Catamaran vs Trimaran

Cat vs Tri

Sorry Anders, but in case you hadn't noticed foils are intrinsic parts of the design of many
modern high performance cats and tris.
Anders, the use of foils on cats and tri's, as I mentioned in my last post, allows for very different hull shapes, increased pitch stability and represents state of the art today. You don't think it should be discussed?
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edit--Ander's I've participated in this thread since it started in 2005 with a guy asking about the advantages of an equal sized high performance cat vs a high performance tri-it was not about cruising multihulls! You simply can't look at a high performance multihull today without, at least, considering the application of hydrofoils in one form or another with the ORMA tri's being the best example.
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Post #1 in this thread
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The More Things Change...

Hey Anders,

This is the same disease that you will see on many other, Doug Lord postings around this forum... that being that foils designed to lift a boat above the water are the Messianic solution to all that is wrong with the boating industry, especially the racing part of the boating world.

It's perfectly appropriate that the initial posting to this thread (way back in July of 2005) suggested the paradigm that is being followed by the Volvo 40 catamarans. Maciek188 asked about the comparison of trimarans and catamarans of the type and extended his query to include racing boats of the type that are built for speed and not comfort. He specifically did not ask about lifting foil equipped boats of the type so incessantly mentioned by Mr. Lord.

Here's his original query from July 2005:

Like almost all boats that go fast for a living, they do have foils in the form of rudders and daggerboards. This is not the type of foils which Mr. Lord wishes to lecture you about, however. He's into the lifting variety that push the entire boat out of the water where it becomes a flying object, much more than it behaves as a traditional boat that you may have come to know and enjoy.

This flying foil thing is Mr. Lord's particular disease.

Let it be known that boats do not need to fly above the water to be considered appropriate for the genre. Mr. Lord has it in his head, in a most peculiar way, that this methodology is necessary to feed the need to always be at the state-of-the-art position on design issues. First of all, this is not state of the art, as it has been going on for a very long time as an adjunct science at the extreme periphery of traditional boating. By far and away, the rest of the boating community does not share his position and you should not feel the need to get the newest and most complex stuff in order to feel as a part of the game.

In short, your instincts are correct, as were the original thread position statements about cats and tris of the Volvo 40 type.

If the conversation were to be confined to that idiom, then eventually, even Mr. Lord will have to sit down with his relentless, self-serving and... some would even say, overly processed, attitude about lifting foils and flying boats.

Every year, there are literally, hundreds of new boats introduced that advance the craft without the use of foils to lift the hull from the water's surface. Comparatively, there are perhaps two or three new boats each year of the foiling variety. The foilers suffer from overly complex mechanisms to get them to fly and nonsensical power to weight ratios that severely limit their usefulness. Their susceptibility to "stuff in the water" being wrapped around the lifting surface, which can instantly ruin the lifting function of the foils, if not damage them beyond repair and functionality, is on the record. Ask Mr. Lord about the French boat, L'Hydroptere, in which it went out for a speed run and had a foil literally slammed right off the end of the ama while at speed due to a foreign object in the water which destroyed the foil. Ask him how fast the boat was after it returned to a waterborne state. Yes, State-Of-The-Art is a really cool place to be. I wonder if it would be so cool if it were your wife, girlfriend or family on the boat when the lifting foil were slammed into oblivion?

You'll be amazed at the answers as given by Mr. Lord as to the frail qualities of foiling boats in general.

Ask Mr. Lord how many commercial, foil-borne craft are still in operation worldwide compared to the numbers once introduced. Ask him about the business of substituting high technology for grounded and measured advancements in the "State-Of-The-Art", as are taking place all over the planet as we speak.

You see, Anders, this is a guy who wants to take the short cuts in life. He doesn't like hard work, sacrifice and painstaking, incremental discovery. He just assumes the feeling that he has the right to jump to the front of the line without doing any of the work associated with the transition. Now to be perfectly fair about all this… I don’t like the hard work either, but I long ago realized that it’s the soundest methodology for a well-developed product. Short-cuts only lead to dead-ends from my experience.

Make your own conclusions as to whether the style of Mr. Lord's behavior in these matters is appropriate.

 

ABSOLUTELY FALSE / foil assist only

Mr. Anders, in the previous post Mr. Ostlund 100% mischaracterized my postings particularly the one you responded to earlier. I did not suggest the use of full flying foil systems; in fact I added an edit to make that abundantly clear when I first wrote the post.( #44)
The foil application that is most widespread and that will probably have the most profound effect on high performance multihulls is FOIL ASISST not full flying hydrofoil systems.
It is particularly applicable in the area of pitch stability as I earlier pointed out.
Foil Assist has an important and growing place in high performance multies-not discussing it won't make it go away. If you were to look at the idea seriously you might find not only performance enchancement but safety improvement as well- in reducing pitch pole.
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POST # 44

 

The Lizard King Speaks

What did I tell ya, guys? Not 35 minutes goes by and Mr. Lord is busy issuing non-denial, denials.

And he says he never reads, nor answers my postings...

Very funny stuff, and oh so transparent in its desperation to be regarded as substantial.

 

Sorry all. I have woken the bear.

Doug Lord:
I don't think you can look at longitdinal stability(pitch resistance) or roll stability on high performance multi's these days without considering the effect of the use of foils whether it's rudder t-foils to aid pitch stability or a combination of rudder and lifting foils to not only aid pitch stability but reduce wetted surface at high speed.
Orma 60's have proved the viability of lifting foils on the ama's as well -on
...
I think the careful application of foils in high performance multihull design can allow shapes that would not be possible w/o foils and lead to better handling, higher speed and greater safety.

I find the original question on tri and cat performace very interesting without arguments about how nice it will be when evering is lifted (oops, assisted) by foils.
How does foils used on TODAYS COMMON racing boats affect the roll and pitch stability and how does that affect the choice between a high performance tri and cat Doug Lord?

Anders M

 

cat vs tri

Anders,I don't believe foils used as "foil assist" appreciably affect roll stabilty* but they certainly affect pitch stability. I think that because the application of "foil assist" is relatively simple on most catamarans that the choice particulary in small "common" boats would be to lean toward a cat whose performance could be markedly improved relatively inexpensively using-at least-rudder t-foils. In one off designs of any size or in larger multihulls designed from scratch I think the tri would have the edge if "foil assist" was designed in from the begining.
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About the Stealth Marine F16
" The t-foil rudders enable more sailing power with the same amount of square meters of sail".
Cathouse Import en verkoop van Stealth Marine Catamarans
Address:http://www.cat-house.nl/Engels/f16.htm Changed:6:55 AM on Saturday, July 30, 2005

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From the F14 forum "..and with every "pitch" that the non-t-foiled cat made the t-foiled one stepped just slightly ahead. "
". The t-foiled F14 gave the F18 a head start and caught up by the bottom mark every time"
Catsailor.com: "T" foils on F14
Address:http://www.catsailor.com/forums/showflat.php?Cat=0&Board=forum14&Number=77606&page=0&fpart=all
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*Production proa where foil assist is used specifically for roll stability:
http://www.hydrovisions.com
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More on T-foils on "common" high performance cats and pictures:
Catsailor.com: T foils
Address:http://www.catsailor.com/forums/showflat.php?Cat=0&Board=Fleet45&Number=84517&page=0&fpart=2[/url

 

Foils for roll stability

Interesting discussion.

I believe that foils for lifting multihulls (or even monohulls like the Moth) completely out of the water are a terrific idea but one with very limited market appeal. This is because they usually require complex control systems, they often require a lot of skill to use, they add a great deal of expense to the boats that use them, and the boats that use them have limited appeal when they are not foil borne. A great example is the Hobie trifoiler. Terrific performance on the foils, but how many have sold?

A few years ago, Rod Johnstone of J-Boats did some market research and determined there was a need for a high performance, car toppable sailboat that was easy to learn to sail (unlike the windsurfer). He approach foil specialist, John Slattebo, with the design brief. John's answer was a foil stabilized outrigger. The design was introduced recently as the Raptor 16. (www.hydrovisions.com) What is unique about the design is that it is very simple AND the boat can be paddled easily without the foil, can be sailed without the foil in light winds, and can be sailed without the foil in higher winds with ballast in the "sidecar." There is a single moving part patented foil system that counteracts roll and that retracts and stows away with a tug on a lanyard.

The Raptor was just listed in Sail Magazine as one of the year's best new boats, and it is a candidate for the 2007 Sailing World Boat of the Year.

Foils can do a lot of things, not just convert a conventional sailing vessel into a flying machine.

Dave

 

Hi all, I'm back.

After two attempts to get Mr Lord banned from this forum but to no avail, I finally decided that it was stupid in the extreme for me to quit just because he happens to exist, and he haunts this forum a bit like "Jack the Ripper", but without the carving knife.
I will just refuse to engage with him from now on. I love the pure design and technical aspects that 95% of guys on this forum want to discuss, and I want to be part of it, and I also believe that I have something useful to offer.
As far as the cat vs. tri argument, there is no better multihull. Both have so many fine attributes albiet a little different from each other that both forms have enormous validity and probably on balance greater application than monohulls, in sailing craft.
Any discussions about which type of multi is better, ultimately has no real answer. It depends on the exact purpose of the boat, many other practical matters such as berthing, accomodations, budget, and most of all individual passion of a prospective owner for one or the other.
Personally I prefer the aesthetics of the tri, but would never claim it to better than a cat.
Hey, it feels good to be back.

 

A Sane and Rational person....

Thankyou frosh,

for saying what some of us might be too
timid to say..............!

Also, you MUST be an most intelligent and capable fellow
- as you share my view on many things.

Like the back and forth on Cats and Trimarans.
It all depends on what the end use is............
As it is with all vessels.

Cheers !

 

Hi CORMERAN, Thanks for your kind and generous comments. Your last posting makes me feel that I made the right decision to come back. All power to you and Chris, and the many other sane and considerate members of this forum!

 

I think you can cite advantages for both. The trouble is that if you say, for example, that a cat is better for cruising, some tri fanatic will be offended, and if you say tris are faster over the usual range of wind speeds, then some cat fanatic will be offended.

 

Waverider 17 Tri

I recently purchased a Windrider 17 Tri based on the priority list below. Previously I owned a Hobie 16, which was great fun but was rather unstable and very wet - now with a family I need something dryer and safer and more suitable for day adventuring around our harbour & coast:


Desire.......WR 17......Hobie 16.....Best
Multihull.....yes..........yes...........Multihulls are best for speed
<$10k US...yes...........yes..........Hobie 2nd hand cheaper
Low draft...yes..........yes...........Both ideal for my tidal harbour
Fast..........yes..........yes...........Hobie is faster
Trailable.....yes..........yes...........Both trailer OK
Dry............yes..........no...........Windrider windward hull out of water
Friends.......yes..........no...........Windrider takes 4 children & 3 adults
Motor.........yes..........no............Windrider has 50cc 2hp outboard
Easy tack....yes..........no............Windrider never gets caught in irons
Dry storage...yes.........no..........Windrider has dry hatches to store all gear
Safe.............yes.........no..........Windrider _very_ hard to capsize
Relaxing........yes.........no..........WR has central skippers seat, no jumping from side to side required
Main adjust...yes.........no...........Windrider has easy halyard to reef or drop main
(My Hobie halyard latched at mast top so return to shore was required)

see www.windrider.com for info on this fun boat

 

Windrider

Thanks! I've been interested in hearing a first hand account of this boat and your comparison is excellent and informative. How about the workmanship on the Windrider-did/does everything fit and work well? Have you tried the bimini?

 

The original question was 'for racing' and the jury is in.
Off the beach it is cats. For bigger stuff it is tris. F40 proved it.
The big RTW boats are cats cos you can get a bigger boat for your money and a bigger cat beats a smaller tri but a same size tri beats a same size cat.
Theorise why all you like, the proof is in the (race) results