A semisubmersible displacing 18,000 long tons has an LCG 2 feet forward of amidships. Bulk, weighing 400 long tons, is discharged from P-tanks located 50.8 feet aft of amidships. What is the new LCG?
• Longitudinal center of gravity (LCG) and how it shifts when weights are added or removed • How to calculate a moment: weight × distance from a reference (here, amidships) • Effect of removing a weight located aft when the original LCG is forward of amidships
• What is the ship’s original total longitudinal moment about amidships, given the original displacement and LCG? • When you discharge (remove) the 400 long tons from 50.8 feet aft, what is the sign and value of the moment you are removing? • After removing this weight, what is the new displacement, and how do you find the new LCG from the new total moment and new displacement?
• Be sure to use the new displacement after discharge when computing the new LCG • Keep a consistent sign convention (e.g., forward moments positive, aft moments negative, or vice versa) and stick with it throughout • Double‑check the units (long tons and feet) and that you are dividing total moment by total displacement for the final LCG
No comments yet
Be the first to share your thoughts!