in the preliminary design, how to check and made a stability curve

Good days, boat's design forumers..

i'm in the duty to design a coastal tugs, and i'v a problem to made a pra stability.
can any body help to made ? my reference are using prohaska's table...


brgds, vigner

 

Hi Vigner,

At the preliminary design stages, if you do not have the lines plan yet, you can estimate the initial stability, as per:

KB = 1/3 (5T/2 - V/Afl)
BM = 0.08*B^2/T

If you now estimate KG, you can get an idea on what GMo is.

Needless to say that if you have already the body lines and the estimated KG, then run the thing in your NA program for the different load conditions and towing criteria.

Tomorrow at the office I'll check more about the designing criteria for tugs and see if I can come with more help.

Cheers.