Industry-wide changes in how fatigue is managed onboard vessels in Canadian waters could avoid more accidents like the Nathan E. Stewart fuel spill near Bella Bella.
The tug spilled 110,000 litres of diesel fuel and 2,000 litres of lubricants into the waters off the northern B.C. coast on Oct. 13, 2016, after the second mate fell asleep.
The Nathan E. Stewart sank the next day, causing $12 million in damage to the 30-metre tug and the empty barge it was pulling. The vessel was brought up and out of the water in mid-November 2016.
In a report released Thursday, the Transportation Safety Board made two recommendations: that Transport Canada require watchkeepers to receive education and awareness training to help identify and prevent the risks of fatigue and that vessel owners bring in individualized fatigue-management plans.
The accident had happened around 1 a.m. on Oct. 13, after the second mate fell asleep sometime after 12:24 p.m.
The tug ran aground at 1:08 a.m. after having continued on autopilot since the second mate last changed its course at 12:24 a.m.
The second mate had taken over steering the vessel at 11 p.m. that night, about an hour before he usually did.
The tug started to go off-course at 12:53 a.m., when the sleeping second mate missed a course change, before running aground at 1:08 a.m. after having continued on autopilot since the second mate last changed its course at 12:24 a.m.
The second mate admitted to investigators that he fell asleep but said he felt he had had “adequate” rest in the days leading up to the accident, despite losing an hour of sleep that night.
“The watchkeepers of the Nathan E. Stewart had been working the ‘six on, six off’ shift schedule for two-and-a-half days prior to the grounding,” said TSB chair Kathy Fox.
“Although this schedule provides opportunity for sleep, the second mate was unable to nap during the afternoon rest periods. You can regulate hours of rest but you can’t regulate how many hours somebody sleeps because that’s very individual.”
The schedule kept by the second mate did comply with Canadian marine regulations, Fox noted, but added that “six on, six off is known to contribute to fatigue.”
“Although this type of shift schedule has been called into question by various international studies and experts, it continues to be used throughout the marine industry,” Fox said.
As a result, Fox acknowledged that it would be difficult to shift away from this schedule, but said that only reemphasized the need to have watchkeepers better trained to identify fatigue and have a “clear, well thought out plan” to address it.
“It’s hard enough to work a six on, six off shift for days on end without getting a good night’s sleep. It’s harder still to do it without the means to recognize and combat that fatigue that this schedule inevitably generates,” said Fox.
Fox recommended that crews be trained to combat fatigue when it “inevitably” does hit, by “being active rather than sitting in a comfortable chair, lowering the temperature rather than raising it, raising the lights, use of caffeine as an alertness strategy.”