Category Archives: New Designs

Design Fusion

At first glance, this has no multihull content, but in fact relates to boatbuilding.
I had always wanted to see if taking the SIP panel method way forward using composite technology could make better land buildings. Could boatbuilding help land building? I decided to try it out over in the desert of eastern Washington.   See http://www.themarsoutpost.com/

 

Last May I met with Grant County Building Dept. They told me if I met code on things like egress and wiring, and got the plans stamped, they would approve it.  I did both.

I also did some research and contacted the people who write the IRC codes to see if there were any avenues to take that would give the county some extra cover. They suggested some, which I forwarded to the building dept.

Dave Nelson, the Building/Fire Marshall head there did not take it well. He rejected the submittal and reminded me that “the IRC gives me, the Building Official, the sole right to interpretation of the building Codes.” Basically saying “we don’t need no city people coming over here and telling us what we can do.” And he then stated that he intends to make it as difficult for me as possible. “…the building official can require testing to be done by qualified testing agencies… This would be required on almost every component of this project.”

 It looks like they are going to make me work for it.  Innovation is a tougher and more expensive slog than I thought it would be.  I didn’t expect them to be so rigid.

Nanno wood fibers

Just heard about this due to come out next year. As I understand it, involves adding processed clay to wood fibers for much higher physical properties. My searches did not find anything useful. Maybe someone can find a useful link.

Rudder Shafts

How much stronger is a solid stainless rudder shaft compared to a tube? Lets see. I can’t attach excel files but I can put the equations here so you can copy and past into excel.

A tube equation for section modulus SM, for bending calculations is                   =(0.098168*((E3^4)-(E4^4)))/E3 where the OD is at E3 and ID is at E4.
Moment of inertia (I) formula for deflection calculations is =0.04908*((E3^4)-(E4^4)) again same for OD and ID.
For a solid tube put zero or near zero in for the ID.  Oddly enough none of my references have a simple solid section properties equations, so I do this.

For section area, to compare weight, use =(6.2832)*(E3/2)*(E5) where E3 is ID again and E5 is wall thickness.

My thoughts on rudder shafts are that the fattest, thickest tube that will fit easily into a 13% section, with the top bearing about at the same distance from rudder top as from the center of effort, will be right for sailing multis. It will also meet ABS ORY.  The one exception is sailing cats with big engines. A pair of caterpillar 500 hp diesels bent anything this side of a solid shaft some years ago and took us to school.

Gecko comes apart

the mast lowered safely
This makes it real for me. First step in going away is lowering the mast. I remembered that her construction was featured in issue #1 of Professional Boatbuilder. I will post that article as soon as I get it. Meanwhile,

Back

Back in the office after a week in Alaska. My room was number 5200. How cool is that? http://www.3m.com/product/information/Marine-5200-Adhesive-Sealant.html
I got the new composites construction manual into Pagemaker/Indesign and about 90% done. After about a week it will be in the do-no-harm stage and I can send it out on CD to KHSD composite boat builders. I can’t polish it until weather gets colder. Too many epoxy projects to do first.  What, $20 as a CD to not yet builders?  With free update when I finish in October, and deductable from plans in future?
The new CM construction manual is about 99% there. Is there any interest in seeing it as a print manual? Those would not have the hot links, but it would be a book. I have to see what the printers want for it and how much all-color photos hurts. Let me know.