NTSB identifies insufficient training, lack of oversight in McCain collision

NTSB identifies insufficient training, lack of oversight in McCain collision Image: US Navy

The US National Transportation Safety Board (NTSB) has said that the August 21, 2017, collision between the US Navy destroyer USS John S McCain and the commercial tanker Alnic MC was caused by insufficient training, inadequate bridge operating procedures, and a lack of operational oversight.

Ten sailors aboard John S. McCain died in the accident and 48 were injured when the ships collided in the Middle Channel passage of the Singapore Strait Traffic Separation Scheme. There were no injuries to the crew of Alnic MC.

Property damage resulting from the collision exceeded US$1.2 million. There was no report of pollution associated with the accident.

The collision happened when John S. McCain, an Arleigh Burke-class destroyer with a crew of 280, and Alnic MC, a Liberian-flagged chemical tanker carrying a partial load of cargo with a crew of 24, were transiting towards Singapore in the westbound lane of the Singapore Strait Traffic Separation Scheme.

The Singapore Strait is one of the busiest waterways in the world, with more than 83,700 vessels of more than 300 tonnes each transiting the strait in 2016.

The NTSB determined the probable cause of the collision was a lack of effective operational oversight of the destroyer by the US Navy, which resulted in insufficient training and inadequate bridge operating procedures.

Contributing to the accident were the John S. McCain bridge team's loss of situation awareness and failure to follow loss of steering emergency procedures, including the requirement to inform nearby vessel traffic of their perceived loss of steering. Also contributing to the accident was the operation of the steering system in backup manual mode, which allowed for an unintentional, unilateral transfer of steering control.

As John S. McCain entered the Singapore Strait, steering and thrust were being controlled by a single watchstander, the helmsman, from the helm station. The commanding officer directed the lee helm station be manned as well and the crew took actions intended to transfer propeller thrust control from the helm to the lee helm station.

The NTSB concluded that during the process of shifting thrust control, a watchstander unintentionally transferred control of steering from the helm to the lee helm station which resulted in a perceived loss of steering by the helmsman, though steering control was available at all times in the accident sequence.

The unintentional transfer was possible because the system was being operated in backup manual mode, which removed a safeguard against inadvertent transfer of steering control.

The NTSB also concluded in its report that the inability to maintain course due to a perceived loss of steering, the mismatch of port and starboard throttles producing an unbalanced thrust, and a brief but significant port rudder input from after steering combined to bring John S. McCain into the path of Alnic MC.

John S. McCain's critical controls while the destroyer was in close proximity to other vessels increased the risk of an accident, the report added.

Based upon its investigation of the collision, the NTSB issued seven safety recommendations to the US Navy seeking:

  • Issuance of permanent guidance directing destroyers equipped with the Integrated Bridge and Navigation System to operate in computer-assisted steering modes, except during an emergency.
  • Issuance of guidance to crews emphasising the importance of appropriate use of very high frequency (VHF) radio for safe navigation.
  • Ensuring design principles in ASTM International Standard F1166 are incorporated when modernising complex systems such as steering and control systems within the Integrated Bridge and Navigation System.
  • Revision of written instructions for bridge watchstanders on destroyers equipped with the Integrated Bridge and Navigation System to include procedures for shifting steering and thrust control between all bridge stations.
  • Revision of Integrated Bridge and Navigation system technical manuals to include a description of and procedures for ganging and unganging throttles.
  • Revision of training standards for helmsman, lee helmsman, and boatswain's mate of the watch for destroyers equipped with the Integrated Bridge and Navigation System to require demonstrated proficiency in all system functions including transfer of steering and thrust control between all bridge control stations.
  • Instituting Seafarers' Training, Certification, and Watchkeeping (STCW) Code rest standards for all crewmembers aboard naval vessels.
  • The US Navy is acting on a number of its own measures to address safety issues identified in the wake of the John S. McCain accident and other recent western Pacific region accidents.

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