Saturday, March 29, 2008
Many boat parts are named after parts of the body: knees, ribs, head. Then there are animal parts: roach, leg-of-mutton, sheep-shank.
Quarter knees provide a bearing surface and reinforcement for joints; in this case the transition from sheerclamp to transom. The sheerstrake is screwed directly to the transom. Nothing is square. The boat has been set up with the bow plumb. A level can be used to strike off a lime parallel to the floor. In the picture above, Newt is using a small bevel gauge to deterine the angle of the sheerclamp to this line, then he'll cut that on one side of the blank. He'll repeat the process to get the angle of the transom.
This last sketch shows how crotch wood was used to make "grown" knees. A chance to make use of otherwise dubious lumber. Knees cut from wood with grain like this are actually much stronger than sawn or cut knees.
Working at the boatshop is a real treat, not only do I get to work on large projects that I would never have the opportunity or resources to do by myself, but the folks who show up to work are such a good community. Some have skills and talents, good ideas, life experiences, job training, and personalities that are different. There are guys who like woodworking (not boats), guys who like boats but not woodworking, artists, sculptors, surgeons, a vegan, retired guys, kids in school programs, a couple engineers, actually it is not all that different than our class, with the exception that I am not the only person with gray hair.
I like composites and am thinking that is the way to go for the boat I am building. We built the rig for Elf of sitka spruce. We built one of the same wood, but with a carbon fiber core for Silent Maid. Test parts showed a minor increase in weight for the composite one, but it was 4x stronger. It was still lighter than a solid mast of the same size. Aesthetics are very important to me in wooden boats. You can not tell the difference between the two rigs by looks since the carbon is on the inside, which keeps the epoxy out of the UV degredation.
There are lots of folks trying out new concepts for sailing all the time, not unlike aircraft design. I've experimented with kites as sails, beach umbrellas, clothing, etc. I have watched the kite surfers at Wellfleet and own a trainer kite. I have wind surfed, which I like very much. I have read about hydro foils and jet propulsion and venturi systems. All of these may have some sustainable practices inherent in design, but application is the end. I have a concept for the boat that is sustainable for me. It must be large enough to sail and row well, take friends out on, sleep overnight or camp for a few days, inexpensive as far a materials, be build-able in a semester, be trailer-able and launched by one person of small stature, be single handed. The boats we are building at the museum are either contract boats or museum accessions. Contract boats are built to specifications. The a-cats I have been talking about frequently in this blog are a class boat,which means that modifications and improvements are made slowly and tested. They are not a one-design class. That means all the boats in that class are almost exactly alike, as in the Laser or Comet classes.
The museum boats were built as or collected as representatives of historically interesting boats. Most bear relation to some aspect of local history, racing, hunting, fishing, etc. Boats develop in relation to the areas and waterways in which they function. That aspect makes them examples of sustainable practices for their time periods. Resources were committed to their development for a purpose that increased the wealth of families or increased their pleasure. The sneakbox and the garvey that I have worked on are example of these kinds of boats. The garvey is a historically accurate replica that was built new about 20 years ago from old offsets. The sneakbox was a Perrine built boat collected by the museum and reconstructed by the boat shop. Most of the original boat was replaced over three seasons of building. This activity of building boats and operating a working boatshop as a museum exhibit passes along not only skills, but inspires visitors in the same way that going camping get people to be more aware of their environment. It helps them think green; where does wood come from; how should we use it? Why doe we need different kinds? The fact that we use a lot of hand tools and power tools comes mostly from the preferences of the people tasked to preform a job. I might be comfortable with one tool, while someone else would choose another. That is one of the delights in working here. You can have as many choices in how to accomplish something based on the number of people you ask.