Small plywood trimaran

[pippo]

I read nice things about the "Virusplus" (what a name) 16' sailing trimaran built by a French company:

http://www.virusboats.com/virus.php?langue=ang

Do you know of a similar (both in size and concept) design in plywood for home building?

[ 09-01-2004, 04:58 AM: Message edited by: pippo ]

[Hwyl]

Dick Newick has a number of small trimarans--one of which uses the same three hulls (wave piercers). This is Dick's Web page http://www.wingo.com/newick/ mostly stuff about his bigger boats.

He also has the Tremolino http://www.geocities.com/tremsetters/ She's 23' but can be built using old Hobie cat parts for everything except the Vacka (main hull). Jim Conlin is building a Newick tri at the moment, I'm sure he'll jump in.

[Dave Carnell]

Check out Thomas Firth Jones at <jomesboats.com>. His "Multihull Voyaging" is a basic treatise on designing, building, and cruising multihulls. Tom studied with James Wharram in UK.

[paladin]

Aurthur Piver plans are still around for the AA-17, Ed Horstman has an 18 footer, Jim Brown (sold by John Marples has a 25 footer and I think they now have a smaller design. The Piver is flat sheet plywood, no centerboard, "V" ama's, multichine Vacka....
Brown designs are multichine ply with warped sheets, very easy construction in a near "round hull" shape...
Horstman designs are cold molded plywood.......
Not familiar with Chris White designs....
Whatever you choose...you need a centerboard...

[brian.cunningham]

A CLC kayak with thier SailRig option (http://www.clcboats.com/boats/sailrig.php/cart_id=eb58d7d8a7661d196476caa61c05aa3d/), will work. You can't carry as much, or go as fast, but you can cartop it, you can go in shallow water, and you can get it as a kit.

http://www.clcboats.com/images/boats/sailrig3.jpg

[Corso]

Forse gli hai gia' dato un'occhiata: Gabriele d'Alì "MULTISCAFI - Autocostruzione", c'e' abbastanza materiale per costruirti un tri in compensato in poco tempo. Puoi cercare in internet i suoi lavori (persona pratica e creativa) e, credo, recapito (o chiedi a qualcuno del sito de "Il Cantierino).

[ 09-01-2004, 03:22 PM: Message edited by: Corso ]

[pippo]

Here's a better translation (hopefully) by yours truly:

---
You've probably already looked at this : "Multiscafi - Autocostruzione" by Gabriele D'Alì; there's enough material to allow you to build a plywood tri in a little time. You might look for his designs over the internet ([he is] a creative and practical guy) as well as, I believe, his address (or ask somebody in the "Cantierino" web site).
---


Originally posted by Corso:
[b]Forse gli hai gia' dato un'occhiata: Gabriele d'Alì "MULTISCAFI - Autocostruzione", c'e' abbastanza materiale per costruirti un tri in compensato in poco tempo. Puoi cercare in internet i suoi lavori (persona pratica e creativa) e, credo, recapito (o chiedi a qualcuno del sito de "Il Cantierino).

[ 09-02-2004, 06:58 AM: Message edited by: pippo ]

[pippo]

That's a very nice boat but is a bit too large for my needs...


Originally posted by Billy Bones:
Here's the one I was referring to...

http://www.chriswhitedesigns.com/discovery20/photos/4.jpg

...From This Page. (http://www.chriswhitedesigns.com/discovery20/index.php)

[Corso]

Sorry guys, i was in a real hurry and i figured that since the book is just in italian it would have been useful only for someone that already knew the language anyways, and that "Gabriele d'Alì" was the name to search on the net its clear enough.
Came back to delete and rewrite it in English but im late. (Apologies)
Pippo: you can scale up and down multihulls with more freedom than monohulls.
Check this: Windrider (http://www.windride.com/)
http://www.corsairtri.com/images/Windrider17.jpg
cant help posting this one too
http://www.hydrosails.com/images/home/afbeeldingen/windriderpaginag.jpg

[ 09-02-2004, 04:06 PM: Message edited by: Corso ]

[brian.cunningham]

Originally posted by pippo:
That's a very nice boat but is a bit too large for my needs...
How about a catamaran?
Warram hitia14 (http://www.wharram.com/ctrek_photos/hitia14.shtml)
http://www.wharram.com/images/hitia14_01.jpg
http://www.wharram.com/images/launch4_sm.jpg

[ 09-02-2004, 07:00 PM: Message edited by: brian.cunningham ]

[Todd Bradshaw]

This one looks interesting:
http://www.duckworksmagazine.com/s/designs/ostlind/a18-t/index.htm

[pippo]

Brian, I'm also considering the Hitia 17 but I have the impression that a trimaran would be more comfortable than an equivalent catamaran, due to the central hull that would work as a big footwell. I have a small (3.8 meter) plastic beach cat and the sitting position is really uncomfortable after one hour of sailing...

I'm puzzled by the fact that both the French boat and this other design

http://www.triumphsailing.com/index.html

start from a dory shaped central hull.

Why is the dory shape considered so appropriate for a trimaran central hull?


Originally posted by brian.cunningham:
How about a catamaran?

[Jack C]

Hey, pippo, whatever happened to the CK17?

Jack

[ 09-03-2004, 08:27 AM: Message edited by: Jack C ]

[pippo]

Hiya Jack!
The CK17 is fully stitched, upside down in my garage, waiting for chine taping. In the meantime, I'm having a ball for multihulls (my little plastic one with a windsurf rig - see www.dbcat.ch (http://www.dbcat.ch) - has been a lot of fun this summer) and discovered those dory derived trimaran designs around. SO, one might think to build a similar one in plywood - I know, I'm never happy :rolleyes:


Originally posted by Jack C:
Hey, pippo, whatever happened to the CK17?

[garland reese]

SeaClipper series from John Marples, at Duck Flat Wooden Boats website.....

http://www.duckflatwoodenboats.com/designers/marples/3mtri3.jpg

[brian.cunningham]

Originally posted by pippo:
Brian, I'm also considering the Hitia 17 but I have the impression that a trimaran would be more comfortable than an equivalent catamaran, due to the central hull that would work as a big footwell. I have a small (3.8 meter) plastic beach cat and the sitting position is really uncomfortable after one hour of sailing...
Here's one way around it.
http://www.hobiecat.com/sailing/images/17sport/photo_1.jpg



I'm puzzled by the fact that both the French boat and this other design

http://www.triumphsailing.com/index.html

start from a dory shaped central hull.

Why is the dory shape considered so appropriate for a trimaran central hull?
It's not, a round bottomed hull it much better. The dory shaped hulls just get you into the water faster, though on a cat they do have merit.

[Keith Wilson]

Well, a couple of days ago I got to sail one of the rotomolded polyethylene Windrider 17 trimarans, the one with the two cockpits above. I don't know how hard it was really blowing, but the forecast was for 25-30 with gusts to 40 (mph, not knots), and it looked about like that.

All I can say is HOLY $#!&! :eek: :eek: :eek:

It was about three times as fast as I've ever gone under sail, and with nothing like the skill or acrobatics needed with most fast sailboats. Maybe this isn't unusual for multihull people, but most of my sailing has been in sort of traditional boats, and it sure was a different experience. On a beam reach, we passed a fairly large pontoon boat with a 60 hp motor.

[Corso]

Keith: i wonder how would do a wooden replica of the windrider

[bainbridgeisland]

Originally posted by Corso:
Keith: i wonder how would do a wooden replica of the windriderChek out the work of Kurt Hughes. You will find windrider-like boats in timber. http://www.multihulldesigns.com/stock/daysailer.html

[pippo]

What about this?

http://www.edhorstmanmultihulldesigns.com/specs/TRI-18_3view.pdf

[pippo]

I take this thread back to life to draw your attention over a new plywood trimaran design which has very recently been put on the market by BCA-DEMCO, a reputable italian company.
Unfortunately the text is in Italian, but there are several drawings. Looks like a very interesting beach cruiser!

http://www.bcademco.it/pdf/piani/TRICKY_FIVE.pdf

I'd like to hear opinions on the boat!

[brian.cunningham]

Nice, I especially like the rig.

[Todd Bradshaw]

I don't. I think they're going to have a hell of a hard time controlling the gaff since their mast is so short and the halyard attachment point on the gaff has so little leverage. I wonder if they've actually built one yet and tried it. No photos leads me to believe that they haven't. It's easy to make things look good on paper. Whether it will work out on the water without being modified is another question. The boat itself looks pretty nice and the Marconi rig looks decent, but I think the gaff version needs some work.

[merlinron]

todd, wouldn't the short couple of the halyard to mast length and being so highly peaked( another almost gunter rig) make for a decent resistance to twist off?....giving it more of a bermuda rig type control. maybe lots of stress, but with alum and or carbon, just haul it up tight and sail.maybe with a vang to to help resist twist, also?

[brian.cunningham]

Looked more like a gunter rig to me, bad rendering angles.

Pippo, I think your best bet is to just pick one of the designs that's been out there, get it in the water and see how you like it. Small tri's like these aren't really a large commitment.

[Todd Bradshaw]

I don't know whether they intended it to be a high-peaked gaff or a low-peaked folding gunter (the line between the two types gets pretty blurry) but that upper spar is over 11' long and the lower end of it has to bear against the mast while the halyard does the "peaking-up". They simply don't have enough overlap with the mast for the system to work well. I suppose it's easy enough to add a couple feet to the mast to get better leverage on the spar, but if they actually had any gaff/gunter experience, they would likely be aware of this problem before publishing the design.

The "short coupling" does nothing for the system other than put tremendous strain on the halyard (gunter) or peak halyard (gaff) and all blocks and fittings involved with it. It can also make getting the sail up and properly peaked a real pain because the sailor has so little leverage working for him.

When designing a multihull rig, one must always keep the "flagpole principle" in mind. A flagpole will stand up to a certain amount of wind pressure, but it can't bend much or lean way over and come back up, so if you exceed the wind pressure you allowed for in it's design, it simply breaks. These boats can't just heel over to relieve stress on the rig the way monohulls do. As a result, everything needs to be more heavy-duty than it would be on a similarly-sized monohull and the fittings can at times be under a lot of strain. This is one reason that hardware costs on small multis often tend to be surprisingly steep. The wires, blocks, eyes, turnbuckles and other "bits" making up the rig on your 20' daysailing multihull may be just as big as those normally used on a 30' monohull. Designing such an important part of the rig in a way that puts it under that much strain before the wind pressure even becomes part of the equation just doesn't make sense.

This could very well be a really nice little boat. It's not all that different from the Farrier trimaran that we used to own, which was fun, roomy and quite seaworthy. But if they're going to offer a traditional rig option on it, I think they have some homework to do first. Performance-wise, the Marconi version will most likely blow the doors of the gaffer anyway, thanks to improved twist control and a fully-battened roach, though it would make more sense to build it with at least twice as many battens as the three indicated on the Marconi version's sailplan.

[JimConlin]

Another worth looking at is MultiMarine (http://multimarine.com/L-7/L-7.html)'s L7.

http://multimarine.com/L-7/images/photos/op/L-7_63_op.jpg

It's mostly plywood. The main hull's bottom is a molded glass part.

Gawd! There are some ugly multihulls. The few pretty ones take a lot longer to build.

[Steve Paskey]

... Jim Brown (sold by John Marples has a 25 footer and I think they now have a smaller design.

Don't know any details at all, but Marples' web sites indicates that he sells plans for a tri known as the "Seaclipper 16" ... presumably she's 16 feet long.

http://www.searunner.com/order.html

[TR]

Here is a small plywood tri http://www.tridarkaraider.com (http://www.tridarkaraider.com/)

Design is by Steve Isaac and Matt Layden. There's a good blog with many pictures of building the boat.

Tad

[paladin]

One of the very first "Dory" designed Tris was a boat designed back in the Piver days called "Sally Lightfoot".....I have a photo somewhere of her sitting in Pattaya Thailand right on the beach, she was about 24 feet on deck of the main hull as I remember....the dude sold her on arrival and flew home.....:D ...as I recall she was designed and built by Walt Glaser.....

[merlinron]

todd, good explination and thank-you! i have to agree with you about the loads the short couple places on the rig, i figured common sence would prevail there in sizing the hardware.... maybe not with some, though.... it certainly doesn't make sence to rig with very little safety margin.... never gave the multi-hull not dumping aspect a thought!, but definately true.....

[pippo]

The late Norman Cross designed many nice trimarans, including the beautiful Cross 18:

http://www.crossmultihulls.com/DSCN0516.jpg

Link to a site devoted to his designs:

http://mysite.verizon.net/res78939/index.html

[pippo]

Press stop: I forwarded Todd's comments to the designer (thanks Todd), who replied that he agrees that the gaff rig needs some rework, even in view of the reef lines which were not foreseen in the beginning. So, he's sending me the plans for the bermudan version, and in a week or so he'll send the revised gaff version.

[Tom Robb]

In the picture of the Cross 18 the arms (real name?) look skimpy compared to what one sees in other tri's. Particularly in as much as they fold and so have a weak link. Why? Do they work out in practice?

[pippo]

I guess they do: I've got sailing reports by the guy who runs that web site, who built two Cross 18 tri's, and he's enthusiastic about the boat. BTW, the cross beams are called aka(s).

[Tom Robb]

Aka(s) Thanks Pippo.
The beams (not akas) on my backyard deck look considerably more stout than that and they aren't going to sea.

[brian.cunningham]

My guess is that there's a supporting strut underneath that you cannot see. But the span between the vaka (central hull ) and the ama(float) isn't that great, and it also doesn't look like the amas don't have enough displacement to float the entire boat. So it would go under before having to lift it.

FYI from:http://en.wikipedia.org/wiki/Trimaran

A trimaran is a multihull boat consisting of a main hull (vaka) and two smaller outrigger hulls (amas), attached to the main hull with lateral struts (akas). The design and names for the trimaran components are derived from the original proa constructed by native Pacific Islanders.

BTW the massive akas ( crossbeams ) you see on most tris are hollow. This has to due with beam theory, and I beam vs a 2x4 is one example.

[Hwyl]

My guess is that there's a supporting strut underneath that you cannot see. But the span between the vaka (central hull ) and the ama(float) isn't that great, and it also doesn't look like the amas don't have enough displacement to float the entire boat. So it would go under before having to lift it.

FYI from:http://en.wikipedia.org/wiki/Trimaran


BTW the massive akas ( crossbeams ) you see on most tris are hollow. This has to due with beam theory, and I beam vs a 2x4 is one example.

Dick Newick told me he got fed up of calling the ama's "floats", so one day he called the museum in Hawaii. They gave him the correct terminology and he introduced it to the rest of the world. I'm not sure it was a good thing.

[wtarzia]

Yes, very fast. I've seen one in New Haven harbor. He came back with broken things needing welding (fast+appendages = great moment forces when you graze even soft stuff at speed, so watch the tide tables. A marvelous boat, though it took a long time to assemble on trailer.

[wtarzia]

Yes, very fast. I've seen one in New Haven harbor. He came back with broken things needing welding (fast+appendages = great moment forces when you graze even soft stuff at speed, so watch the tide tables. A marvelous boat, though it took a long time to assemble on trailer.


--- Sorry, meant to add "The Windrider"...