Great class concept , thanks to all involved for getting the F-14 going.

Many sailors will be much more likely now to get an older 14 ft size range cat out or purchase an inexpensive one knowing they can modify it , add a headsail ,and have a fun class to race in .A number have 14 ' production type cats already .

I,m interested in cat design and being able to experiment a little and to be able to bring {the lattest creation} out for comparative speed testing in a class.

Thinking about the 15 -its a non board type , with 26 ft mast . It would require taking 2 ft off the mast and recutting the main down to a sq top type. Then-shortening up the hulls to 14.3 L canting them and first experimenting by adding some forward angled molded in foils in the mid forward area with larger rudders aft. then add a longer spin pole. The CE -CLR relationship {helm feel}} balanced by the added forward foils ,--the concept being lift from the foils and added lift from the spin now having more luff angle ,-its a heavy boat though -305 Lb.

Some lightweight hulls at 14,3 being more ideal, maybe just building some ,-but then wanting to experiment with hull shape .

The other aspect I,d like to experiment with is the rig ,-
It would require wide beam with the 2 mast concept ,-like the 60 cat , but some variations with a center balanced sail to experiment with ,--better effeciency and lift being the idea , along with a mast head spin and foil concept .
http://www.parlier.org/site02/accueil/1024x768.html

Building an HT type lightweight 14 would be fun in itself , the 107 Lb cat by Bernie sounds extremely fast .

I have 3 younger boys and the 14s may be ideal to get them going ,---if I had one also we would have our own fleet
{4 min}

Think whichever type 14 project , the F-14 class can include all types and add future sub categories as it grows in number .It may be needed sooner than latter.

For those going to the Spring Fever regatta
http://www.TwinHulls.com/springfever
Just for clearity ,are all 14s going to sail as Formula 14s or is there sub categories of production Mystere 4,3s.
It might be fun to bring a sketch pad and rough draft some interesting F-14 concept sailing craft .


Would be interested to read about other F-14 projects or design concepts as well.
Carl

I think the "trick" may be to have the mast-beam and mast further aft than we're used to. Maybe with the boom hanging out past the aft-beam to get enough sail area to make the boat fast when sailing uni-style. This way the spinnaker pole won't have to be so far past the bows and the CE can be more centrally located on the boat when all sails are flying (less bow-burying). I'm still thinking about a true roller-furling jib (just a monstrously large one) that can be used at tight angles upwind. However I don't know how well this sail would perform downwind....

Think we will see some interesting design build projects -
thinking through design options ---

Many know the basics of design and design considerations but it might be interesting to walk through some options and target a design with more aft mast location and the effects ,--then add an optional jib ,--plus optional headsail in any configuration per F-14 rules.

The further aft the mast {and mast rake} is located in a design the greater the distance to the bows and increase in potential volume area from the CE -center of effort on the sail plan . The sail forces trying to push the hulls under and pitchpole which is a bigger problem in a 14 ft Length.-An aft location rig can handle more sail area and be driven and pushed harder at top speeds ,-a good goal to design in .

No question the ht type 107 LB Formula 14s will have a larger speed potential that serveral may design and build from fold up plywd or foam cell core type const..
weight = speed potential ,due to less drag and displacement .

Balance becomes the problem and why we don,t see the aft mast location on many cat designs .- The CE must balance the CLR ,-
CLR is the CENTER OF LATERAL RESISTANCE , which is the area of underwater profile under sailing conditions .Offsetting the area profile under sail of a submerged hull evan a 14 ft one will have approx, a 14 ft total underwater hull profile when flying a hull at av one ft submersion along its length {just rough av}.
This aft mast design needs to be balanced. The CLR and location of the sail plan and its measured CE -Center of Effort ,-or center of total sail area have to coorespond in the final design version .

To find actual CLR hull design shape and volume, calcs are needed to then find theoretic hull waterlines while under sail in varied winds, crew weights , and angles of heel.

CE is effected by mast shape ,-mast rake ,-and sail fullness . The CE is generally designed with the CLR to provide slight weather helm .

If you took a boardless type cat and moved the rig aft by a few ft --say a H-16 ,-it would never balance the CE with CLR --Center of Lateral Resistance -of underwater profile ,- and this design would simply round up to windward AND NOT SAIL ANYWHERE no matter how hard you pulled the tiller.

Conduct the opposite experiment and try sailing with only a jib up ,-the boat just peels off to leeward due to balance ---Board sailors understand this as you tilt the rig forward to bear off ,-and back to head up ,-with no tiller.

The CE of the sail plan in side profile must balance out with the CLR of underwater area profile ,-
The dagger board can be added aft ,-but your dealing with 14 ft of hull area in the calc.
To balance this out requires a huge board placed well aft adding weight and drag beyond any benifits of aft mast location .

So we usually see a balanced location at 50% max. aft with aft board location for a standard type sail plan .

If any can devise an aft mast location design with with more sail area proportionately forward of it , --hmm one solution {CE & CLR} ?

A very hi aspect ratio mainsail being more effecient per area and having a shorter boom is one design aspect that helps locate the CE further forward ,--Another solution?
aahha ! a larger proportional jib ,allowed under F-14 rules of any sail plan configuration up to 300 sq ft -
150 sq ft of main being about the max fit onto a 24 ft limit mast height per rule . it corrects the aft mast location balance problem !

How big a jib can any handle upwind ,---some comparable study ,-a sc 15 has similar area as does a H-14 -Mystere 4,3 etc ,-the H-14 turbo and 15 have about 40 sq ft jibs ,
these fly hulls in about 6 to 8 mph wind given a heavier boat weight and av beam of 7.5 to 8 ft .
More is possible in lighter wind , but less is required with lighter boat and crew weight , more is possible with larger beam ,-but this also limited by earlier noted CE volume of hull TO BOW and ideal equivilant forces.

Larger designs like the A Class cat use only a 150 sq ft main with 7.5 beam ,-though on a longer mast of 28 or so .

A logical conclusion would be that a similar 14 lighter boat would require more beam to be as stable with the same sail area ,-so added jib area of more than 40 would make it less stable , a larger battened jib down to a spin pole would increase jib area and lower the CE ,-MAYBE A 50 max pushing it ,this is alot of sail area ,-maybe reduce the main to a more hi aspect type in 24 ft max.
But now you have an aft mast location larger jib larger beam lighter boat type design ,-but most likely optimized for that 8 mph wind or below dependant on other minor design factors and crew weight . The larger the crew the larger the jib possible , but the more volume in hulls and drag required to carry the added weight and sail forces exerted by it .

When the wind kicked in, the other designs with smaller main only sail plans would roll you as you struggle with too much sail trying to depower a 190 or 200 sq ft sail plan . A reef system is an ideal solution ,-but you now have a design reliant on the larger jib area to balance CE and CLR . The option of a main reef system or 2nd smaller main needed for those breezy forcasted weekend races as another option.

This still leaves a 100 or 120 range sq ft headsail option of any configuration within 300 sq ft total,a smaller spin ? not a good option with larger jib and less effective vs 150 sq ft spin as per Mystere 4,3 -A fully battened jib then?, a double slot effect 2 jib system may work well but how to set and snuff ,-maybe a quad jib with two clews on a roller furler ? {batwing type}--or maybe just a hooter type headsail though high aspect sails with longer luffs are much more effecient per same area .

Maybe a 7/8 rig or masthead type then ?
longer spin pole?
How does this effect balance- and all other cooresponding design features ,-will it theoretically be an improvement or faster in a range of conditions , what other options are open on a standard type ht F-14 .-
Could added angled lifting boards be designed in ,-or how about two smaller sets of angled boards in each hull that would balance the headsail or allow a reduction of sail in different combinations -main only with aft board for those breezy races ,-and balance out a longer spin pole.

How about the option of adjustable rig that would allow mast rake further aft to move the CE back or forward and balance out the added headsail area ,or main only and jib combinations? hmmm -Add adjustable stays .

Thats the fun of this class --the options are OPEN -to the design build project any care to experiment with ,-but suggest applying some basics of design with practical experience and comperable study .
Stongly suggest a model before building and better yet consulting or having a plan review by boat designer before const.

Ht Formula 14 basic design build project specs -
L -14,3 B-8,5 W-120lB Sail AR 150 main --50 jib
100 headsail ,

This is definately a light air optimized F-14 DESIGN boat unless a larger beam is added with coresponding hull bow volume -
but both add weight and drag as does a larger crew .
.
The easier prospect of finding or taking an existing production 14 ft cat and modifying it will be great fun also ,-A spin-snuffer or hooter added with other special mods as noted could be applied or changed to any 14 .
Due to boat weight ,think the production boats will need there own category or sub category F-14 eventually .

More experimental unlimited beam types may be built , some may just want a 14 ft prototype of a larger future design and simpley bring it out to experiment with hull shape or sail plan ideas in a fun comperable race class .

I hope we see a number of interesting creative innovative 14 designs

added note :
there is an interesting cad design thread on the new forum by grob on setting up future design comparison ,--think this will help Formula classes develop ,grow , and establish design measurement type definitions and future rules and sub categories .
http://www.catsailor.com/forums/sho...ed&sb=5&o=&fpart=2#Post30269

Actually, I was thinking of having some big rudders, maybe even a skeg, and having a decidedly aft-set mast. The mainsail would be ~150sqft and the rudders would primarily have to deal with the CE/CLR issue. You'd be footing the hull as much as possible, anyhow. The daggers would be set forward of the mast-beam and used when the head-sail is set. A third beam would most likely be needed, but not so far forwards as seen on current designs. 4' back from the bow might work, just something to help take the forces of the daggers and the rig.

Whatever I use for my first F14, the first headsail is going to be the extra jib from my G-Cat 5.7M. I'm not sure of the square-footage but it's a huge jib.

Sounds good -

That will be the fun of this F-14 class also -
Being able to use existing larger sails , or hulls or masts -parts etc ,and experiment a little .

The existing comparison non board type of cat design would be the H-14 ,-but that uses asymetrical hulls {flat on the outside} -Mysteres and N use a molded in skeg ,rather than board , which makes sence w spin where you need some partial board down ,-its also simple and economical .
The similar type non board is SC 15 {have one} It has no boards on sym hulls and good sized rudders.
It does not track to windward like a boarded boat so boards forward as you noted would help ,-but the CE and mast location is forward on the SC ,-for good reasons ,-
I sail the 15 w jib , it balances well .
Your addition of large jib would enable the aft mast location but in higher wind being reliant on rudders only will place it at a disadvantage with board boats tracking much higher to windward , downwind the Mystere type design with larger spin may have the advantage , the key will be for multiple jib + headsail hooter type configuration sail plans to be as effecient downwind as a spin ,and have the option of carrying it upwind to increase sail area for lighter wind conditions . Developing more versitile rigs and means of balancing out those sail combinations in this 300 sq ft max rule outline .
The main problem as compared to larger cats in the 14s is getting enough volume in the hulls to carry boat and crew weight plus sail forces , particularly towards the bows downwind to prevent a pitchpole prone type design .

A few design options -
aft mast design
larger volume hull and bow design

The other option not yet noted is lift ,-2 types
lift from hull shape and boards or molded in skegs or fins
lift from sails .
along this line -
I,m tempted to modify the SC by adding adjustable stays that allow more extreme mast rake -{same effect}as aft location, but is adjustable during sailing from upwind to downwind mode.
--A better type of rig could be designed with this adjustable for and aft rake than current type, but that is the next development once the basics were proven .
Similarly to your forward boards ,Im thinking a forward angled molded in fin or skeg to help lift the bows.
-The forward placement allows a longer spin pole and more luff angle that creates more lift from the spin .

Forward angled fins and spin lift combined with adjustable rig .
The rig and sail plan for cat design really needs to be improved , It is still an adaptation of conventional monohull design ,-some innovative and interesting ideas should be encouraged .

Or move the mast, beam and boards forward and use a long pole. This has the effect of improving control (distance between boards and rudders) speeding up tacking, improving lift on the bows downwind, allows for longer sterns...... This is more of a skiff type rig. Try and sail a Super Wave to get an idea what it is like.

Designing a cat is like solving A+B+C+D+.....=14. There are a million combinations. You talked about one and I talked about 1. Never forget that when you change one thing, others have to change also.

For example, with a mid mounted mast (7 ft from the bow) . With an 8 ft boom, the back edge of the sail will be a 12-18 in aft of the sterns. Sail area with a 23 foot luff is 92-184 ft2 (triangle - straight leach) Center of force 9.7 - 11 ft from the bow. I found with narrow hulls you need about 2-3 ft of stern length to keep from dragging the sterns so you end up with about a 5-6 ft tramp.

I am not going to talk about computer modeling let's just stick to experience. Also you can adjust an existing boat (mast rake, boards up or down) to give you some feel for what these changes do. This used in the aircraft industry a lot.

The CF location is in the weather helm from hell territory -It is like a big sq top on a uni-rig with a LOT of mast rake. You are going to have to compensate somehow. It is hard to get the boards and rudders to balance. Under some conditions the rudders will load up so much it will be hard to tack.

Weight distribution You always seem to need your weight forward in light to moderate air. You are going to need to sit forward of the crossbeam balanced on a narrow probably rounded hull most of the time where I live

Spinnaker pole - You are going to need a long pole to get enough lift on the bows. This means the CF will be way aft up wind and way forward down wind

None of these problems is insurmountable. You need to be aware what you are getting into. I suspect that a boat like this would be near unbeatable in it's design range and very hard to control outside of it's design range. If I knew I would be racing 90% of the time in say 12-18 kts or 18-24 it might be the way to go.

Hi Brian

an interesting 14 project by a home builder ,
like the rig especially ,
http://www.rclandsailing.com/catamaran/index.html
a larger version with more of a windsurfer sail concept would be a great development , think of the range of full to flat sail shape such a rig could produce on a bendy CF lateen type mast ,-plus a spin off the taller A frame .
Picture it developed as more like a Sunfish rig , larger more verticle spar and a semi balanced boom ,
Little loads and an ability to cant the sail if attached to a traveler on the forward crossbeam ,--much like a windsurfer sail adjustment, canting to windward or leeward in light wind ,--the rig being raked back already .

The catyak 12 produced this type of rig decades earlier, though with fixed heavy alum tubes and fittings and rectangular type pontoon boat type hulls .

It is one way to get the mast -or-masts further aft on the cat and have the main more forward to balance the CE of the mainsail .
If the taller bi-pod rig was set say half way between the front and rear crossbeam ,-then the boom attached to the front crossbeam with a couple feet entended beyond -
{semi balanced } --that would place the masts aft -station 6 or more --and the ce -center of mainsail near the center of hull --CLR

As noted making the A frame rig out of more wing type section shape ,--or adding a small sail on the CF tubes would be an improvement and a good place to run halyards inside of
Wish him all the best on the maiden voyage this spring
.

http://www.rclandsailing.com/catamaran/index.html

Wow, all sorts of very useful information there. I especially like his method of creating round carbon-fiber and fiberglass spars/beams. That could be most helpful to future F14 builders, as kit hulls could be designed with the hull-beam seat designed for a specific common pipe radius.

Hi Brian

He has some good basic ideas ,-

Interesting --the comment on hull shape if folding up another would be more of a G Cat form ,--narrower deeper v type hulls ,rather than the skeg type he built in place of boards ,-
much easier to fold up a basic rounded v than the more compounded curved hull , and the natural radius of a folded shape is always fast.
A number of cat builders back in the 80s folded up numerous A Class cats locally ,-then wanted flatter hull shapes than plywood fold up would allow ,--it only bends so far . They went to nomex cores after that and 18 sq meters which they thought would have a greater appeal to a wider variety of sailors ,---larger sail area 193 ,-and no beam limit .

How do you like your G cat hulls ,the deper V and no boards ,- It would be a simple type to fold up w plywd. for a 14 .

Just for fun ,-drew some basic hull lines for a tunnel hull design ,--tunnel each hull ,planning type hull ,
It has huge volume forward -flat bottom w chines ,canted ,
but would only be a flat water cat , the bows being very wide for the tunnel .

I love the ride on my G-Cat! No slamming at all and very high off the water. I usually sail with/against P18-2s and P19s and I have no trouble pointing with them. When we were both using blown-out sails, I could keep up with the P18-2. He's since gotten a new square-top main and new jib, which gives me hell. Depending on where we're going and which way the wind is blowing, I can take all sorts of super-shallow short-cuts and occasionally beat the other boat to our destination.

In light airs, the G-Cat really beats out the Prindles with it's blown-out Dacron main and huge jib. I can lay on the front trampoline and bungee the tiller down while the Prindle sailors are dancing on their skinny bows trying to get the sterns up.

While Hans can slam these boats around the race-course, I have trouble getting mine to tack quickly. This problem is proportional to size, the longer and narrower the boat, the harder it is to tack. An F14 version of the G-Cat could be pretty nimble.