Because there is a possibility of fuel oil being discharged overboard from a full fuel oil tank, it is decided to transfer 25 kips from tank 14 to tank 13. See COASTAL DRILLER Sample Load Form Number 1 (Rig Move). What would be the change in transverse moments with this transfer?
• Review how transverse moments are calculated: (weight) × (transverse distance from centerline) • Understand that when you transfer weight from one tank to another, you must consider the change in moment in both tanks • Use the tank locations and distances from the centerline given on the COASTAL DRILLER Sample Load Form Number 1 (Rig Move)
• What is the transverse moment contribution of 25 kips when it is in tank 14, using the distance from the centerline given on the form? • What is the transverse moment contribution of the same 25 kips when it is moved to tank 13? • How do you combine the change in moment from losing weight in tank 14 and gaining it in tank 13 to find the net change in transverse moments?
• Make sure you use the correct distances from the centerline for both tank 13 and tank 14 (port vs starboard and magnitude) • Confirm that you apply the correct signs (port vs starboard) when calculating the change in moments • Double-check that your final answer is in ft-kips and that you have accounted for the moment change in both tanks, not just one
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