Trimarans of the Everglades Challenge 2013

If it's not for preventing leeway then I think the design approach is flawed. Either you make a slim hull and put a pod on it in which case the pod is shorter then the hull and well above waterline, or you make a "lightbulb" stepped hull in which case the stern has enough underwater buoyancy to keep the step above water when heeled. what I see here is a very large pod put on a to small hull.
If I would want a small cockpitless "coffin-type" tri I would try to design something like a completly closed tremolino. That would give enough interior volume without getting me into trouble with stern buoyancy.

 

DancesWithMullets at EC2013 finish line.

Note top of centerboard--





From the Watertribe Forums
http://watertribe.org/forums/topic/class-change

 

Thanks a lot. Great, top of the centerboard is to be seen. It is the fourth EC of DWM ( Skipper: DancesWithMullet, basically with a Bluejay 14, Trimaran Finger Mullet is new). Thank you Imaginary!!!!!!

http://www.youtube.com/watch?v=J-9D6UOx58Y&list=PLx8FwrZD5MVDBkE2YNAkdPSwtQbtaZm6T

 

Finger Mullet

This is Danceswithmullet and I will try to answer a few questions. The center hull is built out of 3lb XPS. XPS gets a lot of hate on the boatbuilding forums but I think most of that is from using the wrong density for the application. Hundreds of surfboards are built everyday using xps and surboards have a hard life. I used a grid pattern of holes to link the outer skin with the inner with epoxy and this made for an extremely stiff hull and deck. The foam is 1" thick and glued together with Gorilla glue. Gorilla glue does not make a hard spot, sands easily and can still be cut with a hotwire. Instead of stitching with wire, applying glue then "stitching" with drywall screws is quick and easy, just back them out when the glue is cured. There were no frames or strongbacks used, just a pattern made of cheap ply and traced to the foam. The inside was glassed then the bulkheads were added and tabbed in.
I had made several test panels and destroyed them to figure out a laminating schedule. 3 layers 6 ounce on deck and bottom and two on inside of hull and of course extra around high stress area. No stress cracks anywhere at end of the Challenge, the advantage of no paint was that I could see everything. The amas were 1.5 lb foam with a 1/4" ply stringer and two layers of six ounce overlapping on the top and bottom. I was still finishing the boat on the start line so I don't have a weight total and the rig is from a JY. I
had a choice of two rigs before the start and went with the smaller to be safe. I will eventually switch to the larger rig and a different stay system. I will try to post a build thread on Duckworks and read surfersteves website if you are thinking of building with foam. I got my foam from a company that makes Faux stonework for buildings and luckily were interested in the project and let me interrupt their busy schedule for what was really small volumes of foam to them. The good foam is not cheap, so I don't know if there is any savings over ply. But it was available in whatever dimension I wanted and good okume ply could only be ordered 30 sheets at a time locally. I hope this answers a few questions. I did keep a running list of costs the boat as it sits is close to the 4k mark. This was a big experiment and a steep learning curve, but the lessons learned will be used for future improvements and increased my understanding of trimarans. Money well spent. Danceswithmullet

 

Welcome to the forum, Danceswithmullet. Tell us more.

http://www.youtube.com/watch?v=qcLbvf-Snpk

 

Finger

These are a few pics of the build. The LOG as it was called is 12"x12"x 16' 3lb foam block. After shaping it was glued to the hull. Deciding on the after end was tough, I wanted a clean release and a little bit of an aperature between the end of the log and the rudder since there is no rocker. I wanted the boat to be able to short tack and I was afraid any more resistance at the ends might cause a problem. She short tacks fine and I think more effort in distributing the load will bring the stern up. For the challenge you have to take a weeks supply of stuff and safety gear. My old boat was sensitive to bow weight, this one doesn't seem to care and seems want some. The boat completed the challenge, no damage, I was dry and warm the whole time even when it was raining and in the 40's. My only previous experience with a tri was a sailbird and after twenty minutes of the sailing while being drowned with a fire hose equivalent of spray I wanted off. This is not a high performance tri just a small comfortable boat that can be steered from inside in crappy weather.

 

Thanks for the photos of the build.

 

dwm

Nice build and thanks for sharing! Great little micro tri and a nice vindication to your efforts to finish in your first boat--although that's the WT way in some sense. I wish there were more boats documented on the Watertirbe though. I've tried over the years... Thanks for documenting yours and I'm looking forward to the duckworks articles!

Dan

 

You have lots of clever ideas. Looking forward to your Duckworks article too. What is the hole size and schedule? Would you use any other process to transfer shear loads between to two outer skins? What would you do differently?

 

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Welcome to the forum! Very innovative little tri-thanks for the info.

 

finger mullet

Found a new trace, but it failed: http://www.boatdesign.net/forums/multihulls/ron-white-trimaran-everglades-challenge-46411-4.html

http://www.flickr.com/photos/creativelenna/5741345191/in/set-72157626643420537/ ???????

 

Try Skipjack@Tampabay.rr.com

 

Thank you Hoyt, Oooooouuuuuuuh I should have known that.

 

I didn't figure it out right away. I pondered on it a while.

 

More pics

A lot more good photos from "killerdana" Dana Clark: http://www.flickr.com/photos/28715664@N08/8579619766/in/photostream/