Lessons learned: Sitting while navigating is one step towards further relaxation

The Nautical Institute draws lessons learned from an incident where an ATB ran aground after the officer of the watch alone on the bridge, fell asleep. 

Atug was pushing an oil barge in ballast, so that the two units were operating as an articulated tug and barge (ATB). The OOW took over the watch at 23:00. The vessels were in confined coastal waters with little or no other vessel traffic, light winds and some rain.

The OOW was alone in the wheelhouse acting as navigator and lookout. At 00:20 the OOW made a planned course alteration to port. Some 30 minutes later, a further planned course alteration was missed because the OOW had fallen asleep in the bridge chair.

A few minutes after 01:00, the ATB struck a charted reef. The impact woke the OOW. He immediately reversed both engines and placed the rudders hard to port. The Master, awoken by the impact, went to the wheelhouse and took over the watch. The tug’s starboard engine was disabled, so the Master attempted to reverse off the reef with the port engine while moving the rudder hard over, port to starboard. The ATB pivoted but remained aground.

The Master reported the casualty to shore authorities. Sea conditions worsened and some fuel from the tug was leaking into the sea. The tug’s crew was evacuated some eight hours after the grounding due to the worsening situation. Clean-up and tug salvage operations continued for the next 40 days. The tug was declared a total constructive loss while the barge was salvaged and repaired.

The investigation found, among other things, that the OOW suffered from several fatigue inducing factors at the time of the grounding, including sleep disruption both acute and chronic, circadian rhythm disruptions, and individual factors (ie his inability to nap during ‘off’ hours). In other words, he was fatigued.

Lessons learned

• ‘Sleep hygiene’ is a critical element of safety in the transportation industry, yet one that is mostly self-managed. Take it seriously.
• Sitting while navigating is one step towards further relaxation. Standing and moving (between navigation instruments?) means you are unlikely to experience a micro-sleep and may help your situational awareness.
• source : safety4sea