Several safety recommendations made following ‘Viking Sky’ blackout enquiry

2024-03-27T19:49:57+00:00 March 27th, 2024|Safety|

The Norwegian Safety Investigation Authority (NSIA) has issued a damning report on the near grounding of the ‘Viking Sky’ in the Hustadvika area of the Norwegian coast during the afternoon of 23rd March, 2019 in bad weather.

‘Viking Sky’ experienced a blackout, causing loss of propulsion and steering, during a storm.

It was estimated that the cruise ship came within a ship’s length of running aground with 1,374 persons on board.

The blackout was caused by insufficient lubricating oil in all of the operating diesel generators’ lubricating oil sump tanks, in combination with the vessel’s pitching and rolling in rough seas.

NSIA’s investigation identified operational, technical, and organisational safety issues that in different ways contributed to the blackout.

The blackout recovery was time consuming. It took 39 mins from the blackout until both propulsion motors were operational and the ship had sufficient power available to maintain between 1 to 5 knots steaming ahead.

Blackout drills had been carried out, but recovery from a full blackout without a standby generator had not been tested on board. The engineers were therefore faced with a situation they were not practised in managing, NSIA said.

The situation was described as 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 on 21st 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 she did not comply with the applicable safety standards, she should not have departed Tromsø under the prevailing circumstances.

The investigation has also found that the lube oil sump tank design was non-compliant with applicable regulations.

As a result, NSIA issued 14 safety recommendations to relevant parties with the aim of promoting maritime safety.

Safety recommendation – 1

The investigation showed that the lube oil sump tank design did not comply with SOLAS II-1, Part C, Regulation 26.6 and LR Class Rules Part 5, Chapter 1, Section 3.7 on safe operation under dynamic inclination, nor with the recommendations of the engine manufacturer.

Its design is critical to safe engine operation, yet the shipyard’s design process did not effectively ensure that the lube oil sump tanks complied with the SOLAS requirement for safe operation under dynamic inclination.

NSIA recommended that shipbuilder Fincantieri review and strengthen the design process to ensure that lube oil sump tanks are designed and built in compliance with the SOLAS regulation and class rules in the future.

Fincantieri is also recommended to investigate if any other ships designed at the yard may have non-compliant lube oil sump tanks and take necessary action if relevant.

Safety Recommendation – 2

The sump tank design is critical to safe engine operation, yet Lloyd’s Register (LR) did not independently verify compliance with either the engine manufacturer’s instructions, the SOLAS regulation or LR’s own class rules.

NSIA recommended that LR reviews and strengthens the plan approval process to ensure that lube oil sump tanks are designed and built in compliance with the SOLAS regulation and class rules.

Safety Recommendation – 3

The operational limitations associated with the tank design in terms of dynamic inclination angles or corresponding sea conditions were not calculated.

Therefore, the crew on board didn’t have the safety critical information necessary to know the limits of safe operation.

NSIA recommended that Wilhelmsen Ship Management, in co-operation with Viking Ocean Cruises, takes the necessary action to ensure the vessels are compliant with the SOLAS regulation through calculation and implementation of operating restrictions associated with the current tank design, modification of the tank design, or a combination of both.

Safety Recommendation – 4

NSIA recommended that LR requires action to ensure ’Viking Sky’ and her sister vessels are compliant with the SOLAS regulation and LR class rules through calculation and implementation of operating restrictions associated with the current tank design, modification of the tank design, or a combination of both.

Safety Recommendation – 5

NSIA also recommended that the Norwegian Maritime Authority (NMA) require action to ensure ’Viking Sky’ and her sister vessels are compliant with the SOLAS regulation.

Safety Recommendation – 6

SOLAS specifies the dynamic pitch and roll amplitudes under which the machinery shall be able to operate safely. However, neither SOLAS nor IACS UR M46 provide unambiguous information on the period, duration or pattern of the movement over time to be used for the application of, or verification of compliance with, the regulation.

No technical guideline or industry standard for application of the SOLAS requirement exists.

NSIA recommended that the NMA make a proposal to the IMO that a technical guideline on the application of SOLAS Chapter II-1, Part C, Regulation 26.6, be developed.

Safety Recommendation – 7

NSIA also recommended that LR makes a proposal to the International Association of Classification Societies (IACS) that a technical guideline be developed.

Safety Recommendation – 8

‘Viking Sky’ was not required to be, nor was fitted with a type-approved electronic inclinometer providing recordings to the VDR.

Hence, inclination angle data from the vessel’s fuel efficiency management system was used in the investigation.

An electronic inclinometer providing recordings to the VDR would more efficiently provide reliable data for safety investigations and may thereby contribute to improve safety at sea.

NSIA recommended that the NMA make a proposal to the IMO that inclinometer information compliant with the technical requirements of resolution MSC.363(92) is recorded on the VDRs of all SOLAS ships with a gross tonnage of 3,000 and above.

Safety Recommendation – 9

The shipmanagement company has implemented a new procedure for lube oil management to maintain higher lube oil levels.

It is uncertain whether the revised procedure fully remedies the safety issue, as it does not document that the increased oil levels lead to compliance with the SOLAS regulation, nor what the operating limitations associated with the increased oil levels are.

The crew on board the vessels therefore don’t have the safety critical information necessary to know the limits of safe operation with respect to dynamic inclination angles or corresponding sea conditions.

It was recommended that Wilhelmsen Ship Management, develop and implement a new procedure for lube oil level management, and calculate and implement the associated operating restrictions, to ensure safe operation in compliance with the SOLAS requirement and in accordance with the engine manufacturer’s recommendations.

Safety Recommendation – 10

NSIA’s investigation showed that the remote lube oil sump tank level monitoring system was complex and the resulting on board measurements inaccurate and unreliable.

The as-built sensor pipe offset, representing the physical fixed distance from the bottom of the tank to the bottom of the level sensor tube, was not recorded by the shipyard.

Fincantieri did not take into account the equipment maker’s recommended minimum distance between the sensor tube and oil suction pipe.

In addition, the 3D-model used to convert the level measurements to oil volumes for diesel generator 1 (DG1) was erroneous, causing a significant measurement error.

It was recommended that Wilhelmsen Ship Management, in co-operation with Viking Ocean Cruises, carry out a systematic and holistic review of the remote lube oil sump tank level monitoring system and ensure the vessels are fitted with an accurate and trustworthy remote monitoring system.

Safety Recommendation – 11

NSIA also recommended that Fincantieri carry out a systematic and holistic review of the remote lube oil sump tank level monitoring system and take the necessary actions to ensure that future vessels are fitted with a sufficiently accurate and trustworthy remote lube oil sump tank level monitoring system.

Safety Recommendation – 12

The investigation also found several design and configuration issues related to the engine control room alarm system that likely had a negative impact on the effectiveness and efficiency of engineering officers on watch.

NSIA recommended that Wilhelmsen Ship Management, in co-operation with Viking Ocean Cruises, carry out an operator centric design and configuration review of the engine room alarm system and implement identified improvements.

Safety Recommendation – 13

Ships’ engine room alarm management are not subject to any regulation equivalent to the Bridge Alert Management (BAM) performance standards, with the result that many of these systems, such as the alarm system on ’Viking Sky’ and her sister vessels, do not have an optimal design and configuration.

NSIA recommended that the NMA make a proposal to the IMO that an engine room alarm management performance standard shall be developed.

Safety Recommendation – 14

As mentioned, the blackout recovery was time consuming, and it took 39 mins from the blackout until both propulsion motors were operational and the ship had sufficient power available to maintain between 1 and 5 knots ahead.

It was difficult to understand why it took so long before the filling of oil was started and why the crew continued to struggle to restore power and propulsion.

Sound recordings from the engine control room could have provided valuable insights and contributed to better understanding the interaction in the engine control room and the safety issues present.

Finally, the NSIA recommended that the NMA make a proposal to the IMO that the VDR performance standard is amended to also include recording of sound from the engine control room.