This new 25′ x 10′ power cat design has been created for Uganda, and other places. It will be built using the very rapid CM plywood epoxy construction. The flat parts are ply/core/ply sandwich. 15 hp per side will give 20 knots fully loaded. It could also work with a single motor in the middle.
As configured it seats 10. It could also be arranged for 12 persons. The plan is that I will lead a mass building over there were we build several of them in a few days and video the whole process.
I was, am and will be out for a couple days. Friday last was out for surgery. Today and tomorrow are to be the only sunny days for a while so have to hit the outdoor epoxy and 2 part poly paint on some projects. At least I don’t just sit in the office and opine. I spend time in the trenches doing it.
This could have been a disaster. And only in service what, 2 years? The cap shroud. It was sized correctly but had some defect in it.
People. These COI boats need someone inspecting the rigging every month. This could have been very very bad. The Coast Guard is all about rigs these days, and something like this gives them a chance to be a hero and you the villain. Climb that mast.
The best vacuum bagging frog material is this mesh from Hypervent, part number 3950. http://www.hyperventmarine.com/ .
It is intended to go under mattresses in boats, but is also unmatched under the intake of a vacuum pump. Good under your laptop computer too, keeping the airflow going.
It is sharp enough to damage the bag, so I put a batt of bleeder cloth over it to protect the bag.
Below, the lot sucking. With my favorite corner seal, Liquid Nails Projects. $1.75 a tube. After a day it dries out and can be pulled off of the bag easily so the bag can be reused.
Don’t forget where all the cool pictures come from. Simmo in Italy. They have a daycharter business there.
www.silentbay.it
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.
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.
Gecko into the container. It was just a theory, but it works.
I hear a rumor that I will be called over for the Round Britain Race in the future.
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.