stability calcultion

guys pls HELP

hi I am doing a design of 30 m vessel. I need to do the stabilty calculations and I am kinda stuck???? . what should i take as an initial KG. Should I make the the tankplans first. The thing is dont have time to do a detailed weight culculation or get an estimate. dont have time to model the whole thing in a 3d program.

how should i deal with this fish ?

30 m length
8 m breadth
1.5 m draft
120 tonn displacement

Thanks

 

someone pls some help

 

Would you touch ithis with a thirty-meter pole?

I guess I'm the only guy here who'll stick his neck out.
First off- not enough information. An experienced designer can eyeball this- but still not enough information is given here. Please post a scale drawing of the profile and midship section. Second, don't put the cart before the horse pilgrim. Stability is evaluated when you have some idea of the weights of the collective structure and equipment. Perhaps a designer could heel her to downflooding, assume she is stable, and then peg the VCG with lots of reserve, then finish the design making sure that the actual VCG is ALWAYS below that point. I would never recommend this because it is bad advice. The thirty-plus meter vessels that I have worked on have had upper and lower stability constraints because too stable a boat rides like a horse that hasn't been broke, pilgrim.

 

With a draft of 5 feet or so your stability calcs for a safe design would result in a turned turtle unless you had minimal superstructure.

 

a total height of about 7.4 m above waterline ? I dont think you have considered the beam when you said that. and like Thunderhead19 here you cant really say much unless you get enough information.