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  #16  
Old 03-08-2008, 01:30 PM
Chris Ostlind Chris Ostlind is offline
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OK guys...

A new group of photos has just shown-up with a link on the Watertribe discussion forum. Take this URL:
http://www.carbee.com/EvergladesChal...008/index.html

When the first part of the collection shows for you, click the forward arrow three times and shuttle through the pictures. There are two pretty good photos showing Smyth's tri on the beach prior to launch which are shot from the bow of the boat. They clearly show the shapes of the main hull and the amas. Another two pages further in and there are two shots of the tri as it pulled away from the beach, sails just setting and rudder not yet deployed.

The shots in question are the middle and right hand images on the top row.

The amas show themselves to have very narrow flattish bottoms at the forward sections of the hull form. I'm still of the impression that this flatness is more about the creation of volume and less about planing potential of the ama. There simply is not enough surface on which to plane.

Again, I'm not going to open that festering sore about the whole, planing trimarans, argument. If you want my opinions on the topic, it's more than available on this site through a search.

Smyth's ama and vaka hull forms are very much in keeping with a boat that is running in the classic, multihull slender vessel, style of design purpose. I'm guessing that the ama bottoms are 8-9" across and that the lengths of the amas are no more than 8-9 feet with seriously tapered ends for flow release.
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  #17  
Old 03-08-2008, 03:53 PM
Steve Clark's Avatar
Steve Clark Steve Clark is offline
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I talked to Randy about this project when we were at the A Class Worlds.
The main hull is a stretched Bimare XJ ( a cat) from Vectorworks. It looks like he just extended the stern.
I questioned why this was necessary and Randy said it was because the single A cat hull wouldn't displace enough. I then speculated that a straight A cat ought to be pretty ideal, but Randy felt it wouldn't paddle fast enough.
His ama's look like little more than training wheels and it's my guess that they add zilch to the sail carrying power of the boat.
I guess I can understand the paddling arguement but with the size rig on that little boat it is going to have to be very flat calm before you dig out the stupid stick. And again I am thinking that an A class with a rig optimized for quick drops and possibly some reefing potential would be very hard to beat in the single handed category.
I don't see how the pivoting ama/aka rack thing worls given the images, I also imagine all sorts of issues with rigging length, to say nothing of keeping the hulls in line!
SHC
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  #18  
Old 03-08-2008, 05:51 PM
Doug Lord
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Super Tri-a similar concept

Heres another "tri":
Attached Thumbnails
Tornado Team Takes Everglades Challenge-ltsc_20070610_0080.jpg  Tornado Team Takes Everglades Challenge-ltsc_20070610_0139.jpg  
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  #19  
Old 03-08-2008, 10:04 PM
Paul Scott Paul Scott is offline
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Are those thruster fins at the back of the amas?
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  #20  
Old 03-09-2008, 07:16 PM
Chris Ostlind Chris Ostlind is offline
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Fish Nor Fowl

Quote:
Originally Posted by Steve Clark View Post
... I then speculated that a straight A cat ought to be pretty ideal, but Randy felt it wouldn't paddle fast enough.
Nice contribution, Steve, but really... what does Randy know about paddling in the first place? Paddling seems like the least of Smyth's worries when it comes to fielding a boat of this type. If he really wanted to know what it would take to paddle a boat of a certain hull type for any distance, he could easily contact a really well qualified paddler/engineer such as Olympic medalist, Greg Barton and get it right from the start. Or practice with the example craft in calm conditions and estimate his performance potential.

It has always been the substantive problem of this race... how does one design a boat that needs to live in both worlds? Is it Fish or Fowl is the question and each boat has a very different set of hull parameters in order to perform anywhere near optimum. Anything else is a compromise and needs to be addressed as a compromise.

If the course goes windy, then the paddle-biased hulls will be smoked. If the course goes windless, then sailing craft will get their butts kicked and there is little they can do save for tough it out… or retire.

There is a very narrow design envelope, which addresses both potential issues, but it is not elegant in either full sail, or full paddle/pedal/row mode. It's a do-everything hull form and it does none of the pointed ends of the design bell curve as well as those so dedicated.

Ya' picks your poison, so to speak, and that's the nature of the beast.

Now, if the event were to reflect a real, efficient coastal cruising design mode; it would address the fact that a fast, sailing multihull would have a single, paddled craft stashed aboard. There would be a folding kayak, or inflatable, that would be used to go into the checkpoints when they are strategically awkward, like the first checkpoint in the race. The solo kayak then returns to the mother craft multihull, is stashed comfortably aboard and the race is on again as a sailing craft.

That's how I would do a serious coastal exploration and it reflects the methodology of many others. This business of having but one craft that has to do all these things well, is somewhat outside the design ideology of a really well designed coastal exploration effort. In that consideration, the EC is a forced reality that does not reflect the circumstances that one might experience in a real adventure trip.

Or one could take a heck of a lot longer to do the same trip, weather and conditions permitting. And that is not such a bad idea, considering.
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  #21  
Old 03-09-2008, 07:59 PM
edvb edvb is offline
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Here are the latest video's showing Randy's Tri and the Raptor.

http://www.carbee.com/Blog/?cat=8

I have been tweaking my Raptor for about three years and stage two is almost done. Instead of an 18' carbon mast I went to a 22' carbon mast. The sail is going to be a triradial design with a 21' 9" luff and a 8'4" foot. It will have an 15" squaretop and have 4 to 5 3/16" round fiberglass battens angled like the Hobie Bravo. The sailcloth will be a square Kevlar composite. It is 117.5 Sq Ft. versus 90 Sq Ft. on my old one. The Raptor in the video has 107 Sq Ft. But has a sail track and slab reefing. Mark also put stays on the mast. My Raptor will have Downhaul, Outhaul with Outhaul car on a 40" track and a traveler system where the traveler can be cleated at any position. I am also installing a new carbon boom the same size as the mast and it will flex very little.

By having the gear in the side car and being able to store the mast and boom next to the sidecar on those windless days, you will be able to paddle well without any drag from a rolled up sail on a mast. It takes less than a minute to plug in the boom and mast if there is any wind and get increased speed by paddle sailing.

Once you learn to use the foil correctly the boat is very stable in any wind and is pretty quick.

With the changes I am making on the boat I think it would be a real contender for this race. It is pretty bulletproof right now and just a blast to sail.

Any thoughts before the sail is made?

Before:

After:










Some Of Dave Higgins in the Watertribe Race a few years ago. He weights about 220 Lbs with about 75 Lbs of gear aboard.





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  #22  
Old 03-09-2008, 08:09 PM
Chris Ostlind Chris Ostlind is offline
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This just posted today as a letter from Smyth regarding his boat for the EC...
http://www.watertribe.com/Default.as...trNumReplies=4

Quote from Smyth:
I’m not trying to hide anything it’s just that I haven’t got any sailing photos yet. I do have one of it assembled on the lawn but that camera isn’t here…so you’ll just have to wonder…think carbon A class catamaran main hull that was 18 ft stretched to just over 20’ with a 20” bowsprit. It’s carbon and with rudder etc it weighs 57 lbs. Then think of (2) windsurfer booms as racks with trampolines to sit on protruding out each side attached to the main hull with a universal joint and waterstays. Overall beam is 18’. I built (2) amas of Styrofoam glassed about 6.5” wide x 10’ long x 18” high attached to the racks. The shrouds attach to the racks. There’s a daggerboard type rudder for shallow sailing, a daggerboard, a carbon A Class mast that was run over by a mountain bike cut down to 26’. All up I was shooting for 155 lbs. Actual sailing weight without adventure cruising gear is 168 lbs. I’ve got (3) sails: Main 130 sq. ft. mast 13 sq. ft., roller jib 54 sq ft and a roller Screacher at 140 sq. ft. Total Downwind 337 sq.ft. Upwind total: 185 sq. ft.

No mention of planing amas from the designer.
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  #23  
Old 03-09-2008, 08:37 PM
edvb edvb is offline
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Quote:
Originally Posted by Chris Ostlind View Post
This just posted today as a letter from Smyth regarding his boat for the EC...
http://www.watertribe.com/Default.as...trNumReplies=4

Quote from Smyth:
I’m not trying to hide anything it’s just that I haven’t got any sailing photos yet. I do have one of it assembled on the lawn but that camera isn’t here…so you’ll just have to wonder…think carbon A class catamaran main hull that was 18 ft stretched to just over 20’ with a 20” bowsprit. It’s carbon and with rudder etc it weighs 57 lbs. Then think of (2) windsurfer booms as racks with trampolines to sit on protruding out each side attached to the main hull with a universal joint and waterstays. Overall beam is 18’. I built (2) amas of Styrofoam glassed about 6.5” wide x 10’ long x 18” high attached to the racks. The shrouds attach to the racks. There’s a daggerboard type rudder for shallow sailing, a daggerboard, a carbon A Class mast that was run over by a mountain bike cut down to 26’. All up I was shooting for 155 lbs. Actual sailing weight without adventure cruising gear is 168 lbs. I’ve got (3) sails: Main 130 sq. ft. mast 13 sq. ft., roller jib 54 sq ft and a roller Screacher at 140 sq. ft. Total Downwind 337 sq.ft. Upwind total: 185 sq. ft.

No mention of planing amas from the designer.
Hi Chris

I posted that.
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