The US National Transportation Safety Board (NTSB) has found that the erratic steering of a supply vessel led to a collision resulting in more than 22,000 litres of diesel oil being dumped into the Sabine Pass, a busy waterway between Texas and Louisiana, on November 14, 2019.
The NTSB said the probable cause of the collision between the offshore supply vessel (OSV) Cheramie Bo Truc No 22 (pictured) and the articulated tug and barge (ATB) Mariya Moran/Texas in the Sabine Pass Jetty Channel in Port Arthur, Texas was the OSV turning into the path of the ATB.
Damages from the collision exceeded US$1.8 million, and the waterway was closed for a time for the diesel oil spill cleanup.
During the accident sequence, the on-watch AB and engineer expressed concern to the mate of Cheramie Bo Truc No 22 regarding the latter's erratic steering. The mate ignored them, yet neither the on-watch AB nor the engineer notified the captain.
A post-collision alcohol test administered by the OSV's captain indicated the mate had drank recently but did not demonstrate conclusively that the mate was impaired by alcohol.
"However," the NTSB report said, "attempting to use the autopilot in a channel, nearly colliding with stationary jackups, weaving across the channel, ignoring the warnings from the on-watch AB and engineer in the wheelhouse, and suddenly turning in front of [Mariya Moran/Texas] all indicate a degree of misjudgment, impairment, and/or incompetence."
Contributing to the collision was a lack of early communication from both vessels.
"Safe and effective navigation is not one person's job," the NTSB report added. "Bridge resource management includes the concept of teamwork, which is an essential defense against human error. A good team should anticipate dangerous situations and recognize the development of an error chain. If in doubt, team members should speak up or notify a higher authority. Vessel operators should train their crews on and enforce their safety policies."