How much drill water should be transferred from tanks 23 and 24 to tank 1 to level the COASTAL DRILLER, in transit at a draft of 10 feet 6 inches, if the total longitudinal moments are 1,700,000 ft-kips?
• Longitudinal moments and how they relate to trim correction • Relationship between weight shifted and moment created (Moment = Weight × Distance) • Using the given total longitudinal moments and known distances from the LCB/LCF to find required transferred weight
• How does shifting drill water forward (or aft) create a trimming moment that can counter the existing total longitudinal moments? • What equation links the required trimming moment to the weight of drill water moved and the distance it is shifted? • Once you know the required trimming moment, how do you convert that into a weight of drill water in kips?
• Be sure you are using consistent units: feet for distance and kips for weight so that the moment is in ft-kips. • Check that you used the correct lever arm: the distance between the centers of tanks 23/24 and tank 1, not just the distance from amidships. • Verify that your final answer is a reasonable fraction of the total longitudinal moments, based on the lever arm available.
No comments yet
Be the first to share your thoughts!