String of errors were causes of fire on the Wight Sky, says MAIB

Two catastrophic engine failures on August 26 and December 14th 2018 on board the Wightlink ferry Wight Sky (IMO 9446984), one resulting in a fire at the entrance to Lymington River and before berthing at Lymington Pier, were the result of faults in maintenance management, engine condition monitoring and quality control standards according to a report published by the UK Marine Accident Investigation Board (MAIB) on April 28th (IMN December 17th 2018)

Other contributory causes were factory assembly error and auxiliary system design / configuration and engine operating parameters, which contributed to long-term main engine reliability problems

At 18:35 local time on August 26th 2018 roll-on/roll-off passenger ferry Wight Sky suffered a catastrophic main engine failure as it prepared to enter the Lymington River on its regular crossing from Yarmouth, Isle of Wight.

This was the ferry’s second catastrophic main engine failure in less than a year, the failed engine being the replacement for a previous catastrophic engine failure that had resulted in a fire and serious injuries to an engineer officer.

On December 14th 2018 Wight Sky suffered a third catastrophic main engine failure. On this occasion, the failed engine had been in operation for just 389 hours. Wight Sky was one of three sister ferries operating between Lymington and Yarmouth. Following the third engine failure the ferry owner, Wightlink Ltd, withdrew its Wight Class ferries from service.

After discussions between the ferry owner, the Maritime and Coastguard Agency, Lloyd’s Register, and the engine manufacturer Volvo Penta, a mitigation plan was put in place to enable the ferries to return to service.

The initial mitigation measures included weather and engine load constraints, enhanced engine monitoring and shutdown procedures, and restrictions on personnel entering the engine rooms when the main engines were running.

The investigation found a history of engine failures across the Wight Class feet while operating on the route, dating back to 2010.

As a consequence, the scope of the investigation expanded to include all known failures, leading to a long and detailed technical investigation that comprised forensic examination and testing of five of the failed engines and their components, a full review of the vessels’ system design and operation, and the safety management, planned maintenance and condition monitoring procedures, together with manning and technical oversight.

Although Wight Sky’s catastrophic main engine failures had similar consequences, the complex circumstances that led to them differed. However, many of the underlying factors that contributed to the Wight Sky and other Wight Class engine failures were similar. These included:

  • insufficient technical oversight of engine operating parameters
  • maintenance management
  • quality control
  • engine component and auxiliary system design.

This was exacerbated by a lack of engine maintenance and condition monitoring ownership, which resulted in long-standing reliability issues that were either unidentified or unresolved.

Wightlink Ltd and other stakeholders have taken several actions following their internal investigations and in response to recommendations made in previous MAIB reports. Since December 2018, the ferries have successfully operated without any catastrophic engine failures.

RK Marine Ltd, the local service centre contracted to undertake most of the Wight Class ferry engine overhauls, has had its authorisation as a Volvo Penta Centre dealer removed by the engine manufacturer. Recommendations aimed at addressing specific issues that remain unresolved by the actions already taken have been made to Wightlink Ltd, Volvo Penta, Lloyd’s Register and RK Marine Ltd.

Wight Sky and the rest of the Wightlink feet were classed by LR. The loss or breakdown of the MEs on board the W-Class ferries should have been reported to LR without delay, as such events could invalidate LR’s approvals. However, not all engine failures were reported to LR and the classification society was not fully aware of the magnitude of the problems on board the W-Class ferries.

Most of the engine failures discussed in the report were reported to LR; however, the investigation did identify eight that were not. This meant that on at least eight occasions LR surveyors were denied the opportunity to investigate the circumstances of an engine breakdown and provide technical oversight. The failure to report also affected the amount of historical data recorded by LR, which could have been used for trend analysis and to identify recurring issues.

Lloyd’s Register has engaged with and instructed Wightlink on measures required to maintain the W-Class ferry certification through:

2008-built, UK-flagged, 2,546 gt Wight Sky is owned and managed by Wightlink Ltd of Portsmouth, UK. It is entered with Shipowners’ Club on behalf of Wightlink Ltd.