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remenich

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some new DSS foil assisted sportsboat. looking fwd to seeing the potential of these things - see if they can top the canters. it'd be good to see engines turned off again.

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Looks like a wonderful kelp harvester for So Cal

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J70 ?

 

or the complete rebuild of Viper # 26 with Ultra's best efforts to comply with class rules? :)

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welbourne

 

 

Not exactly - Hugh Welbourn and would be nice if people could get it right occasionally;)

 

Its won its first couple of races and seems quick - 17 knots in about 14 TWS but its early days and getting sails sorted will improve things a bit.

 

Off to Geneva this week to sail the Rolle and then Bol d'Or on the boat and then we'll see how we make out against the bigger quick boats.

post-8861-023288500 1307553432_thumb.jpg

post-8861-041178000 1307553473_thumb.jpg

post-8861-026268700 1307553529_thumb.jpg

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Ah, just caught this. Viper class rules, i thought those were more like guidelines than rules.

 

What, just because i have a little trouble with authority? Damn 58 seems to have the same locker problem 31 did. Ah well, another letter to the tech comedy it is.

 

J70 ?

 

or the complete rebuild of Viper # 26 with Ultra's best efforts to comply with class rules? :)

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welbourne

 

 

Not exactly - Hugh Welbourn and would be nice if people could get it right occasionally;)

 

Its won its first couple of races and seems quick - 17 knots in about 14 TWS but its early days and getting sails sorted will improve things a bit.

 

Off to Geneva this week to sail the Rolle and then Bol d'Or on the boat and then we'll see how we make out against the bigger quick boats.

Hows the BBB going in HK?

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Hows the BBB going in HK?

 

Not winning a great deal, but they look like they're having fun. Interesting to see whether a switch to SMS makes them more competitive.

 

Re: the 28 - good to see a hull shape (and colour) can be reused from something almost double the size!

 

Alt_5RM09_HiRes_Races_Langkawi_015.JPG

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Hows the BBB going in HK?

 

Not winning a great deal, but they look like they're having fun. Interesting to see whether a switch to SMS makes them more competitive.

 

Re: the 28 - good to see a hull shape (and colour) can be reused from something almost double the size!

 

Alt_5RM09_HiRes_Races_Langkawi_015.JPG

 

Is it the perspective or is the chine/sprayrail/whatever less distinctive towards the end?

if so why? And what's it's purpose?

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on the leeward side, immersed, it is causing drag of course, i'm surprised it's not 'reduced' further forward

 

anyway any spray reducing at the transom and aft are not an issue, theres no topside drag or crew to keep dry a metre behind the boat

 

no 'reducing' would be far more questionable than what you are looking at here

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on the leeward side, immersed, it is causing drag of course, i'm surprised it's not 'reduced' further forward

 

anyway any spray reducing at the transom and aft are not an issue, theres no topside drag or crew to keep dry a metre behind the boat

 

no 'reducing' would be far more questionable than what you are looking at here

 

You sure its causing drag? but fairing in and out gradually keeps upper and lower surface more aligned as you want them. There are real reasons for that being there, and picking sheet water off the surface for wsa reduction at pace is only one of them.

 

28 is very different in fact - and the ledge also makes itself useful in that we landed the cockpit floor onto it.

 

And btw, the crew call the ledge the atomiser for turning the water in a nice fine cooling mist:))

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hi hugh

 

why it reduces was the initial Q from q-e

 

aesthetics demand it for starters imho

 

__________________-

 

now look at that, other than the sprayrail ......

 

anyone would think youv'e seen a BS-23 :lol:e.g. nice racks

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hi hugh

 

why it reduces was the initial Q from q-e

 

aesthetics demand it for starters

 

__________________-

 

now look at that, other than the sprayrail anyone would think youv'e seen a BS-23 :lol: e.g. nice racks

 

yes and no.

I'm sure there is another reason besides spray for those edges in the hull, but I had no idea which.

There are only very few boats having sprayrails (especially beyond L/2), additional stability also doesn't seem to be the driving reason.

I thought about it as a way to to make the deck wider without adding flare (for measurement purposes), but then there clearly is lots of flare in this hull form and I don't know if IRC even measures it.

structural advantages are possible but seem to be unlikely to me.

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IRC now measures hull hollow in the perpendicular line from the deck down to the hull at it's maximum point. It didn't used to. Step probably helps to reduce that while still keeping the waterline nice and narrow. Designer can explain no doubt - what is the reason for doing it rating wise?

 

Hifi the 52 footer was introduced with steps AFAIK before this hull hollow measurement was part of IRC measurement; certainly when Hifi is sailed well, the flatter waters here in sub 10 asian condfitions in which she is a weapon that entire rail is clear of the water on the leeward side all the time, and with the extra flair means the crew are providing some decent righting moment. Even now (most recently Samui) Hifi is winning overall against hotted up IRCed TP52s.

 

Having seen the step outs working, they seem to perform for Hifi very well (negating my comments about how it would not win any beauty contests, performance is what matters and after a while they grow on you).

 

I am more doubtful of the DSS thing or how SMS will be able to rate it.

 

Racks and loads of righting moment + big kite = F***ing sweet.

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IRC now measures hull hollow in the perpendicular line from the deck down to the hull at it's maximum point. It didn't used to. Step probably helps to reduce that while still keeping the waterline nice and narrow. Designer can explain no doubt - what is the reason for doing it rating wise?

 

Hifi the 52 footer was introduced with steps AFAIK before this hull hollow measurement was part of IRC measurement; certainly when Hifi is sailed well, the flatter waters here in sub 10 asian condfitions in which she is a weapon that entire rail is clear of the water on the leeward side all the time, and with the extra flair means the crew are providing some decent righting moment. Even now (most recently Samui) Hifi is winning overall against hotted up IRCed TP52s.

 

Having seen the step outs working, they seem to perform for Hifi very well (negating my comments about how it would not win any beauty contests, performance is what matters and after a while they grow on you).

 

I am more doubtful of the DSS thing or how SMS will be able to rate it.

 

Racks and loads of righting moment + big kite = F***ing sweet.

 

DSS is currently unmeasured for SMS, same as canting.

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Hugh,

 

maybe you should blame KOS for the poor spelling in this neck of the woods. I've caught him a few times gigling like a school girl drawing little 'e's at the end of your name!

 

 

 

welbourne

 

 

Not exactly - Hugh Welbourn and would be nice if people could get it right occasionally;)

 

Its won its first couple of races and seems quick - 17 knots in about 14 TWS but its early days and getting sails sorted will improve things a bit.

 

Off to Geneva this week to sail the Rolle and then Bol d'Or on the boat and then we'll see how we make out against the bigger quick boats.

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Hugh - need to brush up on my German, so

~ Question #1: How Much for the Q28?

~ Question #2: When you goin into production?

PM me ...

 

<Rating? We don't need no stinkin rating!!!>

Wookie

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Rolle race was good learning curve for the boat and in fact on TCF corrected then 2nd class/2nd overall out of 240 boats and as a w/l course mostly and not having any reaching time then pretty pleased. Sure is quick in the light, and we know a bit of power reaching its seriously quick. Amongst similar boats...then the tricked up T30 with trapezes and canting keel got away well at the start but once we got going we sailed up, past and then away from them all the time - at the Rolle mark we were sandwiched between the old Full Pelt ( water ballast ) and new one ( canter and 5 trapezes ) and having raced on both of those then that was fun:))

They got away downhill but few knots more wind for us to get up and whizzing, or less and then waterline length not really counting and reckon we would have hung in with them.

 

Bit of an extract from Michi on the race....

 

But back to the race of saturday

 

it was quite hard to get of the starting line. no wind and all the big boats (here that means 12 to 14m and huge rigs, like cathedrals) in the spot we had to go also. so just waiting desparately for about 10 minutes to get some air to move the boat at least some m.

then slowly the bigger boats got away some 100meters and we also started the little rocket with the help of the new headsail (pole half out, up to the top and clew to the middle of racks, sheeting point same as for chute) we got from North-Sails with the help of Kos. after 20minutes we could sail the course we liked to and we started to catch up very very quickly. in fact by then we were the fastest monohull at all. so we sailed along the shoreline and passed one boat after the other on leeward side. after maybe 1 hour we got the lead over all monohulls. all the boats of our size were out of sight totally. we just sailed up the lake by ourselves. i had to concentrate very hard as Kos is quite a tough teacher, shaking is head, when i am not keeping the boat on the proper course (too deep or too high:-).

we sailed about 5.5 to 7.2kts in maybe 3 - 4 kts of breeze. but it is quite hard to estimate true windspeed as you sail almost completely on the apparent wind. then this breeze seems to be dying for some minutes, what was good for us. we extended the lead. slowly the direction of the airflow changed and after some other minutes we were on a real upwind course which of course was not ideal for as us also windspeed was picking up. by then we had to sail another fourth of the course to the first mark. we peeled sails to the basic jib sailing up to 7kts of bsp. then we put out the foil as it got choppy as the waves going on the shore came back out where we had to sail. Nevertheless we raised speed up to 7.3kts. (in my better moments at the tiller - Kos was gettng nervous). i love how this boat is going upwind. it was nice to sail like this but for this race it was a bit too much or too less of windspeed for us. further out 5 or 6 of the bigger boats came up slowly and passed us on weather. we had to tack two times and the hobbycats came down crossing us - a lot of turbulence. we rounded the mark 4.10 pm. hoping to catch up going completely on the foil while reaching. in the first moments we had a few surfs but we saw that it will be not enough going on the foil really. we changed on the big kite. the race more and more turned out to be a real up and down course and the wind was dropping again instead of increasing. it took us about another 2 hours to go back to Geneva, gybing 4times i think and Kos was driving the last part as i got tired a bit. I enjoyed sailing in this quiet and pleasant mode although i was hoping for more wind or a change of a wind direction. sailed real time we ended up as 8th monohull (out of about 320). in our division second elapsed and second corrected. the one boat in front of was a 42 footer with a huge rig ( which should sail in the big-boat division - but he maybe found out to be able to win in our division - you know sailing with rating coefficients is like this.....) it was displacement sailing where length is the thing to have.

as a conclusion: this second place is of big value for us as we know now that this boat is incredibly fast even in conditions not ideal for the boat. All the more as we were too heavy for the conditions maybe.

sailing back into the harbour of the SNG the guys of the big boats were cleaning their yachts - all of them put away what they were doing for a moment looking us passing to our berth, surprised and wondering what tha means. they have to get used to the fact that even small boats can beat them. And if you analyse the time sheets it shows the quite amazing performance of the Q28. not to think about the same situation going downwind in a bit more of wind....

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i see a T-830 in there ( portable SB comparison)

 

noted you beat him last week

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not convinced, stability from wing and then parasitic drag from an induced angle of attack in the water.

Pull the board out and go faster??

 

Would like to see 2 sisterships, one with board, one without.

 

I think it is a very very good design and very fast, not sure on the board. Why have wings if you were convinced of the effect of the board??

 

If it could lift to reduce surface area on the hull as a trade off, yes...but to add drag????

 

Flame away!!

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not convinced, stability from wing and then parasitic drag from an induced angle of attack in the water.

Pull the board out and go faster??

 

Would like to see 2 sisterships, one with board, one without.

 

I think it is a very very good design and very fast, not sure on the board. Why have wings if you were convinced of the effect of the board??

 

If it could lift to reduce surface area on the hull as a trade off, yes...but to add drag????

 

Flame away!!

 

i'd like to see this experiment, but feel the DSS boat'd leave the other for dead due to less weight needed in the keel + better stability. will be interesting to see how these boats go leaping out of waves in any sort of sea state...

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the problem with reducing the weight in the bulb anymore is preserving the self righting aspect of the boats. the most radical sportboats without DSS such as stealth 7's and the shaw boats are already pretty close to the limit. the bulb is certainly only there on those boats to make them self righting. the weight of the bulb on the keel provides a fraction of the righting moment that the crew sitting on the wings provide.

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not convinced, stability from wing and then parasitic drag from an induced angle of attack in the water.

Pull the board out and go faster??

 

Would like to see 2 sisterships, one with board, one without.

 

I think it is a very very good design and very fast, not sure on the board. Why have wings if you were convinced of the effect of the board??

 

If it could lift to reduce surface area on the hull as a trade off, yes...but to add drag????

 

Flame away!!

 

2 boat testing simple - just pull the foil in on one side - been done by everybody who has sailed on the boat and is worried about drag.

 

But really if you think about this it is not really that simple as the boat has been designed to take advantage of the foil and compensate for some of its cost.

 

If you put a stick in the water it is drag but if you put a correctly designed and placed foil then the draggggg cost can be offset by other benefits. I'm sure there are a couple of moth sailors will agree.

 

 

Wings- there is a very good reason to have them on a foiled sports boat and it has a lot to do with how to get the foil to work!!!! if it really works????

 

Last we we took a yachting journalist for a sail. His comment was he arrive expecting to be un impressed, but left the boat with the worlds biggest grin after ripping around lake Geneva when the video was taken.

The only drag he felt was having to give the tiller back.

 

This boat is a very very good design and it has taken a lot of work to get to this level.

Wait until you see the new 7m we are working on as a production boat. It will have more foils??? and more drag????

 

Drag on

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not convinced, stability from wing and then parasitic drag from an induced angle of attack in the water.

Pull the board out and go faster??

 

Would like to see 2 sisterships, one with board, one without.

 

I think it is a very very good design and very fast, not sure on the board. Why have wings if you were convinced of the effect of the board??

 

If it could lift to reduce surface area on the hull as a trade off, yes...but to add drag????

 

Flame away!!

 

2 boat testing simple - just pull the foil in on one side - been done by everybody who has sailed on the boat and is worried about drag.

 

But really if you think about this it is not really that simple as the boat has been designed to take advantage of the foil and compensate for some of its cost.

 

If you put a stick in the water it is drag but if you put a correctly designed and placed foil then the draggggg cost can be offset by other benefits. I'm sure there are a couple of moth sailors will agree.

 

 

Wings- there is a very good reason to have them on a foiled sports boat and it has a lot to do with how to get the foil to work!!!! if it really works????

 

Last we we took a yachting journalist for a sail. His comment was he arrive expecting to be un impressed, but left the boat with the worlds biggest grin after ripping around lake Geneva when the video was taken.

The only drag he felt was having to give the tiller back.

 

This boat is a very very good design and it has taken a lot of work to get to this level.

Wait until you see the new 7m we are working on as a production boat. It will have more foils??? and more drag????

 

Drag on

 

Every racing multihull has a curved foil that essentially does exactly what the DSS does and its fact that they all go faster with them... despite the additional draaaaaggggg.

 

It would be nice to see one in a GP 50 footer that would have the foil properly immersed and not have any ventilation that you will get in a sportsboat when fully launched / planning.

 

My 2 cents worth of ddrrraaaaaaaaaaggggggggggg!

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not convinced, stability from wing and then parasitic drag from an induced angle of attack in the water.

Pull the board out and go faster??

 

Would like to see 2 sisterships, one with board, one without.

 

I think it is a very very good design and very fast, not sure on the board. Why have wings if you were convinced of the effect of the board??

 

If it could lift to reduce surface area on the hull as a trade off, yes...but to add drag????

 

Flame away!!

 

In fact in the first place the foil provides vertical lift and therefore reduces the displacement of the boat. The RM (although the main design goal) is more of a secondary effect.

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not convinced, stability from wing and then parasitic drag from an induced angle of attack in the water.

Pull the board out and go faster??

 

Would like to see 2 sisterships, one with board, one without.

 

I think it is a very very good design and very fast, not sure on the board. Why have wings if you were convinced of the effect of the board??

 

If it could lift to reduce surface area on the hull as a trade off, yes...but to add drag????

 

Flame away!!

 

Draaaag....and no, none us do drag without a good reason:))

 

Look at it this way - every item in the water causes drag, so to be there it has to have a good reason to be doing something important...so keel holds a lump of lead on the end and also provides sideforce which you need. Rudder produces sideforce. Both have viscous and induced drag but you need them.

Hull supports the thing in the water thanks to Archimedes, and has viscous, induced ( from leeway ) and wave drag.

 

So the DSS foil adds viscous and induced drag, but also can operate in various modes depending on immersion depth - so close to the surface it can be a nice effective planing surface, partially ventilated then likewise but a lot of the viscous drag has gone and if its got there then you aren't using all the RM/lift that it might be producing so it doesn't need to be working hard as a fully immersed foil.

 

Lift and RM....both are significant, and each design has its own requirement in how to best approach the foil and overall balance.

 

If you look at the video then you can visibly see how little the hull is contributing to wavemaking, wetted surface is low and also well aerated, and so we're bimbling along steady 15-16 knots and maxed 17 in about 10 TWS and only three up - me driving, German Journalist along for the ride and Kos up front.

Boat is in perfect balance, wouldn't be doing those numbers without the foil.

Bit later on the breeze came up from a thunderstorm and we were doing the same numbers and a bit more just on the working jib.

 

Lots more video from that day, and the weather side views make it look as if nothing is happening - practically no spray, stuff all hull in the water. But note, I'm not trying to fully fly the boat as then you get into all the trim problem - so its designed to have natural dynamic stability.

 

And btw - we've done extensive testing on the 27 in big waves and seas down off Sotogrande and never had any issues from launching off waves or burying or any signs of tripping.

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not convinced, stability from wing and then parasitic drag from an induced angle of attack in the water.

Pull the board out and go faster??

 

Would like to see 2 sisterships, one with board, one without.

 

I think it is a very very good design and very fast, not sure on the board. Why have wings if you were convinced of the effect of the board??

 

If it could lift to reduce surface area on the hull as a trade off, yes...but to add drag????

 

Flame away!!

 

Draaaag....and no, none us do drag without a good reason:))

 

Look at it this way - every item in the water causes drag, so to be there it has to have a good reason to be doing something important...so keel holds a lump of lead on the end and also provides sideforce which you need. Rudder produces sideforce. Both have viscous and induced drag but you need them.

Hull supports the thing in the water thanks to Archimedes, and has viscous, induced ( from leeway ) and wave drag.

 

So the DSS foil adds viscous and induced drag, but also can operate in various modes depending on immersion depth - so close to the surface it can be a nice effective planing surface, partially ventilated then likewise but a lot of the viscous drag has gone and if its got there then you aren't using all the RM/lift that it might be producing so it doesn't need to be working hard as a fully immersed foil.

 

Lift and RM....both are significant, and each design has its own requirement in how to best approach the foil and overall balance.

 

If you look at the video then you can visibly see how little the hull is contributing to wavemaking, wetted surface is low and also well aerated, and so we're bimbling along steady 15-16 knots and maxed 17 in about 10 TWS and only three up - me driving, German Journalist along for the ride and Kos up front.

Boat is in perfect balance, wouldn't be doing those numbers without the foil.

Bit later on the breeze came up from a thunderstorm and we were doing the same numbers and a bit more just on the working jib.

 

Lots more video from that day, and the weather side views make it look as if nothing is happening - practically no spray, stuff all hull in the water. But note, I'm not trying to fully fly the boat as then you get into all the trim problem - so its designed to have natural dynamic stability.

 

And btw - we've done extensive testing on the 27 in big waves and seas down off Sotogrande and never had any issues from launching off waves or burying or any signs of tripping.

 

I get the benefit when sailing across the wind and by all accounts it works pretty well on this point of sail. Do you think it has the same benefit sailing a typical W/L? Boat speeds are significantly less going upwind and generally the up bit is ~68% of sailing time vs the down bit. The down bit also includes looking for depth where ever possible. Do you find that using the additional planning surface adds greater drag than benefit upwind? Downwind are you finding you need to sail higher angles to get the best out of the additional planning surface?

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not convinced, stability from wing and then parasitic drag from an induced angle of attack in the water.

Pull the board out and go faster??

 

Would like to see 2 sisterships, one with board, one without.

 

I think it is a very very good design and very fast, not sure on the board. Why have wings if you were convinced of the effect of the board??

 

If it could lift to reduce surface area on the hull as a trade off, yes...but to add drag????

 

Flame away!!

 

Draaaag....and no, none us do drag without a good reason:))

 

Look at it this way - every item in the water causes drag, so to be there it has to have a good reason to be doing something important...so keel holds a lump of lead on the end and also provides sideforce which you need. Rudder produces sideforce. Both have viscous and induced drag but you need them.

Hull supports the thing in the water thanks to Archimedes, and has viscous, induced ( from leeway ) and wave drag.

 

So the DSS foil adds viscous and induced drag, but also can operate in various modes depending on immersion depth - so close to the surface it can be a nice effective planing surface, partially ventilated then likewise but a lot of the viscous drag has gone and if its got there then you aren't using all the RM/lift that it might be producing so it doesn't need to be working hard as a fully immersed foil.

 

Lift and RM....both are significant, and each design has its own requirement in how to best approach the foil and overall balance.

 

If you look at the video then you can visibly see how little the hull is contributing to wavemaking, wetted surface is low and also well aerated, and so we're bimbling along steady 15-16 knots and maxed 17 in about 10 TWS and only three up - me driving, German Journalist along for the ride and Kos up front.

Boat is in perfect balance, wouldn't be doing those numbers without the foil.

Bit later on the breeze came up from a thunderstorm and we were doing the same numbers and a bit more just on the working jib.

 

Lots more video from that day, and the weather side views make it look as if nothing is happening - practically no spray, stuff all hull in the water. But note, I'm not trying to fully fly the boat as then you get into all the trim problem - so its designed to have natural dynamic stability.

 

And btw - we've done extensive testing on the 27 in big waves and seas down off Sotogrande and never had any issues from launching off waves or burying or any signs of tripping.

You mean Kos was trimming the chute?, geez I thought he was too lazy for that ;)

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I get the benefit when sailing across the wind and by all accounts it works pretty well on this point of sail. Do you think it has the same benefit sailing a typical W/L? Boat speeds are significantly less going upwind and generally the up bit is ~68% of sailing time vs the down bit. The down bit also includes looking for depth where ever possible. Do you find that using the additional planning surface adds greater drag than benefit upwind? Downwind are you finding you need to sail higher angles to get the best out of the additional planning surface?

 

Upwind - well the thing here is to match the wing parameters to the boat so that the net result - in steady state - is just slightly in your favour. So RM gain outweighs the drag cost.

However, what we then find is that as soon as there's any chop or seaway to move the boat around, then the damped motion in all axes makes a significant improvement that is seen on the VMG - even when you only seem to be sailing maybe a tenth quicker than you might. Now that comes from logged data and was a bit of ( pleasant! ) surprise to me until I figured out the dynamics of what was going on.

 

And don't forget, you don't need to use the wing at all until you are running out of natural RM, so no draaaag....until its starts to work and then the balance is in the your favour.

 

Its all a pretty finely balanced configuration but we've got a good handle on thing now from all the r&d and sailing and how to configure the different types of boat to work.

 

Downhill vmg - then same again - if you don't need the wing trickling along then its out of the water, but as soon as you can get into the situation where you can AWA sail then the more power you have to use the better. Bit like cats or skiffs, but cats can't get the spare hull out of the water until theres enough breeze, and skiffs or canters all have a fixed max RM.

 

So the AWA you sail on the 28 downhill is always well forward, but the angles you actually gybe through can be less than more conventional boats.

 

Thing is, got two boats in one here - the light wind one is skinnyish with very low drag, but you can add in the grunt when you need it....

 

Start of the Bol d'Or - dead downhill, bit of breeze - ourselves and the 36' trapeze/canter Full pelt bolted off the line at 15+ and were a mile clear of the fleet in 10 minutes - and crossing gybes with some of the cats that started 300m in front of the mono fleet....they were a bit confused to see us in 'their' water :)

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not convinced, stability from wing and then parasitic drag from an induced angle of attack in the water.

Pull the board out and go faster??

 

Would like to see 2 sisterships, one with board, one without.

 

I think it is a very very good design and very fast, not sure on the board. Why have wings if you were convinced of the effect of the board??

 

If it could lift to reduce surface area on the hull as a trade off, yes...but to add drag????

 

Flame away!!

 

In Wellington/NZ there are 2 Thompson 30's, one with the DSS and one without.. http://www.racetrack.org.nz/class.php?classid=76 but the T30 of course isn't designed for the DSS

 

New boat looks great, when are we going to see one in Aussie to race the other quick sportsboats!

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You mean Kos was trimming the chute?, geez I thought he was too lazy for that ;)

 

Well...same old...had to steer around the thing!

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not convinced, stability from wing and then parasitic drag from an induced angle of attack in the water.

Pull the board out and go faster??

 

Would like to see 2 sisterships, one with board, one without.

 

I think it is a very very good design and very fast, not sure on the board. Why have wings if you were convinced of the effect of the board??

 

If it could lift to reduce surface area on the hull as a trade off, yes...but to add drag????

 

Flame away!!

 

In Wellington/NZ there are 2 Thompson 30's, one with the DSS and one without.. http://www.racetrack.org.nz/class.php?classid=76 but the T30 of course isn't designed for the DSS

 

New boat looks great, when are we going to see one in Aussie to race the other quick sportsboats!

Mr T has already drawn one for here and we have seen Brace before it went to HK

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Mr T has already drawn one for here and we have seen Brace before it went to HK

 

 

well you'd better remind him that we are happy to license the patented system, and that one of our investors is a major international lawyers company.....and if by some chance a boat gets built outside of our 28 and counting patent covered countries then the moment it arrives somewhere else that is covered it will be liable for a licence fee. Its only about the cost of a mainsail for a typical boat btw.

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well you'd better remind him that we are happy to license the patented system, and that one of our investors is a major international lawyers company.....and if by some chance a boat gets built outside of our 28 and counting patent covered countries then the moment it arrives somewhere else that is covered it will be liable for a licence fee. Its only about the cost of a mainsail for a typical boat btw.

 

I think you know him better than me to have that conversation.... FTR he dropped the wingy idea....didn't like it apparently.

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Start of the Bol d'Or - dead downhill, bit of breeze - ourselves and the 36' trapeze/canter Full pelt bolted off the line at 15+ and were a mile clear of the fleet in 10 minutes - and crossing gybes with some of the cats that started 300m in front of the mono fleet....they were a bit confused to see us in 'their' water :)

 

Very interesting boat, and its good to see something different that may just move the game along.

 

i havent been able to find result - how did you get on in the Bol d'Or?

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Start of the Bol d'Or - dead downhill, bit of breeze - ourselves and the 36' trapeze/canter Full pelt bolted off the line at 15+ and were a mile clear of the fleet in 10 minutes - and crossing gybes with some of the cats that started 300m in front of the mono fleet....they were a bit confused to see us in 'their' water :)

 

Very interesting boat, and its good to see something different that may just move the game along.

 

i havent been able to find result - how did you get on in the Bol d'Or?

 

Bit epic! Start was great - legged it off into the distance and then the wind did its usual crap out for the leg from Petit Lac and up past Evian. Didn't seem to be going that well along there but figured maybe just rig height v the bigger boats like the Psaros 40's and Libera that crawled up and past.

By the time we got up to beating up the cliffs on the French side though we started really feeling something wrong - opened up the wetbox ( has the roller drive in it ) and then found that one of the access covers forward wasn't on properly....so the front of the bus had been filling steadily up with the water. Bollocks. Managed to get some of it out but by the time we got to baling it out properly next day we reckoned had about 350 kgs of the lake along for the ride.....and thats not quick! Add in some monster clumps of week we must have picked up in the last few miles and we had a lot of hard work for no result. Reckon that 20 boats passed us in the last 10 miles which was painful but nothing we could do about it.

 

Still - good news was that the rig stood up to it all OK, broke nothing, we know we've got great all-round pace, but must add some draining facilities!! And better hatch covers too....have to come back next year and have another crack at it.

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not convinced, stability from wing and then parasitic drag from an induced angle of attack in the water.

Pull the board out and go faster??

 

Would like to see 2 sisterships, one with board, one without.

 

I think it is a very very good design and very fast, not sure on the board. Why have wings if you were convinced of the effect of the board??

 

If it could lift to reduce surface area on the hull as a trade off, yes...but to add drag????

 

Flame away!!

 

In Wellington/NZ there are 2 Thompson 30's, one with the DSS and one without.. http://www.racetrack.org.nz/class.php?classid=76 but the T30 of course isn't designed for the DSS

 

New boat looks great, when are we going to see one in Aussie to race the other quick sportsboats!

Mr T has already drawn one for here and we have seen Brace before it went to HK

 

The Brace only did one race tho hey, and haven't seen any results from HK for awhile, looked a bit inconsistent - some good and some bad results. Maybe Gybeset can decode some!

 

P.S. Good luck getting anything out of T, he would be in some trouble if he ever came back to NZ.

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The Brace only did one race tho hey, and haven't seen any results from HK for awhile, looked a bit inconsistent - some good and some bad results. Maybe Gybeset can decode some!

 

P.S. Good luck getting anything out of T, he would be in some trouble if he ever came back to NZ.

 

The Bay to Bay is two long races over two days in a wide variety of conditions and is usually contested by the cream of the east coast sports boat fleet. Brace DESTROYED the fleet and beat most of the multi's as well which started 5 or 10 minutes before! Remember that "inconsistencies" are quite often caused by crew work and tactical choices.... at the end of the day it's still a yacht race.

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P.S. Good luck getting anything out of T, he would be in some trouble if he ever came back to NZ.

 

Why do you think I now have a Shaw! :lol: :lol:

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Saw it with my own eyes pal. They were goooone. What

Boat were you on? Or weren't you there?

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Saw it with my own eyes pal. They were goooone. What

Boat were you on? Or weren't you there?

 

Even DL gave up on this crusade once the results were linked, Im not even sure there were two fast 8m boats were there?

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Saw it with my own eyes pal. They were goooone. What

Boat were you on? Or weren't you there?

 

Even DL gave up on this crusade once the results were linked, Im not even sure there were two fast 8m boats were there?

====================

You're dead wrong, Cheesy-I never gave up on that story or that boat and you know better-thats just a crock of shit.

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Oh, nooooooooo.... The infestation has begun!

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Hi guys

 

I own the Q28 and maybe i can end some parts of the discussion with my thread.

 

Listen it is a lakeracer. We (Hugh, Kos, me) designed it like this and for this purpose. A light boat for flat water to sail in light conditions from 2 to 15kts of wind. Sure you can do sail in more (Bol d'or was up to 27kts some of the time) - but as we have the named wind conditions in about 85% of all races it makes sense to do so. ok?

 

Now with this boat, which is different from the 25' of Murphy (much skinnier to sail upwind also very well) we got 2 boats in one: 1 light boat with lots of sail and foil in for light - and second: light boat with foil out and lots of sail for more wind to produce stability. So forget about drag, you just leave the foil in center position or put it to weather side, as you sail along in low windspeeds means no drag but still light boat and looooots of sails.

 

If wind picks up you go fast then you put out the foil and by going fast the foil produces lift to right up the boat and lift to reduce drag of the whole boat (the whole boat is lifted means less drag in the whole system) and also to stabilise the whole system in any axle (you actually can walk around in the boat while going fast, it just doesn't move) this helps aerodynamics and hydrodynamics. if there is some chop, the boat is just hammering over it, like a surfboard.

 

Look at the clips on youtube. The boat accelerates like a some cat and there is now wave at all just look at it and stop silly discussions. no waves means less drag. Ok? Even people on our lake - not the most skillfulls sailors under the sun got it and also people in Geneva got it - although not invented there - they liked the Q28 and the idea from the first moment. Also the Journalist from "Die Yacht" (biggest magazine in Europe) got it quickly. He changed from sceptic to enthusiasm in 2 hours. It is that simple. You do not have to have a DSS boat but it is more interesting, more fun and it is going in the right direction with a amazing simple system that even amateur-sailors just learn to handle in one season. If it is very windy of course it helps if your are a Skiff sailor or Cat sailor because then the boat is a monster, even if it is only 28'. So please no more crusades it is just not worth it - if somebody doesn't like it - ok. no problem.

 

Have a nice day and cheers from Zurich (Switzerland9

 

 

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re Brace te earlier DSS Welbourn

 

One race is only a single sample .... and so many variables

 

however in the B2B beat a GOOD t-8 by six mins 17secs, that is fast for a 25 footer only other smaller boat boat thats does that is the proven rocketship Stealth(Egan) 7.27s

 

note the Welbourn was in just launched sea-trial mode and the 8 had been round a looooong time in the same hands, that makes a difference, the 8 has always laid down pretty consistent results and can generally be relied on as a benchmark

 

the third boat a further 12 mins back is quick-ish, faster than a t-7 to further validate the times of the first two

 

1 Type 2 Div1 OAKDIV1 102 KEVIN COSTIN BRACE BRACE BRACE WELBOURN 24 RQYS BRIS 0.980 0.9604:46:52 4:41:08 4:35:24 4:34:00 0.955 2.5 0.5

 

2 Type 2 Div1SMS OAKDIV1 109 GRAHAM COFFEY RUSH THOMPSON 8 ASSB NSW 0.884 0.924 4:53:094:19:09 4:30:52 4:34:00 0.935 -5.7 -1.2

 

3 Type 2 Div1SMS OAKDIV1 118 ANDREW WICKLUND AS-IF OAK SPORTSBOAT RQYS BRIS 0.843 0.8325:05:05 4:17:11 4:13:50 4:34:00 0.898 -6.5 -7.9

 

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Come on, where is the real GS?

 

Light weight wingged shitter against 800kg+ 2.5 wide boat with tents etc on board!

 

Apples v Oranges

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Turkey you have a short memory if you think any of the T-8s are slow, this year Pierre had Zippier pretty well right on his tail in the SydHbr regatta LINK here Link#2

 

the light boat it won it's first race, it had barely been launched, as I clearly pointed out you cannot make a general rule out of one race result,

 

as you point out look at Brace and its assumed weight etc etc, nothing 'slow' there whatsoever, i can't see any way that boat could be slow

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A few links to results of the Brace Brace Brace in HK.

 

http://www.rhkyc.org.hk/article.aspx?a=798&c=118

 

http://www.rhkyc.org.hk/default.aspx?c=508#Overall

 

no doubt someone else can add more. Certainly looks like it can be very quick at times.

 

Interesting to learn that you sail without the foil in certain conditions. It sounds like it is there to sort of stop the boat from heeling on a reach or upwind, and on a tight reach you also get some lift generated a bit. So in a windward leeward you would presumably not use it and just drive lower on the gusts is that kind of the thinking?

 

Hard to get my head around it; you don't get something for free so I can definitely see a benefit on a tight reach.....the rest.....hmmmm.

 

How do you control the wing to be working at a low angle of attack if you decide to pile everyone in the stern or if you are in big breeze and dropping the chute with the crew weight a bit forward; is it temperamental to foil pitch, needing adjustment like the moths, or you just kind of plug along and power it with the foil pretty much as is.

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so 'jury was out' (for me) till reading the 1st hand accounts

 

Primary aim was RM but fringe benefit of reducing displacement at speed may of became the real breakthrough, but what got me was the possibilities of the third unexpected advantage, reducing pitching by basically dampening the movement of the whole platform

 

you gotta know what pitching does to boatspeed when you go through powerboat wash for example, attached flow across your upper sail is destroyed along with your forward mojo

 

imagine a identical or control boat next to you and that wasn't happening, or it was reduced significantly, you'd need a boat with a fine bow no doubt to take advantage but worth looking into further

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If wind picks up you go fast then you put out the foil and by going fast the foil produces lift to right up the boat and lift to reduce drag of the whole boat (the whole boat is lifted means less drag in the whole system) and also to stabilise the whole system in any axle (you actually can walk around in the boat while going fast, it just doesn't move) this helps aerodynamics and hydrodynamics. if there is some chop, the boat is just hammering over it, like a surfboard.

 

 

 

Q-Man...

 

In the process of a better understanding, perhaps you can elaborate as to how the whole boat is lifted evenly from a single point of reference?

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If wind picks up you go fast then you put out the foil and by going fast the foil produces lift to right up the boat and lift to reduce drag of the whole boat (the whole boat is lifted means less drag in the whole system) and also to stabilise the whole system in any axle (you actually can walk around in the boat while going fast, it just doesn't move) this helps aerodynamics and hydrodynamics. if there is some chop, the boat is just hammering over it, like a surfboard.

 

 

 

Q-Man...

 

In the process of a better understanding, perhaps you can elaborate as to how the whole boat is lifted evenly from a single point of reference?

 

It's not a single point, more like a "plane" of reference.

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It's not a single point, more like a "plane" of reference.

 

 

OK, then perhaps you can describe that technically for me?

 

I ask this because I see single lifting foils (curved) on lots of multihulls with the foil biased to the forward sections of the structure. While the boat is sailing with the leeward foil deployed, the leeward hull is not fully lifted. More, the forward component of the hull is lifted with the aft sections fully immersed due to weight shit and rudder needs. Does this lessen wetted surface... sure, but it does not lift the entire hull with the single foil. Now, we have a person claiming that the entire hull is lifted with the foil very clearly amidship. I'm having a very hard time digesting the potential for that small amount of foil surface being able to lift an entire hull of that weight with that rig aloft.

 

Does the Q see some wetted surface reduction along with a stability enhancing capacity? To be sure and I have no quibble with that reality. Does it, however, lift the entire boat (not necessarily clear of the surface) with no part of the fore, or aft, component now receiving more weight transfer due to foil placement? I think not, but I'm open to a description that can be satisfyingly presented.

 

Can the crew walk to the bow without depressing the bow accordingly? I think not on that light of a boat unless the foil lift is seriously biased to the forward end of the hull. If the foil is biased to raise the bow, which makes sense, then it is not, also, lifting the aft sections equally. The foil has to be biased to lift a component of the hull, but I have my doubts as to its ability to lift the entire form.

 

Let's look at the Moth as an example. This is perhaps the lightest of all foiling machines. A lightness that is not even close to being approached by the Q. The Moth uses two foils to lift the hull and provide stability fore/aft. Yes, it is a free flying machine, but the designers have had to come to grips with the fact that a single foil will not get them airborne, as well as stable in the fashion as described by the Q owner.

 

I'd love to hear the owner make his comments from a technical perspective and not load the commentary up with stuff that is simply meant to counteract the folks who find the results a bit on the questionable side. What do you say, Q? Is it possible to describe what is happening out there in a fashion that allows us to believe the claims you have made?

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It's not a single point, more like a "plane" of reference.

 

 

OK, then perhaps you can describe that technically for me?

 

much like sq. footage of a sail determines how much lift is able to be generated, or the sq. ft. of an airplane wing determines the same. In two dimensions, it is acreage, add the third and you have lift generated almost perpendicular to the foil.

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OK, then perhaps you can describe that technically for me?

=====================

Weight 3' out on a rack adds to the displacement of the boat. Lift 3' out on a foil subtracts from all up displacement. Both add RM.

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Thanks, Doug, but I don't find your reasoning compelling to the point where an entire hull can be lifted equally from a single foil. You'll need more than the bar napkin description. A foil big enough to lift an entire hull with rig, equally, is not what we are seeing here. Take a look at an airplane. How many do you think will get airborne, or even close, without an additional lifting surface that balances the primary forces from the main wing?

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Weight 3' out on a rack adds to the displacement of the boat.

 

 

 

Really? Simply move the crew to windward and the displacement of the hull goes up? Geez, what a magic elixir for designers.

 

Comments like this are precisely why the suggestion is not compelling.

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Thanks, Doug, but I don't find your reasoning compelling to the point where an entire hull can be lifted equally from a single foil. You'll need more than the bar napkin description. A foil big enough to lift an entire hull with rig, equally, is not what we are seeing here. Take a look at an airplane. How many do you think will get airborne, or even close, without an additional lifting surface that balances the primary forces from the main wing?

 

 

 

The B-35 bomber had a wingspan of 172 feet. Elimination of the fuselage and tail surfaces increased its efficiency by cutting down drag and reducing the airplane to a nearly pure supporting surface where every part contributed to its weight-lifting ability. It was produced in 1946.

 

So, I get anything from Teakys desk, but dont look in the drawers.. Cheers.

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If wind picks up you go fast then you put out the foil and by going fast the foil produces lift to right up the boat and lift to reduce drag of the whole boat (the whole boat is lifted means less drag in the whole system) and also to stabilise the whole system in any axle (you actually can walk around in the boat while going fast, it just doesn't move) this helps aerodynamics and hydrodynamics. if there is some chop, the boat is just hammering over it, like a surfboard.

 

 

 

Q-Man...

 

In the process of a better understanding, perhaps you can elaborate as to how the whole boat is lifted evenly from a single point of reference?

I can

 

first we have to do some due diligence

 

Do you agree, or admit that the foil (whether DSS, Moth or i14) is developing lift

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Thanks, Doug, but I don't find your reasoning compelling to the point where an entire hull can be lifted equally from a single foil. You'll need more than the bar napkin description. A foil big enough to lift an entire hull with rig, equally, is not what we are seeing here. Take a look at an airplane. How many do you think will get airborne, or even close, without an additional lifting surface that balances the primary forces from the main wing?

 

First of all we are not talking about lifting the whole boat out of the water and make it a foiling boat here!

The foil creates an upward force and therefore lifts the hull out of the water, reducing displacement. The hull is balanced by the immersed parts of the hull. I think you can also use crew weight for this, at least on smaller boats.

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Thanks, Doug, but I don't find your reasoning compelling to the point where an entire hull can be lifted equally from a single foil. You'll need more than the bar napkin description. A foil big enough to lift an entire hull with rig, equally, is not what we are seeing here. Take a look at an airplane. How many do you think will get airborne, or even close, without an additional lifting surface that balances the primary forces from the main wing?

 

It doesn't get lifted equally! It doesn't need to because half the boat is still in the water providing all the balance and control that you will ever need. This system is not designed to completely lift the boat out of the water. If it was then yes of course you would need a secondary control surface ala airplanes and skiff moths etc. Remember that Hugh's original idea was purely to gain righting moment. Reducing displacement was an extremely very beneficial side effect of the original aim.

 

Watch the video, it's amazing how little of the boat is in the water for the leeward side. In any case, the "compelling reasoning" is a bit of the moot point. DSS works. If watching that video doesn't convince you it works then I doubt any "reasoning" will. Hugh and Koz did a very rough experiment with an old Boatspeed 23 here in Brisbane about 5 or 6 years ago which proved beyond any reasonable doubt that it works.

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Thanks, Doug, but I don't find your reasoning compelling to the point where an entire hull can be lifted equally from a single foil. You'll need more than the bar napkin description. A foil big enough to lift an entire hull with rig, equally, is not what we are seeing here. Take a look at an airplane. How many do you think will get airborne, or even close, without an additional lifting surface that balances the primary forces from the main wing?

 

 

Can you not stand on one leg? :unsure:

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Do you agree, or admit that the foil (whether DSS, Moth or i14) is developing lift

 

 

 

 

 

That has already been mentioned and agreed upon. But that's not the issue as asked.

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The B-35 bomber had a wingspan of 172 feet. Elimination of the fuselage and tail surfaces increased its efficiency by cutting down drag and reducing the airplane to a nearly pure supporting surface where every part contributed to its weight-lifting ability. It was produced in 1946.

 

 

So, are you suggesting that the Q foil is shaped as a flying wing with a similar aspect ratio and available power to weight? There are also delta wing craft, which also break that suggestion of mine. Let's just deal with what we see and know.

 

I do like the flying wing, however. A significant Northrop factory was right near my home as a kid and I used to spend a lot of time trying to sneak into the place to get a closer look at the experimental aircraft they had parked there.

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First of all we are not talking about lifting the whole boat out of the water and make it a foiling boat here!

The foil creates an upward force and therefore lifts the hull out of the water, reducing displacement. The hull is balanced by the immersed parts of the hull. I think you can also use crew weight for this, at least on smaller boats.

 

 

 

 

I'm not talking about the lifting of the entire hull free of the surface, either. I said that in my posts above. The query originated from the suggestion by Q that he could walk about his boat and it had no effect on the pitch angle, or the heel... that the boat was rock steady in all directions. I'm simply asking about a single foil being able to do that when placed amidship and I gave an example with the foils used by cats and tris and the choice of placement for those boats. They have the same wetted surface, pitching and heel considerations.

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It doesn't get lifted equally! It doesn't need to because half the boat is still in the water providing all the balance and control that you will ever need. This system is not designed to completely lift the boat out of the water. If it was then yes of course you would need a secondary control surface ala airplanes and skiff moths etc. Remember that Hugh's original idea was purely to gain righting moment. Reducing displacement was an extremely very beneficial side effect of the original aim.

 

Watch the video, it's amazing how little of the boat is in the water for the leeward side. In any case, the "compelling reasoning" is a bit of the moot point. DSS works. If watching that video doesn't convince you it works then I doubt any "reasoning" will. Hugh and Koz did a very rough experiment with an old Boatspeed 23 here in Brisbane about 5 or 6 years ago which proved beyond any reasonable doubt that it works.

 

 

 

In no post did I say it did not work. In fact, I said the opposite. The question as presented had to do with overall pitch and boat balance as described by the owner in his post. I agree that the boat is experiencing lift from the foil. I agree that the boat is experiencing a slight loss of displaced volume when doing so, reducing wetted surface and enhancing speed potential when functioning at optimal speeds. I have followed the history, have seen the video and find the design solution interesting with potential yet to be developed.

 

The "compelling reason" statement had nothing to do with the original argument per se. I was suggesting to Doug that his overall set of comments had serious flaws that negated a response function. Putting weight out to the side of the hull does not increase displacement. Picture a sport boat with the crew hiked out and shredding along. Their location while sailing has not changed, one bit, the total amount of the weight of the sailed boat in any way, shape or form. They are still the crew weight whether seated on the can in the cabin, or hanging off the gunnel. The boat still has to carry all the weight of the boat itself, as well as any crew, and stores present. The displacement is as designed and built and does not change because you shove a bunch of rail meat on the edge.

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Can you not stand on one leg? :unsure:

 

 

 

 

Yes, I can... but not for long and that is pretty much my point and the source of my query.

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but you could if you had a 2nd foil, lets say a 28' one

 

with the moth it's the rudder

 

with the i-14 or Q-28 its a large very low aspect one, the hull

 

especially with the 14 and to a lesser extent with the larger boat it is trimmed ( or kept 'equal' ) by crew movement, mandatory for boats with a high percentage in crew weight

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It's not a single point, more like a "plane" of reference.

 

 

OK, then perhaps you can describe that technically for me?

 

I ask this because I see single lifting foils (curved) on lots of multihulls with the foil biased to the forward sections of the structure. While the boat is sailing with the leeward foil deployed, the leeward hull is not fully lifted. More, the forward component of the hull is lifted with the aft sections fully immersed due to weight shit and rudder needs. Does this lessen wetted surface... sure, but it does not lift the entire hull with the single foil. Now, we have a person claiming that the entire hull is lifted with the foil very clearly amidship. I'm having a very hard time digesting the potential for that small amount of foil surface being able to lift an entire hull of that weight with that rig aloft.

 

====================

Large tri's with curved ama foils lift up to 70% of the total weight in stable "flight"-all that on a single foil. It is not something that happens

now and then or a freak show: it is modern trimaran design!! A second foil for pitch control(as on the Moth) is not used because the ama still supports 30% of the weight and provides pitch control(most of the time).

 

Interview with Vincent Lauriot Prevost some time ago:

 

"Most radical of all has been the introduction of curved foils below the hulls that act like wings, producing vertical lift and reducing drag by raising even the leeward hull out of the water. Lift equals speed; speed begets more speed. "Sometimes you are even 100 percent on the foil - the whole boat on one single point," says Vincent Lauriot Prévost, the Brittany-based designer behind seven of the multihulls that competed in the Jacques Vabre. "Six years ago, foils took 30 percent of the displacement, and the boats were sailing at 28 or 29 knots," he says. "This year it's 70 percent, with speeds of up to 39 knots, which means you are sailing on the very sharp edge of a knife. We are pushing the limits of the machines."

====================

I did a rough calculation for the 28 showing the following:

If the foil was 4.62' long with an 8" chord, a 63412 section with a .6CI(just within the drag bucket) it would develop about 737 lb of lift 2' from the side of the boat at 12 knots-not too shabby......(assuming no negative affect from leeway or proximity to the surface). That's about a 40% reduction in displacement and a significant reduction in wetted surface.

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but you could if you had a 2nd foil, lets say a 28' one

 

with the moth it's the rudder

 

with the i-14 or Q-28 its a large very low aspect one, the hull

 

 

With the I-14 and the Q, I do not see the hulls as lifting foils the way they are commonly understood. More a stabilising form moving through the water in which buoyancy is generating lift as opposed to a foil, in which the section shape and surface area of the lifting device are generating lift. In any event, the single foil is not lifting the whole boat. It is lifting a section of the boat. I'm still anxious to hear from the owner, as his direct observations have great value in the understanding process.

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how do you lift a section of the boat without lifting the whole boat ?

 

your query was how does the single device lift the hull .... evenly

 

along with the crew, on a Moth its the rudder keeping it 'even', with the Q and 14 it's the hull, whether you like to call it a foil ...... or not

 

are you suggesting that the lift is only reducing heel and not displacement like the centreline devices on the M and 14 ?

 

also as soon as that boat is getting near or exceeding the theoretical hull speed, the hull is also creating lift

 

the 14 has a single device, i.e the T rudder, it lifts the boat and reduces displacement, the hull is the second low aspect foil giving a stabilising effect, as with all fast lightweights the judicious crew placement keeps it 'even'

 

same as the Q

 

i agree that 800-1000mm blade would have FA effect on a leadbelly, and alot on a Moth or 14, is it tangible on a 28 footer (abeit a VERY light one) might be your point ?

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Actually, GS... from the things I have seen from Bieker, he actually attributes less to the lift function of the foil and more to the process of enhancing the effective LOA of the hull by modifying the stern wave with the foil, allowing faster boat speeds.

 

I do not see how a single foil can lift a boat "evenly", fore to aft, while underway. There will always be pitching moments due to rig movement, variable pressure on the rig, variable sea state, crew positioning, etc. I suspect that the foil on the Q is really powerful for the cancelling of heeling moment issues and a whole lot less powerful when it comes to pitching moments. I further suspect that the movement of a single crew member (adult male) to the bow will generate noticeable forward pitch and have an effect on the foil's angle of attack, changing the lift component.

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Actually, GS... from the things I have seen from Bieker, he actually attributes less to the lift function of the foil and more to the process of enhancing the effective LOA of the hull by modifying the stern wave with the foil, allowing faster boat speeds.

 

I do not see how a single foil can lift a boat "evenly", fore to aft, while underway. There will always be pitching moments due to rig movement, variable pressure on the rig, variable sea state, crew positioning, etc. I suspect that the foil on the Q is really powerful for the cancelling of heeling moment issues and a whole lot less powerful when it comes to pitching moments. I further suspect that the movement of a single crew member (adult male) to the bow will generate noticeable forward pitch and have an effect on the foil's angle of attack, changing the lift component.

 

Some people, you just can't reach!

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Some people, you just can't reach!

 

 

 

 

Some people can be reached, Abbo, but it's always nice if the references given match the relevance of the discussion.

 

Looking at a post you made yesterday, it would seem that we are a whole lot closer on the thing than you have allowed. Here it is:

 

 

 

 

It doesn't get lifted equally! It doesn't need to because half the boat is still in the water providing all the balance and control that you will ever need. This system is not designed to completely lift the boat out of the water. If it was then yes of course you would need a secondary control surface ala airplanes and skiff moths etc. Remember that Hugh's original idea was purely to gain righting moment. Reducing displacement was an extremely very beneficial side effect of the original aim.

 

 

 

So, you agree with me that the whole boat is not being lifted as indicated by Q, the owner of the machine. You also agree to what I said, which is... the boat is not a full flying foil machine. By agreeing that a large component of the hull is still not be effected by the lift and that the hull will still behave as other boats do; that weight changes fore and aft will alter the pitch. This also runs against the comments made by Q.

 

 

So, you see, Abbo, we have a meeting of the minds and there's no need to be running up against one another.

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Racks and loads of righting moment + big kite = F***ing sweet.

Yeah, well, you would say that.

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chris it's obvious to even non-sailors the boat is not a foiled flying boat, who said that ? other than your reference

 

abbo, despite the reports you are calling bullshit on the lifting ?

 

the t-foil stern wave effect on 14 and other classes, UK 12s etc

chris, abbo -= are you both claiming the T-foil rudder on a 14 is not lifting the boat,

 

or are filing that under 'suspicions' ? or superstitions ?

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I think Abbo is being misrepresented here. I read his comment as simply sailing that the DSS foil was not designed to lift the boat clear of the water, not that ther was no lift or displacement reduction involved. I also read his comment to say that additional stabilization would only be needed if the boat was designed to be clear of the water.

 

For mine, the lack of wake and the reduction of pitching are real positives.

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