Final answer:
To calculate a ship's forward and aft drafts in freshwater, adjust the displacement for the difference in water density and apply hydrostatic principles to account for changes in trim and buoyancy, involving calculations with buoyancy, hydrostatics, and ship stability concepts.
Step-by-step explanation:
Calculation of Forward and Aft Drafts in Freshwater
The question pertains to a ship's draft calculation when moving from saltwater to freshwater, which involves applying concepts of buoyancy and hydrostatics. As the density of freshwater is less than that of saltwater, the ship will sit deeper in the water. To calculate the new drafts, we will consider the change in buoyancy force due to the difference in water density and apply the hydrostatic principles to adjust the draft accordingly.
First, find the change in displacement when moving from salt to freshwater. Then, using the Moment to Change Trim (MCT) and the longitudinal center of flotation (LCF), calculate the change in trim. Next, apply the change in trim to the mean draft to find the new aft and forward drafts using the perpendiculars. This problem combines principles of buoyancy, hydrostatics, and ship stability.