Your vessel's drafts are: FWD 18'-09", AFT 20'-05"; and the KG is 23.8 feet. Use the selected stability curves in the blue pages of the Stability Data Reference Book to determine the righting arm at 15° inclination.
• Trim and mean draft: How to find the mean draft from different forward and aft drafts • Using the selected cross curves / stability curves in the blue pages to find GZ at a given KG and heel • Effect of KG (vertical center of gravity) on the righting arm GZ at a specific angle (15°)
• First, what mean draft should you use with the given forward and aft drafts, and which displacement curve in the blue pages does that put you closest to? • Once you choose the proper displacement / draft curve, how do you adjust the GZ from the curve for the actual KG of 23.8 ft at 15°? • Compare the scale of the GZ diagram: at a small angle like 15°, are righting arms usually very large or relatively modest in size?
• Correct mean draft: Verify you computed mean draft correctly from 18'-09" and 20'-05" • Correct curve selection: Make sure you are on the proper page/curve for that mean draft (or nearest displacement) in the blue pages • Scale reading: Double-check the vertical scale on the GZ curve at 15° so you don’t confuse tenths of a foot with whole feet
No comments yet
Be the first to share your thoughts!