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Loss of propulsion and near grounding of Viking Sky, Hustadvika, Norway 23 March 2019
In the afternoon of 23 March 2019, the cruise vessel Viking Sky experienced a blackout, causing loss of propulsion and steering, during a storm in the Hustadvika area of the Norwegian coast. The vessel is estimated to have come within a ship’s length of running aground with 1,374 persons on board, and the accident had the potential to develop into one of the worst disasters at sea in modern times. The accident was caused by insufficient lubricating oil in all of the operating diesel generators’ lubricating oil sump tanks, in combination with pitching and rolling in rough seas. The investigation has identified operational, technical, and organisational safety issues that in different ways contributed to the blackout. The blackout recovery was time consuming, and it took 39 minutes from the blackout until both propulsion motors were operational and the ship had sufficient power available to maintain between 1 to 5 knots ahead. Blackout drills had been carried out, but recovery from a full blackout without a standby generator had never been drilled on board. The engineers were therefore faced with a situation they were not practised in managing. The situation was stressful, the control system was complex, and a specific sequence of actions was needed. Insufficient training likely contributed to why the blackout recovery was time consuming. When Viking Sky left Tromsø 21 March 2019, with one out of four diesel generators unavailable, both crew and passengers were unknowingly exposed to an increased risk as the vessel did not have the redundancy required under the Safe Return to Port (SRtP) regulations. As Viking Sky did not comply with the applicable safety standards, it should not have departed Tromsø under the prevailing circumstances.