Question 1

When inspecting a wire rope on lifting/lashing gear, what is the full discard criteria you should assess, beyond the broken-wire count?

Accepted Answer

Broken wires (5% in 10 diameters), corrosion, deformation/kinking, heat damage, and reduction in diameter A proper wire rope discard assessment covers more than broken wire counts. Discard criteria include: broken wires exceeding 5% of total wires in any length of 10 diameters; severe corrosion or pitting; deformation such as kinking, crushing, birdcaging or core protrusion; heat or arc damage; and a reduction in rope diameter beyond an acceptable tolerance. Relying on a single criterion (broken wire count) can miss other forms of degradation that make a wire unsafe for continued use.

Question 2

The yacht is loading additional stores and fuel before a long passage, raising the displacement significantly. What effect does this have on stability that you, as OOW, should be aware of?

Accepted Answer

Increased displacement generally raises the centre of gravity if weight is added high up, and free surface effects in partially-filled tanks can reduce the effective metacentric height (GM) Adding weight changes the vessel's centre of gravity depending on where it is stowed, and partially-filled tanks create free surface effects that reduce GM. OOWs should understand these basic stability principles even on smaller vessels without a dedicated loading computer.

Question 3

During a survey, watertight door seals in a transverse bulkhead below the waterline are found to be perished and not closing properly. As Master, what is the significance of this for the vessel's damage stability?

Accepted Answer

Significant — a failed watertight closure compromises the subdivision the vessel's damage stability calculations rely on, potentially allowing progressive flooding between compartments in the event of damage Damage stability calculations assume watertight subdivision functions as designed. A bulkhead door that cannot seal properly defeats that subdivision, allowing flooding to spread beyond the single compartment the design assumed — this must be rectified before further operation.