Messing about in boats since 1975. Online Since 1997.
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One Day, A Little Round Toad Walked In...
Copyright 1990 - 2011 Michael Kasten
One day a little round toad walked into my office in Port Townsend, Washington.
When this happened, what I actually perceived was that a very short and round 'human' stood before me. He introduced himself as Dave Tarr.
Was I hallucinating?
I put aside the drawings I had been working on, and listened while he spoke: "I'd like you to take a look at a fishing boat I've been considering. What I have in mind is to build one and market it as a small tuna boat, say around 45 feet. I have this one drawing that I like the looks of, but not the hull shape," he continued. "And here's another design that's close to what I want, but it isn't big enough. It's just not what I had in mind."
I looked over the two drawings he had produced. Both looked fine. Dave then asked, "Could you take the lines of this one and make it a little bit bigger? Can you model it with the computer so we can check out the stability and the carrying capacity?"
"Well sure," I said, "that's easy enough to do. The computer model will allow us to quickly derive a target range for the vertical center of gravity. We can work toward a final boat design from there. What sort of timing are we looking at?"
"I'd like to start building it in two weeks..."
There were several moments of silence.
It is possible to do a job like this in a very short time. Two weeks from a cold start, however, is pushing the envelope more than somewhat. Ordinarily, a boat design evolves over a period of time longer than two weeks. Two months may be pushing it.
Boat design does often involve choosing a few design examples as a place to begin, from which preferences are brought to light, and a new direction taken. It is not just time spent laboring over drawings and calculations, although there is plenty of that. Rather, it is time spent reflecting on the course the design is taking; what has been said; what has been drawn; what new ideas may come to light; what those new ideas will cost; whether the cost is justified; and finally, where to take the design from there. Time is simply required to pass. The drawings should be pinned to the wall for a while so that new ideas can percolate.
It takes a certain amount of tweaking for the elements of a good boat design to come together so that the boat will fully satisfy the wishes of her owner, and will meet the demands of the work she will be asked to perform. It is quite a complex task, perhaps seemingly awesome, but it is not difficult.
Rather than being a linear process, it is usually viewed as a spiral - the "design spiral." The design moves around this spiral from Concept, to Specification, to Arrangement, to Hullform, to Sail Plan or Powering, to Construction Method, to Cost. One turn fully around, and the design is brought into greater focus. Looking again at the Concept, new judgments are made, another round of refinements are undertaken, and more detailed drawings are produced.
When finally a round is made, and no changes are required, the design is considered to be finished. The tangible result, the actual drawings, are the record of all those decisions.
The process can happen fairly swiftly, or it can span quite some time. It depends on the speed of the feedback / decision making loop for one, and in the real world, on the existing work-load faced by the designer.
If we view the many iterations required as being broken into roughly three or four "stages," we would have, after the first round, the Napkin Sketch. Another turn of the wheel would bring the Preliminary Plans onto the table. While these preliminaries may represent a finished "Concept" they are not yet a buildable set of plans.
If all has gone well to that point, and the "Concept" is still on track, the Building Plans can be drawn. While there may in the end be several large blueprints, they represent only the "tip of the iceberg." The number of calculations required to back up what has been created represents no small number of hours. They are not visible, yet in order to assure the success of the vessel, they must be done. Anyone who says differently is either trying to fool you, or himself. The point to be made is that, from the moment of the idea, the drawings are a process of discovery and refinement, rather than "final thought" etched on paper.
With these myriad considerations in mind, I was just then faced with a request to squeeze it all into two weeks. I was at a complete loss to put a quick response into words.
"I can enter a set of lines into the computer, and have a look at a few load conditions within that time period, but it will not be a finished boat design." Explaining much of the above to him, I finished by saying, "I really am quite busy just now. It will have to take its turn among the other projects I've already committed to."
"Can you really do it?" he said as he left.
At the end of two weeks, having borrowed quite heavily from my other deadlines to make it happen, I turned over a preliminary set of lines and a preliminary stability study, using an assumed center of gravity.
The next day, the little "man" walked in again. Having had plenty of time to make a copy of my lines and preliminary report, he brought them back. "It's just not what I had in mind," he said. "It's only a rough draft and a bunch of calculations. I can't use this - I need to start building."
Then as he neared the door he said over his shoulder, "So I've decided not to pay for your work."
I realized I'd been tricked. This time, I was not entirely at a loss for words. It is not clear to me just precisely what I then said, but I'm certain it would have instantly burned the hair off any mere "man."
There having been no such effect, I knew just then that when he first walked in, I had been hallucinating. In the flash of an instant, he changed quite suddenly from prince to toad.
Other Close Encounters...
More recently, a fellow called from Indiana... He said, "I have this boat design I'd like you to look at. I want to make some changes to it. What I want is a steel boat for ocean voyaging. I'm six feet tall. The boat has to have full standing headroom. It must be no longer than twenty feet."
Right...
Shortly afterward a call came in from the Northern Territories regarding a new boat design: "I need a boat just big enough for me and my neighbor's wife. What do you recommend..?" It is a tough question put that way, so I asked,
"How big is she..?"
I did not hear back from him... And so it goes...
Michael Kasten
Metal Boat Quarterly #9 - Winter 1997 Editorial
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