Foiling Monohull - what would it look like?

[Terry Hollis 441]

1 hour ago, RobG said:

 

The comment was in regard to the mini 650, which I am quite sure will not be doing foiling tacks for a long time to come.

If you've ever tried to do a foiling tack on a Moth you wouldn't say "just fine". Moths are a unique example, and so far the only monohull that can be considered a successful foiler *. The Quant 23 is still proving itself but is showing promise, though I've yet to see a foiling gybe and tacks are likely a long way off. But give it to some AC guys for a while with a licence to redesign the appendages as required and who knows what it could do in 12 month's time.

* Where success means it has achieved its design goals, foils at the same true wind angles as a non–foiler (not just on particular points of sail) and has gained a decent following with reasonable sized fleets in multiple locations.

I don't disagree with that ,, what I disagreed with was your statement "Like any other mono, foiling tacks are completely out of the question. "

[Team_GBR 198]

1 hour ago, RobG said:

 

The comment was in regard to the mini 650, which I am quite sure will not be doing foiling tacks for a long time to come.

If you've ever tried to do a foiling tack on a Moth you wouldn't say "just fine". Moths are a unique example, and so far the only monohull that can be considered a successful foiler *. The Quant 23 is still proving itself but is showing promise, though I've yet to see a foiling gybe and tacks are likely a long way off. But give it to some AC guys for a while with a licence to redesign the appendages as required and who knows what it could do in 12 month's time.

* Where success means it has achieved its design goals, foils at the same true wind angles as a non–foiler (not just on particular points of sail) and has gained a decent following with reasonable sized fleets in multiple locations.

To say the Moth is the only monohull that can be considered a successful foiler is pushing it a bit, unless you make the criteria so tight only the Moth will fit, as you have done. For instance, foiling tacks aren't influenced by the size of fleet and having fleets in multiple locations. Foil tacks are hard enough without adding unnecessary criteria to make a point.

I think there are a number of monohull foilers which you could say succeed at their designed task - they can tack and gybe on foils (how about the Waszp for starters). It still doesn't get away from the real point you should be making, that it is highly unlikely that we will see these AC boats doing foil tacks.

[hoom 640]

10 hours ago, MR.CLEAN said:

Let's pretend you don't need human power.  Motor + hydraulics on for the maneuvers to cant the keel and move the boards.  What would it look like then?  

Give me cyclor powered foiling cats anyday instead.

 

13 hours ago, MR.CLEAN said:

Why not split the lifting into two fore and aft foils on each side, with one rudder? Anyone with drawing skills have an idea of what that one would look like?

 

You mean instead of a single beamier one? Because beam = righting moment.

[dachopper 24]

It's about time you had a post from me....

 

I give you "the Destroya"

 

It will foil upwind 30 - 45 off the wind, max speed over 40 kts, crew of 2

 

Scrub center of bouyancy, the whole thing is airborne !

[rgeek 160]

2 hours ago, Terry Hollis said:

Any fully foiling boat has to minimize weight and drag to be successful .. a long fin with a bulb on the end fails on both counts.

A fully foiling boat will not be required to heel because it can use the windward foil for stability so in that form a long fin serves no purpose.

If they can't design a hull form that wont fall over at the dock they will have to use some internal ballast .. maybe water ballast that can be discharged when they start racing.

The challenge there is that "traditional match racing" requires a boat that has high static stability. Otherwise it'll just fall over during down speed manoeuvring, particularly a dial up.

It also needs a degree of ability to fall off slowly and differently under the influence of random wind and wave action based on small positioning differences. Otherwise there is little potential for the windward boat to get into difficulty resulting in a penalty.

The relative lack of prestart drama in AC35 was in part due to the ease with which the boats couple hold a relatively static windward position (coupled with RRS 15 and 16). The only time we saw any drama (BAR v TSJ) was when the windward boat deliberately chose not to react to a hook.

[surfsailor 283]

2 hours ago, Terry Hollis said:

Any fully foiling boat has to minimize weight and drag to be successful .. a long fin with a bulb on the end fails on both counts.

A fully foiling boat will not be required to heel because it can use the windward foil for stability so in that form a long fin serves no purpose.

If they can't design a hull form that wont fall over at the dock they will have to use some internal ballast .. maybe water ballast that can be discharged when they start racing.

Add a flap  to the long fin that can generate additional downforce - righting moment - on demand, and it's a different story. The bulb itself as I noted would be very small - just enough to keep it from capsizing at the dock. Remember, we're not talking about a powered up aircraft carrier like Commanche, we are talking about a single-hulled foil launch vehicle - so you've got to think a bit along the lines of a moth, lean and mean, requiring a replacement for the crew weight, which to me would be a  multistage righting system with a lifting foil to leeward plus additional righting moment on tap as needed from a downward acting foil to windward. 

And I fail to see why water ballast - which does anything but 'minimize weight' - would be either advantageous or even manageable around a closed course. There are simpler ways to skin a cat.

[rgeek 160]

You're forgetting the basic requirements.

Reintroduction of traditional match racing (which is a buy product of traditional keelboat design) and 'real' (meaning not pumps used to generate sorted power for appendages) crew with recognisable roles (including grinders) performing manoeuvres (which means a boat that's slow enough to need ropes to be pulled by winches and that's slow enough to need a range of down wind sails.

That means a moderately high performance monohull with sufficient stability not to fall over in the prestart.

Dalton has also made complaint about the lack of after life for the boats.

Twice before the AC has plumped with the fastest inshore class enough numbers and that was financially viable to campaign in the AC (sorry The Jay, not one offs, point and shoot offshore boats or legacy boats that no one could afford to build new). Plumping for a 72 that could be converted to race in Maxi 72 would be consistent with the move to J Class and 12 meters (and consistent with The Jays observations on the relative performance of AC boats to the one offs, point and shoot offshore and legacy boats out there).

It also fits with an agenda propping up the Grand Prix pretentions of the Med based racer/cruiser scene.

[Mozzy Sails 953]

7 hours ago, Tornado-Cat said:

I guess you did not realize that the first video is from september 10, not posted here before as far as I know, and represents the first video I have ever seen of a foiling mono in a strong wind, on the ocean, and with a reef. That was not a Qwant on a lake in perfect conditions.

For the rest, I am not a mono foiler apologist but your comments about foiling gybes and tacks are pretty stupid when you know the progress that was made in a few months with the multis. When was the first foiling tack realized ? a few months ago.

 

What, you mean the video the showing no more than 7 consecutive seconds of flight? 

It may be a new video, but to me it looks identical to this video from February https://youtu.be/si6c9F0P294 , i can't be bothered to search the forums, but I'm sure it has been posted before. 

All these videos are the same, broad reaching with sketchy flight control. It's impressive, and very exciting for offshore sailing, don't get me wrong. However, it is so, so far away from foiling around a short course and the videos you post show no progress to show they are moving in that direction. 

My comment about tacks and gybes is not stupid. The first rumors of the AC cats foiling was 2013... it took them four years to get from there to reported foiling tacks, and even in the cup itself foiling tacks weren't a given for all teams. 

[Curious2 4]

On 22/09/2017 at 8:47 AM, ~Stingray~ said:

In a strict DoG Match, exactly as was set down by the donors, the result of the contemplated competition came down to a Constructed in Country 'fastest boats they could design and build' Match.

There is plenty of other great sailing to follow, yes including Olympic Lasers as dogwatch always points out, but the idea that the fundamental point of this particular competition between nations was ~not~ about designing and building the fastest boats possible requires a very convoluted argument given the AC33 evidence.

MC is obviously a different deal but seriously: if the point is still to be fast, then why even try to do it with lead for ballast? To try replicate 18XX 'Tradition'? It feels like just a cheap, modern money-men, fancy-purse-selling, $ell-out. 

There's a J Class already for the Tradition.

 

Deleted to stop the hijack.

[surfsailor 283]

47 minutes ago, rgeek said:

You're forgetting the basic requirements.

Reintroduction of traditional match racing (which is a buy product of traditional keelboat design) and 'real' (meaning not pumps used to generate sorted power for appendages) crew with recognisable roles (including grinders) performing manoeuvres (which means a boat that's slow enough to need ropes to be pulled by winches and that's slow enough to need a range of down wind sails.

That means a moderately high performance monohull with sufficient stability not to fall over in the prestart.

Dalton has also made complaint about the lack of after life for the boats.

Twice before the AC has plumped with the fastest inshore class enough numbers and that was financially viable to campaign in the AC (sorry The Jay, not one offs, point and shoot offshore boats or legacy boats that no one could afford to build new). Plumping for a 72 that could be converted to race in Maxi 72 would be consistent with the move to J Class and 12 meters (and consistent with The Jays observations on the relative performance of AC boats to the one offs, point and shoot offshore and legacy boats out there).

It also fits with an agenda propping up the Grand Prix pretentions of the Med based racer/cruiser scene.

I was just talking theoretically. In reality, I heard the boats were going to be super-sized TP52's with foil assist for the reaching legs - so conceptually not that different from the Imoca 60s, except minus the canting keel.

[rgeek 160]

Reaching legs??

 

What next? A parade of sail??

[Doug Lord 1,219]

9 hours ago, Terry Hollis said:

Any fully foiling boat has to minimize weight and drag to be successful .. a long fin with a bulb on the end fails on both counts.

A fully foiling boat will not be required to heel because it can use the windward foil for stability so in that form a long fin serves no purpose.

If they can't design a hull form that wont fall over at the dock they will have to use some internal ballast .. maybe water ballast that can be discharged when they start racing.

Terry, don't forget that the first foiling keelboat-the Quant 23-has a "long fin with a bulb on the end.." and takes off in a 5 knot wind and foils upwind in 7-8 knots of breeze. It is for sure "successful"!

[Doug Lord 1,219]

14 hours ago, Doug Lord said:

NZAC ONE-----my initial conception of how the design could work:

1) I don't much like the bow but the idea was to make it a bit safer for anyone working up there.

2) Both foils pivot in their own pivoting trunk to retract-they could also slide up if required.

3) This type of foil doesn't need to be constantly adjusted-very rarely adjusted since it is a surface piercing foil

4) Only one mainfoil and the rudder T-foil in the water providing lift--plus the keel providing lateral resistance.

5) Didn't have time to draw it but the flared section of the main hull is relatively short in a F& A direction to keep weight down.

This boat would not require a canting keel and would be self-righting like any good keelboat with an assist from the buoyancy pods.

[Terry Hollis 441]

11 minutes ago, Doug Lord said:

Terry, don't forget that the first foiling keelboat-the Quant 23-has a "long fin with a bulb on the end.." and takes off in a 5 knot wind and foils upwind in 7-8 knots of breeze. It is for sure "successful"!

Yes that's right Doug but by "fully foiling" I mean that it has the ability to tack and gybe without dropping off the foils like the AC50's did and I don't think that is possible when the boat must drag an extra fin around with a lump of lead at the end.

[Doug Lord 1,219]

Terry, I  heard from Michi, the owner of the Company that conceived of and promotes the boat, that they have done foiling gybes. 

[MR.CLEAN 4,187]

17 hours ago, surfsailor said:

^ The fine line is when power is used to move control surfaces - sails, boards, etc.

Where the line is drawn is 100% opinion, innit.  If not, we wouldn't have canting keel boats racing around the world.

[IPLore 1,116]

We are all thinking in terms of audience and participation.

This was a goal for the last defender.  I think it is also a priority for New Zealand. But what are the important criteria for the Italians.

I suspect the numero uno priority for the Italians is that they have a good chance, or at least a better than even chance of winning the cup. Are the Italians good at foiling? Can we list any outstanding Italian sailors who have extensive foiling credentials?

The kiwis are going to want to have a nationality rule, and the Italians are going to say, "Okay but then we have to choose a boat where Italians can perform". 

Italians have been doing very well in sport boat classes.  Higher performance keel boats that are light and respond quickly to pressure but a world away from foilers.  Clean can speak to the names of these guys. Do the Italians care if their selection doesnt foil gybe or foil tack?  Do they care if it doesnt foil upwind?  If it can plane downwind, in a foil assisted manner...will that meet their modest foiling goals?

The deal seems to be that the Italians choose the boat.  What do they want?

 

[rgeek 160]

1 hour ago, MR.CLEAN said:

Where the line is drawn is 100% opinion, innit.  If not, we wouldn't have canting keel boats racing around the world.

Gerbils pumping up hydraulics to move a vertically lifting foil and horizontally lifting foil, what's the difference? If the mob is against one then so reasonably they must be against the other. Stored power for either that hasn't been generated by humans would be a step beyond anything seen in AC35 in terms of removing the human factor.

May be it's just about the look of the thing? If they had gone full battery on the AC50 leaving a helm, wing trimmer, foil trimmer and float ya gotta wonder if there would of been so much drama.

[Doug Lord 1,219]

IPLore, you may be right. I think radical innovation will probably be squelched by the Italians but I'm not sure why...

[Tornado-Cat 1,082]

Mirabaud is an interesting mono foiler, more interesting would have been a central hull with Z foils on both sides, on two wide beams.

But I agree with the above post, Italians will chose a boat that they like and where they have the most chance to win, which is a mono with a bulb and a small foil to please the kiwis.

It will be big, probably 72 fts, not fast, not beautiful, not classic, not modern. If you want to come back to beautiful and classic you chose a J class, if you want it fast you chose a radical foiler, mono or multi.

[surfsailor 283]

3 hours ago, Terry Hollis said:

Yes that's right Doug but by "fully foiling" I mean that it has the ability to tack and gybe without dropping off the foils like the AC50's did and I don't think that is possible when the boat must drag an extra fin around with a lump of lead at the end.

I think the lead lump could be small enough, and the extra fin turned into an asset by adding a flap to it, but yes - foiling tacks at least would be very difficult. I wouldn't rule out foiling jibes, but all of this conjecture is probably a moot point based on what I've heard. We'll know in a couple days.

[nav 591]

3 hours ago, IPLore said:

The deal seems to be that the Italians choose the boat.  What do they want?

 

That's is not my reading of the various quotes from the team leaders.

PB called for a mono, he's going to get one. But it sounds to me that the details are being worked out by a group of designers (and sailors probably) and given that it's ETNZ's stomping ground I expect they will be setting the broad requirements to be met.

Replicating the AC50 will not be a priority

[Boybland 560]

5 hours ago, Doug Lord said:

IPLore, you may be right. I think radical innovation will probably be squelched by the Italians but I'm not sure why...

It will be squelched by the Italians and re-ignited by the Kiwis using something no one else thought of, i.e. business as usual for the AC.

[Xlot 1,162]

3 hours ago, nav said:

That's is not my reading of the various quotes from the team leaders.

PB called for a mono, he's going to get one. But it sounds to me that the details are being worked out by a group of designers (and sailors probably) and given that it's ETNZ's stomping ground I expect they will be setting the broad requirements to be met.

 

This. And consider that a simple, big-TP52 boat is what the much-despised (by Bertelli) Onorato would prefer, it's a good reason for a more sophisticated formula

[surfsailor 283]

10 hours ago, MR.CLEAN said:

Where the line is drawn is 100% opinion, innit.  If not, we wouldn't have canting keel boats racing around the world.

Not really. Instruments run off a tiny battery, and have nothing to do with making the boat go beyond providing information -  as opposed to say canting keels, or hydraulically driven foils.

With any luck, the development and innovation that comes out of this cup cycle will make powered canting keels redundant and unnecessary.

[jaysper 1,264]

16 minutes ago, surfsailor said:

Not really. Instruments run off a tiny battery, and have nothing to do with making the boat go beyond providing information -  as opposed to say canting keels, or hydraulically driven foils.

With any luck, the development and innovation that comes out of this cup cycle will make powered canting keels redundant and unnecessary.

I hate to agree with CLEAN (trust me I do), but he is right - it is all about opinion just as Cats vs Monos is.

But, and this is a FUCKING BIG ARSE BUTT, my opinion is that using electric or diesel to cant a keel like this is an abomination of the kind that I cannot abide.

So, I agree with you that I hope this cup cycle flushes the need for such shit.

But, it is still only an opinion.

[surfsailor 283]

^ Here, let me unpack it for you: You can sail anything without instruments. You can NOT sail a canter without a motor running.

[RobG 816]

22 hours ago, Team_GBR said:

To say the Moth is the only monohull that can be considered a successful foiler is pushing it a bit, unless you make the criteria so tight only the Moth will fit, as you have done. For instance, foiling tacks aren't influenced by the size of fleet and having fleets in multiple locations. Foil tacks are hard enough without adding unnecessary criteria to make a point.

I think there are a number of monohull foilers which you could say succeed at their designed task - they can tack and gybe on foils (how about the Waszp for starters). It still doesn't get away from the real point you should be making, that it is highly unlikely that we will see these AC boats doing foil tacks.

I don't think my criteria were that tough. A Waszp is a Moth, I don't think anyone is foil-tacking their Waszp in club racing. It just doesn't seem to have the speed to carry it's extra bulk through the tack, nor do the foils seem efficient enough, but I'm very happy to be proved wrong about that.

Again, my comments were in regard to a Mini 650 foiling and was just pointing out that it's not a particularly good foiler yet (but the usual caveat applies - what might it be doing in 3 years with full–on "make me foil you bastard" development). And I really do think the 650 will get a lot better quickly, but not foiling tacks because it just doesn't need to do them.

I totally agree that it currently seems unlikely a 20m mono will do a foiling tack, but we haven't see the design criteria yet. Some kind of Quant-like pectoral foil arrangement may do the trick, but it might also not have sufficient outright speed.

[Tornado-Cat 1,082]

17 hours ago, The Jay said:

Deleted to stop the hijack.

You did not hijack the thread, you just tried to explain us why it was normal, on an historical point of view, that the next AC would be a slower boat contest.

[Schakel 260]

Correct me if I am wrong, why not the following new idea integrated with the new mono foiler?


https://youtu.be/MG0OWz_orK8

[dogwatch 1,314]

20 hours ago, MR.CLEAN said:

Where the line is drawn is 100% opinion, innit.

Not really. RRS draws a clear line. My opinion is that stepping outside that line is the wrong direction for the sport.

[Doug Lord 1,219]

10 hours ago, surfsailor said:

^ Here, let me unpack it for you: You can sail anything without instruments. You can NOT sail a canter without a motor running.

The Schock 40 canted its keel using battery power-no motor running.

[Wolkenzug 33]

35 minutes ago, Doug Lord said:

The Schock 40 canted its keel using battery power-no motor running.

As does the Melges 40.

[Curious2 4]

15 hours ago, Boybland said:

It will be squelched by the Italians and re-ignited by the Kiwis using something no one else thought of, i.e. business as usual for the AC.

How often since the 1850s has the AC used something no one else thought of? 

[~Stingray~~ 38]

Hydrofoils take hold in leading yacht race events

 

https://www.ft.com/content/55ba7412-6aca-11e7-b9c7-15af748b60d0

[Guitar 73]

On 9/13/2017 at 4:33 AM, Terry Hollis said:

They are L class Mullet boats .. 22 feet long, internal ballast and a steel plate for the centre board.  They have been sailing since 1860 and racing as a class since 1902.  They race in winds up to 35 knots and go quite well in light air. There are other classes for different lengths but the 22 foot one is the most popular.

Sounds like the Tempest.

[Guitar 73]

On 9/14/2017 at 4:07 PM, Go Left said:

The SF Cup was amazing, as was the earlier event with the ACC monohulls, although not quite as amazing.

Sitting in the stands when the AC 70's rounded the first mark and came right at us, foiling and getting bigger FAST, the whole crowd, maybe 10,000 people in those ticketed bleachers and lots more just on the shoreline, simultaneously said "Holy Shit!!!"   First and last time I've heard that from a sailing spectator crowd.  I've said it plenty of times during a leeward broach, but meant something else.

So.....Stadium sailing with fast, close boats.  With predictable winds.  Doesn't even have to be a lot of wind anymore.  You could maybe improve Bermuda with bleacher barges, but walking around the Marina Green meeting lots of people was just plain fun.

All the above and more, epic. Burmuda = fail.

[Doug Lord 1,219]

Are Italians into  hydrofoils?   I would think so based on this quote from the financial times:

https://www.ft.com/content/55ba7412-6aca-11e7-b9c7-15af748b60d0

" In 1898, Italian inventor Enrico Forlanini obtained patents in the UK and US for his hydrofoil designs....." 

But maybe the real question is: "Are rich Italians into hydrofoils?"

 

 

[surfsailor 283]

The Schock 40 canted its keel using battery power-no motor running.

An electric motor is still a motor, and requires stored energy - lots of it. 

This is not 'rocket science' - you are either using stored energy to sail the boat, or you aren't.

[Doug Lord 1,219]

NZAC  revised

1-no canting keel

2-retractable foils by pivoting

3- foils don't need to be "flown"-they are automatic

4- LOA 78'(changed from version one),  Beam 59.5'

[jaysper 1,264]

11 hours ago, Doug Lord said:

The Schock 40 canted its keel using battery power-no motor running.

Presumably the battery was connected to a motor?

[Tornado-Cat 1,082]

2 hours ago, Doug Lord said:

NZAC  revised

1-no canting keel

2-retractable foils by pivoting

3- foils don't need to be "flown"-they are automatic

4- LOA 78'(changed from version one),  Beam 59.5'

Doug, your drawing is interesting but much too extreme for the Italians. IMO, there will be no pod and foils will probably be shorter.

[Doug Lord 1,219]

You're probably right , TC. Sad, though.......

[pacice 74]

3 hours ago, Doug Lord said:

NZAC  revised

1-no canting keel

2-retractable foils by pivoting

3- foils don't need to be "flown"-they are automatic

4- LOA 78'(changed from version one),  Beam 59.5'

I believe you would need the keel canting to give the righting moment and therefore the power to use the foils.

Would also need double rudders.

 

[Doug Lord 1,219]

Maybe on the keel-depends on the number of crew. The foils provide RM since only the lee foil is in the water and the center of lift of the lee foil is a long way from the CG of the boat..... No need at all for double rudders-look at the Quant 23. This thing won't heel enough to reduce the effectiveness of the central rudder.

[rgeek 160]

@TheLord: How does that provide for the static stability required for a traditional match racing prestart?

@TheJay: How often have the Kiwi's used something in the AC that no other team thought of? Cyclors, glass fibre build, gennikers and the hula?

@dawg: The RRS contain Rule 86

[Doug Lord 1,219]

5 hours ago, rgeek said:

: How does that provide for the static stability required for a traditional match racing prestart?

 

The boat has a ballast keel!! 

[Left Shift 3,617]

What a lot of gymnastics to avoid just being a foiling catamaran.  

Why throw away 10 years of amazing development.  IF there had been two NZL boats on the course in Bermuda, we would have seen match racing like no other.   I would bet that by the end of the regatta Burling was tacking his cat quicker and faster than any AC boat in history.

[Doug Lord 1,219]

On 9/27/2017 at 4:49 PM, Doug Lord said:

NZAC  revised

1-no canting keel

2-retractable foils by pivoting

3- foils don't need to be "flown"-they are automatic

4- LOA 78'(changed from version one),  Beam 59.5'

Interesting the revised version above is only 3' off. The original was about the same length as the new boat at 75'.Too bad we have to wait until Nov 30 for design details.....

[rgeek 160]

Actually you're going to have to wait until March

[Curious2 4]

15 hours ago, rgeek said:

 

@TheJay: How often have the Kiwi's used something in the AC that no other team thought of? Cyclors, glass fibre build, gennikers and the hula?

 

Cyclors were first used in the AC by Sweden with the 12 Metre Sverige.

I seem to recall that Australia III used the first gennicker.

The hula was just another example of a rule dodge or (normally short-lived) design innovation, to be ranked alongside the open cockpit in 12s (the UK), the bendy fibreglass topmast in 12s (UK), the Park Avenue boom and bendy boom (UK/US), the duralimun (sp) mast (USA), the multiple rating certificate (USA), the shark skin (USA), the canard foils (USA), the bulb keel (USA), the fin keel (USA), the bustle (USA) etc etc etc.

Glass fibre is just one of several construction methods that countries have brought into the AC; there's been aluminium, tobin bronze, etc. There were plans for a run of Petersen GRP Sixes years before and of course there had been decades of 'glass production boats so it wasn't bleeding edge but a very smart move to create two identical boats to get a new AC country up to speed ASAP.

 

 

 

 

[KoW 16]

With the protocol bringing back the spectator seat, whatever boat design they come up with will have to be much safer than the foiling cats from the last 2 ACs... perhaps the new class rule won't feature foiling as much as many are anticipating?

[DT Wanderer 0]

10-12 crew. trust me when I say there's going to be a big chunk of lead at the bottom of a long, skinny carbon shaft.

[surfsailor 283]

^ Yep - TP 75, with the addition of reaching foils and probably a tricky rig with a partial wing mast.

[Doug Lord 1,219]

Reaching foils?!

[surfsailor 283]

^ Yep. Think IMOCA, minus the canting keel. Unless they go for stored power and motors.

[Doug Lord 1,219]

I think a foil system for this big boat could be designed to work around the clock-I don't think it has to be limited to reaching but it may well be due to pressure from the anti-foilers which will be a real shame.

Welbourns "Q" foils(DSS2) would provide incredible RM and a boat using them could be simply extraordinary if the other elements of the design, like beam weren't restricted. I don't expect to see it though.......

[surfsailor 283]

^ There are a grand total of zero large monohulls foiling upwind or even doing foiling jibes much less tacks. Not saying it's impossible, but there is certainly nothing at the moment that is remotely close.

[jaysper 1,264]

41 minutes ago, surfsailor said:

^ There are a grand total of zero large monohulls foiling upwind or even doing foiling jibes much less tacks. Not saying it's impossible, but there is certainly nothing at the moment that is remotely close.

I would suggest that with anything upto half a Billion dollars of design and CFD being thrown at the design, we will get a pretty good indicator of whether it actually is possible in about 3 years time.

[RobG 816]

No one seems to be considering canting Z foils. We know the AC35 boats (and probably A Class) would like to have canted further out, but were limited by design rules. So if unlimited cant is allowed, what foil shape do you end up with? I'd guess something more extreme than shapes from the last cup. It would help with overall beam too, as the foils would go down rather than straight out like other pectoral foils.

Would Zs also allow controlled foiling with less power? If the rig and sails are manually controlled, does that reduce power requirements sufficiently that the foils can be driven by say two traditional grinders? Also, I think a lot more can be done by allowing adjustable rudders to control pitch more effectively. It shouldn't take much power and would also reduce the need to adjust the main foils so frequently, reducing power requirements further.

I don't think there's any getting away from a lead keel. The boats have to stay upright in say 20kn with no sails hoisted, and while head to wind sailing backwards with full sail. You can't have a situation where forcing a boat head to wind causes a capsize.

Even if there isn't a "no pre–start foiling" rule, boats will still try to force each other off foils, so they will need to be good performers off the foils too.

Edited September 29, 2017 by RobG
Added a bit…

[surfsailor 283]

^ Pretty much everyone in foiling world is looking at Z foils. Not sure how that applies to monos with a beam limitation - don't forget beam = righting moment arm. Plus you need to heave the additional weight of a lead bulb - not promising.

[Sailbydate 3,607]

3 hours ago, surfsailor said:

^ Yep. Think IMOCA, minus the canting keel. Unless they go for stored power and motors.

Minus a canting keel? It will fall over.

[rgeek 160]

stand by fir a "they broke our foils in the prestart deliberately" contoversey

[surfsailor 283]

3 hours ago, Sailbydate said:

Minus a canting keel? It will fall over.

It'll have a keel. It just won't cant - unless they have stored power and a motor and/or gerbil wheels.

[RobG 816]

5 hours ago, surfsailor said:

^ Pretty much everyone in foiling world is looking at Z foils. Not sure how that applies to monos with a beam limitation - don't forget beam = righting moment arm. Plus you need to heave the additional weight of a lead bulb - not promising.

Until we see the design criteria, there is no beam limitation. IMOCA 60 Safran has a beam of 5.8m, an AC50 cat has a beam of 8.47m, say a difference of 2.7m. Make the mono scow–ish and widen it by 1m. Now cant the foils 1m beyond max beam and you have slightly more foil-induced RM than an AC 50.

An IMOCA 60 has way more sail area on a much taller mast, so power is not an issue.

Weight is though, an IMOCA–like boat would need to lose about 60% to get to AC50–ish weight. Maybe a light weight scow, with reduced sail area on a canting rig, would not need a lead bulb, so maybe no canting keel and no stored power. That would go a long way to slimming it down.

[surfsailor 283]

^ Don't get me wrong - I'd love to see a big, full foiling (upwind and down) mono. But it's really hard to beat the cat geometry for a launch vehicle (lightweight, slippery at low speed, lots of beam, doesn't fall over) and it's really hard to beat the wings as a power source - the AC50s were using them for righting moment at the top of the wind range, for example, and their L/D ratios are off the charts compared to soft sails. It'll definitely be interesting to see what they come up with.

[RobG 816]

Multis are a natural, I was just trying to see how close a mono could get to AC50 specs.

Just read the "protocol", I don't think there will be any foiling. The penalty to windward will not make up for the minimal gains downwind. Safran claims only 2kn, so while it looks fast, it's actually not that much faster than non–foiling.

I'd love to be proven wrong, but not holding my breath.

[3to1 733]

how about moderate to wide beam chined hulls, fixed super deep but light weight bulb keels, single rudders set well forward of transom, 75 foot waterlines, partial wing masts, square top main/jib, flat downwind sails, huge shallow cockpits and simple retractable moderately sized open 60 like L foils to double righting moment.

why all the stress around foiling? they're not gonna' foil so why not optimize what they will be doing? a simpler more straight forward design philosophy would be more elegant with less bs. these aren't offshore boats doing long drag races, so design 'em for aggressive buoy racing.

[jonas a 48]

42 minutes ago, RobG said:

Multis are a natural, I was just trying to see how close a mono could get to AC50 specs.

Just read the "protocol", I don't think there will be any foiling. The penalty to windward will not make up for the minimal gains downwind. Safran claims only 2kn, so while it looks fast, it's actually not that much faster than non–foiling.

I'd love to be proven wrong, but not holding my breath.

Also the wind and wave range will be larger than in Bermuda, which makes it harder to design a fully foiling boat. If enough appendices are allowed, they could retract "the foilboards" in lighter conditions, or use them upside down  

[Tony-F18 82]

So they decided to use VOR70s for the AC? 

With the required specs I don't see how it will look much different from this:

 

 

[3to1 733]

that mighty 70 is designed to live offshore, they'll be vastly different in all kinds of ways.

[Tony-F18 82]

59 minutes ago, 3to1 said:

that mighty 70 is designed to live offshore, they'll be vastly different in all kinds of ways.

Unless they are designing a scaled down version of the old AC90s I doubt it will be much different from a wide TP52/VOR70-ish yacht.

[jonas a 48]

I guess this is the closest to an AC75 to date.....

[WetHog 581]

14 minutes ago, jonas a said:

I guess this is the closest to an AC75 to date.....

To my uneducated eye it looks like a big TP52.  And would that CQS like bow work in the Hauraki Gulf?  I guess the bow shape is a minor detail.

WetHog  

[Mozzy Sails 953]

BAR says there are: 

Quote

strong hints the boat will foil like the multihulls used in the last Cup

I'll believe that when I see it. 

The only way I see a 75' mono 'foiling' is with appendages sticking out well past an already wide beam. How they will handle moving appendages outside max beam in the rules I have no idea (maybe they will be treated similarly to spinnaker poles?). I also don't see how they will tack quickly; but then tacks and gybes haven't really been a consideration of all previous foiling mono's (except dinghies). 

And if you have a fully foiling mono, why is it even an issue if it is mono or multi, in the end it's just a platform and will be miles away from the traditional tactics and match racing the mono lobby was wanting to get back too. 

I think we'll see a TP52 type vessel. Possibly the main difference from pre-DoG will be asymmetric kites and apparent wind sailing with possible foil assisted planning. And to be honest, I wouldn't mind that. It will be more relatable to the sports boat many people sail. 

 

[jorge 36]

3 hours ago, mozzy656 said:

BAR says there are:  strong hints the boat will foil like the multihulls used in the last Cup

I'll believe that when I see it. 

The only way I see a 75' mono 'foiling' is with appendages sticking out well past an already wide beam. How they will handle moving appendages outside max beam in the rules I have no idea (maybe they will be treated similarly to spinnaker poles?). I also don't see how they will tack quickly; but then tacks and gybes haven't really been a consideration of all previous foiling mono's (except dinghies). 

And if you have a fully foiling mono, why is it even an issue if it is mono or multi, in the end it's just a platform and will be miles away from the traditional tactics and match racing the mono lobby was wanting to get back too. 

I think we'll see a TP52 type vessel. Possibly the main difference from pre-DoG will be asymmetric kites and apparent wind sailing with possible foil assisted planning. And to be honest, I wouldn't mind that. It will be more relatable to the sports boat many people sail. 

 

Agree. Not a chance that is going to happen.

[~Stingray~~ 38]

GD said in several interviews yesterday to 'just wait until you see what the ETNZ designers are coming up with, you will be amazed' while stressing how the same design team introduced foiling AC boats in the first place, and how they are now going to take aim at a monohull. So, I agree with BA's assessment that the hints are all there, about it being a foiler.

In one NZ article the reporter got a quote from someone who had supposedly seen the design, who used the word (iirc) 'shocking.'

Full-out foiling? No idea.

[~Stingray~~ 38]

^ An example of that

"We have been the primary driver of foiling in multihulls. We are looking to bring that same level to the monohulls," Dalton said.

...

 

Privately, one yachting insider at the packed press conference in the hallowed halls of the Royal New Zealand Yacht Squadron told me he had been given a brief look at part of the new concept and described it as "jaw-dropping".

"I was like, holy smoke," he said. "I think people will be happy."

https://i.stuff.co.nz/sport/other-sports/97394709/peter-burling-endorses-new-americas-cup-monohull-its-going-to-be-a-really-cool-boat

[Doug Lord 1,219]

Anyone who thinks a monofoiler can't be as fast as a multifoiler need just look at the Moth vs most other small boats under 20'. "Jaw-dropping" sounds good.....

[Sailbydate 3,607]

11 hours ago, surfsailor said:

It'll have a keel. It just won't cant - unless they have stored power and a motor and/or gerbil wheels.

There's no way this boat won't have a canting keel. We're talking big rigs and tons of power and all the RM you can muster.

[MR.CLEAN 4,187]

6 hours ago, mozzy656 said:

Possibly the main difference from pre-DoG will be asymmetric kites and apparent wind sailing with possible foil assisted planning.

What are they planning?

[3to1 733]

8 hours ago, Tony-F18 said:

Unless they are designing a scaled down version of the old AC90s I doubt it will be much different from a wide TP52/VOR70-ish yacht.

maybe hull length/beam ratios will be close, but that's about it. different animals, different characteristics.

[Sailbydate 3,607]

9 hours ago, Tony-F18 said:

So they decided to use VOR70s for the AC? 

With the required specs I don't see how it will look much different from this:

 

 

Cool eh?

[3to1 733]

18 minutes ago, MR.CLEAN said:

What are they planning?

to reach the facefuk generation.