The Viking Sky cruise ship that had to be evacuated off the coast of Norway over the weekend had low oil levels that led to engine failure, reports USA Today.
What happened?
The Viking Sky sailed from the northern city of Tromso over the weekend bound for Stavanger in southern Norway when the ship had engine failure, started listing dangerously, then took in water.
Viking Sky’s crew sent a mayday call and anchored in heavy seas to keep the ship from being dashed on rocks in an area known for shipwrecks. Five helicopters lifted 479 passengers off with winches.
The rescue operation ended Sunday when the engines restarted. The ship traveled under its own power to a Norwegian port with nearly 900 passengers and crew members still onboard.
NMA Investigation
Norwegian officials opened an investigation into the incident Monday, and the NMA has been working with Viking Ocean Cruises and Lloyd’s, the ship’s classification society, to identify why the cruise ship suffered a power blackout Saturday.
The engines of the luxury cruise ship that narrowly escaped disaster during a storm off Norway failed because of relatively low levels of lubricating oil in the engines, the Norwegian Maritime Authority said on Wednesday after investigation.
How low oil level caused engine failure?
Lars Alvestad, the head of Norway’s Maritime Authority, said Wednesday that low oil levels were the “direct cause” of the engine failure that stranded the Viking Sky on Saturday.
The NMA indicated that while oil in the tanks was relatively low, it was within set limits. But as the ship crossed rocky seas, movement of oil in the tanks triggered an alarm. Norwegian media reported gusts up to 43 mph and waves over 26 feet.
“The heavy seas in Hustadvika probably caused movements in the tanks so large that the supply to the lubricating oil pumps stopped,” Alvestad said.
“This triggered an alarm indicating a low level of lubrication oil, which in turn shortly thereafter caused an automatic shutdown of the engines.”
Company procedures revisited
Viking Ocean Cruises said in a statement that the company is revising procedures to ensure the issue doesn’t happen again.
“We have inspected the levels on all our sister ships and are now revising our procedures to ensure that this issue could not be repeated,” the statement said. “We will continue to work with our partners and the regulatory bodies in supporting them with the ongoing investigations.”
Did you subscribe to our daily newsletter?
It’s Free! Click here to Subscribe!
Source: USAToday
Continued.
Such gravity tank is fitted at highest point of engine room ( more head more pressure).
Capacity of tank should keep engine running without seizure for at least 12 min.
As engine lubrication is maintained by electric driven lube oil pump which is useless in case of blackout .sure this arrangement will survive engine from damage when lube oil starvation occurred in this case.
Another point to take in consideration not to rely on shaft generators in case of rough weather especially with electric driven main engine lube oil pump.
As well time delay of engine shut down in case of low lube oil pressure should be revised depending on such gravity lubrication is always maintained even in black out condition.
I believe M.A.N already took in consideration such problem.
Here we have to pin point on wet sump tank design and location of bell mouth suction pipe of lube oil pump.
It is the yard design of wet sump tank that should be revised thoroughly taking in consideration suction pipe location and adjacent frames to keep such design of ( oil well ) small tank in wet oil tank granted it is always full regardless ship list or weather roughness.
As per my experience of M.A.N engines of old designs it is equipped with lube oil gravity tank which maintains lube oil supply even with less oil pressure to prevent engine seizure.
Spot on, Kishore. Good watch-keeping practices are handed down by way of on-the-job training. This is not the case with classroom dependent ‘fast-track’ pathways adopted in most cases today. An entire generation of professionals have gone missing. Today, it is not uncommon to see a candidate attempt the Chief Engineer’s exam without any dry-docking experience. Hence topping engine oil levels during rough weather would be considered ‘novel’ by shipboard practitioners of today.
All Engine Sump oil tank level ( Main Engine and Aux. Engines) should be checked regularly during rough weather and filters kept clean. In the days gone by this was a regular practice to check oil levels regularly – manually and not depending too much on automation and alarm systems. In fact sump oil level was kept at slightly higher levels considering rolling and pitching of the vessel. Also during the rough weather the sludge settled in the bottom is more likely to be disturbed and mixed with oil causing filters to choke leading to low pressure and shut down.