Insufficient monitoring and ineffective bridge resource management led to grounding

TSB investigation report of the tanker Nanny, run aground in Nunavut

The Transportation Safety Board of Canada (TSB) hasreleased its finalinvestigation report into the grounding of the tankerNanny in the Chesterfield Narrows, Nunavut.

On 25 October 2012, theNanny departed Baker Lake, Nunavut for Lewisporte, Newfoundland and Labrador, then anchored north of Chesterfield Narrows to await high tide before continuing the passage.

Tanker Nanny / Image Credit : Canada TSB report

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In this occurrence, theNanny was initially required to proceed off the charted course in order to pass another tanker. Once clear of the other tanker, instead of returning to the planned route, theNannycontinued on a roughly parallel course that was off the charted route by distances of up to 0.12 nautical miles (nm).

This deviation continued even as the vessel turned into Chesterfield Narrows, an area marked by unlit range beacons, that allows for little margin of error; the vessel ran then aground on a shoal.

Two days later, the vessel came off the shoal due to strong winds and proceeded towards St. John’s, Newfoundland and Labrador for repairs. No injuries or pollution were reported.

The investigation found that theNanny ran aground because it deviated from the charted route when passing another tanker after departing the anchorage and did not return to it.

The route deviation was not discussed by the bridge team, nor did they share navigational information throughout the voyage. Due to insufficient monitoring of the vessel’s navigation and ineffective bridge resource management, the bridge team was unaware of the extent to which the vessel was off the charted course as it entered the narrows.

Since the accident, the vessel operator initiated a confined waters policy. This policy includes improved procedures to mitigate the risks of entering and sailing through confined waterways.

The operator enhanced and accelerated its personnel training plan for bridge resource management and vessel handling. The operator has also implemented voyage data recorder training to ensure that available voyage data will be preserved after any incident.

Findings

Causes/ Contributing Factors

The vessel ran aground when it deviated from the charted route upon departure and did nto return to il. This deviation was not dscussed by the bridge team members, nor did they share navigational information throughout the voyage
The deviation from the charted route continued as the vessel turned into Chesterfield Narrows. Prior to the grounding, after turning into the narrows, the master focused his attention on manoeuvring the main engine controls and thrusters, rather than monitoring the navigation of the vessel
Due to insufficient monitoring of the vessel’s navigation and ineffetive bridge resource management, the bridge team was unaware of the extent to which the vessel was off the charted course as it entered the narrows.
Available navigation aids were not adequately cross- referenced, nor were they optimally set up to facilitate navigation
The searchlights were not used to visually confirm that the vessel was lined up wiith the range beacons.

Risk

If navigational equipment and its associated features, such as alarms, are not optimally configured, potentially useful information to assist in the vessel’s safe navigation may not be available to bridge teams
Without formal training and continued proficiency in the principles of bridge resource management for all bridge officers, there is an increased risk that bridge team awareness and effectiveness will be impaired, thereby increasing the risk to the vessel, its crew and the environment
Without a complete and formal assessment of a vessel’s seaworthiness prior to a refloating attempt, as well as readily available search and rescue resources, there is a risk that such attempts may place a vessel, its crew, and the environment at risk.
Not promptly reporting occurences to appropriate authorities during an emergency may prevent a timely and coordinated response
If data from the voyage data recorder/ simplified voyage data recorder are not available to an investigation, this may preclude the identification and communication of safety deficiencies to advance transportation safety.

Other

The availability of lit range beacons would enhance the ability to navigate safely in Chesterfield Narrows at night

According to the report, the company initiated a confined waters poliy as safety action. Many of the waterways in which the company operates are extremely narrow, with insufficient sea room for equipment failures or emergency manoeuvres. Prior to entering a confined waterway, their Entry into Confined Water Checklist must be completed to ensure reasonable precautions are taken to guard against grounding or collision. The master is encouraged to add any other items deemed appropriate to this checklist through his or her standing orders.

More information may be found at Marine Investigation Report issued by Transportation Safety Board of Canada (please click at image to download the report)