Tornado Plans

Does anybody know where I can obtain plans to build a Tornado. I have a guy in OZ that wishes to build a wooden spinnaker Tornado. (his 3rd).
Thanks

There used to be a link on the US Tornado Website. Try contacting them to see if anyone remembers.

Gougeon Brothers (West Systems Epoxy) should know, they were one of the designers of the tortured ply Tornado and built them for several years. Try contacting them through there "homebuilt" projects forum.

Check out your local T class association, then ITA if you don`t get any help there. Problem is that most plans for T will be old plans which might produce heavy boats by today`s standards. Could also check out the building plans for the Mosquito, then scale all materials up by 1.25, ie from 16ft to 20ft. so 4mm ply would become 5mm (have to use 6mm, don`t think 5mm is available.) Could build hulls to 25-30kg each, how does this compare to epoxy boats / class rules. Depends on how tight class rules are about internals on wooden boats. If interested, contact Tim Mozzie on Forum Database for more info in Auz.

Cheers
Steve

Scale up will not get you a class legal boat. Hull tolerances are quite tight on the Tornado.

Hi Simon,
I didn`t mean scale up the plans ie hull shape, I meant apply the building method, so if the mozzie plans say 4mm ply bulkheads at beams, then scale up material thickness proportionately, use 6mm. If Mozzie building regs say 20mm foam bulkheads at 200mm c/c, use 25mm foam bulkheads at 250mm c/c. you should then build hulls lighter than the old Tornado plans would allow, but have to make sure they comply with current rules. You would have to do this in conjunction with the Tornado plans so the hull shape is correct & within spec. Also need to make sure that all framing internals etc conform to class rules, as well as skin thickness & weight etc.
I merely suggested this as an option, since I`m not sure if building plans for plywood T`s are updated to be competitive with the newer production built T`s in terms of min. weight. Obviously need to stay within class rules if you`re going to all that effort of building a boat.

Cheers
Steve

I'm not quite sure about this, but I dont think the minimum weight limit of the Tornado has changed over the years. So a plywood tornado would weight about the same as a production boat.
BUT, there would be a huge difference in stiffness of the platform.

The Gougeon T's was cold moulded with western red cedar and had a hull thickness of 6 mm. They also used an internal support structure to add stiffness. I dont think the plywood T's had anything like the same stiffness.

The yearbook has some information about the hull shapes, but by far not enough to build a boat from. If you got the measurement templates, the allowable hull lines could be deducted..

I read in Seahorse, that there is a Gougeon T in sweden still sailing. Dont remember their exact words, but I think it was quite stiff compared to the Marstrøms. The hull forms has evolved a bit since the 80's, so we dont know.

But, it would be interresting if a wooden T could be competitive!

Steve,
If you can't source the plans I know of two different people that have them. I'll give you a call.

Regards,
Phill

The Tornado plans & Templates are availabe from the ITA...but I believe there are rules about homemade builds...something to the effect of only being allowed to build one boat per year as a amatuer builder. If you want to build more in order to sell them as a business, you need a builder's certificate from the ITA for the boats to be class legal.

As to construction methods, the plans only define the overall hull section shape, dimensions of fittings and their locations, the minimum weight and also stipulate the boat must support a crew of specified weight with both hulls completely flooded (safety). I don't believe the plans outline how the boat must be built to meet these requirements. This allows for innovation is design & construction techniques.

Wooden boats of cedar were extremely stiff in their day, but were somewhat heavier than the same vintage glass boats. They were competitive, with many top crews sailing them at the Worlds. Problem was that as labor & material costs rose, wood became basically an "exotic" material to build a boat out of. That plus the added maintenance issues with wood made them less popular.

I've got a friend in Sacramento that just purchased a very nice condition wooden boat ("Holden" I think) for a song. It had been stored for the past 20 years and has almost no hours on it. What a find! Hopefully he'll bring it down to the LA region this summer for a few events where we can compare it to my Marstrom performance-wise.

Mike.

I agree, in some ways wood is superior to glass (and the core doesn't dent the way it does on a Marstrom). The major problem is, it is expensive. It is more difficult to build a wooden production boat. You can't buy things premade up (for example prepreg) and subcontracting out is harder. Also wood is a commodity, some years are good and some years are not.

You could probably build a wooden Tornado that would meet or exceed the Marstrom. I have some friends in the exotic furniture buisness, the only hi tech wood buissness I know of, we came up with 3 ideas.

First, using a computer controled table cut single layers of venier and laminate them with kevlar cloth(for my core) into a mold pretty much the way Marstrom does. Price would be $28,000-30,000 minus sails based on 20/year.

Second, strip plank. Use a CNC router/cutter to cut each strip so there is an exact fit between each strip. Kevlar inside and glass outside. Price - a little cheaper

Third, wooden dowels. .5-1mm epoxy coated wooden dowels along with a dry filler are placed in a mold and then vacuumed. It is kinda like building things out of unidirectional carbon. If fact you could probably use hot melt the same way they do with carbon to hold the dowels into a sheet. I suggested something like this years ago to them to solve one of their weird problems, I have never heard of anything but a few pieces of high dollar furniture being built this way. Price - I have no idea

Something to think about

Ouch, kevlar and carbon are restricted materials within the tornado class. Sorry..

http://www.tornado.org/html/rules.asp

I dont think strip planking is a good way to build a Tornado. You will get to many horizontal glue joints that adds a lot of weight. At least that was what Farrier discovered when he started to use vertical joints between foam sheets.

I really liked the Gougeon system used as internal stiffening. Building out of plywood is easy, but I'm afraid the panel stiffness would not be very good.. Perhaps the Taipan builders can correct med ?

If plywood boats was good, why did the Gougeons use cold moulding ?

I looked into how to get the hull lines for the Tornado, and found some interresting things.
1: Measurement of the hulls are very detailed, not much room for error if home building/designing.
2: Measurement blanks costs £ 800 !!! (I know where I can source som old ones for free, but..)
3: Marstrøm, Yves Louday/Reg White are launching new models with new hull shapes. Basically they have made the hulls slimmer in front and less bouyant at the stern.

I have a set of plans for the stresses-ply tornado.

Give your friend my e-mail.

David Melcon petaluma@deepnetgaming.com

Carl,
JUst as side note.
I was fortunate enough to attenbd a lecture by Meade Geogeon
a few years back when he cam eout to Aust, I was building a 32ft cedar strip cat at the time.
He went thru a lot of the research they performed with NASA when they were designing wind turbines. They found the most superior material when it comes down to cyclic stresses as as experienced by turbine blades (and boat hulls alike)
Is wood laminate with 6% carbon.
This was after they tested all manner of materials both natural and man made.

Regards,
phill

In reply to Rolf:

I understand Kevlar is restricted. You can use it, if you can show a cost/life benefit. For example the nomex or Kevlar core used by Marstrom. I am pretty sure, I can show that on a Tornado. I am building a 14 ft cat. Cost/life was very important to me in the design. I ended up with glass outside and Kevlar inside by a wide margin.

Concerning strip plank. Take a look at Gougeon's book on wood construction. Strip plank/glass ends up about an 1 oz per sq ft less than plywood/glass for the same stiffness. The difference is the relatively heavy adhesives used in plywood.

Cold Molded vs. Plywood - Cold molding is basically building custom plywood around a mold. There are many advantages, choice of veneers, use epoxy instead of the heavy flexible adhesives needed for plywood, use extra in high stress areas, add glass, etc. The biggest advantage for cold molded is the results are very consistent. You can build one identical hull after another, very important for production.


What really killed Gougeon is Marstrom hulls are a little faster under certain conditions. I have forgotten, I think it was chop and the suspected reason was the hulls are a little fuller forward and the bows sharper. It really doesn't matter if it's true, people thought it was true.

Don't get me wrong, I love my Marstrom. If fact one of my goals for the 14 ft cat is the decks be just as solid as my Marstrom.

The way I read the Tornado rules, the building materials are glass, foam, wood and glue. Carbon/kevlar is allowed where mentioned specifically in the rules. Am I missing something in the rules, due to not speaking english natively ?
I think you will have to make a change in the class rules to be allowed to use carbon in the hulls, and that is a long process. The class ballot has allowed an testing period with carbon masts for 2004 (not in cometitions), but we will not vote wether ut allow carbon masts until 2005. Changes takes a lot of time..


Good point about heavy glues in plywood and cold moulding!

I have heard, and read about new hull shapes coming from both Reg White and Marstrom. Apparently the new rig can benefit from a slightly differen hull shape. Reg White has buildt some boats with finer bows and not as much fullness in the back. Marstrom has something called the B1 under development..

I also like my Marstrom very much, but wooden boats are also really beautiful. Gougeon are testing the durability and stiffness of wood/glass vs foam/glass now. Epoxyworks magazine has an article about this as applied in a skiff in the current issue. I'm looking forward to the next Epoxyworks magazine, where I hope they have som conclusions.
If wood/glass can compete both in stiffness/strength, or perhaps even surpass glass/foam, it would make for some interresting changes with regards to home building.

It's a shame Tornado plans are hard to come by tough!

Good luck with your 14 footer!

Rolf: I'm in the process of buying an all carbon/kevlar tornado, and have been told by more than one person that it is NOT class legal.

Kevlar or Carbon are definatly not permitted in a Tornado hull. Only in Rudder stocks, tiller extension and cross bar, plus spinnaker pole and snuffer. You can also use it in blocks / pullies.

This boat would be somebodies home built project and if you intend to race in Tornado regattas or as a Tornado at a regatta, you could not in this. Re-sale would not be very good with this boat also as there is no market for illegal Ts.

My advice would be leave this boat alone unless it is going VERY cheap, such as for rig price only.

I have zero interest in sailing in tornado class regattas. I'm not nearly good enough to compete with them, and really, I could care less about competing at that level.

I soley interested in going fast (which this boat definitely can do) and doing some distance races with my girlfriend.

I really can't stand class racing, probably deriving from a personality flaw where I like to be unique. I couldn't stand driving a car that everyone else drives, can stand doing what everyone else does. So don't worry, I wont be rolling up in your tornado regattas with my snazzy carbon kevlar boat.

In Reply To Rolf

Concerning Kevlar. Look at Tornado Class rule 7f

"7.f Kevlar, or any similar fibre, shall not be used in the Tornado Catamaran except for running rigging.
Core materials require prior approval of the ISAF. Those containing Kevlar or other high
modulus fibres may be permitted but in addition to their structural properties the primary criteria
in deciding whether a particular core material is acceptable will be its cost and durability."

Any Kevlar I would use on a wood veneer boat would be as a core.

There is an old trick, called starved cloth core. There is an update where you use a knitted material that looks like lace with big hexagonal holes. Use just enough epoxy to mostly saturate the yarn but leave the holes free of epoxy. Use this as a core.

For various reasons this does not work well with true composite construction. However, it works quite well in veneer construction.

I hope this clears things up.

In response to MauganH-17's post about the composit T boat, is the rating the same? How much lighter is this composite boat?

If you like going fast and being unique, why stop with composite materials? How about radical boat designs (20' beam, carbon rig, foils instead of sails, etc.)?

Am I also to presume that with this "illegal boat" you won't be in "official" distance races (Atlantic 1000, Tybee 500, etc.? That would be a disservice to your sense of adventure and competition!

And, just for kicks and giggles, what kind of car DO you drive?

waterbug:

20' beam? Why when 10' would be suited fine.

I never figured out why they didn't allow T's on the t500. Again, don't mind, not like I could compete with those people anyways. If you people think its silly, thats fine, you're not the ones buying the thing.
The guy I'm buying it from says that the local club he sails it in lets him use a the basic tornado rating. I wouldn't really care what its rated considering I sail for the thrill of it and not for a pickle dish at the end of the day.

Maughan,

I would LOVE an all carbon T. Would not buy one as I already have a T, plan to buy a late modle Marstrom soon as a second boat and after that would prefer to put the rest of my money into something else.

However, If it was going for rig price, I would snatch it up.

My advice would be that it would not be worth much more than rig and other equiptment value. ie platform not worth much.

By all means buy it and pay premium price if you are happy or use the above information to bargin down.

If you are not intending to race as a Tornado ever, this boat should be great fun. You can put carbon beams, mast, foils or hydrofoils on it, increase sail area ect.

If you were in Australia, I would be the first to put my hand up for a ride and we might even let you un-officaly race in the Tornado regattas.

I believe Marstrøm buildt an all carbon T once. I seem to remember a weight of 97 kilos, but might be way off

The carbon T has a Texel rating, and can race in texel rated events.

Ref: http://texelrating.knwv.nl/

The Tornado class rules has some provisions for 'experimental' boats. It would not get a score if allowed to start at an ITA event..

I dont see why a carbon/kevlar T should not be allowed to race in open events if it has a handicap number ?

Carl: Thanks for the clarification. I understand that I have much to learn about wood construction yet. Great fun tough.

Stephen: I have asked this on the ITA forum already, but.. I belivel Marstrøm sells an all carbon selftacker setup. Ie. track and traveller car is carbon. Is it room for this within the Tornado rules ? As my selftacker is in pretty bad shape, I would like to build a new carbon selftacker and fit on my Marstrøm.
What do you think ?

If Phill Brander reads this, it would be very interresting to get some ideas about how you made the carbon tubes for the rudder setup on your site. Specifically, how did you do the layup of epoxy/carbon in the mould and what kind of bag did you use.

Ref: http://au.f1.pg.photos.yahoo.com/ph...omponents&.dnm=Carbon+Tube+Setup.jpg

To finish this totally off topic posting off, how on earth do Marstrøm build those M-20's without seams ??

Ref: http://www.marstrom.com/administration/Boats/M20/index.asp

Rolf,
In reply to your questions:-
First the bag is made from some clear plastic and packaging tape. It doesn't have to be strong just air tight. The mould takes all the load.

Second part is a bit trickyer. The carbon is layed out flat and wet out. The width of the carbon is just greater than the dia of the tube to be made. It is layed over the bottom half on the mould (centred) The bag with a bit of 16mm dia conduit inside is layed on top pushing the carbon down into the mould. The carbon is then folded over the bag overlapping. The top of the mould is put on and hose clamps fixed in place. This is the hard part because the tube to be made is only 1 inch in dia and the carbon wants to unfold itself. So you need a second pair of hands to slide the top half of the mould along as you fold the carbon. With hose clamps in place just inflate the bag. End result is a shiny black carbon rod.

The mould is just aluminium tube sliced down its centre and lined with packing tape (because it is so shiny) and coated in PVA as a mould release.

There are 3 different ways that I know of making carbon tubes depending what you are going to use them for.

Did you have anything in mind?

Regards,
Phill

why would the platform not be worth much? The guy that built it knows what he's doing. He's been building tornados since he was in college, working on an f18 design and is currently designing/building a 36 foot trimaran. He's sailed it for two years now, and is confident that its a solid structure. He's done a lot of work engineering the thing from adding kevlar for impact resistance to making the carbon beams stout enough to eliminate the dolphin striker. He's eliminated weight aloft on the CF mast, using kevlar for the spreaders. Dimensionally, its identical to his marstrom sitting next to it, and sails the exact same. Just because it can't race in tornado class events does not mean that its not worth anything IMHO.

I think it sounds awesome, Maugan. And I don't think resale value is relevant -- even class-legal Tornados can be purchased very inexpensively after they have been used several years because the serious racers don't want an old boat. They usually are purchased by recreational sailors or open-class racers. So in that context, yours might actually be worth more than a class-legal one, especially if it is faster.

Phill: Thank you for the information.

I asked becouse I'm about to make a set of carbon rudder stocks for an old, tired, Tornado this summer.
I tought that the seam in the bag used needed to be able to withstand a lot of pressure. But I realise now that the tube takes the pressure and not the seam (if the bag is big enough). How did you get rid of any excess epoxy, as I could not see any bleeder cloth ?

As for other kind of tubes, I guess the same could be done for a spinnaker pole of 40mm diameter if the right cloth could be found. But now we are probably a bit on the side where engineering needs to be applied.

It seems like you have a lot of knowlegde (like other persons frequenting this site), and it is just fantastic to be able to tap into it now and again!

Best regards
Rolf

Thanks Mary,

You get the first ride

Maughan

Is the Tornado regeistered as an "X" boat . It should have an "X" on the stern for experimental and and ITA sail number or an ITA and a USA sail #

"X" boats are Tornado's that conform to all rules except materials. They are legal to race at a local level, they can only be raced at a national or international level with permission. The permission can range from "we would be happy to have you" to "stay out of everybody's way plus you will not be scored".

If the boat is not registered, contact the Tornado measurer. I think you just have to have the boat measured, fill out the forms and pay your fee.

There are some nasty features to the rules for light Tornado's though. To race, you must meet minimum weight, which means adding corrector weights. The corrector weight for the mast goes on top of the mast.

Good Luck

not sure about the X on the stern, I'll look for it.

It doers have a US sail # though.

There are no other tornados around here that I know of, so there are no tornado regattas. There are open regattas at the local level, I'll talk to the race chairman in the club about what will happen if I show up with the T.

I really just want to use it in distance races like the key largo steeplechase. Even if I can't compete, I'd just like to be there with everyone and have a good time sailing it.

Maughan,

Don't get me wrong, it sounds like a good boat. What I am trying to say is that as a Tornado it is not worth that much. As a one off special it might be.

A boat for sale is only worth what somebody is willing to pay. If you are willing to buy it and pay premium price, than the boat and platform are worth premium price.

You may or may not intend to race it as a Tornado (X boat). However the advice I am trying to give you is use my information as a bargining tool. Every body would love to pay the least possible price for their toy.

If you can get pictures, please post them as I and I am sure others would love to see it.

Thanks guys for your help regarding Tornado plans. I have now obtained an original set of ISAF plans form John Forbes.

Rolf,
The excess resin comes out the join in the mould.

I've made half a telescopic spinnaker pole the same way
36mm dia. (Just carbon uni and a light layer of glass to make handling the carbon easier after its wet out)
The female section will have a 40mm internal dia. There will be two built up bands on the inside section of pole to take up the slack when the pole is fully extended.

I think it will be a good thing to have if I can make it work. Apart from making it easty to transport it would be good to get rid of that extra windage upwind.

Just another thing to play with.

Regards,
Phill

Phill:

I have also been thinking about a telescoping pole. With the mid pole snuffers used these days, it should be feasible.
Reducing windage is a 'good thing' but if it is on the expense of weight some consideration must be done.

One of the problems would be to find a good solution to replace the stays used from the tip of the pole to the bows. I have sailed an old Tornado with the spi-stays run back to the bridle fittings. Works quite well when pre-bend is induced. Some force would be needed to get the pole out the last centimeters and pre-bend induced tough.

Having a pole without stays at the tip would really make lots of difficulties disappear when thinking about a telescoping solution. Increasing the diameter of the pole would perhaps make the increase in weight smaller, and perhaps also make the front stays uneccesary ?

If pre-bend is not used, the pole needs to be lowered to take full advantage of the spinnaker luff. Would stuffing the pole be a potencial problem ?

Launching the pole would need to be done before you launch the spi, an extra thing that can go wrong while racing.
Sadly, the Tornado class rules forbids such a system. You must have the tip-stays and are not allowed to adjust the pole while racing. But evoulution can not be stopped if such a system is succesful. Ref: Rule 19.b at:

http://www.tornado.org/html/rules.asp

I seem to remember reading somewhere that you also was thinking about your own carbon mast ?

Rolf,
The stays stay.
Why would you remove them?

The stays are taught when the pole is out and taught when retrieved.

Work it all out and see what you get. It may not work on a Tornado but on the Blade F16 the numbers all fall into place.

Can you tell me the length of pole, distance from main beam to bow and distance from front of the mid pole snuffer to main beam and distance between the C/L of the Tornado hulls?
I would be interested to see if I could adapt my design to the T.
If it works it will be single line operation. The pole goes out, the kite goes up. The kiye comes down the pole comes in. JUst the one line.

I made a carbon mast. The deflection tests were spot on to what I was after too.

This is a great sport there is just so much to play with.

Regards,
Phill

Phill:

The pole is not allowed to be longer than 4000mm, and we use a 4000mm long pole.

My Tornado is disassembled for the winter, but if the weather permits we will assemble it this weekend or on monday. I will get the measurements for you then, and also have a look at how long the stays are with regards to retracting.

Hi Rolf,

With regards to your question about carbon jib track. The ITA rules state

Rule 7 (Materails)

c. The materials for rudderheads and tillers, tiller connecting arm, mast tiller, spreaders, beam attachment straps, blocks, pulleys, cleats, compass holders, wind indicators, and bowsprits are optional.

d. Except for such fastenings, all marerials when dry to the measurer's satisfaction shall be of high electric resistance.

Reading this, it states that the jib track shall not be made from material that is low in electrical resistance.

I think the jib track has been overlooked by the class rules. If you are not allowed to use carbon because of its low electrical resistance, than they also should not be using the metal I tracks.

I say build a carbon one....... I don't think anybody would protest. Or you could call Marstrom to find out if its is class legal or your nearest National/International Measurer.

Maugan, for your info

Stated in Rule 7

g. Tornados built using such prohibited materials shall remain illegal: however, they shall be permitted to race in the club and local events for evaluation purposes, provided that they are registered with ITA (not the National Authority) and also provide:
i. both hulls are indelibly marked on the outside of the transoms with the letter 'X' and with a number allocated by the ITA.
ii. the mainsails have a letter 'X' of size and position in accordance with Rule 6(b). The letter 'X' shall be either in addition to or instead of national letter(s).

h. The International Class Fee as stated in Rule 2, shall be paid in respect of each experimental boat although it remains illegal. Such illegal boats will not be permitted to race in qualifying open meetings of any kind, National Championships, European Championships, World Championships or the Olympic Games unless approved by the ITA and ISAF as required by ISAF Regulation 10.3.6.


I could not see any problems with you racing this type of boat at your local club but if you were to enter a Regatta, If somebody had a problem with it, they would have grounds to protest you out.

You may want to register the boat as an 'X' boat if you got it to avoid this situation.

Hi Phil!

when do you think I can get the plans for those tiger rudders?

keep up the good work,

Tom.

Tom,
My apologies I've been really busy with the Blade.
I just haven't had the time to pull it all apart and draw it up for you.
Co-incidently while I was working in my shop today I ran across some drawings I did when I was designing the Tiger rudders.
Send me a private email and I will reply with a scan of the drawing.
That with some notes that I will put together for you should be enough for you to make the carbon rudders and carbon steering system.

Regards,
Phill

Hi Steph:

I think you are right, they have forgotten about the jib track. The rules are quite clear and to the point with what the measurer shall do if he is in doubt tough
But, it may be that they did not want more carbon on the boat, to keep cost down..

I will make the carbon track, and give it a shot. But bring the old one as a backup when travelling to events..

Phill: I can not get the measurements for you yet. It began to snow again on saturday.. I will post them as soon as the weather permits and the boat is assembled again.


Ref: http://www.istad.no/index.php?page_id=74
(Web-cam, GMT+1)

Rolf,

Carbon jib tracks are not illegal...as many currently active teams are using them. There is not a big advantage to them, just a little lighter...and a lot more expensive. Not sure why the rules don't mention it, but I suspect they just forgot about it when they were updated in 2000.

Mike.

hypothetical situation,

if my new boat were not registered as an x class and I did race it and win and WAS protested, I wouldn't even bother. I'd hand over the trophy, shake the guy's hand and make mention that he obviously cared more about the shiney hardware than I did. I'd be happy if all I walked away from the entire ordeal was a sun tan and a tshirt.

different strokes, different folks.

no worries phil, I can understand you would be busy from the goings on of your site!

I myself am thinking of starting on a blade later in the year.. its about time Perth got another class other than hobies and windrushes!

Tad, you are missing the point.

ISAF Racing Rules of Sailing 2001-2004

BASIC PRINCIPLE
SPORTSMANSHIP AND THE RULES
Competitors in the sport of sailing are governed by a body of rules that they are expected to follow and enforce. A fundamental principle of sportsmanship is that when competitors break a rule they will promptly take a penalty or retire.

PART 1 - FUNDAMENTAL RULES
1. SAFETY
2. FAIR SAILING
A boat and her owner shall compete in compliance with recognized principles of sportsmanship and fair play.
A boat may be penalized under this rule only if it is clearly established that these principles have been violated.
A disqualification under this rule shall not be excluded from the boat's series score.

What you are talking about is CHEATING and hoping you don't get caught or that the real winner doesn't protest.
It is not about some $10 trophy.
It is about fair competition and the "thrill of victory".
Forcing the true winner to file a protest and go though a hearing, tarnishes their victory.

And not just the real winner, what if there were ten boats and you finished fifth?
Those boats that finished behind you have just as much right to a fair score as the first place boat

If all you wanted was a tan and a t-shirt, why wouldn't you register properly?

Maugan,

I agree with you totaly. At a club level and low key regatta I am not that bothered with protesting (Unless somebody did somthing very wrong intentionaly.

Come the Regattas that count, I will come out all guns blazing if there is an infringment.

Although, to show good sportsmanship, in any race I would compete in in those circumstances I would fill out on the sign off sheet that I intend to retire. Will keep everybody happy.

sam, wait a second, who says I'm cheating?

I plan on racing open class distance races (PN). If I have an adjusted PN number and all my equipment is out in the open, how is it cheating?

Like I said before, I have no interests in competing within the tornado class, I just like the boat.

You said "if my new boat were not registered as an x class and I did race it and win and WAS protested".
That is not "open class distance races (PN). If I have an adjusted PN number".

Just because "all my equipment is out in the open," doesn't mean that anyone else there knows what equipment is Class legal on your boat.
And can someone see that your hulls are carbon and not the Class legal material.

How is registering a non-Class legal Tornado, as a Class legal Tornado, and beating the Class legal boats, NOT cheating?
It is a lighter, faster boat which gives you an unfair advantage.

The most important rule about racing is sportsmanship and fairness.
We are expected to be honorable and self-policing.

I don't know how you do things in the US but in OZ if I registed for the regatta in a boat like this, I would not register as a Tornado. May be Custom Tornado or Carbon Tornado.

This will declair to everybody what you have and the race committe can decide on a suitable handicap.

This would keep everybody happy. I would like to think that nobody would ban a boat like this from racing (other than maybe important Tornado Regattas) Most would like to see the carbon monster in full flight.

Alive's got it, I'd never register it as a bone stock tornado! Thats what I meant as "out in the open" sam. I'd never deceive anyone about what was keeping me above sea level.

Believe me I don't want to upset other people about this. Before I enter any race I'll clarify with the committee or the sponsor or whoever I need to about how to participate fairly.

If it takes X's on my hull transoms then.... why not.

Hey Guys,
Slow down a minute. We need alot more facts and not so much fanticy. Marstrom built a or some Tornados that weighed 100 or so pounds less than a standard Tornado and raced them in the Texel race. A standard weight Tornado won the race.
The M20 has raced in the Texel race for several years. The M20 is 130 pounds lighter in weight than a Tornado. The M20 also has a more efficient sailplan, higher aspect ratio boards and rudders, carbon mast etc, all the best. This year the M20 won the Texel race by 10 seconds over a standard Tornado. In a two hour race, that is a tie; no significant difference in boat speed.
Here's my experience with lightweight boats. In light winds a light weight boat will tiptoe away from heavier boats. Weight determines drag and lighter weight means less drag everything else being equal, a lighter boat is faster in light winds than heavier boats. Now when the wind picks up and people start getting out on the trapeze, the advantage of the light weight boat goes away. The greater righting moment and sail thrust from the heavier boats can compensate for their greater weight and things even out. In double trap conditions, I see heavier boats beating lighter weight boats; everything else being equal.
Someone really interested in this lightweight Tornado needs to get the straight story from Mastrom. Lighter isn't always faster, especially in top speed.
Bill

Bill,

The thing about this boat I'm buying is that its not significantly lighter than a standard M tornado. The builder says that the hulls weight almost the same to the M, but the beams and mast weight less, how much, he's not sure. The real advantage of the design is no striker, and rounded beam ends so when heeling, they don't drag in the water. Oh, and just like a pirate is completely obsessed with treasure, I'm complete obsessed with carbon/kevlar, so its a good match for me

Dear Bill

I agree with what you say!
Just a little correction, if you refer to the texel race last year, the M20 lost by 10 seconds to the standard tornado and even worse, there was a other tornado with about 1-2 minutes leed on the other two (M20 and Standard Tornado), but they got a dsc, because the went over the startline to early. Not only this, they also capsized in the surf when returning from the finish.

Anyway, the M20 is a superfast and beautiful boat and I belive that the results from last year, reflect more the skills of the crews, as the conditions were quite moderate (3-4 Bft).

Good sailing!
Andi

Hey Maughan17, seems to me you've been in the process of "buying" this tornado for many months now...what's the deal here?

Beam ends dragging in the water? Hmm, I think you'd have to have the boat beyond 60 degrees of incline before the beam ends were causing drag in the water on a tornado. At that point, the heel of the boat is causing you way more lost performance and any drag from the beams.

Mike.

tornado:

The reason I'm waiting is twofold:

a) just graduated from college, and paying off my debts there first.

b) I don't have a place where I can keep it yet, and I need to build a trailer for it.

c) sorry for the hold up, didn't know I was under pressure.

No pressure...was just curious...

Do you have an arrangement with the seller so that he doesn't sell to anothr person while you get the funds together?


Mike.

Not really. He's got two tornados for sale, the carbon one and a 95 marstrom. Like so many have pointed out, its more than likely that a buyer would pickup the marstrom before the carbon one anyways.

Basically the arrangment is "I'll buy it from you definitely when I can and no later than this summer" :P

He's an incredibly cool guy that understands my position, and for that I'm very grateful.

Hey Andy, I like the picture of your boat. What kind of boat is it?
Cheers,
Edmund

Hi Edmund

thanks for the interest!

It's a Ventilo HT18, a F18HT Class boat.


The boat is uni rigged like a A-Class Catamaran, but for a crew of two and with gennacker!

If you want to know more, drop me a email!
a.lutz@ bst.ch

Hi Phill

Spring has finally come, and I have gotten the measurements for you.

Length of pole: 4000 mm

Distance from main beam to bow: 2960 mm

Distance from tip of mid pole snuffer to main beam: 2100 mm

Distance between C/L of hulls: 2610 mm

I did some quick measurements of the stays as well, and it looks like the stays will not be taught when the pole is retracted. It definately looks like it will work!


Rolf

Mr ROberts,

Your allegations that an M20 is not faster than the new Tornado are wrong. Did you see the results of the ISAF Evaluation event? The M20 won every race, I believe, and by large margins, over the world's best offerings of cats suitable for the Olympics. Lightweight is critical. Allows tighter tacking angles, better acceleration, faster downwind speeds, etc etc. A designer of your experience should know this. Tisk tisk

oh no.



Poor noob doesn't know what he just resurrected.

What did I resurrect? A well known designer makes erroneous statements, and no one calls him on it??!!

oh, plenty have. It just opens a can of worms that is hard to close :P

Hi cat_scratch_fever

you are of course free to have your opinions, but it would look a lot better if you posted under your real name.

Maugan,
Instead of discouraging a new person to the forum, maybe you could send him a private message and explain what you are talking about.

Mary,

Agreed, but I'd just prefer to post it here to save us from travelling down the same roads over and over again.

That was my intent.

Cat scratch fever…

The best thing for you might be to do a search of Bill’s past posts on this Topic before taking him to task for his comments. He has explained his reasoning adnauseam. Just when the dust settles someone new comes on board without the benefit of his prior explanations and stirs the pot all over again…Mr. Roberts must have the patients of Job to keep answering the same questions over, and over, and over again…Read with an open mind. If you are really interested in the topic the time spent researching this thru past posts will be quite rewarding.

Bob

Hello CSF,
I have not seen or read about the M20 winning an ISAF Trials. I did read about an ISAF Trials a year or so ago where the M20 was damaged the day before the race and was not able to compete. A Tornado won every heat of that race series. It was written up in Multihulls World magazine.
I have seen the M20 in 4 or 5 Miami to Key Largo Races and it has never won. I don't think it has beaten the first Tornado either.
I have read about the M20 in the Around Texel Race for the past few years and the M20 hasn't beaten the first Tornado yet. It is always a very close race.
My comment about the M20's performance and its light weight is that I do not clearly understand why it is not light years faster than the other boats. The race results that I have seen do not comfirm its super superior performance. It leaves me puzzled.
Bill

Any chance you would write a column explaining how sailboats work? Beyond CE/CLR, I'm lost!

I've just started "Principles of Yacht Design" by Larsson and eliasson, and it is easy to see that this project alone will take years to fully understand. That is, if it can be done at all in a self-study mode.

Pete,
That's a pretty big question -- "how sailboats work"? Can you narrow that down a little? I'm not sure this web site can handle an answer to the "how."

The question is general in scope. Often, the technical jargon is so arcane that I'm unable to follow the conversation. Specifically, I have no idea what "prismatic coefficient" means or why I should care.

The question was asked precisely because it is so broad and complex. So much so, that I doubt I'd ever figure it out on my own.

"Prismatic coefficient"??? Why would you care? Why would any normal sailor care? Pete, you are getting me very worried about the future of sailing if people are thinking about things like that.

Hi Mary,
You might have reason to worry about the forum turning into a technical debate site! I appreciate the others tolerating some occasional nerdishness. Seems like a high percentage of catsailors have some kind of engineering training. Anyway, if the last poster wants to know about yacht design more power to him! One more guy who can help keep the commerical boat marketeers honest. Some good books that even I can read and understand: Skeene's elements of yacht design (Kinney); Sailing Yacht Design (Douglas Phillips Birt); Yacht Design (Mead and Jan Gougeon); The Science of Yachts Wind and Water (H. F. Kay); The Common Sense of Yacht Design (L. Francis Hereoff).

Kevin Cook

Hey Guys,
Mary is right. Prismatic coefficient will not help any of us sail a boat faster. It is already built into our hull shapes and there is nothing we can do about it.
For those who are interested, it is a ratio of two hull volumes below the waterline. It ranges in value from 0.0 to 1.0. The numerator is the actual hull volume below the design waterline. The denominator is an imiginary hull volume equal to the maximum actual hull cross sectional area integrated over the full length of the boat below the same waterline. So, when this number is small, it means the hull max cross sectional area occurrs for a very short length of the hull with almost straight lines connecting the max cross section of the boat to the bow and stern. You would call it a "pointy" hull shape. On the other hand if the prismatic coefficient is large, like near 1.0, then the hull maximum cross sectional area or near maximum cross sectional area is carried well forward and well aft from the point of max cross sectional area and the hull lines appear full with a blunt bow and stern. A barge hull shape has a large prismatic coefficient. A canoe hull shape has a much lower or smaller prismatic coefficient. See, I told you it wouldn't help you make your boat go any faster.
Bill

In addition to Bill's post, consider the two hull shapes shown below (in a rather simplistic form), hull A would have a low prismatic coefficient and hull B would have a high prismatic coefficient if length and displacement were equal (I hope I have that right).





However, because the prismatic coefficient is a function of the length of the hull, it alone is not enough to define or even compare hull shapes (i.e. a short stumpy hull can have the same PC number as a long fine hull). It's kind of like saying "I live on the east side of town". It tells us the general area but it's not enough to get us to your house for dinner. In fact, it is a number that's really used near the end of the design phase of a hull.

Looking very generally at sailboat hulls, first we define a target speed we want to achieve the highest efficiency at. There are then two routes we can take to define the basic displacement type hull shape (not including planing hulls) and we need to decide which one we must use first. This decision depends on the ratio of hull length to width (finess ratio). Somewhere around 11:1 and lower (a 20' boat with a 1.9' or wider hull; monohull territory) you need to consider the speed that the hull generated bow wave travels in order to try and optimise the hull shape. Unless you've figured out how to make it plane, this wider hull is limited to the speed of that bow wave. However, higher finess ratios than 11:1 (i.e. catamarans) no longer contend with the bow wave and play in a different set of rules since it can drive through the bow wave (and doesn't create much of one). Once you have decided what kind of hull you have, you can calculate a few more parameters to define it's behavior nearing your target speeds at the boat's available power limit. Once you've got all this, you can start drawing your hull to conform to the optimum prismatic coefficient (length and finess ratio being the same). The thing that gets complicated is that the finess ratio, the speed to waterline length, the prismatic coefficient, and any other hull design parameter are all intermingled. If you change one you very likely affect the others - yikes! You can either just start building in your garage like the creators of the Tornado did, experiment with drawing different shapes and recalculating these parameters until you arrive where you want to be, or try and remember all that calculus you studied in college so you can arrive at the hull shape you want in one sitting. This is where my bus stops - it's at my recollected knowledge limit - everyone off!

A great little primer regarding hull shape, speed, and power design for finess ratios less than 11:1...i.e. monohulls...can be found here:

http://www.kastenmarine.com/coefficients_of_form_equations.pdf

I just realized I did not phrase the above properly. I did not mean that the people on this web site could not handle the answer to the question -- what I meant was that a complete explanation of how sailboats work would probably be too huge in volume for the website to handle.

Mary:

Sorry about all the fuss, just wasn't thinking straight.

Bill, Jake and Kevin: Thanks, I needed that!