eiasu 3 Posted November 21, 2011 Share Posted November 21, 2011 The new Atlantic 47 has a completely new sail plan: MastFoil ™ looking forward to see the first one launched ! ciao eiasu Link to post Share on other sites
trenace 1 Posted November 21, 2011 Share Posted November 21, 2011 Well, for a cruising boat, perhaps it is a fine compromise. Fundamentally the mizzen staysail and mizzen wingmast are going to be in dirty air, so there will be an efficiency hit analogous to that between a unirig (say an A-cat) versus a cat ketch. It will be slightly interesting if the Patent Office will prove so lax that taking the existing idea of wingmasts (certainly the main wingmast is not novel) and saying "Let's have TWO in a ketch layout!" will be accepted. Agreed, I will be interested to see it launched. Link to post Share on other sites
Doug Lord 1,219 Posted November 21, 2011 Share Posted November 21, 2011 This was also posted on boatdesign-appears to be a two element ,extremely high aspect wing sail. Can't find any more detail so far. Link to post Share on other sites
brian eiland 4 Posted November 23, 2011 Share Posted November 23, 2011 ...from "The Chris White Designs MastFoil" Why eliminate the mainsail? Most sailors agree that the mainsail' date=' particularly the large roached, full battened mainsail combined with the aft-led-shroud, no-backstay-configuration that is used in most catamarans today, is by far the most troublesome sail to hoist, reef/unreef, furl and cover. In addition, mainsails create significant safety liabilities because they cannot be easily or quickly reefed or furled when sailing downwind. In violent squalls this feature has caused more than a few capsizes. The conventional catamaran mainsail can also be somewhat risky to gybe in a blow. For all the trouble associated with the mainsail, what do you get? Per unit of sail area, the mainsail is the least efficient sail on the boat. Sailing upwind, the mast - at the aerodynamically critical leading edge of the mainsail - robs a great deal of its power. Sailing downwind, the shrouds prevent easing the sheet enough to unstall the sail. At the other extreme in sail handling is the modern roller furling jib. You don't need to hoist and drop the sail every time you use it. It reefs easily on any point of sail. It furls completely in seconds. Couple these attributes with a rugged self tacking set up and there is not an easier to handle or more efficient soft sail. In the quest for simplified handling and improved safety, let's just do the obvious. Get rid of the mainsail. And in its place substitute more jib area combined with a super efficient MastFoil™.[/quote'] I came to some of these same conclusions LONG ago....get rid of the traditional mainsail and put on some efficient jibs....and lower the aspect ratio & overturning moments... Only I did it with a more simplified single mast arrangement. http://www.runningtideyachts.com/sail/ http://www.boatdesign.net/forums/sailboats/aftmast-rigs-623-7.html#post198605 Regards, Brian RunningTideYachts.com Link to post Share on other sites
Kenny Dumas 211 Posted November 23, 2011 Share Posted November 23, 2011 Makes sense to me. I'd like to see the data on their test model, or better yet, the real thing. Link to post Share on other sites
trenace 1 Posted November 24, 2011 Share Posted November 24, 2011 I came to some of these same conclusions LONG ago....get rid of the traditional mainsail and put on some efficient jibs....and lower the aspect ratio & overturning moments... Only I did it with a more simplified single mast arrangement. http://www.runningtideyachts.com/sail/ http://www.boatdesig...html#post198605 Regards, Brian RunningTideYachts.com Hi Brian, I'd seen your site some while back and found what you were saying interesting. Of course I'm stating the obvious, not for you but as many are reading, that overcoming the "non-traditional appearance" issue is always going to be a major hurdle. I was wondering when reading your site and even moreso now, do you have boats sailing now with your design? On the flip side: Undoubtedly there are any number of books and articles, and also data that will suggest, that the mast is a horrible evil to mainsail performance and jibs are so much better. Yet still it's a fact that for example A-cats are very fast and point very well... and for example, Marstrom could have done whatever he wanted with his M32 but chose the unirig for better pointing and upwind VMG. In theory, mainsails may be inherently inferior to jibs due to the mast... in practice, clearly it doesn't have to be so. Link to post Share on other sites
GybeSet 19 Posted November 24, 2011 Share Posted November 24, 2011 Fundamentally the mizzen staysail and mizzen wingmast are going to be in dirty air, so there will be an efficiency hit analogous to that between a unirig (say an A-cat) versus a cat ketch. It will be slightly interesting if the Patent Office will prove so lax that taking the existing idea of wingmasts (certainly the main wingmast is not novel) and saying "Let's have TWO in a ketch layout!" will be accepted. In theory, Patent ? Theory ? hi doug II xmas present for you above is your max smart style chute outta here we actually sail boats Link to post Share on other sites
brian eiland 4 Posted November 24, 2011 Share Posted November 24, 2011 I was wondering when reading your site and even moreso now, do you have boats sailing now with your design? On the flip side: Undoubtedly there are any number of books and articles, and also data that will suggest, that the mast is a horrible evil to mainsail performance and jibs are so much better. Yet still it's a fact that for example A-cats are very fast and point very well... and for example, Marstrom could have done whatever he wanted with his M32 but chose the unirig for better pointing and upwind VMG. In theory, mainsails may be inherently inferior to jibs due to the mast... in practice, clearly it doesn't have to be so. First let me say that I don't consider mainsails inferior at all. In fact in many situations they are great sails. I've chosen my arrangement due to both the all-furling handling, and the fact that the aerodynamics tell me that the leading sail (the genoa) is improved significantly by the following sail (the mainsail, what I refer to as the main-stay-sail). And I put them in parallel with one another. See Sails in Combination in that forum discussion, and Shorter Rig, Lower Aspect Ratio Here is a related rig built in Thailand My link My link Link to post Share on other sites
trenace 1 Posted November 24, 2011 Share Posted November 24, 2011 So it appears you have two boats delivered now: http://www.powerandsailing.com/boats-catamarans/catamaran-power-sailing-HK40.html Congratulations! Link to post Share on other sites
GybeSet 19 Posted November 24, 2011 Share Posted November 24, 2011 . I think you have strayed from the topic brought up in the original post that rig pictured has no technology on the FLOATING CONDOMINIUM I would sub that for my residence and not my boat copious amounts of eye bleach please what is there to congratulate ? those two berthing spaces could accommodate a proper sailing vessel i notice the terms A-cats, Marstrom etc in this thread, can someone draw the comparison for me again? Link to post Share on other sites
brian eiland 4 Posted November 24, 2011 Share Posted November 24, 2011 I think you have strayed from the topic brought up in the original post that rig pictured has no technology on the FLOATING CONDOMINIUM I would sub that for my residence and not my boat copious amounts of eye bleach please what is there to congratulate ? those two berthing spaces could accommodate a proper sailing vessel I was asked if there were any vessels out there with a rig like I purposed. These vessels were not designed to be pure sailing vessels, but rather sail-assisted power-cats. So unbleach your eyes and take the subject of MotorSailer more seriously...they are coming back in a big way when fuel prices continue to increase. And I'm sure you will find fault with many of their sailing qualities. Link to post Share on other sites
brian eiland 4 Posted November 24, 2011 Share Posted November 24, 2011 I've made a posting about this new rig concept over on that Sail Aerodynamics subject thread. It should be interesting to see what replies come up, as there were quite a few really knowledgeable people contributing to that subject thread (Tom Speer, etc) Back to Chris White's new rig, the subject of this thread. Did all of you take notice that his 'mastfoils' were two element foils themselves?? "Why does the foil have an articulating trailing edge flap? Because a flap adds lots of power to the foil with very little additional weight and complication. Reaching and running the flap is set at a significant angle (approx 40 degrees) to the main foil which increases the overall camber of the foil and can nearly double its power. Sailing upwind only a small amount of flap angle is used but it helps create additional lift with very little drag" This is an important and distinguishing feature of his design. This imparts a much greater contribution to their effectiveness, both alone, and in support of that headsail located in front of each MastFoil. This unique design deserves more analysis before being tossed to the trash pile by the 'traditionalist'. Link to post Share on other sites
trenace 1 Posted November 24, 2011 Share Posted November 24, 2011 It seems possible that the design, or perhaps an evolution of it, might have a lot of cruising or motorsailing application for boats at or past say 40 feet. It seems they are always going on about difficulty of handling the mainsails, and in any case the performance comparison would be to rolling-reefing setups rather than anything higher performance. So far as selling these things: A huge mistake in "selling" people is adding in unnecessary arguments that they don't buy. These just cause whatever valid things one might be saying to be questioned also. Both for Chris White's and yours, why not drop all the mast turbulence, mainsails-are-inefficient stuff and focus like a laser on cruising benefits, if that is the market? Link to post Share on other sites
brian eiland 4 Posted November 24, 2011 Share Posted November 24, 2011 Both for Chris White's and yours, why not drop all the mast turbulence, mainsails-are-inefficient stuff and focus like a laser on cruising benefits, if that is the market? You have to have been in the 'boat selling' market for a while to realize the obstacles involved. A power boat salesman I was talking with long ago was making the observation as to how easy is was to sell powerboats. Basically he said he had two major questions to answer after the person determined the size and price he was looking for...."what size engines can I get, and what colors does it come in". After that the client brought out his check book. On the other hand you have the sailing customer. Your extremely lucky if he buys a boat from you within a year of first inquirying....sometimes 2 or 3 years. And you will answer enumerable questions about the technical aspects of that vessel before he ever commits to buy. Sure would be nice to ignore all the other 'noise' but it just doesn't happen in reality. Link to post Share on other sites
richardsstephens 3 Posted November 24, 2011 Share Posted November 24, 2011 I wonder about this claim: Other Benefits.... Pinned to the dock by a 30 knot wind on the beam? We think that by trimming the MastFoils opposite each other that enough sideways lift can be created to actually pull the boat away from the dock! The author seems to think that an airfoil can generate a net force with a component into the direction of the wind (ie, a negative drag). I don't think this is possible. Link to post Share on other sites
Y-Bar 0 Posted November 24, 2011 Share Posted November 24, 2011 I wonder about this claim: Other Benefits.... Pinned to the dock by a 30 knot wind on the beam? We think that by trimming the MastFoils opposite each other that enough sideways lift can be created to actually pull the boat away from the dock! The author seems to think that an airfoil can generate a net force with a component into the direction of the wind (ie, a negative drag). I don't think this is possible. I wonder how it would go at anchor. Far as I am aware and have seen even on smaller foil type masts they do tend to sail around a bit. Link to post Share on other sites
Amati 1,523 Posted November 24, 2011 Share Posted November 24, 2011 Do the wing masts create enough lift (circulation) so the jibs are operating in higher relative aoa? If so, and if the drag of the mast/airfoil is less, why not? Paul Edit- has to be better than the off/on of a jib only.... Link to post Share on other sites
SeaGul 83 Posted November 25, 2011 Share Posted November 25, 2011 The concept remids me of something Wharram has on his Tiki 36 - with two small mast and a "wingsail" solution that is low tech but looks very healthy. Adjusted to the lates carbon wingmasts and high-tech sail -it could work very well on many boats wich is designed for hard weather. Link to post Share on other sites
trenace 1 Posted November 25, 2011 Share Posted November 25, 2011 This is why I was saying to not include such arguments, at least in the main presentation of the idea. It's what I call the Marcia Clark method of losing an argument or a sale. What you need is up to 3 reasons why OJ is guilty. Make them short and understandable. If you make it 40 reasons why he's guilty and each and every one you bring in eggheads who go on and on and on about ultra-technical matters that no one can follow, you're just going to confuse things and it will turn out that 5 of your reasons suck and will be exposed. Some of your bad, attempted useless proofs such as "Look, the glove fits him!" will blow up in your face. Pretty much guaranteed, when you try too many arguments. Saying this with respect to Brian, having done something the same way for years doesn't prove it's the best way to sell, particularly if this way only two boats got delivered with the design after all this time. Those results hardly prove that the way to reach people with this is to make it part of the main pitch that mainsails are just so inefficient aerodynamically. Even if it were true, if someone is buying a boat like this aren't there 100 other things that could stand improving for speed first if he wants it to be faster before going to wingmasts? I don't think it's going to work for Chris White to sell this by, as a main argument, attacking aerodynamic efficiency of mainsails in general. Make it instead about the safety and ease of use of this (if true.) Small sidepoint if it can be proven true, it's faster. But without making highly-arguable adverse claims about mainsails. That's basically like doing the glove thing. It raises questions on the credibility of the entire argument. "Is it all bullshit? I don't know anything about whether this arrangement will really be safer or easier to use, but this part that I do know about, is bullshit." You don't want people thinking that. Removing the questionable claims prevents that problem. Link to post Share on other sites
preischmann 0 Posted November 25, 2011 Share Posted November 25, 2011 I guess it depends if you are talking upwind or downwind. Mainsails are much more efficient that genoas off the wind since twist and sail shape can be controlled. This has been proven in years past with ketch cat rigs racing against monohull sloops. Chris is right about the tradtional catamaran rig with swept spreaders not being the best solution for cruising cats since they dont sail at high speeds and apparent angles sufficient to keep the sails off off the rigging and are hindered at sailing deeper angles, reefing etc. While his new rig idea is interesting, I think a much simpler solution for ALL cruising boats is the free standing mast. No rigging to interfere with sails or people on deck, lower cg than a stayed mast, ultimate reliability with no rigging failure to worry about, auto depowering with tip deflection. Of course and even better idea would be a rotating free standing mast (Check out Eric Sponberg N.A.) this would offer the best performance and ease of handling. For the foretriangle I am a big believer in self-tacking with twist control. Again jib travellers work but dont really help you with twist and sailing downwind. I have prouced over 100 boats with self-tacking arrangements, and in particular with the Berig Camber Spar, which self-tacks and controls twist. I am a big fan of Gary Hoyt, and think he has not recieved near the attention he deserves for many of his ideas, in particular the Hoyt boom which is probably and even better solution for both the mainsail and jib. Many decades ago Olin Stephens said "genoa's are the blight of all cruising boats" and " travellers were useless and dangerous on most cruising boats". Back in the day we rigged plenty of performance dinghies with a vang sheeting arrangement with no traveller and I dont see why that cant be done on larger boats. I recently completed a 50ft. custom aluminum cruising cat for a client with free standing mast by Composite Engineering, with self tacking Camber Spar that can be easily handled by one person, www.hytechmarine.com Link to post Share on other sites
trenace 1 Posted November 25, 2011 Share Posted November 25, 2011 Do you mean this boat? http://www.hy-techma...Fastwater52.pdf But I did not find anything about the camber spar you refer to. Link to post Share on other sites
preischmann 0 Posted November 25, 2011 Share Posted November 25, 2011 Do you mean this boat? http://www.hy-techma...Fastwater52.pdf But I did not find anything about the camber spar you refer to. The Camber Spar is in the standard specs and can be see in all the drawings and sailing photos. Link to post Share on other sites
trenace 1 Posted November 25, 2011 Share Posted November 25, 2011 Okay, I'm ignorant... I still can't see it in the PDF. It's visible in the pics there? I'm not familiar with the Camber Spar at all, so please forgive the ignorance. I would like to understand it. I also don't know if this PDF is the boat you are talking about, because you said 50 foot but the PDF is a 52 foot boat. It is however the only boat on your site for which I found an article that might have explained it. EDIT: Maybe I had a wrong expectation of what to look for, from my interpretation of the word "spar." Is this it, basically much like a batten? Link to post Share on other sites
preischmann 0 Posted November 25, 2011 Share Posted November 25, 2011 It is the Fastwater 52 the Camber Spar is a bent tube inside a pocket in the sail that rotates from tack to tack, it is like 1/2 of a wishbone boom, it also creates dynamic head stay tension, you can clearly see the pocket and camber Spar in the photos and it is shown in the drawings as well. Link to post Share on other sites
trenace 1 Posted November 25, 2011 Share Posted November 25, 2011 Do you mean this boat? http://www.hy-techma...Fastwater52.pdf But I did not find anything about the camber spar you refer to. The Camber Spar is in the standard specs and can be see in all the drawings and sailing photos. It is the Fastwater 52 the Camber Spar is a bent tube inside a pocket in the sail that rotates from tack to tack, it is like 1/2 of a wishbone boom, it also creates dynamic head stay tension, you can clearly see the pocket and camber Spar in the photos and it is shown in the drawings as well. I guess one can clearly see it if if expecting something looking far more like a batten than a spar. Anyway I have no idea what the relevance of this batten is to wingsails on cats, or efficiency of mainsails. Link to post Share on other sites
preischmann 0 Posted November 25, 2011 Share Posted November 25, 2011 It is an aluminum tube, hence the spar, and does much more than a batten as I detailed. The relevance is in the discussion of rig design like other comments made. Good luck. Link to post Share on other sites
trenace 1 Posted November 25, 2011 Share Posted November 25, 2011 Well, thanx for the really helpful explanation, and the condescending tone. I'll be absolutely sure to get one of your boats. You're a swell guy. A quick effort to see what other people think of this thing is that this "spar" is not exactly setting the world on fire, to say the least. I have no further interest in it, so your poor attitude and poor explanation really don't matter. Good luck to you too. Link to post Share on other sites
preischmann 0 Posted November 25, 2011 Share Posted November 25, 2011 Well, thanx for the really helpful explanation, and the condescending tone. I'll be absolutely sure to get one of your boats. You're a swell guy. A quick effort to see what other people think of this thing is that this "spar" is not exactly setting the world on fire, to say the least. I have no further interest in it, so your poor attitude and poor explanation really don't matter. Good luck to you too. Freedom yachts used them first, and I have over 150 boats with them, owners love them. Link to post Share on other sites
preischmann 0 Posted November 25, 2011 Share Posted November 25, 2011 Club foot dosent control twist or create headstay tension like the Camber Spar. Roller furling is a quick way to put the sail away, dosent reef very well, will not sail broad angles or downwind without a whiskerpole. Hoyt boom with roller furling is probably the best of all worlds. All of my owners have had the opportunity to convert to roller furling genoa's but once they weigh the pluses and minuses, stay with the Camber Spar. Of course the sail plan needs to be optimized to perform with just a blade jib in moderate conditions upwind. Link to post Share on other sites
preischmann 0 Posted November 25, 2011 Share Posted November 25, 2011 Forgot to mention also the Camber Spar can be hoisted by the clew end to clear the foredeck when not in use. No winch grinding, no flailing jib sheets. Link to post Share on other sites
preischmann 0 Posted November 25, 2011 Share Posted November 25, 2011 Not saying its perfect, just pointing out the advantages. Hoyt boom wasnt available at the time I developed the Manta catamaran. A flogging jibsheet can make widow's too. Link to post Share on other sites
eiasu 3 Posted December 15, 2011 Author Share Posted December 15, 2011 On Chris's website there is a video with Chris and Henk de Velde (recently back from an mainly-solo world tour with trimaran juniper) about wing masts Link to post Share on other sites
phillysailor 2,580 Posted April 15, 2012 Share Posted April 15, 2012 Kudos to CW for having the courage to change the basic idea of sail plan as an option for a cruising catamaran. Rather than continue producing what is expected, he is innovating solutions only recently adopted by racing catamarans. Having seen the advantages, he is eager to solve several problems in one fell swoop: 1. Improve the process of reefing. With a single control line, you can dump power from inside or outside the cabin. 2. Decrease the complexity of sail handling 3. Create a mast with no holes which is therefore stronger, less prone to failure 4. Provide redundancy (ketch rig with two masts) 5. Improve behavior at anchor 6. Lower the center of gravity, and presumably lower the height of the overhead clearance, which opens up cruising grounds I would like to see how the top of the masts look, seems the mast would have to be considerably taller than the wing, to allow for the stays. Or is the wing tapered? Link to post Share on other sites
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