An investigation by the Canadian Transportation Safety Board (TSB) has said that the second mate on 302 gt tug Nathan E. Stewart (IMO 8968210) fell asleep while he was alone on watch, causing the tug to run aground off Vancouver Island after missing a planned change of course.
About 107,000 litres of diesel and more than 2,200 litres of lubricants, including gear and hydraulic oils, leaked into the Pacific Ocean after the tug ran aground in October 2016.
The TSB found that the second mate had been working a schedule that did not allow for sufficient rest while off duty. It said the second mate had been alternating between six hours on duty and six hours of rest for more than two days. TSB recommended that watchkeepers be trained to help identify and prevent the risks of fatigue, and that all vessel owners have fatigue-management plans tailored to individual operators.
The TSB report also found that the spill response and recovery efforts were within prescribed time standards, but that there had been confusion about who had authority over the operation.
The board also noted that keeping watch alone on the bridge of the tug would have been contrary to Canadian regulations.
The U.S. National Transportation Safety Board released a report in November which said that Houston, Texas-based Kirby Offshore Marine had implemented safety management procedures ineffectively, which contributed to the accident. It also found that there was a lack of documentation on safety rounds and no evidence that safety management rules were implemented on board.
2001-built, USA-flagged 302gt Nathan E Stewart is owned and managed by K-Sea Operating LLC of East Brunswick, New Jersey, USA.
http://www.bst-tsb.gc.ca/eng/rapports-reports/marine/2016/m16p0378/m16p0378.asp