875. A jack-up with displacement of 10,000 kips has its LCG 100 feet aft of frame zero (AFO). If 200 kips are loaded at 60 feet AFO and 100 kips are discharged from 20 feet AFO, what is the new LCG?

The LCG remains 100.0 feet AFO because the changes in weight and moment are proportional, maintaining the LCG ratio. Initial LCG was 100 feet, total displacement was 10,000 kips, initial moment was 1,000,000 kip-feet. Loading 200 kips at 60 feet adds 12,000 kip-feet, and discharging 100 kips at 20 feet subtracts 2,000 kip-feet. The new displacement is 10,100 kips, and the new moment is 1,010,000 kip-feet, resulting in an LCG of 100.0 feet.