Amaryllis

[rayaldridge]

Yipster brings up an interesting point. I tend to not be a believer in flexible beam fastenings. In my perhaps unscientific view, any movement of the boat components tends to eat up energy that might be applied to driving the boat.

[Doug Lord]

The Gougeon brothers designed and built a tri(or two*) with flexible ama mounts-it was pretty fast. These days a lot of multies are using lifting foils-flexible attachment of an ama with a lifting foil is probably a bad idea in most cases.

http://www.jamestowndistributors.com...+-+West+System :

"The last commissioned boat the Brothers built was Adrenalin. Started in 1984 and launched in 1987, she was a trimaran with articulating amas built to Formula 40 rules for Bill Piper of Ossineke, Michigan and intended to race in the European circuit. She shocked the sailboat racing community by placing a very close second in her first regatta on the Grand Prix circuit in 1988.

She raced for two seasons in Europe against the traditional big cats until, as Jan put it, "They couldn't stand being consistently beaten and changed the rule so the boat became illegal and only cats could race." Adrenalin was purchased by New Zealander Grant Beck in 2007 and is awaiting his attention to get back on the water."

* Prior to Adrenaline Meade Gougeon built at least four small tri's-one, "Victor T" (a C Class tri) won the North American Multihull Championship in 1969. You can see the articulating ama if you look closely at the Victor T picture and compare the pitch attitude of the two amas......

[brian eiland]

Originally Posted by Doug Lord

The Gougeon brothers designed and built a tri(or two) with flexible ama mounts-it was pretty fast. These days a lot of multies are using lifting foils-flexible attachment of an ama with a lifting foil is probably a bad idea in most cases.

Had a senior moment there and couldn't remember the name of that flexible tri that was being built for the original Forumla 40 races.

Just found it being rebuilt over in NZ:

http://forum.woodenboat.com/showthre...aran-Adrenalin

[brian eiland]

Originally Posted by Doug Lord

From SA.( Apparently "borrowed" from Brian Eilands excellent site: http://www.runningtideyachts.com/mul...Amaryllis.html ) Great reading-take the time!---(some results have been omitted because the text is the interesting part):...

So you found that old original article
I had originally posted link to that article on my website, but then on second thoughts figured it was too long a version for people to read, ...so I modified the link to the shorter version/description.

Thanks for posting it anew Doug.

[Doug Lord]

Originally Posted by brian eiland

Had a senior moment there and couldn't remember the name of that flexible tri that was being built for the original Forumla 40 races.

Just found it being rebuilt over in NZ:

http://forum.woodenboat.com/showthre...aran-Adrenalin

-------------------
Hi, Brian- the link here doesn't seem to work-will you doublecheck it, please.

UPDATE-Thanks Brian!

[catsketcher]

I never get the idea of active flex unless you are up against the limits of the material and need to limit shock loads.

Although pushing a bow through a wave rather than over it may seem to need more energy it may not. Energy will still be needed to move the bows up and down - to overcome the hulls rotational inertia in that plane. I think that history tells us (beach cats, racing boats etc) that stiffer boats are faster.

I don't even like Wharram's beam bolt idea. It actually concentrates load onto specific bolts. If an engineer looked at the thing they would probably find more highly stressed parts because of the localised loading rather than Wharram's aim of reduced loading. Much the same would have happened with Amaryllis I suspect.

There are also second order effects of a flexible platform. Basically the rig is held up by the platform - if the platform wobbles then so to does the rig. I don't like wobbly rigs. This used to happen on my Twiggy when the under wires were too loose. A wave would hit the float, the float would shake, the windward stay would vibrate, the mast would shake, the whole boat would flex which would start the whole thing over again. One good wave could vibrate the darn thing for 15 seconds. When I tightened the underwires (waterstays) properly the rig didn't shake and the vibrations settled down much quicker. Made me feel so much happier.

cheers

Phil

[CT 249]

Originally Posted by Gary Baigent

I'm not going to answer your rose tinted, Pollyanna viewpoint CT249 - except to say that if you check out Howard Chapelle's History of American Sailing Ships, you'll see a section on the sandbaggers and line drawings of Susie S, Pluck and Luck, Comet and others; yes, their origins were work boats ... but these highly specialized versions were not work boats but flat out racers, and expensive ones at that, carrying clouds of sail no workboat would ever set. The sandbaggers were not originals like the NZ mullet boat, which truly retain their working boat shape and figures; skimming dish sandbaggers were extreme developments. Supposedly you could say Herreshoff's Amaryllis was also derived from "work boats" ... the Polynesian double hull canoe ... but it is a specious comment not dealing with reality.

1- I've checked out Chapelle, of course. That "rose tinted Polyanna viewpoint" is an objective view of the available facts - such as the facts that catamarans were not banned, and were sailed by influential sailors.

2- Your claim that the Sandbaggers were not used as workboats contradicts the research of people such as Ben Fuller as I recall his article in Wooden Boat. Ben was the curator of the Mystic Seaport museum, which has a vast historical database and an original Sandbagger. Ben's writings helped to spawn Sandbagger recreations and he basically had the perfect database at work; I'll go with him, thanks.

We also know that Sandbaggers DID work after their racing careers - for example Shadow and Walter F Davids worked into the 20th century. So there is nothing specious about the workboat comment - it is reality.

3) If the excessive anger you claim we had against multis and IOR lightweights was real, then surely it shows that such anger is negative and therefore something we should not encourage, particularly when historical documents are now so easily available that we can re-examine the myths of the past.

[Gary Baigent]

Only one reply to you CT249, yes, sandbaggers were originally work boats, never denied that, but Susie S, Comet and the others were race boats, and expensive ones at that.

[yipster]

Originally Posted by catsketcher

why add flex?

havent given this real deep thoughts and dont have what i read up front, you have good points tho; enough flexing going allready
than again; flexing hulls may give a smoother ride, possibly take rig flex down, reduce wave drag and what else..