The Norwegian Maritime Authority said low oil pressure on
the Viking Sky is suspected of causing the engine shutdowns that left the ship
without propulsion on March 23 and led to the helicopter evacuation of 479
passengers.
After losing three of the four engines, the captain of the
Viking Ocean Cruises ship declared a mayday, as his vessel was dangerously
close to shore in the shallow Hustadvika passage along Norway's west coast. In
consultation with the Norwegian Coast Guard, an evacuation by helicopter was
ordered.
Viking was later able to restart the engines, discontinue
the evacuation, and reach port in Molde, Norway.
In a preliminary finding, the maritime authority said that
while the level of lubricating oil in the tanks was within set limits, it was
relatively low when the vessel started to cross Hustadvika.
"The tanks were provided with level alarms, however
these had not been triggered at this time," the agency said. "The
heavy seas in Hustadvika probably caused movements in the tanks so large that
the supply to the lubricating oil pumps stopped.
"This triggered an alarm indicating a low level of
lubrication oil, which in turn shortly thereafter caused an automatic shutdown
of the engines," the statement said.
Viking said it welcomed the "prompt and efficient
investigation" and that it fully understands and acknowledges the
findings.
"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," a Viking statement said.
The maritime agency said it has issued a general safety
notice about the problem.
It also said it will continue to talk to Viking, Lloyd's
Register and the Norwegian Accident Investigation Board to determine the
underlying causes of the incident.