Software recommendations and comments wanted

[jwilliams113047]

I own Hull #12 of the original C-Dory series. It is a 22 foot true dory and is supposedly a Wm Garden Design. I have used it offshore for years out of Illwaco on the Columbia River for salmon and in the San Juans.

My current project is to upgrade and outfit it for tuna over the Astoria Canyon and that upgrade includes retanking it and repowering it. The repower will include conversion to twin outboards on a bracket and the tanking will be part of setting up both prime movers on fully independent fuel and starting systems. I will probably build both the tanks and the bracket, so I can optimize the configurations as needed to avoid unintended consequences.

As a practical exercise, I would like to use some shareware/freeware modeling software so that I can evaluate the impacts of various combinations of configurations of motors, bracket configurations and tankage size and arrangements on the dynamics of the vessel. I have significant layout, fabrication, and construction experience, good computer skills and no formal familiarity with vessel dynamics evaluation or design beyond an understanding of stationing and coordinate systems and a very practical mind.

The situation is further complicated by the fact that none of the original design drawings and/or calcuations are available [ Hull #012 was produced in 1981.] So, I am pretty much going to have to survey the existing hull and input the stationing data to even have a baseline from which to work

Obviously, I am planning on getting some schooling from the experience as well.

All that having been said, I would like to see if there is some consensus of opinion regarding an approriate program, or programs to achieve my ends without undue fanfare or complication.

As my old daddy used to say...."The best plan need not be easy....it does want to be simple though."


What say you?

[Gilbert]

I don't want to discourage you from doing as much as you like in the way of drafting and tinkering with various options, but you should be able to get good results with very simple methods. If your boat performs very well as it is you could just figure out where its center of gravity is by determining where it balances. Then simply arrange the weights of the changes so it continues to balance very close to the same spot. I would suggest determining the balance point with tanks half full or weights representing tanks half full.

[jwilliams113047]

Thanks. Good and practical advice.