A total of 18 alarms about low lubricating oil levels sounded on board cruise ship Viking Sky (IMO 9650420) several hours before a complete blackout left the ship at the mercy of stormy seas, with a total of 1,373 people on board, according to a preliminary report from The Norway Accident Investigation Board (AIBN). It said that it would be looking closely at these alarms as the investigation continued.
The cruise ship came to within a ship’s length of grounding on rocks in what was a notoriously dangerous area off Norway’s northwest coast, and could have passed over some dangerous reefs while she was drifting, the preliminary report said.
William J Bertheussen, director of AIBN, said that he and his staff were particularly interested in the “low volume” alarms registered by the operational diesel generators that supplied Viking Sky’s electricity. They went off between 04:00 and 09:04 on the morning of March 23rd 2019. Each of the alarms was cleared within seconds after being accepted by the crew.
No more alarms were registered until 13:37, when Diesel generator (DG)4 registered an alarm indicating that the DG was shedding load as a result of low lubricating oil pressure. A few seconds later it registered a low lubricating oil pressure alarm. At 13:39:52 DG1 registered a low lubricating oil sump level alarm. A little over five minutes later, at 13:45:26, DG4 shut down, followed by DG2 eight seconds later. DG2 was restarted after approximately 11 minutes, but shut down again, along with DG1 at 13:58:31. This caused a complete black-out and loss of propulsion.
The bridge team immediately called the engine control room. However, at that early stage, the engineers were unsure of the cause or causes of the blackout and therefore could not estimate when it would be possible to restore power. The officer on watch called the master, who quickly made his way to the bridge.
Having assessed the situation, the master broadcast a mayday at 14:00. He then instructed the crew to drop both anchors. However, the anchors did not hold, and the ship continued to drift astern towards the shore at a speed of 6-to-7 knots. The General Alarm was activated at 14:13, and the passengers and crew began to muster.
Viking Sky was sailing at the time through stormy seas in the notoriously dangerous area called Hustadvika.
A massive rescue operation then began. However, only 479 of the 1,373 people on the vessel were evacuated – which took many hours – before it was considered safer for the remainder to stay on board. The weather was too severe for lifeboats to reach the vessel.
Within 30 seconds of the blackout, the emergency diesel generator started and powered the emergency switchboard. The engineers transferred a total of 10.8 m3 of lubricating oil to the lubricating oil sump tanks of the three operational DGs. They then started DG2. Power was restored to the main switchboard, in manual load-sharing mode, at 14:22. At 14:29 the port propulsion motor was restarted and, approximately five minutes later, the starboard propulsion motor was started. This provided sufficient propulsive power to maintain slow speed ahead. Over the next hour, DG1 and DG4 were restarted in automatic load-sharing mode, and the starboard propulsion motor was restarted to enable the propulsion motors’ output to maintain between slow ahead and half ahead.
Although the three operational DGs had been restarted, the engineers had to continuously balance the electrical load manually. The vessel was manoeuvred towards open waters, still with both anchors lowered.
The first helicopter arrived at approximately 15:00. The crew manoeuvred the vessel to head into the weather to give the helicopters the best possible working conditions in order to start evacuating the passengers. The master had considered evacuating passengers and crew to the lifeboats but this was considered to be too dangerous. The first helicopter hoisting operation took place five minutes later and evacuation of passengers continued until the next morning.
The first tugboat arrived at around 16:40. However, the weather conditions were too severe to secure a towline. At 06:30 on March 24, the weather conditions had improved sufficiently to enable tugs to be made fast and towlines were secured fore and aft, although the vessel maintained its own propulsion. At approximately 09:15, the master decided that the vessel was out of danger and that it was safe to stop the evacuation of the passengers. The local Police reported 479 evacuated passengers had been received at the emergency centre ashore.
Viking Sky berthed safely in Molde on March 24th. The near-miss was seen industry-wide as a “wake-up call”, with questions being asked about the confidence with which such cruises were undertaken, given the potential dangers on the Norwegian coastline.
AIBN said that it intended to study the earlier alarms more closely. The report showed that lubricating oil levels were measured at between 28% and 40% of capacity. Recommended levels for a vessel such as the Viking Sky are 68% to 75%. Since the oil levels were so low, the vessel rolling from side to side could have been the cause of three diesel generators failing within 20 minutes and the resultant loss of power.
AIBN has recommended that all vessels fill up on lubricating oil, especially in bad weather. They are looking at the systems for alarm management in the engine room, route planning especially in bad weather, evacuation and safety procedures, and systems for safe return to port.
All vessel owners and operators were recommended to ensure that engine lubricating oil tank levels are maintained in accordance with engine manufacturer’s instructions and topped up in the event of poor weather being forecast.
Areas of further investigation to be undertaken by the AIBN included:
- Engine room alarm management
- Passage planning
- Decision support
- Lubricating oil management
- Evacuation and LSA
- Safety management
- Local weather conditions and bathymetry
- Safe Return to Port.
The board said that its investigation would continue as swiftly as possible. Once it is completed it will be distributed to key stakeholders for a 30-day comment period before it is published.
2017-built, Norway-flagged, 47.842 gt Viking Sky is owned by Viking Ocean Cruises Ship II care of manager Viking River Cruises Inc of California, USA. ISM manager is Wilhelmsen Ship Management AS of Lysaker, Norway. It is entered with Steamship Mutual (European Syndicate) on behalf of Viking Ocean Cruises Ship II Ltd.