18' Trimaran vs F18 Catamaran

[Doug Lord]

Originally Posted by Chris Ostlind

by simply inferring that the Magnum hull has gone through a similar engineering regime to arrive at an optimal hull.

==========================
I infer nothing of the sort. I point out several times the performance enhancements I would make-and that would be necessary to make for the tri to be faster.They are mostly design changes which I describe in detail. And even with those improvements included cost is the same.
You are dead wrong and can't admit it! Funny.....

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1

Originally Posted by Doug Lord

----------------------------------
What this proves is that a performance tri can be built and sold for $19,235(including spinnaker)
compared with the cost of the state of the art Wildcat F18-the latest creation of Martin Fischer and Hobie- at $22,499(not sure this includes all sails-see below). It probably isn't as fast as an F18 though it can be sailed singlehanded which makes its sailing weight substantially LESS than the F18.
For the performance,design and comfort enhancements I'd probably include in a final design the two would be close in price-with the tri more comfortable and faster.
-------------
http://www.ahoy-boats.info/lists/Magnum18-prices.htm


http://www.ahoy-boats.co.uk/Magnum-1..._utmk=68449553



TRIMARAN SPECIFICATION
1) Construction--Composite glass/polyester
2) Hull Length-5.30m (18ft)
3) Float Length -3.8m
4) Float Volume -200 litres each (filled with bouyancy) -451lb. buoyancy in salt water. VERY IMP: this means that this boat cannot fly the main hull since there is no method of dynamic lift associated with the ama.
5) Widths:
--4.30m trimaran overall
--0.92m (max) Principle hull at waterline
--1.72m on the road
6) Mast length -18: 7.0m 18S: 7.30m
7) Mast height above waterline -18: 7.75m 18S: 8.05
8) Standard Sail Areas
--Classic 18: Main 11.5m2 18S: Main 12m2 129 sq.ft.
--Classic 18: Furling Jib 4.5m2 18S: Furling Jib 4.75m 51
--Total upwind SA 18S-180 sq.ft.
9) Draught 0.2m ,1.0m with centreboard down
10) Weight 200kg

11) Standard Rigging:
--Rotating mast.
--Bowsprit.
--Full battened main with downhaul.
--Traveller.
--Furling jib is standard.
--All sheets and halyards supplied.
--Trapeze kit optional on classic 18 but std. on 18S
--Composite (racing) rudder foil std.
12) CE Classification-Category "C" (unsinkable)


++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Hobie Wildcat F18

Background:
Hobie Cat Europe asked a panel of esteemed naval architects(Martin Fischer-see interview url in a previous post), Olympic sailors, and sailmakers to design and build an F18-class category killer. The result? The all-new Hobie Wild Cat F18. This no apologies racing cat will unquestionably make its presence known in F18 racing. Wave-piercing hulls, integrated wing mast section, and minimal drag from its high-aspect rudders and centerboards contribute to outrageous lift when sailing to windward. Downwind is a sleigh ride with the full spinnaker rig. Whether fleet racing or blistering across the water for the sheer thrill of it, the Wild Cat will most certainly satisfy your need for velocity.


Specifications:
Length: 17' 11" / 5.46 m
Beam: 8' 6" / 2.59
Draft w/Rudder Up: 7.1" / 0.18
Mast Length: 29' 6" / 8.99
Sail Area: 454 ft2 / 42 m2
Weight (with spinnaker): 397 lbs / 180 kg
Hull Construction: Fiberglass/Foam Sandwich

Standard Features:
>> Fiberglass hulls with EVA anti-skid and one inspection port at the rear
>> Carbon reinforced rudder blades and daggerboards
>> Carbon telescopic tiller extension
>> Mesh trampoline
>> Harken mainsheet blocks
>> Harken spinnaker blocks
>> Spinlock Cunningham blocks
>> Jib tack line and jib sheet integrated in the front crossbar
>> Spinnaker tack point and spinnaker halyard are separated
======================
Type: Hobie Wildcat F18
Hull: multi
Year: 2010
Length: 17'11"
Beam: 8'6"
Draft: board up: 7"; board down: 4'2"
Weight: 397 lbs
Upwind SA: 227 sq.ft.
Sail Total Area: 454 sq. ft. upwind and downwind
Base Price: $22,499-may not include spinnaker!
Intro Year: 2009
Designer: Hobie Cat Europe Design Team
http://www.sailmagazine.com/sail-buy...ide/hobie_cat/

-----------------------

2

Originally Posted by Doug Lord

-------------------------------
You're caught dead to rights. You simply can't admit when you're wrong-very wrong.
Weight difference 44lb. SA difference 50 sq. ft.
So if you REMOVE the weight at the cost per lb of the Wildcat you get 44 X 56= $2464 . Add SA at $15 per sq.ft= 50X 15= $750. Total additional cost: $3214
Tri as it is now: 19,235 add $3214 in improvements TOTAL COST IMPROVED TRI= $22,449 (cost F 18-probably w/o spin= $22,499)
There you go-a tri comparable to an F18 for about the same cost.

====================
You're also wrong about the spinnaker-especialy on the F18 killer: since it flys the main hull with "dynamic heel control"(foils*) and has dynamic lift designed into the ama the boat would just fly with the spin....
*foils add no cost: F18 Cat has TWO daggerboards and TWO rudders. F18 killer tri has ONE daggerboard(with small lifting foil) and ONE rudder(with small lifting foil)-no net gain in cost.

-----------------------

3

Originally Posted by Doug Lord

There are a number of considerations in a possible F18 killer tri. This is just one angle to look at:

1) the tri would have between 14' and 18' of beam.
2) the tri would be designed to fly the main hull from a 5 knot wind
3) the tri could be designed to have the same or much more SA than the cat
4) the tri would be designed to achieve maximum RM either single handed or with two people aboard
5) the tri could be designed to have crew seating near the center of the boat virtually regardless of SA(within reason)
6) the keys to this kind of tri, in my opinion are:
a. use of lifting hydrofoils on the main hull daggerboard and on the rudder,
b. the foils enhance the pitch stability of the boat but can also be designed to use an altitude control system
that can be designed to allow the tri to fly with the main hull just above the water,
c. The altitude control system will allow the main hull to fly earlier than it would otherwise AND prevent the boat from heeling too far by pulling down as necessary and automatically.
d. The foils + altitude control system are why the boat will always develop maximum RM regardless of how little the crew may weigh and why it could be singlehanded at full power.
7) Because of the foils and altitude control system a tri like this would allow the crew to sit near the center of the boat in the most comfortable way possible with no need for trapezes and running side to side.
8) Because this boat would use a two foil system both foils would seriously augment the pitch stability of the boat.
9) There are a three(or more ) ways the amas can be configured but one critical aspect is that they must be very small-approx 70% of total displacement-maybe less.
a. a displacement ama would definitely use foil assist like the ORMA tris do or with an an adaptation of Hugh Wellborns DSS system using a pivoting horizontal board-both of which allow easy foil retraction. This is the "mini-USA" option!
b. A concept I've been working on a little at time for several years is the ROH -rotating hull ama. If it proves out it would allow the same hull to be both a displacement and a stepped planing hull. It might have a top end speed advantage. Either this or "a." would probably be the best(and most marketable) system.
c. a displacement ama using a surface piercing or t-foil designed to fly the ama(when the main hull is flying). Seems to me the foil would have to be easily retracted for light air,
10) the boat could fold or just use plug in amas..

---------------------------
[b]Just a few ideas that I think could result in a design that could beat an F18-both on the water and in the market.

=======
4

Point is that both boats are built with similar material and with a few low-cost design changes the tri could ,without a doubt, be competitive with an F 18-probably beating it in most conditions-NOT THE MAGNUM but a tri built using the same materials with design changes that enhance performamce-the biggest being that the "peformance" tri would fly the main hull. Cost will be in the same ballpark as an F18 Wildcat......

[Chris Ostlind]

How much do you think it costs to hire Fischer to design a proper and much faster hull, foils, etc. for this remarkable machine you say can be produced for the same amount? This boat has more hulls, more tooling required to produce those hulls and more shop space to store and produce the boat in question. Do you think all that stuff is free?

All of those costs, along with all the needed upgrades for an equivalent trimaran, have to be included in the price of the boat, or whatever company that risks building this, will soon be out of business. I know that in your world of balsa gizmos and art paper sails with crinkled blue drop cloths as photo backgrounds, you tell yourself it can be done and everything is going to be free, cause you won't charge yourself... but it just doesn't work like that for anybody outside of your little zone there.

This has become a boring, tedious discussion. One that you should enjoy with your fans.

[Doug Lord]

Originally Posted by Chris Ostlind

This has become a boring, tedious discussion. One that you should enjoy with your fans.

====================
What discussion? You said "Prove it". I did. Just admit that you were dead,flat wrong! You'll feel much better......

[powerabout]

Originally Posted by Chris Ostlind

How much do you think it costs to hire Fischer to design a proper and much faster hull, foils, etc. for this remarkable machine you say can be produced for the same amount? This boat has more hulls, more tooling required to produce those hulls and more shop space to store and produce the boat in question. Do you think all that stuff is free?

All of those costs, along with all the needed upgrades for an equivalent trimaran, have to be included in the price of the boat, or whatever company that risks building this, will soon be out of business. I know that in your world of balsa gizmos and art paper sails with crinkled blue drop cloths as photo backgrounds, you tell yourself it can be done and everything is going to be free, cause you won't charge yourself... but it just doesn't work like that for anybody outside of your little zone there.

This has become a boring, tedious discussion. One that you should enjoy with your fans.

If toyota can get a chinese mainlander to work in a car factory for usd180/per month then there is plenty of margin to get cheaper boats!

[Doug Lord]

It's not a question, so much, of needing cheap labor to do a tri at the same cost as a top end cat. The design of the tri is critical. For instance, on the Magnum, the total buoyancy of the ama is 100% of the weight of the boat WITHOUT CREW! That means the boat will not fly a hull. According to the company it also means the costs can be lower. The small ama is less than half the "skin area" of an F18 hull which addresses a major myth of those that say you can't build three hulls as inexpensively as two.
This is what the company says about the Magnum 18:

Can the Magnum 18 be sailed on one hull?
No. The volume of the leeward float, 200 litres, displaces the same weight of water as the whole boat when fully immersed, 200kg. This means that it will sink before the main hull will lift off the water. This gives the skipper the clue that either he or his crew need to sit further to windward or the sheets should be released or the sail reduced if it is happening a bit often. Thus it acts a bit like a safety valve or fuse. If the amas were made big enough to support the whole weight of the boat then the akas (cross beams) and their fixings would have to be made stronger and this would add weight to the boat.

-----------------------
The fact is that whether a tri flys the main hull or not is a design choice and the tri that is the subject of this thread would be about the same size as the Magnum ama but it would have one huge difference: it would be designed to
use dynamic lift to fly the main hull using one or more of the methods discussed earlier. Flying the main hull is the major key to beating an F18 for an 18' tri. Doing so with a small ama and dynamic lift is one of the keys to keeping costs in check.

[Chris Ostlind]

Originally Posted by powerabout

... then there is plenty of margin to get cheaper boats!

And cheaper hardware and cheaper sails, spars, tramp material, etc. It doesn't remove the fact that there is still going to be more tooling, design work, engineering, additional parts (foils and trunks, to name but a couple) and added shipping costs due to fewer boats fitting into the same container, and on and on the list grows.

Like I said with tongue in cheek... one can probably get them built very cheaply in Rwanda by the Tutsis, with a gang of Hutus standing nearby with machetes, but that doesn't make them comparable, or even satisfactory.

Maybe you've seen the quality of finish on Hobie Wildcat in person?.. Or the Capricorn, which was the original example shown at the start of the thread? Both of those boats have gone through very stringent engineering and design study, prior to being introduced. The work was performed by the top guys in the field. That work doesn't come for free and it has to be amortized during the early part of the production run in order for the profit numbers for the boat to be recouped by the investor. To produce a comparable trimaran design will also require a similar, if not better, design program which will have to be added to the cost of the boat. That figure is not being shown in the so-called analysis being shown.

The necessity for curved foils, their specific trunks and control systems are also not being shown in the weight, or cost analysis. There are two of them for each boat and they are not simply glued in place and called good. They have to be engineered specifically to match the requirements of the boat. They also require seriously reworked ama-to-aka juncture points, stronger aka beams and a whole host of other improvements that must be properly engineered, or the boat will break regularly when being used. The standard, sliding tube aka setup of the Magnum will never be able to handle that kind of load.

Changing the convenient consumer oriented sliding tube system will also require a reworking of the aka-to vaka hull mounting locations to provide enough strength.

The rig will have to be quite a bit bigger, in order to get the tri to a comparable power to weight ratio. One can sidestep, partially, the addition of a heavier mast by going to carbon, but that will also drive the final price upwards. The bigger rig and its attendant compression forces will necessitate a stronger mast step and the load bearing bulkhead beneath it will also need to be reworked by the engineering team.

I'll stop here, but I think it's more than obvious that the Magnum example is so completely irrelevant that it's kinda comical that it was brought forth as a credible, weight/cost example in the first place. This magical boat will not meet the weight of a Capricorn without the use of exotic materials, such as carbon. That will drive the price upwards. It will not meet the needed power requirements without a significant change in the rig and all the rest of the connected inventory to service the rig, e.g., hardware, mast, boom, sheeting system, the whole works that should be on a boat that is being claimed as a beach cat killer.

The supposed boat will need to be as good looking, or better. This means styling/design costs up front, before any tools are built for production. It will have to be kitted-out with as good, or better, of everything one see on the Carpicorn to be considered in the same game. This is also added weight over the already over the line existing weight of the Magnum. It will need substantially fresh engineering, with costs to be borne up-front, to allow for all the "enhancements" needed to maybe get it into the game. It will need the use of exotic materials at higher production and retail prices in order to try to get the weight down to something like a competitive relationship to the Capricorn and its known abilities. This trimaran will need some kind of trick and very expensive marketing plan to get sailors to switch over from a boat which is much easier to rig, trailer and sail... and is already on the market with huge market penetration already in place.

So, you see, this isn't a simple, “I'll sketch this thing on a napkin” exercise, if one really wants to produce an equal length trimaran that is a beach cat killer. It was asked way back at the front of this thread, why hasn't anyone done this already? I think that the answer is obvious and in a general fashion, I've laid that answer out before you. Specifics will only drive home the reality more conclusively. You can argue until you’re blue in the face, but you can't change the facts. You want to equal the speed of the Capricorn, you need to get out the check book and be ready to throw quite a bit more money at the boat that "might" be able to do that. In the meantime, you're missing out on a lot of really cool sailing days while the existing boats are sitting on the beach, waiting for sailors.

This idea is DOA until something enormous changes in the way that small craft are built and marketed.

So, that's it with the Magnum as the answer, Doug. It's not even close to an answer and no amount of jockeying around with the numbers and ignoring certain spendy and weight adding aspects is going to change that fact. You've pulled a dead fish argument out of your pocket and tried to foist that on the nice folks who read these pages, as a substantive argument. It would be good if you stopped assuming that the members are fools and will bite on the next wild idea that comes out of your thought process.

It might be fun to imagine a boat that was as affordable as the Capricorn with more power and more comfort, but in this case, the path to getting there means that one of those things will have to be delisted in order for the boat to make any sense at all.

Affordable, power, comfort.... pick two.

[Doug Lord]

Originally Posted by Chris Ostlind

1) The necessity for curved foils, their specific trunks and control systems are also not being shown in the weight, or cost analysis. There are two of them for each boat and they are not simply glued in place and called good. They have to be engineered specifically to match the requirements of the boat. They also require seriously reworked ama-to-aka juncture points, stronger aka beams and a whole host of other improvements that must be properly engineered, or the boat will break regularly when being used. The standard, sliding tube aka setup of the Magnum will never be able to handle that kind of load.

2)So, that's it with the Magnum as the answer, Doug. .

===============================
1) There are a number of options for foils: DSS retractable foils are probably the best solution since there is nor no requirement whatsoever in my proposed solution for lateral resistance to be generated by ama foils. In fact development may prove that the rotating hull is the best solution
requiring no foils whatsoever.


-------------


2) the Magnum was not presented "as the answer"-far from it. It was merely an illustration that an 18 foot tri could be built and sold in the ballpark of
what an F18 is. I carefully and thoroughly explained earlier just what the Magnum illustrates. Since the Magnum is several thousand dollars less expensive than an F18 it is reasonable to say that a high performance 18' tri could be produced and sold at a cost comparable to an F18.




-------------

Originally Posted by Doug Lord

----------------------------------
What this proves is that a performance tri can be built and sold for $19,235(including spinnaker)
compared with the cost of the state of the art Wildcat F18-the latest creation of Martin Fischer and Hobie- at $22,499(not sure this includes all sails-see below). It probably isn't as fast as an F18 though it can be sailed singlehanded which makes its sailing weight substantially LESS than the F18.
For the performance,design and comfort enhancements I'd probably include in a final design the two would be close in price-with the tri more comfortable and faster.

-------------

-------------

[Chris Ostlind]

Doug,

The use of a boat that, by itself, is unsuitable for a proper comparison (the otherwise nicely targeted recreational oriented Magnum 18) is not a comparison at all. It's a fallacy.

If you really think that you have some magic elixir for this made-up issue, then do this: Go pay for a qualified designer to draw-up a boat that will do all that you think is necessary to get to the place you stipulate, take the drawings to a professional boat builder, or twenty, and get them to offer bids as to how much the designed boat will cost to build and fit-out properly as a completed craft. Add the cost of marketing, transporting, etc., along with the all-important profit margin needed to pay overhead and the ongoing costs associated with the get-ready phase for production. (e.g., tooling, storage of same, administrative costs to negotiate on going problems, etc) That is going to get you to something like an understanding as to how much a specific boat will actually cost to the consumer.

When you get that number, you let us all know by showing the complete paper trail that was used to get there, as well as the design of the craft, in detail, so that all of us can see just exactly how the solution was achieved.

Until you do that, you're whistling in the wind and nothing more. Since nobody has actually built this type of boat before, your numbers, even then, will be highly suspect until a boat is on the water and you can show that the business plan is viable through continued sales and the process of keeping the doors open.

Like I said, DOA. The rest of this is more hooka puffing. As a hooka exercise it's just dandy, but just as the cloud eventually clears from a late night smoke-out, so will this exercise and there'll be nothing to show for it.

[Cheesy]

Originally Posted by Doug Lord

This thread started out to try to see if there were any high performance 18' tris around that could beat an F18-either existing boats or designs whose numbers reflected the probable ability to do the job. To me, it is a very interesting design challenge that could produce and exciting, comfortable and very fast boat. With the numbers for the Magnum 18 tri and Wildcat F18 available to use as a benchmark it is clear that an 18' performance tri with small amas and lifting foils on the main hull(as per my suggestions) and either foils or a planing hull to provide dynamic lift on the ama could be in the ball park pricing range of a Wildcat F18. It is further clear that with careful design and engineering the boats would be comparable in weight as well.( Keep in mind that as beachcats go the F18 is on the heavy side). The technical aspects of the boat show a high probability that the tri would be faster than the F18, would be able to sail in the same pressure as an F18 with one or two crew, and would do this while allowing the tri's crew to sit on the side of a center cockpit very comfortably:
--the main hull on such a boat would be physically much smaller than the Magnum 18-with perhaps 20% less weight,
--the rig with 50 sq.ft.(277 all up-1' higher CE) more SA than an F 18 would insure the power required to be faster than an F18
-- using carbon tubes for the cross arms would assure the strength and light weight required for a 16' beam vs the Magnums 14'.
--Righting Moment: Max RM for the tri with two 175lb crew sitting on the side of a center cockpit would be 6700ft.lb. which means it could carry the 277 sq.ft. of sail(1' higher CE than an F18) in about the same pressure that an F18 can with two 175 pounders on trapezes (1.5lb./sq.ft. pressure). But while the F18 requires two 175lb crew to sail in this kind of pressure the tri would not. In fact, it could be sailed with a single crew in that pressure with the contribution from the mainfoil of 218.75lb. of downforce. The mainfoil, in concert with the rudder foil,(both on the main hull)act to control pitch and can be used to maintain the sailing angle of the boat with the main hull flying thru a significant variation in crew weight. The mainfoil would not be much larger than a Moth foil( 1.1=Moth; 1.4 sq.ft. tri). The F18 has 4 foils-the tri main hull four as well except that two of them are very small-about half an F18 foil. Learning from the F18 Capricorn(and other race boats) the tri would have a gybing daggerboard assuring excellent windward performance.
-- Ama- the key to the design is that the main hull flys almost all the time. At max RM the ama must support 750lb.(boat weight+ 350lb of crew weight,or approx. 175lb crew +175lb main foil download). The ama could be a single rotating hull that would allow a displacement hull or a stepped planing hull as the case may be. Very experimental.
OR: the ama could be a high L/B design incorporating and retractable (pivoting) foil with 3.36 sq.ft. of area in each ama. This would allow the ama foil to carry 70% of the boats weight(same % as an ORMA tri) using a proven foil system(DSS) that works somewhat differently than a "typical" curved foil: it develops no lateral resistance as a by-product so that 100% of its area is dedicated to vertical lift making it much more efficient than a curved foil. The least expensive of these two options may be the stepped planing hull but that still has to be proven. The DSS foil is proven....
====================
If you look at the Magnum as a rough guide only and keep in mind that we're just looking to be in the ballpark with pricing it is faily exciting-and accurate- to consider a tri such as this at + or minus, say $2000.
If you look at the technical aspects it is undeniable that the tri would beat the cat-and that's with one hand tied behind its back! The crew of the tri sits on the side of a center cockpit while to sail in the same pressure(1.5lb.sq.ft-max design pressure for the F18) the F18 requires two crew on trapezes.Not only that but the tri can be sailed in the same pressure that an F18 requires two 175lb people on trapezes-singlehanded! More comfort ,more speed-the tri could be a tremendous addition to "beach sailing" multihulls and the first of its kind(that I know of-even ostlind agrees with that!).
Yes it can!
=====================
F18
Specifications:
Length: 17' 11" / 5.46 m
Beam: 8' 6" / 2.59
Draft w/Rudder Up: 7.1" / 0.18
Mast Length: 29' 6" / 8.99
Sail Area:
227 sq.ft. upwind SA
454 ft2 / 42 m2 downwind SA
Weight (with spinnaker): 397 lbs / 180 kg
Price as of 6/21/10= $22,500 including everything except trailer
---------------------------------------------------
18 Tri
Specifications:
Length: 18' / 5.49m
Beam: 16' / 4.88m
Draft w/Rudder Up: 6.4"
Mast Length: 31.5' / 9.6m
Sail Area:
277 sq.ft. upwind SA
575 ft2 / 53.4 m2 downwind SA
Weight (with spinnaker): 400 lbs / 181.9 kg
Hull Construction: Fiberglass/Foam Sandwich and some carbon/foam sandwich
Price estimate-$22,500-24,500
(Note: Magnum 18=$19,235)

Im not exactly sure why the question is being put forward in the first place considering the proposed tri has almost twice the beam and same displacement as the F18? you would have to screw up pretty badly for it not to be faster

[Doug Lord]

Originally Posted by Cheesy

Im not exactly sure why the question is being put forward in the first place considering the proposed tri has almost twice the beam and same displacement as the F18? you would have to screw up pretty badly for it not to be faster

==================================
The question is "put forward" because the tri develops its F18 killer speed with the crew sitting comfortably near the center of the boat-no trapezes,no running back and forth. In addition the tri can be sailed in the same conditions as an F18 single handed or doublehanded...
More power, more speed, much more comfort, much easier to sail fast.....

[Munter]

I'm only interested if it has a powered sliding ballast system and bench seats. Without those the design doesn't realise it's full potential.

*Edited for clarity.

[Capn Mud]

Originally Posted by Doug Lord

..... 18' performance tri with small amas ....

Danger with small (short) amas is the tendency for the craft to go to pitchpole. The Weta (4.5m) has relatively largish long amas and it still pitch poles. In a boat that size that is OK as she rights pretty easily (I know from experience) but in an 18 footer? Not sure that would be alot of fun.

Still I guess beach cats will do that as well so it suits the comparison.

As for the rest of it - Chris' commercial comments are spot on. Doug, you keep saying things like "the performance improvements I would design" but mostly it seems to be just words and a heap of numbers. Show us some 3D renderings or one of your famous models so we can see what performance enhancements you mean. Do you have a background of the design of high performance tris that sail fast?

Cheers,
Andrew

[Gary Baigent]

Doug, going into production with a complex foiling trimaran sounds like a hell parade - Chris obviously knows heaps about the process and it sounds again like purgatory to me. And I like the idea of a minimalist tri taking on the F18 cats - but no thanks. Chris is right, to compete you're going to have to go to near all carbon ... and that's the end of the dream because of cost ... unless you can use very reasonably priced carbon tows like Rob Denney does constructing his proas and their masts in the Kelsall manner. An 18 foot version of Scissoring Sid would maybe be competitive but look at the structure: main hull, wide single airfoil beam, smart main beam bearing, floats and foils and cases, then attachments, then rig - it is just too much boat to build compared to what a simple thing a catamaran is.

[Capn Mud]

So you won't be buying shares in Doug Lord Beach Tris Inc then Gary?

[Doug Lord]

Originally Posted by Capn Mud

Danger with small (short) amas is the tendency for the craft to go to pitchpole. The Weta (4.5m) has relatively largish long amas and it still pitch poles. In a boat that size that is OK as she rights pretty easily (I know from experience) but in an 18 footer? Not sure that would be alot of fun.

Still I guess beach cats will do that as well so it suits the comparison.

As for the rest of it - Chris' commercial comments are spot on. Doug, you keep saying things like "the performance improvements I would design" but mostly it seems to be just words and a heap of numbers. Show us some 3D renderings or one of your famous models so we can see what performance enhancements you mean. Do you have a background of the design of high performance tris that sail fast?

Cheers,
Andrew

------------------------------------
Andrew, it might actually help to read this stuff-as it seems that you may not have. This proposed design uses lifting foils on the daggerboard and rudder of the main hull and would therefore have tremendous pitch resistance as compared to an F18 or a trimaran sailing only on the small ama(like a Magnum 18). And if it worked, might be able to use a ROH hull.....
"Just words" and a heap of numbers?! Well, yeah, you're right....... You should really make an effort to understand those words and numbers. In fact, without understanding them there is no way you can intelligently comment on Chris's commercial comments as they may or may not apply to this design or the viability of the design. So ,please do try.....
-I've designed and built two small tri's that were very fast-a 14 footer and a 20 footer-both with planing main hulls. I've designed and built as well as doing the tooling for two production RC tris and experimentally built and tested many more as well as numerous other state of the art RC models. Production boats based on my design have sold over 300 boats.