I continue seeing references to a international F-20 class, but I am unable to find a webpage.

I found: http://www.formula20.org/ but it's a defunct webserver.

http://www.f20.nl/ is the dutch F-20 homepage, but it's in dutch The rules I found there are so simplistic I cant help but like them (look under "reglement").

Does anyone know where I can find a set of class rules for the international F-20's?

Carl?

Just heard that the platform weight for the international F-20 is 190Kg. That sounds excessive if its correct, even a good ply boat will be 40-60Kgs less. The Tornado is around 160 ready for action (sails and all)

Still have not found an on-line set of international rules..

Hi Rolf hello Eric

The only I f-20 link I have is through the UK Catsailors web site -not sure of its status -

http://www.catamaran.co.uk/IF20/IF20.htm

It is nice to see the F-18s going strong .
I prefer the 20s

Havn't been able to sail much this season .-
slow economy ,daughter starting college etc -
but hope to get out towards the end of Aug.

Hope your all out racing

take care .

Well, they are sailing, but re-direct any questions to catsailor.com

Looks like the only information available about an international class is the dutch site at http://www.f20.nl/ then..

What do you guys think about the class limit of 190Kg's?

That effectively eliminates all the CF boats. Enter I-20, H-20, etc...

In racing the Tybee 500 this may there was one Marstom twenty in the mix , it seemed like any time they chose to get the boat dialed in correctly and steer a consistant course it just sailed away at faster speed being substantially lighter .

I don't know of any good method to equalize boats that are this far apart in weight and the coresponding speed advantage.

I;d love to purchase one but don't currently have the extra 25K
The old I-20 will have to do , I think that is the reason for the F-18 weight as well ,-more affordable cost that enable more people to race .

Happy sailing

Yes, huge weight differences will create a performance gap. I think 190Kg's are excessive tough, as even 20 foot plywood boats are lighter than that. I find the Tornado heavy to handle on the beach, and its only 165-170Kg's (and I am no lightweigh myself). I am quite sure Marstrøm could build the T's lighter, as they are seriously overbuildt today. Just look at how long the Olympic competitive life of a Marstrøm T is today.

I think the F-18's could have been buildt considerable lighter, without being more fragile. Take the Taipan 5.7, a boat longer than the F-18's, but still weighting in at 135Kgs. I dont know for sure, but I hear that when AHPC buildt the Capricorn, they ended up looking for ways to add more weight to it, as they keept on finding themselves below minimum weight.

On the dutch site, they operate with a max width of 2600mm, still 400mm narrower than the Tornado. and 393mm narrower than the M-20.

Carl, in the Tybee, did you race the M-20 first to the line or on handicap?
I just checked the tybee500.com site, and there was a plethoria of classes listed under point 4 of the SI..


If there was to be an active F-20 class, I think minimum weight should be set somewhat agressive, to give producers an incentive to build lighter boats. Width should not be set to accomodate legal trailering width, these are sailing boats, so optimal sailing performance should be the priority.


I know I'll get flamed for this, but.. To get this thing flying, the F-20 class need a Wouter (and his background helpers)!

Well in North America there isn't a need for it right now. There is only one boat the fits in except the sail plan. The Nacra 20 has proven to beat all other comparable 20 foot boats including the Nacra 6.0NE. The Hobie Fox is gone as it's a dog. If 98% (globally) of the F20 fleet is Nacra 20s then why would the rules change to allow wider and lighter boats. It won't fly. The N20 will just race one-design and allow other boats (we allow the N6.0NE to sail heads up locally) to sail against us.

I think the topic here is an eventual international F-20 class, not a Nacra/Inter-20 US based one-design class who allows other 'stray dogs' to race with them? We can always discuss philosophy and one-design vs. formula racing, but humor me and lets discuss true formula.

There are many other 20 footers than the Nacra/Inter-20, you will have to document 98% before I belive that. There have been buildt several thousand T's up trough the years, then there are M-20's, Eagle 20's, Taipan 5.7's, Ventilo's etc. The rules found at http://www.f20.nl are probably tailored for the Nacra/Inter-20, but if they are opened up a bit, many other boats can compete.

I guess the Formula 16's met many of the same arguments in the start. After all, the Hobie 16 is probably the largest catamaran class out there, but they seem pretty successful in their class building.

The 98% I was referring to was the current F20s boats racing under the current rules. The F18 class model is there and the current F20 rules mirror that. Why mess with a proven model. If you open them up then you ARE creating a “stray Dog” class. The M20, tornado and Eagle 20 are all over 30K in North America. So what I see out my back door is that if the rules were opened to lighter and wider boats the current F20 boats would not support it.
In summary I am in support of a F20 class but not at the cost of changing the rules to allow wider and lighter boats.

Barry, could you point me to the North American F-20 rules you are racing under? Who govern them? Seriously, I would like to read them and know this. I have been unable to find anything like it, except some suggestions made by Carl on this forum.

I have failed to find an international set of rules or organisation also, so I have so far concluded that there are no international F-20 class. Would be good if there indeed was somebody taking care of this.

What you describe in north america doesn't sound like formula racing, it's one-design racing with a few stray dogs. If you have a good racing circuit going for the Nacra/Inter-20's and the 6.0's, thats great. If you was to gather the 'light and wide' 20-foters in a formula class, what would you call that class (please dont say Formula-20HT)?

Rolf
There aren’t' any real F-20NA rules. I am referring to http://www.f20.nl/. I don't see the rules on the site but I think I have them at home. This is the only active F-20 class I know of.
The "stray Dog" is how the F-16 was started.
Not sure what I would call the class. HT works I guess.

Carl is the stay dog...Good job BRO!, trying to muster enough interest to start F-20. This class has much potential. There are many 20' boats that are getting left in the wake of F-18.

20' boats are awesome....

There are a number of active 20 ft cat sailors that will now support a F-20 class based on current I-20 specifications.

The larger beam lighter weight boats would just as introducing 18 ft versions into the F-18 result in an unfair advantage to those able to afford the 30K LIGHTWEIGHT versions.

In the Tybee we raced all together , the Marstom though sometimes very eratically sailed was serveral percentages faster when dialed in . The team sailing it was good but not the calibur of the top few teams on I-20s in the Tybee who have years of Worrell and Tybee racing experience and are among the best in the world at it ,-no offence intended to any. My own lack of racing -practise time really showed this year as we were only competitive and near the front either when there was below 5 or above 15 wind speed conditions . Our 400 plus crew weight killed us in the mid range conditions especially with chop . It is the weak point of the Inter 20 design ,its wide front forward hull sections in chop and waves ,this compounded and magnified by added crew weight.

Barry -Rolf-Eric or any ,please propose a set of F-20 rules based on the I-20 specs. I think what is really needed is a Hobie version F-20 ,perhaps upgrading the Fox to match the I-20 ,then we would have a similar F-18 Tiger vs Nacra F-18 basis to unite the two main brand classes into another Formula 20 class .

Any have a connection with Hobie Europe in FR ?

BELIEVE FROM THERE MANY OTHER 20 VERSIONS WOULD FOLLOW AND MODIFY TO RACE F-20 , we should be ready with a basic set of rules .

Some are posted here -this is the lattest version I proposed
http://www.catsailor.com/forums/sho...ew=collapsed&sb=5&o=&fpart=1

Thanks for filling in on the M-20 Tybee-500 boat Carl. It's strange, but I dont think I have seen it do well in any major events? Perhaps the really good crew's stay on their preferred platforms..
What class did the M-20 race in, open class?

I think it's wrong to say that lighter 20 footers need to cost US$30K. It might be so today for production boats, but even plywood hulls can be buildt lighter than boats fitting a F-20 rule based on the Inter/Nacra 20. If AHCP manage to build boats of identical stiffness and lifetime in either plywood or glass (Taipan 4.9), I am sure Nacra and Hobie can do the same.

I will not do any work on a F-20 rule based on the I-20 design. As said earlier, I think and feel that it is to heavy and narrow (there is also the issue of the US version vs. the EU version with less sailarea). Sorry, that's the way I see it..

I would be more interested in a rule setting e.g. the M-20 as the reference boat. Such a rule and class could produce boats able to race Tornado's, and T's are the current benchmark, first over the line.

Hi Rolf

I agree on the current I-20 basic design being too close in weight beam SA and performance and think I,m also ready for a lighter wider faster 20 class to emerge.

We have proposed in several versions the F-20 concept based on I-20 specs for 5 years, as Barry noted most already sail the I-20 and see no need for F-20, the negative aspect is the 20s are disappearing from the race scene .
Here in MICH --Great Lakes area --lake Michigan ,-we have a major regatta called the Catfight .
http://www.catfightrace.com/Muskbch.htm

There are only 3 20s entered ,plus 4 Tornados , so there are already more T to race locally if a F-20 was developed to include them .

Lets propose an international lightweight F-20 class and leave the old tech behind . I would like to build my own design ,so would prefer a more open developmental type class rule structure. Things like angled boards -foils and sail plan variation allowed .

just my 2 cents

Boat Type Skipper Crew Sail
NACRA F18 Brent Carlson Jennifer Carlson 338
NACRA F18 Daniel Hearn Morgan Hearn 344
NACRA F18 Mark LeBel Peggy Gillespie 563
NACRA F18 Marc Kennedy Frank Burns 315
NACRA F18 Matt Struble Domonique Struble 558
NACRA F18 Leah Duby Travis Duby GBR 123
NACRA F18 Chad Schwall Brian Jurmo 555
Hobie Tiger Paul D. Krutty Kim 1457
NACRA F18 Chad Schwall 555
Hobie Tiger Olli Jason Kelly Jason 1461
Hobie Tiger Dave Stiemsma Andy Stiemsma 1609
NACRA F18 Tom Liston Mary Jo 316
NACRA F18 Mike Kletke Ashley 80
Hobie Tiger John Bauldry
Giselle Vasiri 1317
Hobie Tiger Matt Bounds Michael Ehnis 1808
NACRA F18 Bruce Inwood Jenny 343
NACRA F18 Tom Powers Lori Arrowood 126
17

NACRA 20 Guy Selsmeyer Debbie Selsmeyer 851
NACRA 20 Claus Schnabel Rick Olt 250
NACRA 20 Dave Reese John"JJ" Johnson 852

Tornado (Int) Matt Johnson Kent Kruckeberg USA 04
Tornado (Int) Martin Malcheski Benjamin Malcheski USA 824
Tornado (Int) Kurt Wellenkotter Josh Garrett TBA

http://www.catfightrace.com/attending.htm

Tornado (Int) Chris Tuckfield Nina Barlow 817

Carl,

I feel that a 20 footer should be suitable for us 'heavyweights'. People become heavier every year, so there should be some natural potential for recruitment

What I would like in a 20 foot formula class is:

Max 20 feet length 10 feet wide (2x1, the age old formula for cats), but open for shorter/less wide boats.
Minimum weight 120Kg's including 5Kg corrector weights, no upper limit.
Sailarea upwind, max. 25square meters
Sailarea downwind, max. 50 square meters
Mast area/2 included in sailarea
Mast max. 30cm chord (to stop solid rigs, let the C-class keep the wings)
Not sure if mast height should be included, initially I would say no.
T-foils allowed on rudders, no other hydrofoils intended to lift the hulls allowed.
No glued beams.
No material restrictions

Open enough to allow experimentation, but closed enough to allow some good racing must be the goal. I always tought that was the idea behind Formula racing.

Why not adopt the old B-Class Rules and add a 25 sqm spinnaker?

Max overall length of 20'
Max overall beam of 10'
Max overall sail area (including mast) same as current International T.

You might want to adopt some form of weight adjustment to equalize boat weight/crew weight that allowed heavy weight crews to sail on lighter boats (reduce boat weight by 1/2 lb. for each extra lb. of crew weight) to make the sailing more equal, just like F18 does. Just some thoughts that would stimulate boat development and allow existing International T's, M20s, Eagle 20s to compete boat for boat.

I dont know if I would go so far as that. I think it's sensible to limit both lower weight and rig type (no solid sails).
I would also like a double trapeeze..

Good idea Less -think that should be the basis for the class .
Rolf ,I forgot where your from , but lets start a thread on the proposed international F-20 class and list the existing cats that would race within it -Tornado -Eagle -Ventilo 20 w 10 ft beam -
etc ,then allow others imput on the rules variables TAKEN CATEGORY BY CATEGORY

Crew weight boat weight sail area trade offs being the most contentious area generally .

DO YOU HAVE THE EXISTING 4 OR SO BOAT TYPES AND THEIR BASIC SPECIFICATIONS.

I would suggest a very basic A class type basic box rule to begin the class ,then let it evolve based on class partisipants .
As Less noted the B class exists but needs updating to reflect existing designs and modern material weights.

The big question ,how does a 376 LB Tornado compete with a 200 +LB mARSTOM ? Spin area compensation ,-jib compensation , then we have to verify this in realistic design theory terms and hope it proves out on the race course.

Perhaps a basic B box rule only is best

Hey, we dont need to call it F-20 something if the B-class rules are resurrected, it just happens to be the B-class

I tried to find the last revision of the B-class rules, but was unable to find them. I did browse trough the A-class rules tough, and they seem very sensible and easy to adapt.

Some boat data:
M-20
L 6.1 m
W 2.93 m
All up weight 115 kg
mastheight 10.5 m
Sa upw 22 m2
Sa downw 44 m2
Ref: http://www.marstrom.com

Tornado
L 20 foot
W 10 foot
All up weight 170kg
Mastheight 9.8m (approx)
SA upwind 25m (approx)
SA downwind 47m (approx)
Ref: http://www.marstrom.com

Carbon Eagle 20
Length: 6,10 m / 20 feet
Beam: 3,00 m
Mast Length: 10,3 m
Main Sail Area: 19,25 sqm
Jib Sail Area: 4,80 sqm
Spinnaker Sail Area: 28 sqm.
Weight (with spinnaker): 145 kg
Ref: http://www.eagle-cat.com

Taipan 5.7, not a 20 foter, and not 10 feet wide either in it's original form, but a very potent platform. Macca widened it to 10 feet, put a carbon mast on it with a selftacker and feels pretty competitive. Out of production tough
Weight 142Kg
Length: 5.7m
Width: 2.5 or 2.6 meters (2x1 formula again)
Upwind: 23.3 (but can add 0.5 more with a extreme squaretop)
Downwind: 27m
Ref: http://www.ahpc.com

Ventilo Pulso
L: 6.09m
W: 2.9 or 2.55m
Mast length: 10.5m
Upwind: 22m
Downwind: 46m
Weight: 162kg
Ref: http://www.ventilo.ch/

Any others?


Perhaps it would be a good idea to consult with some designers what a sensible minimum weight should be for now, and allow designs below the limit to use correctors?

There have been rumors from time to time of a new 20 from Vectorworks. Might be worth chatting with Matt to find out what he has in mind. Clearly a successful Formula class would need to represent a viable business proposition for someone, and presumably Matt has had to think through that side of the equation.

Mark.

Rolf,
The original B-Class rules (circa 1960) were very basic -- maximum 20 feet in length, maximum 10 feet in width, maximum of 235 square feet of sail area. I can't remember if there was a minimum weight.

I'm quite certain that the Tornado was originally designed (about 1967) to exactly fit the B-Class. The Tornado is now, of course, an international class on its own, and changes the class has made have nothing to do with the old B-Class, which no longer exists as far as ISAF is concerned.

If anyone were to ask me, and they probably won't, then I would reply that you guys shouldn't go below 130 kg all-up weight. It may actually be wise to set the min weight at 140 kg. Reason, Builders want to be able to produce hulls relatively cheaply and 20 foot hulls with such a rig will take alot of load. Producing such hulls below 35 kg per hull may be a bit much to ask. Especially if you want to the rig to allow for a jib. I know that the jib has gotten a pretty bad reputation over the years but that is undeserved, especially for distance races the jib is a booster that you want to have on board.

Also I wouldn't decide for a very big sail area. Look more to the balance you are trying to achieve. Sometimes less is definately more. Pardon my example but the F16 has the SAME upwind area as the Hobie 16 design and shares even its hull length, still it is a huge amount faster. The trick is all in optimizing the RATIO'S and not in just supersizing the specs. In this respect, going smaller may actually be faster. This holds for the hull length as well.

Think along the lines of

20 ft length (although I think 19 foot would be faster because of better ratio wetted surface to prismatic ratio)
10 ft wide
9.5 mtr tall mast (less overall weight means less volume in the bows so don't make the mast taller)
18 sq. mtr. mainsail with max 9.1 mtr luff (aspect ratio 4.5 more than F20, F18 and tornado, less than A-cat)
5 sq. mtr. jib sail with about 6 mtr luff (otherwise the bridles will be too far forward, bad for loads and dive recovery)
21 sq. mtr. spinnaker with a long luff (Narrow spis are fast much more than when keeping stacking area in there)

Maybe even get 22 sq. mtr. spi is you want to come out at 45 sq. mtr. total area.

Wouter

Wouter, getting the ratios right is the challenge for the designer. As I see it, the formula just defines a box to work within.
If the goal of this class is to provide an opportunity for some experimentation and development, the parameters of the envelope need to be large enough. Hence, I dont see a reason to limit mast height. Yes, let the uni-rigs play as well, then we will know if they really are the best on distance racing as well. Personally, I think a jib is a very good thing to have on a boat for distance racing.


As for minimum weight, I have sent some messages to some knowledgeable persons (both designers and builders) to ask what they think a sensible minimum weight should be. Hopefully they have the time to answer.

Great input , perhaps it is finally time to resurect or rather use the non existant {thanks mary} B class outline similar to the A class rule . Also perhaps as Wout noted adding some definition or rules to limit development .

As Rolf noted previously the starting up of a B class or F-20 type class requires all the help and people it can get .
Wout did an excellent job with F-16 ,already has the basic data and procedures required outlined and I,m sure all interested would be very pleased to have that experience applied to the rules aspect and establishment of this class.

I would like to see it outlined and published rapidly and possibly applied in the Tybee 500 next May , which already has some T teams interested as well as other new B class cats {myself inc } -perhaps a Marstom or two again,-and possibly several others or reps from the various 20 builders that wish to establish their boat with racing credentials to race in this new class category in the Tybee 500 ,as seen on OLN tv .
The race organizers have already indicated that if 5 enter a class category will be provided , --preferably with seperate start time .

I think the basic specs of existing 20s as listed should be used as rules basis , need some time to study them myself but agree with consulting the designers and builders and following their basic advice and proposed outlines , Matt inc ,though obvious differences exist and will need to be worked out .

Please ,any offer proposals they wish to see incorporated in the rules and class structure.
Wout Rolf and all , this being an International class I think it is important to have numerous people form a base group interested , My organizational skills are obviously lacking , so please someone offer to act as group administrator until class officers can be elected .If no one else will I'll volunteer BUT WOULD PREFER someone more qualified and capable take the reins .

Thanks ,-this is very exciting, my interest has been waining but this class will bring me for one back into more active racing again .
Carl

If the I20 is going to be a slug in the class, or not even qualify, then count me out.

I'll go make an F18 for half the money.

Can someone help me by translating the rules on this site:
http://www.f20.nl/
I can't run them through bable fish because it is a picture and not text.

Thanks.

I am quite sure the I-20 will fit within the B-class box. How much sailarea does it have?

Will it be a slug? Perhaps.. I dont know. But consider that the point in resurrecting the B-class (or a derivative of it) is becouse we want higher performance boats and some room for experiments.
I am quite sure there is a large enough number of I-20's to keep the class healthy and active. Our toughts and ideas should not be viewed as a treath to the current F-20's and I-20's. As others have said here, the I-20 is strong in the US.

Are you considering building an F-18? Great if you do, but consider where you will find the mast and crossbeams. An old T can be donor for a B class rig/beams (might need new aft-beam), and then you just need foils, hulls and new sails to have a competitive B-class. Thats one of the attractions for me (plus that we mostly do distance races and need the speed. We are a beefy team who will not be competitive on a F-18)

Carl: What exactly is it you want? I'll report back when/if I get some feedback.

If someone have connections within Hobie Co., Nacra or AHPC, it would be great if you could ask them what they think about minimum weight and sailarea.

Mike,

Mainsail:
18m2 + half mastarea
Dacron/Mylar
maste height max 9850mm above mainbeam

Spi:
Weight class 1-2: 23m2
Weight class 3: 25m2

Jib:
Weight class 1-2: 4.15m2
Weight class 3: 4.85m2

Hulls:
max length: 6200mm
max width: 2600mm
material: polyester

Daggers:
max 7kg

Rudders:
max 3 kg

Crew:
Class 1, 135kg tot < 150kg (including correctors)
Class 2, 150kg tot < 165kg (including correctors)
Class 3, 165kg or more

Security equipment:
1 paddle, min length 1meter
1 towing line, min 15m long 6mm thick
1 righting line, min 6m long 10mm thick
2 PFD's (dont understand what "op lichaam te dragen means". Dragons who like to drink tea perhaps..)
1 compass fitted to the boat

Dont forget your measurement letter..

Thats all there is there.. (I hope, perhaps Wouter can correct me if I have done any mistakes translating)

Sorry, I'm having too little time to keep up with my own class work. So I'm not checking this data, you are on your own guys.

Wouter

I have recieved some feedback from both designers and builders. They suggest a range from 125 to 135Kg's as minimum weight. That weightrange is achieveable for a 20 footer with a jib both for manufacturing and homebuilding (in plywood if need be)in their opinions.
I would suggest a minimum weight of 130Kg's, based on that input.

Another issue, well debated earlier, is the 10 foot beam. It's viewed as an detriment for the average sailor Joe, not beeing able to put it on a regular trailor. Options are either a tilt trailer, disassembling, or some sort of folding/sliding mechanism. Personally, we use 1 hour to tear down our boat for travelling, and two hours to put it together again. We can leave the boat with the mast up at our club, so we dont rig the boat every time we want to go sailing.
Having sailed a cat with a 10 foot beam for some years now, I would not consider a high performance cat like what we are discussing here with a 8 foot beam. Even if it's more convenient when you need to trailer the boat around.
If assembling the hulls/crossbeams/trampoline platform is to much, I seriously suggest a kind of tilt trailor. There are many types of tilt solutions, but one of the best one I have seen used the area under the boat as a gear-storage/camping shelter. It looked kind of like a scewed metal tent, provided great storage and a place to sleep if need be, plus, I think it helped with the aerodynamic problems of trailering a tilted 20 footer (crosswinds and meeting trucks).

2 PFD's (dont understand what "op lichaam te dragen means". Dragons who like to drink tea perhaps..)

"to be worn on the body", although I quite like the idea of a tea-drinking Dragon

Rolf, suggest you go with 10ft beam, or even unrestricted. If guys don`t want the extra rigging time or tilt trailers they can go with 8ft beam and add racks like skiffs, the F16 rules actually allow for this as well, if the boat is less than max. allowable specs (2,5m)you can add wings / racks such that the boat width plus one extended rack is at or less than max. beam.
Would be fun to see 20ft cats with massive rigs and huge racks out pitchpoling all over, make good tv coverage

Right Steve, to be worn on the body of course.

Racks are a good idea if trailering is a large problem! Are they included in min. platform weight on the F-16's, or are they 'extra'?

I would like to limit sailarea, but let the 'daredevils' put extra high masts on their boats if they want to. I was considering putting racks and a Tornado rig on a 16 footer once, but never got around to it (in hindsight, I am glad I never did. Would have been a real pitchpole machine).

1.3 Boat weight

The minimum weight of the boat ready to sail, excluding non permanently fitted wings, is fixed at :

1.3.1 Singlehanded mode (cat rigged with gennaker) : 104,0 kg. (= 230 pounds)
1.3.2 Doublehanded mode (sloop rigged with gennaker) : 107,0 kg. (= 236 pounds)

So min. weight excludes the wings / racks. Just have to make them really light then, eh ??
(Above from F16 class rules, not to confuse F20 interested parties, in answer to Rolf`s question.)

The boat Wouter described is already out there, known by the name of "Super Taipan 5.7", right Macca?