slightly too acutely upwards for the upper speed range, so whilst the normal reaction is to max the keel for max RM (which whilst Static is unquestionably the optimum) , the added lift of the fin and increased drag ultimately both reduced overall RM and lowered VMG. Remember that the inclined pin will contribute nothing at vertical axis but increases fin lift with cant angle. DF found that the ultimate speed sweet spot was in fact to drop the keel a small amount in certain conditions.

With both HB and Charal, the high heel angles makes the fore deck chamfer not only "a La mode" but both essential and faster.

I believe Ran VII has been quoted as saying that the chamfered foredeck allows the jib to "see" 5 or 7% more wind...... So food for thought.

In Imoca and Class 40 measurement terms - chamfered decks not only lower the overall COG of the structure - but also lower the COB during 90 degree pull down tests - thereby allowing max bulb weights to be implemented. It all becomes a virtuous circle to chase these shapes.

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On 10/12/2018 at 4:07 AM, JL92S said:

Hugo Boss spotted testing in the Solent today. Looks like they have a bit on!

Photo taken by John Green Cowes

77E6826D-B9A7-448F-8144-E63DC3854C91.thumb.jpeg.f35f5320f8fa1e42e3618bef4271213d.jpeg

Another keel walk stunt?

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14 hours ago, 3to1 said:

on youtube- 'Charal, le film'. better than average 7 minute video in french.

weapon 

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One interesting comment in the video from Vincent Lauriot Prevot, the architect.

In the past, for IMOCA boats, the goal was to increase power. To increase power, you had to increase righting moment, and that was done by the hull shape.

Now, the righting moment is dynamically generated by the foil; so the shift is to make a hull form to reduce drag, no longer to generate humongous amount of righting moment.

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The automatic translated sub titles work quite well on the Charal video (just checking being myself a frog ..)

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9 hours ago, Boink said:

Exactly - Context is everything. Still shots have been used way too much to prove or disprove whatever argument you support. Dare we remember the fLordia fucKwit?

The Dongfeng trick was leaked accidentally/on purpose and created quite some controversy as a result. Team DF played a classy hand and didn't let it derail them.

It is based on the inclined hinge pin being set slightly too acutely upwards for the upper speed range, so whilst the normal reaction is to max the keel for max RM (which whilst Static is unquestionably the optimum) , the added lift of the fin and increased drag ultimately both reduced overall RM and lowered VMG. Remember that the inclined pin will contribute nothing at vertical axis but increases fin lift with cant angle. DF found that the ultimate speed sweet spot was in fact to drop the keel a small amount in certain conditions.

 

i understand the IMOCAs have been 'decanting' the keel for some time, but the Volvos were first to have the keel pin inclined so the keel foil became an active lifting foil. Ger O'rouke told me they were using the keels back then to 'surf, so i bet it was well known back in 2005/6.  Certainly IMOCAs were decanting  before last the Vendee as the boat go faster.  It is to do with inclination of the keel pin so the keel foil  becomes a lifting surface as it cants so HB etc are flying on both keel and foil

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9 hours ago, Laurent said:

One interesting comment in the video from Vincent Lauriot Prevot, the architect.

In the past, for IMOCA boats, the goal was to increase power. To increase power, you had to increase righting moment, and that was done by the hull shape.

Now, the righting moment is dynamically generated by the foil; so the shift is to make a hull form to reduce drag, no longer to generate humongous amount of righting moment.

I wonder how far they’ll stretch this part of the rule before there’s a class meeting?  We’ve always looked the max, what’s the minimum end of the rule allow? 

Seems the next logical progression to me. 

A canoe style hull supported on foils? 

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18 minutes ago, mad said:

I wonder how far they’ll stretch this part of the rule before there’s a class meeting?  We’ve always looked the max, what’s the minimum end of the rule allow? 

Seems the next logical progression to me. 

A canoe style hull supported on foils? 

There's still the pulldown test and inversion self-righting tests. Both are static without foil generated RM. 

Boats also still have to perform for the light conditions between vendee and southern ocean passage so there's probably a huge diminishing return on going to extreme. 

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10 hours ago, SSolo said:

i understand the IMOCAs have been 'decanting' the keel for some time, but the Volvos were first to have the keel pin inclined so the keel foil became an active lifting foil. Ger O'rouke told me they were using the keels back then to 'surf, so i bet it was well known back in 2005/6.  Certainly IMOCAs were decanting  before last the Vendee as the boat go faster.  It is to do with inclination of the keel pin so the keel foil  becomes a lifting surface as it cants so HB etc are flying on both keel and foil

No,  The volvo 70 rule did not allow inclined pins.  This is not true.  Perhaps with tons of heel the fin would become a planing surface with a ton of gear piled at the back, but certainly no incline.

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5 hours ago, Miffy said:

There's still the pulldown test and inversion self-righting tests. Both are static without foil generated RM. 

Boats also still have to perform for the light conditions between vendee and southern ocean passage so there's probably a huge diminishing return on going to extreme. 

Going narrow would help in both of these tests. I see this as the way to go. It also reduces structural weight and is the natural progression. At the moment in IMOCA the hull shape and foils are designed separately. That will change

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15 hours ago, mad said:

A canoe style hull supported on foils? 

Reminds me of another kind of boat.  

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4 minutes ago, southerncross said:

Reminds me of another kind of boat.  

ssshhhhhhhh! don't mention his name :unsure:

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21 hours ago, Chimp too said:

Going narrow would help in both of these tests. I see this as the way to go. It also reduces structural weight and is the natural progression. At the moment in IMOCA the hull shape and foils are designed separately. That will change

VLP has already gone on record to say that Charal was explicitly designed around the foils, both hydro and aero foils. They start with potential "propulsive" power available from the rig, and then try to match that to the RM required and end with a hull design that will support all of it. 

The Hull "cannister" now needs to be structurally outstanding - but at the lowest hydro and aero drag, whilst also being physically large enough to carry one sailor, provisions and gear for 70 days.

It is unlikely that few appreciate how "petite" the latest IMOCA designs have become for 60 footers. Very small  freeboards - expecially compared to VO65's, and how Charal has gone back to a closed in rear deck, not seen for the last 10 years or so which allows a more efficient structure than open cockpits allow. it also creates an opportunity to make a more cohesive aero structure - even though the gains to be had here would be very small. 

Ultimately the design spirals down to the smallest possible hull structure - offering the smallest drag, lowest weight and stiffest platform. Yet thate are still class manadated minimums, static measurement requirements and a thousand other details to wrangle simultaneously.

Greater gains are then going to be had by focusing efforts on foil design - going longer, slimmer, higher lift, yet more forgiving to height and pitch control. Charal is published as having 80% lift capacity, compared to HB which was/is around 60%. No rudder foils prevent the main foils ever going to 100%. The other notable difference is how Charals foils erupt out of the hull deck whereas HB"s remained within. Probably a function of both their larger size, longer length and angle, as well as the smaller hull to house them in. 

All of this dovetails into why an IMOCA designed for VG and solo duties would be optimised to a design most likely disctinctly different to a design that would be used for Volvo and fully crewed duties. Just where would all the media gear go? Let alone all the extra sails, food and paraphenalia that the VOR brings. Can one size fit all? Budgets will probably force them to compromise to a shared optimum - possibly not a bad thing for the IMOCA's overall longevity and capacity to give sponsor ROI, which ultimately allows the class to both operate and flourish - but for a design purist, harder to swallow against what might emerge if left unchecked. 

Not an easy nut to crack

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Some info on Charal's foils:

Charal rocket ready for take-off

By Adrien Pinot In News On 30/08/2018


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August 21st in Brittany, the boat Charal (member of IMOCA category which major event is the Vendee Globe) touched the water for the first time. She is the first of new generation units to be built for the Vendee Globe in 2020 to be afloat.

Efficiency of foils -even on monohulls- is not to be proved anymore and they are the masterpiece around which the conception of the boat is made. These appendages serve to lift the boat above the water and they are particularly impressive on Charal with their great length meaning great power and sharp angles.

The parts were made by C3 Technologies’ team in about 1000 hours just for one part (with a mould needing 300h, the total is about 2300h to make the two foils) ! These part are mainly composed of carbon and will have to support very strong efforts. They were challenging to manufacture in order to achieve the better ratio between high resistance and light weight.

C3 Technologies also manufactured the rudders, the main bulkheads which constitute the skeleton of the boat -still in carbon- and the trailing edge of the keel (all parts are cured in autoclave).

Everybody is now looking forward to the performances of the Charal rocket.

http://www.c3technologies.fr/charal-rocket-ready-for-take-off/

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In what other country would you see families out for a Saturday afternoon walk, able to have free and unrestricted access, close enough to touch them, to the latest, highest profile racing machines?

Lorient on a sunny October afternoon.

IMG_7627.jpg

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A few years ago but the same spot, Lorient is truly amazing. Docks were open to the public.

 Y2GsOTRwG--n48p-tQkEhF0ojw9oB4elV2n6Q3FpPrnTegAknP8Y1OO7R9pumzkwlcSc99y-pTxTrmW2rcegHzNilm1-irh2OGv2Zkx1DLmpxZ12hhXNwQT5aGFbAwPxDoexsZp-dgXQcWpH4R-Q9kMUw3MwJV8m-6AMRqwwhPVFWUL80er9JKa1rOTDJHSdWu4RVdymv6LUUheaCQUboVWNcjZ57zIWejUgjhxtf6dkzli_OAYQ6WQo_4iT-__ACBkBKYRjYoJ5pNBlEcuXyzda2dZwlcjiAuVA0UU68olncq14k_S8l3CRkfndAcrwv3_rT36ODQnWjL4mJnZwPCLvUWXjmOk_FtgUK9h54DIK_jYh8TiJ9h9EYGL-Dr4SM_6-VlOwNjYDBdSA3svbW0Sm55YVq-aay5TQFVnQKT8jqlwqmIZ2DSxhC-0VyDT-5s-VOmTcg1Aj-dM5Q0RFaHOmSJGc5HseEZtIci48t7m4LcuZnsgadML3EJvQjQ9Ng0k6AblGTBMMOXp2qVKWU0CMjApffdZmjT7EqkJlICetomVamToH8PvSIdoGry9oiKkdrbhGoOIzLX6NN3ZgOkOyLk0r13LWlNAACJU9dM82n4BlyR6LsBcWW7MhbRg=w493-h657-no

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Remember that Charal is the 1st boat of its generation, meaning future HB and any other new builds will be slightly improved compared to Charal. However, Alex has stated that his next boat will be 100% green adding about 100 kilos according to him. I hope he has a trick or two up his sleeve, it would be a fitting end to finally have AT win the bloody race. 

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1st of it's generation means squat, plus they have time on the water. 

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12 hours ago, Raptorsailor said:

Remember that Charal is the 1st boat of its generation, meaning future HB and any other new builds will be slightly improved compared to Charal. However, Alex has stated that his next boat will be 100% green adding about 100 kilos according to him. I hope he has a trick or two up his sleeve, it would be a fitting end to finally have AT win the bloody race. 

Is Armel Le Cleac'h doing the race next time? If not Alex has a great chance. Like always whoever wins will need some luck and all foils in tact. 

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No Armel is fully committed to his ultim program, but for sure Alex will have some serious competition, and I also hope he wins this time, this race needs a non French winner.

Would have been great if it had been Mike Golding in 2008

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On 10/20/2018 at 1:16 PM, Boink said:

VLP has already gone on record to say that Charal was explicitly designed around the foils, both hydro and aero foils. They start with potential "propulsive" power available from the rig, and then try to match that to the RM required and end with a hull design that will support all of it. 

The Hull "cannister" now needs to be structurally outstanding - but at the lowest hydro and aero drag, whilst also being physically large enough to carry one sailor, provisions and gear for 70 days.

It is unlikely that few appreciate how "petite" the latest IMOCA designs have become for 60 footers. Very small  freeboards - expecially compared to VO65's, and how Charal has gone back to a closed in rear deck, not seen for the last 10 years or so which allows a more efficient structure than open cockpits allow. it also creates an opportunity to make a more cohesive aero structure - even though the gains to be had here would be very small. 

Ultimately the design spirals down to the smallest possible hull structure - offering the smallest drag, lowest weight and stiffest platform. Yet thate are still class manadated minimums, static measurement requirements and a thousand other details to wrangle simultaneously.

Greater gains are then going to be had by focusing efforts on foil design - going longer, slimmer, higher lift, yet more forgiving to height and pitch control. Charal is published as having 80% lift capacity, compared to HB which was/is around 60%. No rudder foils prevent the main foils ever going to 100%. The other notable difference is how Charals foils erupt out of the hull deck whereas HB"s remained within. Probably a function of both their larger size, longer length and angle, as well as the smaller hull to house them in. 

All of this dovetails into why an IMOCA designed for VG and solo duties would be optimised to a design most likely disctinctly different to a design that would be used for Volvo and fully crewed duties. Just where would all the media gear go? Let alone all the extra sails, food and paraphenalia that the VOR brings. Can one size fit all? Budgets will probably force them to compromise to a shared optimum - possibly not a bad thing for the IMOCA's overall longevity and capacity to give sponsor ROI, which ultimately allows the class to both operate and flourish - but for a design purist, harder to swallow against what might emerge if left unchecked. 

Not an easy nut to crack

I was lucky enough to jump on Seb's boat when it came into Freo last time, I don't understand how he fitted it it let alone a crew. It was poky as hell for my 3yo and I.

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On 10/19/2018 at 4:46 PM, rmb said:

No,  The volvo 70 rule did not allow inclined pins.  This is not true.  Perhaps with tons of heel the fin would become a planing surface with a ton of gear piled at the back, but certainly no incline.

wasn't there a couple of VO70's with trailing (as opposed to T-shaped) fin/bulb combos ?  I recall some discussion of fin twist on these designs when canted.

Maybe I'm imagining things.. and I've no idea if its structurally viable

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Duncan,

All of the VO70s had T keels. With solid, forged fins and the load requirements I doubt that there was much room to use twist as a benefit. The rule was specifically written to prohibit inclined pins as a way of trying to control development costs. Same reason that hydrofoils (Dail/DSS etc) were prohibited.

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The noise about fin twist is just that, noise. The V60 and V70 rules required extremely high fin fatigue life and I do not believe it would be possible to meet those requirements with a fin that had interesting amounts of torsional deflection under static conditions as the fatigue would be considerable in dynamic conditions.

There is one V70 fitted with a trim tab on the fin's trailing edge specifically to generate lift. The sailing team indicates it's been an overwhelmingly positive change in terms of performance, that it sails like an entirely different boat.

I'm unsure of the rating hit and whether the increase in performance at certain angles overcomes the rating penalty that's carried at all times.

 

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On 9/27/2018 at 12:55 PM, Boink said:

Farr used to invoke fin twist in VO60's with L shaped fin and bulb packages. Go the other way and hang the bulb's COG forward of the fin's COE and you can do the opposite - but you need to get some very carefully calculated and repeatable materials response to make this manageable, you are trying to suspend a Bulb for RM generation as well as not detrimentally alter leeway resistance.

The whole package is moving in in all axis of free movement. At vertical the relationship of COG to COE between Bulb and fin is neutral. At max cant, any lateral displacement between the COG to COE position will induce the most amount of of twist on the fin. So on fixed keel(fin) boats e.g. VO60 - at moderate heel, the fin twist gave useful Fin twist to reduce leeway - that only became increasingly unhelpful in terms of RM at the moment that a broach was about to happen. 

 

aha - it was here I read it, and VO60, not 70.

 

I'm not sure I believe it, either.

 

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7 hours ago, Moonduster said:

The noise about fin twist is just that, noise. The V60 and V70 rules required extremely high fin fatigue life and I do not believe it would be possible to meet those requirements with a fin that had interesting amounts of torsional deflection under static conditions as the fatigue would be considerable in dynamic conditions.

There is one V70 fitted with a trim tab on the fin's trailing edge specifically to generate lift. The sailing team indicates it's been an overwhelmingly positive change in terms of performance, that it sails like an entirely different boat.

I'm unsure of the rating hit and whether the increase in performance at certain angles overcomes the rating penalty that's carried at all times.

 

Moonduster - which VO70 is this?

Recently Carkeek have been experimenting with Trim Tabs on the trailing edge of canting keels - using external actuators - which was the unexpected part.

Which would certainly add another dimension to these foils - not to mention complexity.

But as a means to generate gains in both RM and Foil lift it seems to be the lowest hanging fruit as it were to chase in this design space, which would be of interest to Imoca's, Supermaxi's, Wally's and generally anything that is Canting its keel - now or in the future - so constitutes both tangible potentail for both uptake as well as marketability/trickle down - depending on your perception. 

Whether you add to that mix, vertical daggerboards, curved but predominantly vertical boards, horizontal DSS style fins or Dali style foils would be dependant on class and or intended use (racing vs. Wally esque performance crusing).

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2 hours ago, Boink said:

Moonduster - which VO70 is this?

Recently Carkeek have been experimenting with Trim Tabs on the trailing edge of canting keels - using external actuators - which was the unexpected part.

Which would certainly add another dimension to these foils - not to mention complexity.

But as a means to generate gains in both RM and Foil lift it seems to be the lowest hanging fruit as it were to chase in this design space, which would be of interest to Imoca's, Supermaxi's, Wally's and generally anything that is Canting its keel - now or in the future - so constitutes both tangible potentail for both uptake as well as marketability/trickle down - depending on your perception. 

Whether you add to that mix, vertical daggerboards, curved but predominantly vertical boards, horizontal DSS style fins or Dali style foils would be dependant on class and or intended use (racing vs. Wally esque performance crusing).

Creating lift with trim tabs isn't a whole lot different to inclining the keel pin.  Perhaps more draggy but would cop a rating hit that an inclined pin doesn't, and the VOR65 experience seenms to suggest that generating lift from a canting keel that cancels out RM is a double edged sword.  Combing a lifting keel with a DSS foil out the other side, however and you're lifting the whole boat up, especially useful when you have a maximium net RM dictated by a one design mast.

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2 minutes ago, DickDastardly said:

Creating lift with trim tabs isn't a whole lot different to inclining the keel pin.  Perhaps more draggy but would cop a rating hit that an inclined pin doesn't, and the VOR65 experience seenms to suggest that generating lift from a canting keel that cancels out RM is a double edged sword.  Combing a lifting keel with a DSS foil out the other side, however and you're lifting the whole boat up, especially useful when you have a maximium net RM dictated by a one design mast.

I agree entirely that the inclined pin has become a double edged sword.

 

I think where my wagons have circled to is that inclined keel pins and their overall sucess is entirely dependent on it being set "exactly" right at the time of build - and we all know that what is right in one scenario, be that speed, trim or sea state will not remain fixed for all time.

Foils are increasingly higher aspect, slimmer, narrower chord and ultimately more trim critical. Because ultimately both materials and construction techniques have improved so dramatically that these more efficient shapes are more ideal to employ.

The range of speeds that foils they are running through are also greater. Fixed foil shapes and a fixed trim attitude can only be optimised for one type of scenario. The capacity that a commercial jet has to deform a wing shape to suit its 3 modes - take off, cruise and landing mode - is all the inspiration that should be needed to extend the sweet spot that sail boat foils need to improve upon. 

The lack of rudder control surface is what will ultimately restrict or slow down development in IMOCA's - be that good or bad - not part of the consideration here.

This is where I think foils on sailboats can only extend their range of optimisation by having trim tabs, and generally speaking the types of boats we are referring to here are either open development classes, line honours machines or not focused on IRC/ORC issues. Let the development roll.

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The problem with inclined pin angle is that it is fixed. A trim tab can be adjusted to the optimum for the specific conditions and configuration wanted. The Cookson 50 even used it initially to remove the need for dagger boards, although most later added something.

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3 hours ago, terrafirma said:

Nice shot of Charal flying the hull..! 

Well, I guess that answers the question why the foils are so overbuild. :)

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I believe you'll find that the only aspect of an IMOCA 60 that is over built is the skipper's confidence that he/she will make it around the planet without a failure.

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Need to see more than a still photo. Video of what happened next would be good. On that basis I remember seeing a Mumm 30 fly!

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6 hours ago, Chimp too said:

Need to see more than a still photo. Video of what happened next would be good. On that basis I remember seeing a Mumm 30 fly!

Comparing Charal to a Mumm 30? OK .... There are plenty of videos that show what happened next. A Mumm 30 would bury the nose and submarine. LOL

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I believe that this video would help. It is not the instance of the photo posted by Terrafirma - the conditions were not as nice, different tack etc 

This video is from the Defi Azimut - and the music is cheesy (from a can) bad..... It cuts between footage of the solo offshore start to the fully crewed speed runs.

At around a 1.00 minute the boat erupts out of the water - momentarily - to the surprise of the chase crew and crashes back down - not a broach in the traditional sense - but not super fast either - especially when you consider the primary aim of this outing.

The results were telling - Charal was more than 10% faster than 2nd and 3rd place. 

Again context is everything - still photos are cool - often much higher resolution - allowing detail to be seen - but tell the story of that moment only - and have been used and abused too often - especially on these forums to maker a case or refute a statement.

Without rudder wings - full flight is NOT sustainable - It will happen, but cannot be maintained. 

 

 

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4 minutes ago, Boink said:

I believe that this video would help. It is not the instance of the photo posted by Terrafirma - the conditions were not as nice, different tack etc 

This video is from the Defi Azimut - and the music is cheesy (from a can) bad..... It cuts between footage of the solo offshore start to the fully crewed speed runs.

At around a 1.00 minute the boat erupts out of the water - momentarily - to the surprise of the chase crew and crashes back down - not a broach in the traditional sense - but not super fast either - especially when you consider the primary aim of this outing.

The results were telling - Charal was more than 10% faster than 2nd and 3rd place. 

Again context is everything - still photos are cool - often much higher resolution - allowing detail to be seen - but tell the story of that moment only - and have been used and abused too often - especially on these forums to maker a case or refute a statement.

Without rudder wings - full flight is NOT sustainable - It will happen, but cannot be maintained. 

 

 

THIS! all that being said I really do wonder how long it will be before designers and skippers start playing around with T foils on the rudders. 

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23 minutes ago, frozenhawaiian said:

THIS! all that being said I really do wonder how long it will be before designers and skippers start playing around with T foils on the rudders. 

Charal being 10% faster makes this coming Route De Rhum interesting. (Conditions notwithstanding) . Armel is on a Trimaran so he's out of the Imoca class for now. Vincent Riou, JB, Alex would then be my first 3 favourites. A lot of people picking Sam Davies but against these 3 she will have her work cut out IMO. Vincent is a great sailor, one of the best so will also be interesting to see how he goes with his retro fitted boat against Alex and then JB. An older retro boat vs last generation vs new generation. No figures on Charal for sail area, displacement etc, being published on the RDR site?

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17 minutes ago, terrafirma said:

Charal being 10% faster makes this coming Route De Rhum interesting. (Conditions notwithstanding) . Armel is on a Trimaran so he's out of the Imoca class for now. Vincent Riou, JB, Alex would then be my first 3 favourites. A lot of people picking Sam Davies but against these 3 she will have her work cut out IMO. Vincent is a great sailor, one of the best so will also be interesting to see how he goes with his retro fitted boat against Alex and then JB. An older retro boat vs last generation vs new generation. No figures on Charal for sail area, displacement etc, being published on the RDR site?

agreed on all points, the RDR is going to be very interesting to watch play out. 

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