GMt

[wicher]

Hello all,

I have a question: is it possible to get a GMt value as output from orca 3d? I am just starting to learn the basics of ship-design and I am not even a student, so this may be a very stupid question . If this is possible, how to get it?

Best Regards, Wicher

[Admin]

Yes; simply check the box in the Hydrostatics & Stability Analysis dialog that says "Compute Righting Arm at these Heel Angles," and enter a heel angle of 0 (and others if you wish). Be sure to enter the Vertical Center of Gravity, VCG (upper left area of the dialog).

Hit Calculate, and the report will now show GMt. Let us know if you have more questions.

Bruce Hays

[wicher]

Dear mr Hays,

Thank you for your quick response! I used a VCG of a ship that is similar to my project and I found an reasonable output indeed! As a result, the following question comes up: can I let orca3D compute the VCG for my 3d model? I made a 3d model of the hull in Rhino surfaces based on given Loa and Boa.

Best Regards, Wicher

[Admin]

Dear Wicher:

VCG is not a function of the shape of the ship; it's a mass property, totally dependent on construction materials and how the equipment, machinery, cargo, tanks, etc. are positioned. At the early stages of design, you have to estimate the value. In very early stages, the best way to estimate is based on similar vessels, as you've done; as the design progresses and becomes more detailed (e.g., you have chosen the engine(s) and their location, the structure has been designed, etc.) you can begin to compute the weight and center of gravity of all of the components to determine the overall weight and center of gravity.

Hope this helps,
Bruce