The Maritime Accident Investigation Branch (MAIB) have today (Thursday) published an interim report following investigations into a series of catastrophic engine failures on board Wightlink’s W-Class ferries.
On 12th September 2017, Wight Sky’s ME2 suffered a catastrophic failure during the vessel’s approach to Yarmouth, which resulted in an engine room fire and caused serious injuries to an engineering officer. The engine was replaced and processes changed to reduce the likelihood of debris ingress, as previously reported by Island Echo.
Then, on 26th August 2018, Wight Sky’s replacement ME2 engine catastrophically failed as the vessel was preparing to enter the Lymington river with 127 persons on board. One of the engine’s connecting rods and various other internal engine components were ejected through the engine block. The engine lubricating oil ignited, causing a fireball to engulf the engine.
Shocking, on 14th December 2018, Wight Sky’s ME4 engine suffered a catastrophic failure as the vessel was closing on the berth at Lymington with 52 persons on board. Once again, a connecting rod bottom-end failed and various internal engine components were ejected through the engine block. There was no fire, but the fixed fire-fighting system was operated immediately as a precaution.
Initial Findings
Officials say that the investigation into the Volvo Penta D-16 engine failures experienced on board Wightlink’s Yarmouth to Lymington ferries, and Wight Sky in particular, is technically complex and is ongoing. The technical investigation team have identified 2 other recent non-catastrophic engine failures that occurred on board Wight Sky’s sister vessel, Wight Light, and are including them in the scope of the investigation.
It has now been revealed that one of the Wight Light engines suffered a crankshaft main bearing failure on 2nd February 2018, the other a melted piston and partial seizure on 3rd August 2018.
The initial findings in the lengthy investigation support the conclusions made in MAIB report No.14/2018 with respect to the first Wight Sky ME2 engine failure in 2017, and have identified direct causes for 2 of the other 4 engine failures.
According to the MAIB, Wight Sky’s newly built ME4 engine suffered a catastrophic failure after 380 running hours because of an assembly error during build in the Volvo Penta factory. In addition, Wight Light’s ME1 engine seized because of an assembly error during overhaul conducted by the local Volvo Penta dealer.
Although direct causes have not been established for all 5 engines, the investigation has identified several underlying factors that might have contributed to this unusually high incidence of failures. These include the way the vessels and their engines are driven during entry to and departure from port; the setup of the engines’ auxiliary systems; the management of maintenance on board and ashore; quality control during engine assembly and overhaul.
The MAIB say they are working closely with Wightlink, Volvo Penta, the local Volvo Penta dealer, Lloyd’s Register (Wight Sky’s Classification Society) and the Maritime and Coastguard Agency to investigate the 2 latest engine failures.
Actions Taken
Following the failure of Wight Sky’s main engine (ME4) in December 2018, Wightlink immediately withdrew its W-class vessels from service but a mitigation plan was put in place to enable the vessels to return to the cross-Solent route.
The initial mitigation measures included weather and engine load constraints, enhanced engine monitoring and shutdown procedures, and restrictions on personnel entering the machinery spaces when the main engines were running.
Further precautionary steps have also been taken as the technical investigation has progressed, including: shorter periods between routine fuel injector overhauls; modifications to the engine alarm system; replacement of flexible engine mounts; reduction of oil replacement and oil sampling hours; and testing of engine coolant.
Following the discovery of the assembly error Volvo Penta has strengthened its standard operation process to prevent this from occurring again. Volvo Penta confirmed the same error had not been repeated on engines manufactured around the same time.
Wightlink’s Chief Executive Keith Greenfield says:
“We welcome the release of the interim report by the Marine Accident Investigation Branch (MAIB) into engine failures on Wightlink’s ships on the Lymington-Yarmouth route in 2017 and 2018.
“The investigation is complex and not yet complete however we have been able to ensure that the manufacturing and rebuild assembly errors are not present on any of our other Volvo Penta engines.
“We continue to work with the MAIB, Volvo Penta and other parties to establish root causes for all engine failures in 2017 and 2018.
“Wightlink has excellent engine reliability on all its other ships and routes and we are working hard to eliminate the problems we have had on our Lymington-Yarmouth route
“Over the last three months, the Lymington-Yarmouth route has performed with 98.7% reliability, including cancellations caused by adverse weather.”
What Next?
The MAIB will continue to work closely with all the stakeholders involved in order to progress the investigation as swiftly as possible and ensure appropriate action can be taken in order to further reduce the likelihood of similar accidents in the future.
Once the MAIB’s investigation is complete, a combined report will be published.
You can read the full interim report at https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/801926/2019-InterimReport-WightSky.pdf.
The information contained in this interim report is based on investigations to date. Readers are cautioned that there is the possibility new evidence may become available that might alter the circumstances as depicted in this report.
