Navigate safely: Keep water out of service tanks

ISSN 2369-873X

15 December 2017
Posted by Mélissa St-Jean

Over the last few years, we have seen significant changes take place in the marine industry. Increased traffic, variation in fuel prices and emerging technologies have all impacted the way we navigate our waterways. What hasn't changed is the need to navigate safely, which remains a top of mind priority.

Recent TSB investigations have highlighted a safety issue with respect to engine room practices aboard ships, more specifically regarding fuel oil service tanks (service tanks). Investigators discovered that not all vessel procedures include the practice of regular draining, even though this practice is well known in the industry.

Image of TSB investigator Luc Charbonneau in a vessel's engine room
TSB investigator Luc Charbonneau
in a vessel's engine room

Preventing water accumulation in service tanks is crucial, because when water accumulates, there is a risk of engine shutdown or power loss, which can make the vessel more challenging to control. Keeping the water out of the tanks is the first and most important step. Unfortunately, there is no way of ensuring that water stays out. A simple change in the tank's temperature can create condensation. This is why it's so important to regularly drain service tanks: it is the most effective way to prevent water accumulation.

Looking into an occurrence involving the grounding of a vessel, TSB investigators learned that the main engine's revolution (rpm) had suddenly dropped, reducing the oil pressure in the main gearbox to the point where the vessel's safety system shut down the main engine. Because appropriate action to control and anchor the vessel was taken, crew members were able to prevent damage and pollution to the environment. Investigators determined that the presence of water in the service tanks had caused the main engine to lose power and reduce rpm. The vessel's maintenance procedures did not include the practice of regularly draining service tanks.

The presence of water in service tanks will not automatically cause the engine to shut down. But if appropriate steps to keep it out are not taken, it will accumulate rather quickly and put the vessel, its crew and the environment at risk. Proper draining is a simple way to proactively reduce the risk of engine failure and potential accidents.


Image of Mélissa St-Jean

Mélissa St-Jean has been a senior marine investigator at the Transportation Safety Board of Canada (TSB) since 2016. Prior to joining the TSB, Mélissa has worked at the Canadian Coast Guard for 10 years in various positions She also worked as Marine Safety Coordinator for the Société des traversiers du Québec. She is a mother of 2 and an outdoor enthusiast.

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