Of all the IACC models produced world wide America One is the only one with a working fully gybable spinnaker. A spinnaker that can be carried from a beam reach to a beam reach and be set and doused in 2.5 seconds.
This boat captures the essence of racing the full size boats where the spinnaker plays such a large role.
It is also the only IACC model to have a square top main as did most of the full size boats in the recent America’s Cup.
Racing an America’s Cup model with a spinnaker is an incredible experience with one of the great parts of the experience being able to watch the boats coming downwind with multicolored spinnakers set-such beauty!
The America One was sailed by Chris Jackson editor of Marine Modelling around three years ago and there is a small mention and picture of two boats racing on page 74 of his new book…
UPDATE: Chris’s book “Radio Controlled Racing Sailboats” is available in the USA from Traplet USA Distribution Limited ,1-800-695-0208, in the UK at:01684 595399,in Australia at: (02) 9520 0933 and everywhere else at; +44(0)1684 595399 or check the website: www.traplet.com
UPDATE 10/27/03 : there is discussion amongst the original owners of this boat on whether or not to update the boat to a canting keel to increase performance and because some are convinced the full size IACC boats will do this before too long. At any rate, since there are just a few boats in the US a change could be made now at relatively low cost
considering the dramatic performance gains possible. Only the canting keel winch and new hull would be added with all hardware and radios the same and transfered to the new hull…
High Technology Sailing/Racing
America One and our racing 36/600 have just received a new spinnaker design from Sandy Goodall a world renown sail design consultant known mainly for his full size work but who is now consulting on our models.
The new sail is a high aspect spinnaker with broader shoulders than the current design and looks really good.
See video of America One in action(with the old sail) on the website.
High Technology Sailing/Racing
I think your spinnaker models are really cool, but I have always thought that the spinnakers were too small. I’m not sure how much extra sail area you are adding, but it does not seem like much. Most full sized boats have spinnakers that are bigger than their total upwind sail area. Some boats have spinnakers that are almost double their upwind sail area - even with a fractional hoist.
Your spinnaker pole system seems like it could accomidate a larger spinnaker. If you are taking votes (and I know you are not), I would like to see you and Sandy try to design a bigger spinnaker.
BTW, have you seen the large black "V"s that the ocean racers use on the luff tapes of their spinnakers? These "V"s help the trimmers to see when the tape begins to curl - especially at night. I would think that trying to trim a spinnaker from shore would be a lot easier with that extra visual aid. Here is a pic:
Will, there are several factors that determine the size of an rc spinnaker using my system.None of them include how it looks… One, is that the hoist is limited to twice the on-deck distnce a double fiddle block can move. Another is the inside room available for the stowage tube and still another is whether or not the designer wants the boat to have just one spinnaker for all conditions or multiple spinnakers for different conditions like multiple rigs.
On the 50 and America One the original owners made the decision to have just one spinnaker for simplicities sake so we started with the biggest that the boat could handle with the restraints listed above.(see most recent post this date for additional design restraint) For an all out racing boat those retraints could be designed out, though. So on America One we started with an A rig and an A spinnaker: both were too much for the boat in over 8mph. So we finally settled on the B rig with B spinnaker. Nobody wanted to have to change rigs-conditions here can be light and heavy on the same cousre at any given time; same thing on the 50.
Another design consideration is that as the spinnaker hoist position increases in height the angle between the pivot point of the poles on deck and the hoist position gets more vertical. This is important because one of the coolest thing’s about my system is that when the sail gets hit by a gust it LIFTS the bow; the early bigger spinnakers did not. The spinnaker on both those boats allows the boat to be sailed in stronger winds WITH the spinnaker than without it.
The new 36/600 racing spinnaker boat will have two spinnakers and the new 3R model will have a spinnaker that will be much larger in appearance and still meet all the design criteria because the upwind sail area is limited.(similar in appearence to a reefed Spinnaker 50)
So there are multiple interrelated factors that result in th spinnaker you see; they are all a result of making the compromises necessary for the performance and handling desired. The most important considerations were and are that the sail be able to be carried from a beam reach to a beam reach gybing w/o collapsing the sail(after practice) and that the sail set and retract quickly and reliably–they do that 100%.
High Technology Sailing/Racing
I have raced spinnaker dinghies for many years (E-scows, M-20 scows, 470s, etc.). All of these boats use a fractional hoist just above the jib. All of these boats have the foot of the sail well above the deck. And all of these boats have more sail area in the spinnaker than the totoal of the jib and main.
These boats also have something that your boats do not - the ability to tip over.
One of the most critical tactical decisions you can make in any of these classes is the decsision to hoist or not on a reach. In moderate winds, you can sail almost up to a beam reach with the spinnaker flying and hike hard enough to keep the boat from tipping over. However, I have seem many times that the guys who do not hoist under those conditions can sail faster than the guys that do.
As the wind gets higher, that decision point gets to a lower and lower sailing angle - mostly because of the risk of tipping over.
How does this relate to your boats? i think your requirement to be able to sail the spinnaker up to a beam reach is overconstraining your design. While it might be faster to sail that high with the spinnaker in light winds, it may be faster to sail without the spinnaker on a beam reach in heavier winds. I would prefer to have a bigger spinnaker that will give me a bigger power boost when I sail deep than to have a smaller sail that I could sail on a beam reach in strong winds.
I do not think you need to increase your hoist to do that. I think the sail is just fine with the fractional hoist you have. But I think you should add more foot girth and mid girth This would allow for more projection away from the jib which will help the flow through the slot on a reach, and will allow the max VMGL to be higher and occur at a lower sailing angle.
The larger sail area would also allow you to “heat it up” and build up more aparent wind and would make sailing downwind a skill. As it is, with the spinnakers you have, I don’t think the sail will add enough to the boatspeed to make it worth reaching up. I would guess that the barndoor approach is still faster with that small sail. sure, you will be faster with the spinnaker than without, but it will still be faster to sail DDW than to reach up a bit. Reaching up to hit your max VMGL is part of the challenge of full sized spinnaker boats.
I will be very surprised if Sandy does not agree with that…
Will, you are misjudging how these sails on my models actually work: they are 50% or so faster on a reach than deaddownwind-it almost always pays to tack downwind. Since the jib is always left up on a reach the jib+main and jib+spin form a double slot that you can actually see kick in speed wise. As the wind gets stronger(above 15 or so) you are forced to head lower since
the spin wants to knock the boat down if you reach up too far. On a racing boat in one of the development classes you could design the system so you could go with a smaller spin if you knew the conditions would be heavy; on the standard boat you can sail deaddownwind in almost any condition but over 15 your ability to reach up becomes more limited. But in the range of normal conditions between 2 and 15 reaching up is almost always faster.
The way the system works there are many interrelated factors : one that I failed to mention earlier is that there is a specific maximum foot girth for each boat-more than that and the poles will not fold properly when the sail is doused. There are ways to make the system work with a bigger girth sail but they are complicated and unwarranted in a one design class-besides in model sailing the higher aspect sail works better.There are no pix posted with the S50 main reefed and the spinnaker set but in that set up the spinnaker and main+ jib are about the same in area and the spinnaker is virtually masthead.
I’ve been sailing most every weekend at least part of the time with a spinnaker boat for over 8 years and think the system functions quite well. It is unfortunate that my system is illegal in every recognized development class except the 36/600 and until recently it didn’t seem possible to put a competitive system on that small a boat but that has changed. Now it will probably be used by the defending champion in that class as well as in the unrecognized 3R class and F100. Early spin rules were written by people who had never flown a spinnaker by radio and had/have ridiculous ,arbitrary restrictions on the poles-except for the 36/600.
I’m looking forward to the time when this system can be raced against other systems but based on my research there is nothing even close anywhere.
One thing is for certain: this system works very well and is loads of fun to race with. But if it could be used in competition it would surely be refined(or made more complex some would say) . Most people don’t have a clue how much fun this is ,how well it works or how much it adds to racing–thats because of my poor marketing -no fault of the system. There are almost 17 boats sailing across the USA but there should be a lot more-and one day there may well be especially now that the much smaller systems are about to debut…
High Technology Sailing/Racing
Doug won’t admit that there’s a diminishing return on the present spin setup as it appears the predominant advantage is on a reach (based upon his admission).
We both know that sailing deeper as the wind increases is best for VMG. Unless the boat will plane is about the only caveat there is. It’s why a code 0 is what it is while a code 5 is a symmetric spin made to go deep. http://na.northsails.com/Racing_Sails/spinnaker_coding.html
Doug’s new sail design is “broader shouldered” which is a design aspect for sails designed to sail deeper. But what do we know.
Rob, did you not even read what I wrote? I specifically mentioned sailing lower as the wind increased…
Sandy Goodall has done a great spinnaker design for the system and for the new development classes–it works extremely well.It is broad shouldered compared to my sailmakers earlier designs but you are 100% wrong about the reason why: the broad shoulders of the new sail combined with its relative flatness ENHANCES the effective aspect ratio of the sail making it even better on reaches. A spinnaker system on a boat that also has a jib needs to be optimized for reaching because in lighter winds on too low a course the jib can intefere with the spinnaker.The basic sailing technique that has proven fastest is to “engage” the double slot and then “follow” the greatr apparent wind down syncronizing that with gusts–requires skill and practice to do well. In most conditions opitimizing the double slot set up has proved faster; in stronger winds when the heeling from a reaching spin is too great you have to sail lower as I mentioned before(because of excessive heeling) but the jib has less and less negative effect until in over 15 you can sail deaddownwind with the jib and main wing and wing and the spinnaker full and lifting the bow of the boat.
I would welcome racing my system against any new ideas— which don’t appear on the horizon-- but that will eventually help to spread the message that rc spinnaker sailing adds a whole lot to any class in which it is used. For now my system is the only beam reach to beam reach system around and that capability is important for a model spinnaker because of the frequent windshifts on many rc sailing venues as well as for the reasons stated earlier. But I hope others will join in with “improvements”—it will be great for the sport.
PS- this spinnaker system allows much design variation and adjustability and it allows the sailor to do anything that you can do with a full size symetrical spinnaker and more.It can only get better: but I welcome anybody with a “better” idea to get involved in one of the great new classes : the F100 and 3R or the one recognized class in which a system like this is legal the 36/600 and lets race!
High Technology Sailing/Racing
It sounds like your spinnaker system is quite effective despite its size. The sailing technique that you describe is exactly what it feels like to sail any high performance spinnaker boat from the E-scow to the J-120. So you are definitely on the right track and are getting a bit of a perfomance benefit from the system.
My initial comment was that it “looks” like there is even more perfromance there if you want to go after it.
You mention that there are 17 some odd boats out there? Any of them in my neck of the woods? I’d like to take a look at the system up close and personal… (Minnesota is too far away…)
The only class that seems to have a good foothold in our area that allows spinnakers is the AC class. I took a look at their class rules and the only restriction I could see regarding the spinnakers is that the pole can only project 135% of the J measurement from the mast. Is that the rule that you thought was unreasonable, or did I miss one of the other rules somewhere? I’m not sure how that would be that unreasonable. I know that the spin pole system that you have on your boats extends pretty far to either side of the boat and in a reach configuration it would probably extend forward of that restriction. But if you only used the system on the run, it seems like you would be able to use it for this class. I may look around to see if any used ACs are available. I already have too many boat projects in the pipeline, what’s one more boat that I don’t have time for…
BTW Doug, can you explain again why the poles on your spin system extend so far out to either side? They don’t need to be that long for the spinnaker - the clews only go out about 1/2 way. It seems like if you limited the length of the poles, you would be able to meet the 135% rule of the AC class…
(Edited for typos)
Will, I don’t remember where you are! Thought you were close to Minnisota where David Goebel has a boat. There is a 50 in Chicago-boats scattered across the country. I’ll look for your address and look up the nearest boat-some addresses aren’t current though. Your best bet is to come down here and race in a fleet of spinnaker boats-an experience you won’t soon forget!
The spinnaker poles are long because in racing the boat you wait till you’re actually in the process of rounding the lee mark before you douse the sail. That means the sail blows back along the side of the boat as the wind comes forward. If the poles are short the spinnaker will wrap around the end of the pole and jam; All kinds of experiments have been tried to come up with an effective shorter pole but to no avail so far. But they work real well long…
Rich Matt -listed in the front of Model Yachting --is currently working on a spinnaker for an AC class boat. He is the first person so far as I know to ever fly an rc spinnaker in a recognized class race and win it with a chute.
There are major limitations to an effective system with the AC pole restriction but talk to him. His earlier system was non gybable and could come up about 20 degrees from deaddownwind on one side and about ten on the other. In his writing in early model yachting’s he felt that a truly viable system would have to be carried much higher and be gybable.
The AC rule limits the system a lot but in certain conditions the spin would work.
The critical angle to allow the spinnaker to lift the bow which is very important in heavy air probably cannot be achieved with the A or AC rules…
Talk to Rich: he is a pioneer, brilliant and a hell of a nice guy…
High Technology Sailing/Racing
<blockquote id=“quote”><font size=“1” face=“Verdana, Arial, Helvetica” id=“quote”>quote:<hr height=“1” noshade id=“quote”>[i]…It is unfortunate that my system is illegal in every recognized development class except the 36/600 …
High Technology Sailing/Racing
<hr height=“1” noshade id=“quote”></blockquote id=“quote”></font id=“quote”>
Really tired of hearing this same false statement year after year. I think I have mentioned to you for the last two years that the J class is open to spinnakers. I would think that this would be a perfect boat to set up this system. This is a growing class with new open-minded skippers that I know might be interested in this system.
Gee Greg hate to hear you’re so tired! I’ve never considered the J class a development class since as far as I know the rules specify that you must build a hull based on one of the existing J boats. But as you often remind me I could be wrong so I’ll go look at the rules. But just off the top of my head I would think my spinnaker pole system would look ridiculous on a J as it is presently configured. Also from memory it seems that the J measurement of the J class is too large for an effective spinnaker system without a roller furling jib. But maybe that doesn’t matter since in a development class you can put the mast anywhere.
So thanks for so thoughtfully calling this to my attention; I’ll check it out.
UPDATE: While the J class is listed under “development classes” the rule specifically requires a boat to be built to scale and ,apparently, unless I misread requires a scale sail plan.Just out of curiosity where does the development come in?
I think the J is a spectaculary beautifull model ! But according to the rules ,as I said earlier, the Hoyt-Lord spinnaker system could not be used.
- the system would not produce a scale sail plan since the pivot point of the spinnaker booms is at the very bow.
- It would not produce a scale sail plan because the jib would have to be significantly shorter on the foot(J measurement)
- In order to prevent the jib from having an adverse effect on the balance of the boat the mast would have to go forward even as the tack position of the jib comes aft.
- Generally, a boat has to be designed specifically to use this system because of the many interrelated factors contributing to its design and effectiveness.
With some study it may be possible to create a system for this boat but the rig would have to be able to be substantially changed and the compromises resulting from that would have to be analyzed to determine whether there is an adverse affect on the upwind performance of the boat.
High Technology Sailing/Racing
I agree that the spinnacres do look small for the boats, but where is it stated that they have to be big. The keels on rc boats are nowhere near a scale keel lenght because it just wouldn’t work because the boats would be drastically overpowered in moderate winds. I see where the thought that they look like they should be bigger comes from but, I think it has been realized that rc boats are no where near scale in apperence because in a lot of cases because it simply just wouldn’t work. Doug has showed the numbers and has done his math… I could be wrong but he seems to have the most spinnacre experience (rc) of anybody and if they could be bigger I think they would be because he is all about making the best and fastest boats out there and if making the spinnacre bigger would make it faster then he would probably do that.
Ok, this is what I’m interested in doing, but I have only the vaguest idea of how to do it…
Goal: Build a free sailing boat capable of planing on a reach with a spinnaker. This is the sole purpose of the boat. Due to this I’ve come up with this design scheme:
stocky wide shallow skimming dish hull with multi chine bottom. This would allow a planing form while heeled.
large low aspect rig for lots of power and not as much heeling moment.
sprit mounted spinnaker for the extra umph. << this is the one that i’m pretty much clueless about. I realize the number of variables in this equation is quite impressive, but I think the payoff of watching this beast track off on a full plane with no strings attached would be way too cool. Anyway, I was wondering what anybody thinks of this: Lower boom/upperboom arrangement with guidelines off the top boom attaching to the mast, and a sheet attaching to the hull.
All comers welcome…
Graham,Have a look at www.themodelyacht.com for details of the Balmain Bug model yacht class perhaps the all time ultimate spinnaker model yacht.
nerds of the wold untie
Those things are truly awsome! More rig than boat, thats the way for ultimate speed!!
If its not blowing it sucks!
I am looking for information on nzl 32(black majic. I want to build one for myself in the one meter size. I already have Australia II and now would like to have the other superboat. I have alway beem in awe of the boat. I need pictures storys plans, drawings anything
Thanks in advances
When we were kids we used to build “Skimming dishes”
these free sailing models could sail downwind faster than we could run.
Build a lightweight simple flatbottomed hull,stick a big tinplate fixed rudder at the stern.But a stone from the beach in the stern area.Step a mast near the stern leaning forward. Stick the biggest spinnaker on it you could make from a plastic bag with a spinaker pole each side.
let it go and watch it fly!!
ours where about 18inches long and seriously they where dam quick.