437 replies to this topic

[Rawhide]

Hello Tim you still out there?

[Tim Shuwalow]

I wasn't at Kings Cup myself but am happy to provide some insight and info on a few points.

All round performance - The underlying premise of the SC26 concept is a One Design boat, and one that will give the best platform from which to develop an international class in time. It was therefore designed to be a boat that could be sailed and raced in a wide variety of conditions and provide fun racing in stronger conditions rather than pure survival sailing. It was never meant to be a lake flyer like the Swiss M2 or D35 designs, naturally you don't find boats like that in any numbers around the world.

Rating - The OMR rating is not particulary kind to the 26, things like air draft are not considered, so if you have a deck stepped mast rather than on an elevated cabin top you'll gain an advantage without being penalised. But that said we're not complaining because it was not designed or has not ben optimised for any rating rule, once again our objective is OD racing.

Weight - Initially at Kings Cup they were sailing with a crew of 4 guys (avg 80kg), this in addition to the need to carry a considerable amount of safety gear inhibits performance lighter airs when the boat was not designed to carry excess weight. The boat turned out a bit heavier than initial estimates because of things like the curved foils, the design of which was modified adding complexity to the build. The foils are more effective but are of no benefit in light airs.

Development time - All things considered the boat is still very new and is far from being race tuned. To date there's been no opportunity to do 2 boat testing or anything close. Some of the newer F18 designs have taken 12 months to reach their potential so a boat more complex will require at least as much before performing at it's max.

So in summary, the 26 was not designed to be the fastest boat in light airs, but gains will definitely be made in 2012. But you can take it anywhere in the world and know that you'll have a solid boat that will blast away bigger boats from medium condition upwards as was evident on the final day of Kings Cup in a 20nm coastal race left EVERYTHING else in its wake, including 50ft cats and 70ft monohulls with uncomparible budgets.

Check out the new vid with Torvar Mirksy on the front page.

[Tim Shuwalow]

[eric e]

nice video

something about non-native speakers dropping the f-bomb in promo videos

[ColinG]

Torvar was refreshingly honest about it not being for him. Don't see that very often.

[SlackWater_SF]

Thanks for the pics guys found another in the Kings cup results and speaking of results not to hijack but the Sidewinder cleaned up and the Seacart
did not do what I expected. Still no news on what happened from Seacart Central? Anyone out there from the regatta with a low down.

There are videos of some races. Lightish air, pleasant conditions for the races online as seen from this pc monitor. There were four (4) people aboard the Seacart 26 in the videos and not much hiking.

The Seacart 26 OMR rating for the Kings Cup shows no WCD (Weight Crew Declared).
The auto-crew weight assigned was 237 kilograms = 522 pounds.

The boat needs > 8-10 knot conditions to sail close to a rating with 4 people aboard and foils.

Wt.Meas.OMR = 984 kilograms = 2,169 pounds (texel.AUS.THA, w/sails, outboard, safety gear, anchor, tackle).

[Edake]

Hi Tim

Looks good. Am watching closely development. My interest is OD. Bob W put me onto this as an idea that might appeal. He is just doing up the 30 and I will then go and try. When there is a commitment in Sydney for a class count me in. Subject to selling a boat or two ofcourse.

[Edake]

Hello Tim you still out there?

Are you watching these too? Can we get a class here?

[Y-Bar]

I wasn't at Kings Cup myself but am happy to provide some insight and info on a few points.

All round performance - The underlying premise of the SC26 concept is a One Design boat, and one that will give the best platform from which to develop an international class in time. It was therefore designed to be a boat that could be sailed and raced in a wide variety of conditions and provide fun racing in stronger conditions rather than pure survival sailing. It was never meant to be a lake flyer like the Swiss M2 or D35 designs, naturally you don't find boats like that in any numbers around the world.

Rating - The OMR rating is not particulary kind to the 26, things like air draft are not considered, so if you have a deck stepped mast rather than on an elevated cabin top you'll gain an advantage without being penalised. But that said we're not complaining because it was not designed or has not ben optimised for any rating rule, once again our objective is OD racing.

Weight - Initially at Kings Cup they were sailing with a crew of 4 guys (avg 80kg), this in addition to the need to carry a considerable amount of safety gear inhibits performance lighter airs when the boat was not designed to carry excess weight. The boat turned out a bit heavier than initial estimates because of things like the curved foils, the design of which was modified adding complexity to the build. The foils are more effective but are of no benefit in light airs.

Development time - All things considered the boat is still very new and is far from being race tuned. To date there's been no opportunity to do 2 boat testing or anything close. Some of the newer F18 designs have taken 12 months to reach their potential so a boat more complex will require at least as much before performing at it's max.

So in summary, the 26 was not designed to be the fastest boat in light airs, but gains will definitely be made in 2012. But you can take it anywhere in the world and know that you'll have a solid boat that will blast away bigger boats from medium condition upwards as was evident on the final day of Kings Cup in a 20nm coastal race left EVERYTHING else in its wake, including 50ft cats and 70ft monohulls with uncomparible budgets.

Check out the new vid with Torvar Mirksy on the front page.

I wasnt asking the question trolling or to bag the boat because I like it and would jump at the chance to own one. It certainly would make a good one design class but they are hard to get off the ground in this global shitfight. Just interested as this seemed to me to be its first regatta and performance comparisons are always made against other designs.
It did seem to get better with every race over there so obviously it does take some getting used to. The 30 probably isnt as weight sensitive and is a bit more powered up. Keep us informed as things develop. Have a Merry Christmas.

[Tim Shuwalow]

Hi Tim

Looks good. Am watching closely development. My interest is OD. Bob W put me onto this as an idea that might appeal. He is just doing up the 30 and I will then go and try. When there is a commitment in Sydney for a class count me in. Subject to selling a boat or two ofcourse.

Great Edake, Sydney is going to be focus for establishing an OD class. No doubt you'll love a ride on the 30 with Bob and Leon, but the 26 is the future for class racing. Bob is certainly promoting it to many keelboat stalwarts, and seperate to that I've had some enquiries from prominant CYCA members, even ex Directors.

In addition there are a group of mulithull sailors that are looking for a more cost effective OD boat with simpler logistics so all this holds well for a strong fleet.

If you like, email me you details so we can stay in touch, tim@oceanlakemarine.com

Ask Davey Chapman for a quick appraisal of how the 26 went at Cowes Week - made the new Ker 40 look like it was standing still upwind! ;-)

[Tim Shuwalow]

I wasn't at Kings Cup myself but am happy to provide some insight and info on a few points.

All round performance - The underlying premise of the SC26 concept is a One Design boat, and one that will give the best platform from which to develop an international class in time. It was therefore designed to be a boat that could be sailed and raced in a wide variety of conditions and provide fun racing in stronger conditions rather than pure survival sailing. It was never meant to be a lake flyer like the Swiss M2 or D35 designs, naturally you don't find boats like that in any numbers around the world.

Rating - The OMR rating is not particulary kind to the 26, things like air draft are not considered, so if you have a deck stepped mast rather than on an elevated cabin top you'll gain an advantage without being penalised. But that said we're not complaining because it was not designed or has not ben optimised for any rating rule, once again our objective is OD racing.

Weight - Initially at Kings Cup they were sailing with a crew of 4 guys (avg 80kg), this in addition to the need to carry a considerable amount of safety gear inhibits performance lighter airs when the boat was not designed to carry excess weight. The boat turned out a bit heavier than initial estimates because of things like the curved foils, the design of which was modified adding complexity to the build. The foils are more effective but are of no benefit in light airs.

Development time - All things considered the boat is still very new and is far from being race tuned. To date there's been no opportunity to do 2 boat testing or anything close. Some of the newer F18 designs have taken 12 months to reach their potential so a boat more complex will require at least as much before performing at it's max.

So in summary, the 26 was not designed to be the fastest boat in light airs, but gains will definitely be made in 2012. But you can take it anywhere in the world and know that you'll have a solid boat that will blast away bigger boats from medium condition upwards as was evident on the final day of Kings Cup in a 20nm coastal race left EVERYTHING else in its wake, including 50ft cats and 70ft monohulls with uncomparible budgets.

Check out the new vid with Torvar Mirksy on the front page.

I wasnt asking the question trolling or to bag the boat because I like it and would jump at the chance to own one. It certainly would make a good one design class but they are hard to get off the ground in this global shitfight. Just interested as this seemed to me to be its first regatta and performance comparisons are always made against other designs.
It did seem to get better with every race over there so obviously it does take some getting used to. The 30 probably isnt as weight sensitive and is a bit more powered up. Keep us informed as things develop. Have a Merry Christmas.

No problem at all Y-Bar! Send me an email (see previous post). Are you in SF? Another hot spot for a building fleet in the new year.

Totally agree, new boats will always be compared against existing designs and although we're all about promoting and developing OD racing our boats will always being raced under rating as well. We don't shy away from lining up in major regattas with essentially brand new boats as we have done this year at Cowes Week and Kings Cup. There'll always be good results and average ones as the boats are being fine tuned and the owners and their crews learn the boat. Part of the fun! As you say, the 30 has a higher power-to-weight ratio and has much higher volume and designed to carry additional gear (weight) for offshore sailing.

Merry Christmas to you and all!

[Multihauler]

Lots of really nice new "detail" shots of SC-26 no.2 "Sweet Chariot" in the Seacart 26 gallery.

linky

GOOD STUFF!!!

Cheers!!!

-MH

[Edake]

Lots of really nice new "detail" shots of SC-26 no.2 "Sweet Chariot" in the Seacart 26 gallery.

linky

GOOD STUFF!!!

Cheers!!!

-MH

whats with the 2 snaps on the end of the boom for? no a muli sailor so please excuse my ignorance.

[B30]

Lots of really nice new "detail" shots of SC-26 no.2 "Sweet Chariot" in the Seacart 26 gallery.

linky

GOOD STUFF!!!

Cheers!!!

-MH

whats with the 2 snaps on the end of the boom for? no a muli sailor so please excuse my ignorance.

I would guess reefs.

[Edake]

thought that might be it but I assume you would have to decide and put it in before going on the water. no way you could do it once on the water could you?

[B30]

thought that might be it but I assume you would have to decide and put it in before going on the water. no way you could do it once on the water could you?

I have never seen the boat, but I don't see why not? It is a fully battened main so it won't flog too much if at all when let out. We "park" an F31R and corsair 37 all the time. The main just sits there quietly till you decide to pull it in and go. Great feature of multis that is hard to dupicate on mono's.

[mononowmulti]

Yes, the small clew wichard snappies are for reefing. Plus another two at the tack acting as cunningham > moves up to reef position.
No probs taking a reef on the water > it’s safe and fast to work on the trampolines (compared to a not so wide mono).

More trailer etc. prictures added here http://seacart26.com...bum=1&gallery=7

[mononowmulti]

Newly posted Video. Anders Lewander, North Sails, Checking Code 0 on a SeaCart 26 in Thailand

http://seacart26.com...26-code-0-test/

[richie]

...need an update Tim...How many boats are in the water already(how many in Thailand)?If I make the order today(hypothetically speaking),how soon can I get one(in Thailand)??

[mononowmulti]

Hi Richie, Tim is on daddy leave. Please contact me on info@oceanlakemarine.com or send me your email address.
Regards,

Calle Hennix

[mononowmulti]

Boat show video - just sailing - no talk!


Enjoy!

[richie]

hey,send email more than a week ago...still waiting for the reply...??

[Trevor B]

Calle,
Did the price get increased? Or was that just a currency fluctuation?
Is the weight on the website accurate currently?
Is there a boat headed for California? Seems like it would be perfect for the Bay Area.
How does the boat do against an F-18?
Thanks,
Trevor

[Multihauler]

From the Seacart 26 page......

Secart 26 Pricing:

USD ex.VAT Clean Boat One Design, Pre-Order,
3DL Config OD 3DL deposit
1 x SC26 $124,300 $154,200 $15,419
2 x SC26 $234,612 $308,376 $30,838
4 x SC26 $477,280 $616,751 $61,675


Seacart 26 Featured News:
On a world market having large industries demanding huge amount of material we have seen steady increased costs in build material. E-glass, epoxy, carbon does not come cheap any longer. On top of that we have the yearly price update on deck hardware and software, such as block, furlers, halyards and sheets.

Since the SeaCart 26 is an above standard advanced high tech trimaran using the best materials, build methods and equipment, we are influenced by these changes. The price of the SeaCart 26 will increase but we can ensure you we are doing our best to continue deliver one of the most advanced production boats there is on the market to a competitive price.

We are open for new dealers. Are you and your company interested to become a dealer contact Oceanlake Marine.

With more dealers in place we are able to supply good service at local markets outside Sweden and Thailand. Buying a boat from a dealer means paying a premium but you can expect a valuable local relationship. Things like helping out assembling the boat at delivery, carry out boat maintenance and winter storage by people that know the boat well is invaluable and appreciated.

The timing has never been more right to make a move into multihull. Rapidly growing interest in the world. The SeaCart 26 OD is a New class where no team is ahead. Now is the time to get ahead and order a SeaCart 26 OD – Pure Performance Guaranteed!

The SeaCart Team
Categories: News, Press Releases


-MH

[PIL007]

This boat after seeing it first hand is a cracker. The build quality is very good and it's a giant killer. I couldn't more impressed.
Also it's a bonus having people like Henry Kay owning one. Nice bloke and helpful in Ko Samui.
Nice work team......I'm impressed.

[richie]

This boat after seeing it first hand is a cracker. The build quality is very good and it's a giant killer. I couldn't more impressed.
Also it's a bonus having people like Henry Kay owning one. Nice bloke and helpful in Ko Samui.
Nice work team......I'm impressed.

Just looking at the results....they got "only" 3rd overall(?)...but the team and the boat looks great !! Good job Henry !!!

[steveromagnino]

they won in Top of the Gulf regatta beginning of May too against many of the same boats in Samui. That was in biggish breeze on the first day slowly fading each day down to nothing on the last day.

The guys sailing it in TOG did a big nose down handstand on the bows right in front of us downwind on the first day in breeze which we were reasonably fortunate to avoid (wind was 18-20 knots, reasonably choppy sea, they had gybed under us and were sailing higher across our bow when it happened, those trimarans have a large area you need to steer around when they stop right in front of you!). The boat just looks quick and the results seem to support it.

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[eric e]

nothing like pulling a stoppie on a tri

[Strategery]

they won in Top of the Gulf regatta beginning of May too against many of the same boats in Samui. That was in biggish breeze on the first day slowly fading each day down to nothing on the last day.

The guys sailing it in TOG did a big nose down handstand on the bows right in front of us downwind on the first day in breeze which we were reasonably fortunate to avoid (wind was 18-20 knots, reasonably choppy sea, they had gybed under us and were sailing higher across our bow when it happened, those trimarans have a large area you need to steer around when they stop right in front of you!). The boat just looks quick and the results seem to support it.

Is that a screecher it's flying at the start? What was the breeze?

C.

[joey g]

Interesting that the SeaCart is the only one( that can be seen) that is flying a screecher.

[richie]

They also used a downwind asymmetrical sail on the roller(can't call it a spinnaker anymore)....

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•  SamuiRegattaDay4Race50.JPG   186.99K   101 downloads
•  SamuiRegattaDay4Race79.JPG   206.2K   87 downloads

[Another day on the edge]

Seems to me you'd get an awful lot more benefit from lifting foils if you had a canting mast. But then, I'm not a dedicated 'follower of fashion'...

[eric e]

probably quite true

but i think the seacart 26 was designed to be an easy, fast 1-design thrill for monoslug sailors

perhaps as a step to the more performance oriented seacart 30?

[Another day on the edge]

Probably a bit unfair to single out the Seacart 26 but the point I'm trying to make is this whole foil thing is largely a bit of a marketing / fashion thing being sold by boat builders...

[oomummado]

Probably a bit unfair to single out the Seacart 26 but the point I'm trying to make is this whole foil thing is largely a bit of a marketing / fashion thing being sold by boat builders...

Clearly you have never sailed on a boat without a foil and then put one on.

[Tim Shuwalow]

Probably a bit unfair to single out the Seacart 26 but the point I'm trying to make is this whole foil thing is largely a bit of a marketing / fashion thing being sold by boat builders...

Clearly you have never sailed on a boat without a foil and then put one on.

Very true - the difference is amazing when you're pushing the boat hard.

[Another day on the edge]

The point I'm trying, badly, to make is that before I 'd put foils on a boat I would be canting the rig. If foils were the best way to make a boat quicker then Irens would have put then on Carbon3. He didn't ...

[PIL007]

Interesting that the SeaCart is the only one( that can be seen) that is flying a screecher.

Henry beat to weather with that screecher all week. It handled a lot of breeze.

Canting the mast is simple and should be an option, imo.

[Corley]

Probably a bit unfair to single out the Seacart 26 but the point I'm trying to make is this whole foil thing is largely a bit of a marketing / fashion thing being sold by boat builders...

Clearly you have never sailed on a boat without a foil and then put one on.

Very true - the difference is amazing when you're pushing the boat hard.

Yep a guy who has just purchased a Formula 40 ocean racing trimaran is a complete raving conservative when it comes to innovation. Clearly he requires stern reproach by the good people of this forum until he mends his ways and becomes obsessed with foil assist.

[bfp]

The point I'm trying, badly, to make is that before I 'd put foils on a boat I would be canting the rig. If foils were the best way to make a boat quicker then Irens would have put then on Carbon3. He didn't ...

Canting the rig does not have anything like the effect of adding foils in trying to keep the bows up when you are pushing a tri. They are not a fashion accessory for boats that actually need the lift.

[diggler]

Canting the rig does not have anything like the effect of adding foils in trying to keep the bows up when you are pushing a tri. They are not a fashion accessory for boats that actually need the lift.

Are you speaking from practical experience where you've done comparitive tests on a boat equipped with both features?

I am very interested and I ask this because all the scant information I've uncovered on the longitudinal positioning of the lifting foil says that it can't be too far forward of the ama LCB. I assume this is a safety constraint to prevent/limit pitch instability in the event that foil lift is lost. With such a constraint, and assuming a normal trimaran configuration with the max righting moment at around 25 degrees heel, a quick look at the physics involved just doesn't seem agree with your statement - the downwards force component from the sail plan is just too big a percentage of the displacement of a light boat.

[THOR]

now we been schooled ...... and all should know everything about them foily thingies

maybe we should ask the real intelligent folks, what boat they have sailed with foils and without foils ...

intersting enough a couple folks who have foils have not chimmed in.....

thor
foil less and never sailed one either.... but if I would built a new boat it would have foils for sure ...

[msouth]

Probably a bit unfair to single out the Seacart 26 but the point I'm trying to make is this whole foil thing is largely a bit of a marketing / fashion thing being sold by boat builders...

Been sailing foils assisted trimaran for 10 years, it just helps the boat going thru the waves easier and the stability fore aft and sideways is simply stunning when things gets loaded up.
I would never buy a sailboat without foils.

[Keith]

If anyone wants to gain some knowledge about foils, simply have a look at the ORMA 60 designs as they advanced through the generations, and now the MOD 70s, these foils work very well, and have been real time tested, in all conditions... you might even find a cool N. Iren's design there as well, or even a couple of them.





Here's one of my favorites....

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[Another day on the edge]

Of course we're all aware of the ORMA 60s, some of us may even have sailed on one or two in our time (pre foils unfortunately) however it's almost certainly the case that every single one of the foil equipped amongst them will have a canting rig.


Rig canting = reduction in healing force and ∴ dynamic displacement => hydrodynamic drag and increased drive force as well as the gains in aerodynamic efficiency of the sail plan for minimal weight yields a significant performance gain on all points of sail save very deep downwind.

A 60'er is much more stable in longitudinal pitch so the angle of attack of the foils giving lift most of the time but on a small boat once it pitches nose down the foils are going to work against you. What happens at 00:49 in the Seacart 26' video here? My link Flat water (!) and she's 'going down the mine'. Looks like the foils are driving the bow down not up... If that had been accelerating down a wave into the back of the next in a bit more breeze it'd have been game over... How much performance sapping weight are you having to carry around all the time? 100kg on a 26'er by the time you've added hull reinforcement etc?

Again, if foils were going to make Carbon 3 faster she would have them, she doesn't.

Still an unconvinced 'complete raving conservative' )

[the loose cannon]

Again, if foils were going to make Carbon 3 faster she would have them, she doesn't.

Still an unconvinced 'complete raving conservative' )

To a degree she does have lifting foils, just not the big banana foils. Nigel seems to have chosen the depth of a straight canted board (and it looks like rig adjustment) as his solution - I sure as heck won't argue with him. He has forgotten more than I will ever know....

[macca]

Of course we're all aware of the ORMA 60s, some of us may even have sailed on one or two in our time (pre foils unfortunately) however it's almost certainly the case that every single one of the foil equipped amongst them will have a canting rig.


Rig canting = reduction in healing force and ∴ dynamic displacement => hydrodynamic drag and increased drive force as well as the gains in aerodynamic efficiency of the sail plan for minimal weight yields a significant performance gain on all points of sail save very deep downwind.

A 60'er is much more stable in longitudinal pitch so the angle of attack of the foils giving lift most of the time but on a small boat once it pitches nose down the foils are going to work against you. What happens at 00:49 in the Seacart 26' video here? My link Flat water (!) and she's 'going down the mine'. Looks like the foils are driving the bow down not up... If that had been accelerating down a wave into the back of the next in a bit more breeze it'd have been game over... How much performance sapping weight are you having to carry around all the time? 100kg on a 26'er by the time you've added hull reinforcement etc?

Again, if foils were going to make Carbon 3 faster she would have them, she doesn't.

Still an unconvinced 'complete raving conservative' )

Cost of tooling and production might have a substantial impact on the choice to use curved foils on such a boat... It's a big ticket item I can assure you.

[Graham M]

Tim S, Just out of interest, what do the foils (and their cases) weigh ?

Thanks, Graham.

[PIL007]

Where's Doug when you need foil assisted answers....?

Fact is, boards work in amas and have done for ever so the extra cost initially to curve those boards out weighs the negatives.....well proven on 95% of every exotic BIG budget racing tri built in the last 10 years.

[Multihauler]

Tim S, Just out of interest, what do the foils (and their cases) weigh ?

Thanks, Graham.

Grahm,

The latest from Tim S. is that he is no longer associated with Oceanlake Marine.


Cheers!!!

-MH

[Graham M]

Cheers indeed MH , thanks !

Does anyone know the SC 26's foil weight, or for that matter, the weight of the Farrier foils ?

Cheers.

[Doug Lord]

Cheers indeed MH , thanks !

Does anyone know the SC 26's foil weight, or for that matter, the weight of the Farrier foils ?

Cheers.

=======================
Farrier F32R foils are 19kg(41.8lb) each: http://www.f-boatmar...productid=16240
Cases are 2.9kg(6.38lb) each: http://www.f-boatmar...&cat=253&page=2

[Graham M]

Thanks Doug .

[BigSquid]

The point I'm trying, badly, to make is that before I 'd put foils on a boat I would be canting the rig. If foils were the best way to make a boat quicker then Irens would have put then on Carbon3. He didn't ...

What's that saying about the first thing to do when your in a hole is stop digging?

Irens did put foils that provide lift on the Carbon 3. Someone will know better but inclined foils could be providing more than 25% lift at speeds in the teens. They are not curved but the angle of their attack combined with their +15 degree orientation while flying the center hull adds up to a diagonal providing vertical lift very similar to a curved foil. Because that boat is a racer for Scandinavian archipelago (minimal waves and no swells) there is less need for lots of lift than if it was an ocean racer.

[diggler]

Because that boat is a racer for Scandinavian archipelago (minimal waves and no swells) there is less need for lots of lift than if it was an ocean racer.

So, you are pretty much endorsing his original point that the Seacart 26 could do with a canting rig before adding expensive curved lifting foils then. Unless of course you consider the 26 an ocean racer.

[eric e]

i would want the factory

to design, test and build in

something like banana boards

a canting rig can be easily added later by owners who want to break out of the 1-design limits

[oomummado]

Of course we're all aware of the ORMA 60s, some of us may even have sailed on one or two in our time (pre foils unfortunately) however it's almost certainly the case that every single one of the foil equipped amongst them will have a canting rig.


Rig canting = reduction in healing force and ∴ dynamic displacement => hydrodynamic drag and increased drive force as well as the gains in aerodynamic efficiency of the sail plan for minimal weight yields a significant performance gain on all points of sail save very deep downwind.

A 60'er is much more stable in longitudinal pitch so the angle of attack of the foils giving lift most of the time but on a small boat once it pitches nose down the foils are going to work against you. What happens at 00:49 in the Seacart 26' video here? My link Flat water (!) and she's 'going down the mine'. Looks like the foils are driving the bow down not up... If that had been accelerating down a wave into the back of the next in a bit more breeze it'd have been game over... How much performance sapping weight are you having to carry around all the time? 100kg on a 26'er by the time you've added hull reinforcement etc?

Again, if foils were going to make Carbon 3 faster she would have them, she doesn't.

Still an unconvinced 'complete raving conservative' )

Mate - serious question. Do you own a performance multihull and have you experimented with the things you are talking about or are you just an armchair admiral sportsman that spends too much time on the internet.

I do own one and it started life without a canting rig and foils. Now we have developed both of these and I can tell you that you are talking shit. eg. you say an extra 100kg of weight for the foil. How about you calculate the drag factor of your leward float being under water up to the beams Vs being bow up and unloaded with a foil. The seacart foil is actually set into the boat at almost no angle of attack. It is relying mostly on the foil shape for lift. If you add 1 - 2 degrees of angle the whole attitude of the boat changes. The seacart guys can experiment with this. So instead of talking shit - how about you get educated on what you are saying.

[Another day on the edge]

I did wonder how long it would be before some one came out with a foul mouthed outburst like that

I do own an 12 m all carbon Irens designed offshore racing trimaran, if you'd taken the trouble to read my profile you'd know that. As for being an 'Armchair Admiral', with 12 posts?

Not withstanding your attitude I'd be interested to learn more about your boat and your experiences in developing it. Am almost certainly going to go to a canting rig but still not convinced about foils.

As for Carbon 3 having foils, she doesn't. Those are daggerboards, asymmetric and yes they will generate an element of lift but they are not foils per se.

Maybe oomummado, when he's calmed down can explain why what must be the most state of the art trimaran out there is configured this way?

[macca]

From my time sailing 60 tri's I would say without a doubt that the foils had considerably more influence on performance and seaworthyness than the rig canting.

I seriously think that the reason some non race boats neglect the foils is the cost... I know what they cost and its very expensive to do them right!

tooling for a set of these things on a 40ft boat would be in the 10's of thousands and the prod cost would be around 8-15k per foil. (euro)

[vmg]

Another consideration, if fitting to an existing boat, is that the beam structure may need some work

My understanding is that, although the righting moment of the boat doesn't change with foils, the forces on the beams are different and need to be accounted for. More money!

[Doug Lord]

I did wonder how long it would be before some one came out with a foul mouthed outburst like that

I do own an 12 m all carbon Irens designed offshore racing trimaran, if you'd taken the trouble to read my profile you'd know that. As for being an 'Armchair Admiral', with 12 posts?

Not withstanding your attitude I'd be interested to learn more about your boat and your experiences in developing it. Am almost certainly going to go to a canting rig but still not convinced about foils.

As for Carbon 3 having foils, she doesn't. Those are daggerboards, asymmetric and yes they will generate an element of lift but they are not foils per se.

Maybe oomummado, when he's calmed down can explain why what must be the most state of the art trimaran out there is configured this way?

==============
Yes, they are foils(!)designed to generate lateral resistance and vertical lift. The disadvantage of straight angled foils as compared with the curved foils on a Nacra 20(that do the same thing these do-in different proportions) is that with a curved foil you can change the angle of incidence of the vertical lift portion of the foil without changing the angle of incidence of the lateral resistance portion of the foil. With a straight, angled foil any adjustment affects both lateral resistance and vertical lift simultaneously.
Again, the only difference between a straight angled foil and a curved foil, when both are designed to develop lateral resistance and vertical lift, is the proportion of each chosen by the designer-and the greater adjustability of the curved foil.

[Corley]

The other recent Iren's trimaran without lifting foils that comes to mind is the 63' cruiser/racer trimaran Paradox. So it's obvious that Nigel doesn't think that lifting foils are an essential way of addressing every SOR and Paradox has proved to be a very fast racing platform although obviously not carrying as much sail as an ORMA60. It's also a bit of a stretch to suggest that a trimaran will handle like a float burying pig just because it doesn't have lifting foils that has more to do with the overall design. Another point is that Francis Joyon's round the world record was set when his boat had no lifting foils fitted I suppose that boats not seaworthy enough for you?

[Doug Lord]

The other recent Iren's trimaran without lifting foils that comes to mind is the 63' cruiser/racer trimaran Paradox. So it's obvious that Nigel doesn't think that lifting foils are an essential way of addressing every SOR and Paradox has proved to be a very fast racing platform although obviously not carrying as much sail as an ORMA60. It's also a bit of a stretch to suggest that a trimaran will handle like a float burying pig just because it doesn't have lifting foils that has more to do with the overall design. Another point is that Francis Joyon's round the world record was set when his boat had no lifting foils fitted I suppose that boats not seaworthy enough for you?

=====================
Idec and Sodebo, both designed by Irens were engineered and built to have foils added at a later date-and they have been added to both boats. There is no doubt whatsoever that a racing tri equipped with curved lifting ama foils will perform better than one not so equipped.

[THOR]

couple blocks... a little line .... you have a canting rig ..... for 500 bucks ...

foils.. with the needed extra strength beams, paying somebody to have them designed to actually work, maybe around 30 grand .... ( that would be a good figure to put some foils on my boat .... I assume)


just sayin
thanks thor

[Corley]

The other recent Iren's trimaran without lifting foils that comes to mind is the 63' cruiser/racer trimaran Paradox. So it's obvious that Nigel doesn't think that lifting foils are an essential way of addressing every SOR and Paradox has proved to be a very fast racing platform although obviously not carrying as much sail as an ORMA60. It's also a bit of a stretch to suggest that a trimaran will handle like a float burying pig just because it doesn't have lifting foils that has more to do with the overall design. Another point is that Francis Joyon's round the world record was set when his boat had no lifting foils fitted I suppose that boats not seaworthy enough for you?

=====================
Idec and Sodebo, both designed by Irens were engineered and built to have foils added at a later date-and they have been added to both boats. There is no doubt whatsoever that a racing tri equipped with curved lifting ama foils will perform better than one not so equipped.

I'm not arguing that point when your chasing that last few percent of performance the lifting foils are worthwhile VPLP design group when they studied the issue found that they are worth 3-5 percent in terms of improved average speed. I've not seen a study on canting rigs and what percentage performance addition that it adds. It's just some of the responses in here are virtually saying that the boat will be a pig without them which should not be the case and that points more to a poor initial or overpowered design than anything. The lifting foils are a useful design element which aids performance so are canting rigs.

[Doug Lord]

The other recent Iren's trimaran without lifting foils that comes to mind is the 63' cruiser/racer trimaran Paradox. So it's obvious that Nigel doesn't think that lifting foils are an essential way of addressing every SOR and Paradox has proved to be a very fast racing platform although obviously not carrying as much sail as an ORMA60. It's also a bit of a stretch to suggest that a trimaran will handle like a float burying pig just because it doesn't have lifting foils that has more to do with the overall design. Another point is that Francis Joyon's round the world record was set when his boat had no lifting foils fitted I suppose that boats not seaworthy enough for you?

=====================
Idec and Sodebo, both designed by Irens were engineered and built to have foils added at a later date-and they have been added to both boats. There is no doubt whatsoever that a racing tri equipped with curved lifting ama foils will perform better than one not so equipped.

I'm not arguing that point when your chasing that last few percent of performance the lifting foils are worthwhile VPLP design group when they studied the issue found that they are worth 3-5 percent in terms of improved average speed. I've not seen a study on canting rigs and what percentage performance addition that it adds. It's just some of the responses in here are virtually saying that the boat will be a pig without them which should not be the case and that points more to a poor initial or overpowered design than anything. The lifting foils are a useful design element which aids performance so are canting rigs.

==================
Corley, the foils add more than speed-they add pitchpole resistance and heave resistance ,improving the overall seakindliness of the boat.
Francis Joyon on curved lifting foils for IDEC. (I once read an article where he said he wished he had them for the round the world race-I'll try to find it.)

Victory Joyon

Francis Joyon (FRA ), skipper of the maxi trimaran IDEC , has won the Tour of the Isle of Wight , in 4 hours and 24 minutes. 1754 boats took part in this classic English .

" We have consistently exceeded 30 knots , thanks to new foils , but the wind was a little too low and the current too unfavorable to improve our record . If the departure was given one hour later it might have been playable "Said Francis Joyon, who is in his fifth victory .

The maxi -trimaran IDEC surpassed the Extreme 40 and ICAP, the famous maxi monohull .


http://www.eurosport...flashnews.shtml

[msouth]

The other recent Iren's trimaran without lifting foils that comes to mind is the 63' cruiser/racer trimaran Paradox. So it's obvious that Nigel doesn't think that lifting foils are an essential way of addressing every SOR and Paradox has proved to be a very fast racing platform although obviously not carrying as much sail as an ORMA60. It's also a bit of a stretch to suggest that a trimaran will handle like a float burying pig just because it doesn't have lifting foils that has more to do with the overall design. Another point is that Francis Joyon's round the world record was set when his boat had no lifting foils fitted I suppose that boats not seaworthy enough for you?

=====================
Idec and Sodebo, both designed by Irens were engineered and built to have foils added at a later date-and they have been added to both boats. There is no doubt whatsoever that a racing tri equipped with curved lifting ama foils will perform better than one not so equipped.

I'm not arguing that point when your chasing that last few percent of performance the lifting foils are worthwhile VPLP design group when they studied the issue found that they are worth 3-5 percent in terms of improved average speed. I've not seen a study on canting rigs and what percentage performance addition that it adds. It's just some of the responses in here are virtually saying that the boat will be a pig without them which should not be the case and that points more to a poor initial or overpowered design than anything. The lifting foils are a useful design element which aids performance so are canting rigs.

==================
Corley, the foils add more than speed-they add pitchpole resistance and heave resistance ,improving the overall seakindliness of the boat.
Francis Joyon on curved lifting foils for IDEC. (I once read an article where he said he wished he had them for the round the world race-I'll try to find it.)

Victory Joyon

Francis Joyon (FRA ), skipper of the maxi trimaran IDEC , has won the Tour of the Isle of Wight , in 4 hours and 24 minutes. 1754 boats took part in this classic English .

" We have consistently exceeded 30 knots , thanks to new foils , but the wind was a little too low and the current too unfavorable to improve our record . If the departure was given one hour later it might have been playable "Said Francis Joyon, who is in his fifth victory .

The maxi -trimaran IDEC surpassed the Extreme 40 and ICAP, the famous maxi monohull .


http://www.eurosport...flashnews.shtml

Tru dat, pitch damping if often forgotten, but very needed to go fast.

[bfp]

I did wonder how long it would be before some one came out with a foul mouthed outburst like that

I do own an 12 m all carbon Irens designed offshore racing trimaran, if you'd taken the trouble to read my profile you'd know that. As for being an 'Armchair Admiral', with 12 posts?

Not withstanding your attitude I'd be interested to learn more about your boat and your experiences in developing it. Am almost certainly going to go to a canting rig but still not convinced about foils.

As for Carbon 3 having foils, she doesn't. Those are daggerboards, asymmetric and yes they will generate an element of lift but they are not foils per se.

Maybe oomummado, when he's calmed down can explain why what must be the most state of the art trimaran out there is configured this way?

Mate, you are just wrong. The sooner you realise this and stop quoting one boat that doesnt have foils as the reason foils are not worth it, the sooner you may open your eyes and mind to see what the rest of the multi world has been experimenting with for over a decade and have already worked out what does work.

No doubt rig cant is effective, but it is nothing at all like the effect foils have in allowing you to push your boat harder.

[diggler]

No doubt rig cant is effective, but it is nothing at all like the effect foils have in allowing you to push your boat harder.

Once again, could you please provide the basis for your statement. Macca provided a very useful empirical data point and I am very interested in finding more of such data points.

[BigSquid]

The seacart 26 is intended as a multihull version of a melges 30 and this might explain the absence of a canting rig. If there is reinforcement in the floats to do it, bridles on the shrouds would allow a few degrees of rig cant in a simpler buoy racing setup. As to using boards with a symmetrical section versus foils with an asymmetrical section to provide lift I can't imagine a single argument against foil sections (lift). As to the particulars of their chord shape (J, C, inclined, etc...) this would be determined by so many factors that generalizations dont make sense. Bottom line is that there has been progress since 1994 and unless it is a cruising boat trading performance for simplicity it makes no sense to put a symmetrical centerboard in main hull without foils in the floats, canting rig or not.

[bfp]

No doubt rig cant is effective, but it is nothing at all like the effect foils have in allowing you to push your boat harder.

Once again, could you please provide the basis for your statement. Macca provided a very useful empirical data point and I am very interested in finding more of such data points.

We launched our tri without foils. We tipped it over (in pretty passive conditions). We put curved foils in the floats. We haven't tipped it over (yet) with the foils. They work.

And yes, we have a rig that cants more than 10 degrees sideways and we have the forestay on a ram and can change the rake by more than 8 degrees, while sailing.

[eric e]

No doubt rig cant is effective, but it is nothing at all like the effect foils have in allowing you to push your boat harder.

Once again, could you please provide the basis for your statement. Macca provided a very useful empirical data point and I am very interested in finding more of such data points.

We launched our tri without foils. We tipped it over (in pretty passive conditions). We put curved foils in the floats. We haven't tipped it over (yet) with the foils. They work.

any pics?

[hump101]

No doubt rig cant is effective, but it is nothing at all like the effect foils have in allowing you to push your boat harder.

Once again, could you please provide the basis for your statement. Macca provided a very useful empirical data point and I am very interested in finding more of such data points.

We launched our tri without foils. We tipped it over (in pretty passive conditions). We put curved foils in the floats. We haven't tipped it over (yet) with the foils. They work.

And yes, we have a rig that cants more than 10 degrees sideways and we have the forestay on a ram and can change the rake by more than 8 degrees, while sailing.

I'd really appreciate more numerical data on this if you have it, as I am starting down the same route on my F40 cat. In my case the COE is at 12m. With a beam overall of 7.75m then the rig is generating a force of 0.27xdisplacement at max righting moment. At 15 degrees of heel, 25% of the sail force is acting down, so 6.75% of displacement. This is how much I could save by canting the rig 15 degrees, which is as much as I can realistically achieve with the current geometry.

If I have a lifting foil that can provide 25% of displacement (4500N for my boat), then the rig cant will reduce loads on it, and hence drag, by 27%, which seems to me to be significant from the perspective of the foil structure, but not so much for performance.

As an aside, if you have a tri that you want to fit foils on but don't want to modify the beams, then consider lift-only T foils at the float LCB instead of curved, as the loads on the beams and beam connections don't significantly change, assuming the float is already high volume.

[diggler]

Awesome, thanks bfp. Could I trouble you for a rough length of your boat?

hump, your comment on the t-foil isn't entirely accurate. a lifting foil, t, curved, or otherwise, can and at some point will provide massive negative lift, thus creating a load case that was almost certainly not considered in the original design.

[Samin]

We launched our tri without foils. We tipped it over (in pretty passive conditions). We put curved foils in the floats. We haven't tipped it over (yet) with the foils. They work.

Must have tiny floats?

as I understand it the biggest performance gain in the Orma class was the canting rig closely followed by the foils

my 28ft tri has no foils and doesnt need them, its just extra expense, weight and complication and Id rather spend the money on new sails.

if you have an unlimited budget then.... build a longer tri!

[oomummado]

We launched our tri without foils. We tipped it over (in pretty passive conditions). We put curved foils in the floats. We haven't tipped it over (yet) with the foils. They work.

Must have tiny floats?

as I understand it the biggest performance gain in the Orma class was the canting rig closely followed by the foils

my 28ft tri has no foils and doesnt need them, its just extra expense, weight and complication and Id rather spend the money on new sails.

if you have an unlimited budget then.... build a longer tri!

No the floats are not small. They are large. If your 28' tri does not need foils then you must be well underpowered and / or do not puch it hard enough. I think your missing the point. We could sail our tri without the foils without any problems but the point is that a) we would not be able to push hard in any wind its much safer c) because it allows you to push harder - you can go faster. Thats the point. Canting the rig adds more righting moment to the boat and allows you to push harder still. In combination it makes the boat much faster. If you have a overbuilt heavy alloy rig with stainless rigging and spreaders everywhere - then canting the rig will offer great benefites. In our case we have a marstrom carbon rig and the foil is much more beneficial than rig cant. If you dont have the budget to go the foils - then adding cant to the rig is a great and cost effective option for you.

[Samin]

my 28ft tri has no foils and doesnt need them, its just extra expense, weight and complication

If your 28' tri does not need foils then you must be well underpowered and / or do not puch it hard enough.

It doesnt need foils because its designed to not need foils. its not underpowered and we do push it hard.

yes we can and do sail it with the main hull out upwind, reaching and downwind with no nosediving issues.

[eric e]

If your 28' tri does not need foils then you must be well underpowered and / or do not puch it hard enough.

It doesnt need foils because its designed to not need foils. its not underpowered and we do push it hard.

yes we can and do sail it with the main hull out upwind, reaching and downwind with no nosediving issues.

so if it is a design feature

that allows you to avoid tripping over the leeward float bow when the rig is fully loaded

what is it?

floats longer than the main hull?

reverse, full volume, wave piecing float bows??

a short rig, unable to generate sufficient moment to overcome the leeward bow volume???

can we know the length and top speed so far recorded?

not trying to rattle any cages

just wanna know!

i spent the afternoon sailing my 14' weta tri in the strongest winds i've sailed in 3 years of ownership

the limit is very simple, it's when the leeward bow tries to go down the mine

i can imagine a lifting foil that would allow more speed by counteracting the rig's moment, unfortunately the weta demount-able beams don't appear strong enough to support such loads

the weta rig also can't really be canted, but if it even could, i can't see how that would overcome the length - volume limit of the leeward bow

[hump101]

hump, your comment on the t-foil isn't entirely accurate. a lifting foil, t, curved, or otherwise, can and at some point will provide massive negative lift, thus creating a load case that was almost certainly not considered in the original design.

Could you explain that? A T foil with section arranged to provide lift relative the hull will only provide negative lift if the hull itself is trimmed down to such an extent that the foil has a negative angle of attack, and in such conditions the hull itself, burying into the water, will generate far higher loads than the foil can. Since the beams must be designed to cope with such a plant, they should cope with the reduced negative load that the foil can generate. Or have I missed something?

[diggler]

you got it pretty much right other than the part about burying the hull generating far higher loads than the foil. i'm speaking from my own research experience with foils in waves and also from what a few designers have said about issues to consider regarding lifting foils.

edit: you also have to remember that to get a good lift to drag ratio the lifting foil has to operate at a fairly low angle of attack, so the zero lift trim angle might not be as big as you were envisioning.

[hump101]

you got it pretty much right other than the part about burying the hull generating far higher loads than the foil. i'm speaking from my own research experience with foils in waves and also from what a few designers have said about issues to consider regarding lifting foils.

edit: you also have to remember that to get a good lift to drag ratio the lifting foil has to operate at a fairly low angle of attack, so the zero lift trim angle might not be as big as you were envisioning.

I think we'd need to get into a lot more detail about specific geometry to determine this, but firstly I'm talking about loads on the beams, not the root of the foil. The pure lifting foil may be able to generate very high loads at its root, depending on its geometry, but the corresponding loads on the beams are not the same as those that can be generated by the hull as it slams or plants. That's what my FEA shows, and I've broken a few foils, but not beams. Curved or inclined foils that also generate side load are a different kettle of fish, of course, but that is not what we are discussing.

Secondly, I've not heard of a lifting foil having an AOA negative relative to the base line of the hull. On my flying foiler the flat underside of the foils is +4 degrees relative to the hull, and the asymmetric section won't generate negative lift until the foil section is at -4 degrees, so 8 degrees negative trim of the boat required to start producing negative lift. The foil won't produce a negative lift equivalent to the hull displacement until the boat has 22 degrees of negative trim @15m/s, but at 15 degrees of negative trim the flow into the foil becomes disturbed by the hull ahead of it and negative lift is diminished. In my case the lifting foil is relatively close to the hull, so a very deep foil may have different characteristics, but my foils are sized to fly the boat, so foils designed only to provide lift of 25% of displacement would have correspondingly less potential to generate negative lift. As such, I can't see such a foil generating higher loads on the beams than the hull can, but agree that each arrangement would need to be analysed on its own characteristics.

[Silver Raven]

my 28ft tri has no foils and doesnt need them, its just extra expense, weight and complication

If your 28' tri does not need foils then you must be well underpowered and / or do not puch it hard enough.

It doesnt need foils because its designed to not need foils. its not underpowered and we do push it hard.

yes we can and do sail it with the main hull out upwind, reaching and downwind with no nosediving issues.

Gooday 'K1' - how did your weekend sailing go - - very well - I hope. Could you please give some detail about your comments above - Thank you. What is the size & weight of you 'lill-green-doodle-bug' machine - How many people to you sail/race with ??? - - I'd sure like to see some pics - so I could looking at emulating your success. Thanks mate. Looking forward to learning from you knowledging & winning a few races. That sure is a very 'hot' fleet of multi's you chaps have right there in your own back yard (front pool) - Yes. Ciao, james

[Samin]

yes we can and do sail it with the main hull out upwind, reaching and downwind with no nosediving issues.

so if it is a design feature

that allows you to avoid tripping over the leeward float bow when the rig is fully loaded

what is it?

Its a combination of ;
lower aspect sailplan
narrower overall beam
Big floats (300%+) with Centre of Boyancy slightly foward of the Centre of Boyancy of the main hull
very light carbon rig
Very light hull and beam construction
If I was to add 40 kg of lifting foils I would rather have and extra Meter or so of waterline in this size boat for the weight.
Also on a 28ft boat the location of the crew fore and aft makes a big difference to fore aft trim.

The Weta has tiny floats, totally different (still good) design philosophy, its designed to bury them and uses crew weight for righting moment as much as float volume.

In saying that I dont agree foils are necessary on this size Tri I still think the Seacart 26 is an awesome little racer and hope someone brings one back to little ol NZ so we can line up.
The smaller floats/foil assisted design is certainly going to be faster in some conditions, but for the people in this thread saying foils are essential for a small performance Tri they are not correct in my experience, its a different- not necessarily better or worse design philosophy.

[eric e]

thanks

it brings to mind idec and sod'the'name

in the auckland 8.5 mtr class it's a pity cubic

the farrier 82Rr tri never fully got up to speed or seems to have used it's straight lifting foils

was going to post the link but can't find it

has it sold?

Attached Files

•  cubiclift.jpg   172.44K   33 downloads

[oomummado]

yes we can and do sail it with the main hull out upwind, reaching and downwind with no nosediving issues.

so if it is a design feature

that allows you to avoid tripping over the leeward float bow when the rig is fully loaded

what is it?

Its a combination of ;
lower aspect sailplan
narrower overall beam
Big floats (300%+) with Centre of Boyancy slightly foward of the Centre of Boyancy of the main hull
very light carbon rig
Very light hull and beam construction
If I was to add 40 kg of lifting foils I would rather have and extra Meter or so of waterline in this size boat for the weight.
Also on a 28ft boat the location of the crew fore and aft makes a big difference to fore aft trim.

The Weta has tiny floats, totally different (still good) design philosophy, its designed to bury them and uses crew weight for righting moment as much as float volume.

In saying that I dont agree foils are necessary on this size Tri I still think the Seacart 26 is an awesome little racer and hope someone brings one back to little ol NZ so we can line up.
The smaller floats/foil assisted design is certainly going to be faster in some conditions, but for the people in this thread saying foils are essential for a small performance Tri they are not correct in my experience, its a different- not necessarily better or worse design philosophy.

No Foil = fat draggy heavy floats
Foil = light low drag racing floats
There is no free lunch in yachting. With that much volume comes drag. With lower volume comes faster shapes that have high speed potential - but require the foil to compensate and to add safety and ability to keep pushing.
I can only guess Samins boat may have a cruiing slant to it. If thats the case its fine to have such massive floats. But if you want a proper race boat - it does not work like that. Too heavy and too draggy. Hence why everyone puts the foils into race boats. Its not reinventing the wheel. Its been proven for the last 10 years.

[eric e]

by all accounts the catri has tiny foil assisted floats

and so ends up penalised when not foiling...

http://en.cosasdebar...1102975355.html


this tri has big floats
 stealthmission.JPG   265.81K   68 downloads

[eric e]

while i blab on about things i don't understand

is this a mast canting system?

Attached Files

•  cant.jpg   314.15K   53 downloads

[Samin]

Hence why everyone puts the foils into race boats.
Its been proven for the last 10 years.

everyone reading your statement will know its not true.
i cant even be bothered listing all the racing tris that have been launched without foils id be here all night!

P.s look foward to more pics and results from the Seacart 26!

[bush sailer]

a couple of comments from my boat:
Foils are a benefit for a surprisingly small amount of time on a racecoarse. No good in light wind. No good down wind in medium conditions. Boat speed needs to be 11 knots up wind to benefit. Only capsize on my was the result of the foil We got hit by a gust and the boat accelerated too much for the amount of foil down and the boat lept out of the water dived back in and we also had a wrap on the kite winch which resulted in a capsize. However they can also be very good as per comments above.
The curved foil puts compression loading on the underside of the beams. I think this is what someone said was negative load. This does not happen on boats without foils so beams are not designed for this.
Still foils are great when everything is just right.

[msouth]

a couple of comments from my boat:
Foils are a benefit for a surprisingly small amount of time on a racecoarse. No good in light wind. No good down wind in medium conditions. Boat speed needs to be 11 knots up wind to benefit. Only capsize on my was the result of the foil We got hit by a gust and the boat accelerated too much for the amount of foil down and the boat lept out of the water dived back in and we also had a wrap on the kite winch which resulted in a capsize. However they can also be very good as per comments above.
The curved foil puts compression loading on the underside of the beams. I think this is what someone said was negative load. This does not happen on boats without foils so beams are not designed for this.
Still foils are great when everything is just right.

Sounds like some training on how to dial the foils in right can be a good investment.

[diggler]

I think we'd need to get into a lot more detail about specific geometry to determine this, but firstly I'm talking about loads on the beams, not the root of the foil.

No need to get into the geometry. Hopefully bush sailor worded it in a better way for you.

Just looked at the latest pics of the SeaCart26 on their website, sure is a sexy little boat.

[msouth]

I think we'd need to get into a lot more detail about specific geometry to determine this, but firstly I'm talking about loads on the beams, not the root of the foil.

No need to get into the geometry. Hopefully bush sailor worded it in a better way for you.

Just looked at the latest pics of the SeaCart26 on their website, sure is a sexy little boat.

Here is a close up - fish perspective that is

 DSC00458.jpg   473.62K   22 downloads

[Vincent DePillis]

Hi Bush Sailor--

Nicely specific and useful comments. What kind of boat?


"a couple of comments from my boat:"

[bush sailer]

a couple of comments from my boat:
Foils are a benefit for a surprisingly small amount of time on a racecoarse. No good in light wind. No good down wind in medium conditions. Boat speed needs to be 11 knots up wind to benefit. Only capsize on my was the result of the foil We got hit by a gust and the boat accelerated too much for the amount of foil down and the boat lept out of the water dived back in and we also had a wrap on the kite winch which resulted in a capsize. However they can also be very good as per comments above.
The curved foil puts compression loading on the underside of the beams. I think this is what someone said was negative load. This does not happen on boats without foils so beams are not designed for this.
Still foils are great when everything is just right.

Sounds like some training on how to dial the foils in right can be a good investment.

You are correct. We are still playing with the foil angle and have reduced it to nearly 0. I also made the mistake of setting the foil up so the tip is nearly horizontal when the main hull is out of the water. I should have put the foil more vertical which would have given it more lift to windward and not so much vertical lift. It would also mean the foil would have exited the hull 100mm deeper which would have been better for cavitation.(Changing that is a bit of a major) As it is i have not looked at the boat for 9 months but one day!!!

[msouth]

 post-23477-064735300%201340005695_thumb.jpg   14.32K   25 downloads

thanks

Gosh, that is a way aggressive AOA foil - bet it does not perform 100 % well

[BigSquid]

Hence why everyone puts the foils into race boats.
Its been proven for the last 10 years.

i cant even be bothered listing all the racing tris that have been launched without foils id be here all night!

The last racing trimaran without foils in the floats and only a board in the mainhull is the Seacart 30 as far as I know. Are there others more recent than this? I thought this thread was about owners of older boats contemplating a refit and redesign for foils in the floats but now it seems to be taking a turn towards questioning what is already the norm for race boats and no doubt will become standard on cruising boats soon. For example, a lightweight trimaran like the Seacart 30 might benefit in performance overall by substituting its centerboard with foils in the floats and certainly the gain in interior volume would make the boat more cruising friendly.

[Corley]

Most of the Multi 50's dont use lifting foils. Prince De Bretagne has near vertical daggerboards in the float that I imagine could generate some degree of lift at high angles of heel. No translation of the rules to English so I'm not sure if lifting foils are not allowed or the teams have chosen not to use them.

Multi 50 association

[Doug Lord]

Most of the Multi 50's dont use lifting foils. Prince De Bretagne has near vertical daggerboards in the float that I imagine could generate some degree of lift at high angles of heel. No translation of the rules to English so I'm not sure if lifting foils are not allowed or the teams have chosen not to use them.

Multi 50 association

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This Open 50 uses reverse dihedral T-foils on each ama-like Gary Baigent uses on a couple(?) of his boats. http://www.class-mul...teaux/pir2.html
There must not be a rule against them so I wonder why no curved foils when they are so well proven on race boats?

Attached Files

•  Open 50 trimaran pir-2-deco.jpg   38.79K   20 downloads

[rule69]

Most of the Multi 50's dont use lifting foils. Prince De Bretagne has near vertical daggerboards in the float that I imagine could generate some degree of lift at high angles of heel. No translation of the rules to English so I'm not sure if lifting foils are not allowed or the teams have chosen not to use them.

Multi 50 association

Forgive the Google xlat but I think this is the rule:

2.6.4 Lift
General: Appendices should not develop vertical lift (excluding
buoyancy and lift linked to a heel)
For purposes of this gauge, a plan is sustainer of all or part Appendix can
create a vertical force to zero bed, with the exception of the following:
- Spade rudder at an angle with the maximum longitudinal plane of symmetry of
boat less than 10 °, with no deposit and with zero rudder angle.
Outgrowth affecting any section of an appendix of less than 10mm, measured by its
generator, and the profile of less than 50mm (fences).
Forms of appendages that can give lift to the boat (not buoyancy) in
acting as a foil, is strictly prohibited, and any appendices angulation
drift.
The plates creating an airfoil on the rudders and fins are prohibited.

[Doug Lord]

Most of the Multi 50's dont use lifting foils. Prince De Bretagne has near vertical daggerboards in the float that I imagine could generate some degree of lift at high angles of heel. No translation of the rules to English so I'm not sure if lifting foils are not allowed or the teams have chosen not to use them.

Multi 50 association

Forgive the Google xlat but I think this is the rule:

2.6.4 Lift
General: Appendices should not develop vertical lift (excluding
buoyancy and lift linked to a heel)
For purposes of this gauge, a plan is sustainer of all or part Appendix can
create a vertical force to zero bed, with the exception of the following:
- Spade rudder at an angle with the maximum longitudinal plane of symmetry of
boat less than 10 °, with no deposit and with zero rudder angle.
Outgrowth affecting any section of an appendix of less than 10mm, measured by its
generator, and the profile of less than 50mm (fences).
Forms of appendages that can give lift to the boat (not buoyancy) in
acting as a foil, is strictly prohibited, and any appendices angulation
drift.
The plates creating an airfoil on the rudders and fins are prohibited.

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Thanks for that-but how does Pir^2(last post) fit into that rule with the reverse dihedral foils??