Your vessel is limited to a maximum draft of 27'-06". The present drafts are: FWD 24'-10", AFT 26'-00". How much more cargo can be loaded and where should it be located if a drag of 1 foot is desired? (Use the reference material in Section 1, the blue pages, of the Stability Data Reference Book)
• Maximum allowable draft versus current drafts and desired final drag • Using the Stability Data Reference Book (blue pages) to find tons per inch immersion (TPI) and the longitudinal center of flotation (LCF) / tipping center • Relationship between loading a given weight at a certain longitudinal position and the change in trim by the stern or by the bow
• First, figure out what the final forward and aft drafts must be if the ship is limited to 27'-06" and you want exactly 1 foot of drag by the stern. Which end will reach the limiting draft? • From the blue pages, determine how many tons you can add before reaching that limiting draft, using the appropriate TPI value for this draft range. • Use the trim and LCF data to decide where the added weight must act longitudinally so that you end up with the desired 1-foot difference between the forward and aft drafts. Does it need to be placed forward or aft of amidships/tipping center to get that trim?
• Be sure your final aft and forward drafts satisfy both: (1) max draft not exceeded, and (2) exactly 1'-00" drag by the stern. • Confirm you used the correct TPI and trim/LCF values from the Stability Data Reference Book for the draft range that corresponds to the final condition, not the initial condition. • Check whether the calculated longitudinal position of the cargo is being described relative to amidships or tipping center in the answer choices, and match units carefully (feet, tons).
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