🔍 Key Concepts

• Mooring line pretension in deep water anchoring (what “balanced” lines mean when there is no wind, current, or waves) • How equal load sharing among all lines affects the target tension in each line • Relationship between water depth, catenary geometry, and line tension when the unit is on location with zero environmental load

💭 Think About

• Think about what the total horizontal and vertical forces on the DEEP DRILLER should be when there are no environmental forces—what should the net force be? • If all mooring lines are properly adjusted in a symmetric spread, how should the individual line tensions compare to one another? • Consider whether the correct pretension should be relatively high or relatively low in order to keep the unit on position without overstressing the lines when environmental loads later come on.

✅ Before You Answer

• Verify whether the question implies a symmetrical mooring pattern (e.g., 8 or 12 lines equally spaced) and thus similar tensions in all lines • Check that the chosen tension would allow a margin below the line’s minimum breaking strength (MBS) while still being high enough to maintain good restoring force • Confirm that you are thinking about initial pretension at zero offset, not the maximum working tension under storm conditions