The motion that can significantly increase...

The motion that can significantly increase mooring line tension is __________.

🔍 Key Concepts

• Ship motions: know the names for movement in all 6 degrees of freedom (surge, sway, heave, roll, pitch, yaw) and which ones act along the ship’s length vs across it. • Mooring line direction: consider how mooring lines are usually led from the ship (fore-and-aft vs athwartships) and which ship motion stretches them the most. • Effect on line tension: think about which motion produces the largest change in distance between the ship’s bitts and the shore bollards.

💭 Think About

• For each motion in the choices, picture how the bow and stern move relative to the pier and mooring bollards. Which motion most changes the fore-and-aft distance? • Ask yourself: are the main mooring lines usually more aligned with the ship’s length (fore-and-aft) or its beam (sideways)? Which listed motion works along that alignment instead of mostly sideways or rotational? • Visualize the vessel at a pier in a seaway. Which motion would cause the lines to alternately slack and snap tight as the ship moves toward and away from the bollards, rather than just moving up/down or swinging?.

✅ Before You Answer

• Be clear on the difference between translational motions (surge, sway, heave) and rotational motions (roll, pitch, yaw). • Identify how breast lines vs spring lines are oriented and which type of motion would load springs the most. • Eliminate any motions that mainly move the ship up and down or rotate it without much change in distance to the mooring points.

🔍 Key Concepts

💭 Think About

✅ Before You Answer