Question 1

After the event, the spring line that took the heavy load is inspected. It shows visible damage (stretched fibres, a section of reduced diameter) but did not part. What should be done with this line?

Accepted Answer

It should be taken out of service and not relied upon again as a primary mooring line until properly assessed by someone competent to judge its remaining strength, since visible damage from an overload event can significantly reduce a line's safe working load even if it did not actually part — "it held, so it must still be fine" is not a safe assumption A line that survived an overload event without parting has likely still sustained internal damage that reduces its remaining capacity — continuing to use it as if nothing happened risks it failing at a lower load than expected in a future event, precisely the kind of "near-miss equipment" that should be flagged and assessed, not quietly returned to service.

Question 2

A single-screw vessel is unberthing, using a spring against slow ahead engine to walk the bow off the berth, with a moderate offshore wind. The engine suddenly fails to respond to an order to go astern. What is the OOW/Master's first action?

Accepted Answer

Immediately inform the engine room directly (not just via telegraph) of the non-response, assess the vessel's current trajectory and what is still controlling it (the spring line, remaining wind effect, any tug), and prepare to use those remaining resources while engine control is investigated — do not wait passively for the engine to respond on a repeated order A non-responsive engine during an unberthing manoeuvre removes a resource the plan was actively relying on — direct communication with the engine room (not just repeating a telegraph order into the void) and an honest reassessment of what control remains is the first priority, exactly as it would be for any sudden loss of an assumed system.

Question 3

With the engine still not responding, the spring line continues to hold the stern while the offshore wind pushes the bow further off the berth than planned, putting more load on the spring than intended. What is the risk now developing?

Accepted Answer

The spring line could be overloaded beyond its safe working load by the combination of wind force and the bow swing, risking it parting under tension — if it parts, the vessel would suddenly lose the one remaining controlling line with no engine available to compensate, and the snap-back risk to anyone near the line increases as load builds This is the developing compound risk that makes this scenario a genuine cascade — the original single fault (engine non-response) is now combining with wind force to threaten a second failure (the spring parting), which would remove the last line of control entirely.