Hoegh Duke - August 1992

The starboard lifeboat with 12 persons on board was being lowered into the water when the aft hook slipped off its davit fall lifting ring. Consequently the lifeboat swung about the forward hook before free-falling upside down into the water.

Immediate cause of the accident was the improper resetting of the “on-load" release hook mechanism in the starboard lifeboat
During lowering of the lifeboat into the water the aft hook released as load on it applied a moment to the half-moon cam face. The resulting compressive force in the operating cable overcame the constraint of friction in the cable and in the cam spindle, resulting in rotation of the spindle and release of the hook.

Inspection of the aft hook "on-load" release mechanism confirmed that because of stiffness in the aft operating cable and cam spindle the aft quadrant was not in the full reset osition, so that the faces of the cam and the hook tail were not in flat contact. Because the aft quadrant was improperly reset, the three safety devices in the release handle assembly were ineffective in locking the quadrant in position.

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Hoegh Duke - Aug 1992