NTSB: Fatigue and "Microsleep" Caused Seattle Ferry Accident
Fatigue and complacency were behind the allision of a Washington ferry and a mooring dolphin at the Fauntleroy terminal in Seattle last year, the National Transportation Safety Board said Thursday. The accident caused $10 million in damage to the vessel and $300,000 in damage to the dolphin.
At about 0800 on July 28, 2022, the ferry Cathlamet was making a routine crossing of the Puget Sound with 94 people aboard. The master took over the helm from his quartermaster at 0810 in preparation for docking. As the ferry approached the Fauntleroy Terminal in West Seattle, it drifted off course. At 0814, four minutes after the master took the helm, it struck a dolphin adjacent to the pier at a speed of 16 knots. One person sustained a minor injury, and two passengers narrowly escaped from harm's way as the dolphin stove in the vessel's topsides. The ferry sustained extensive damage.
The moment of contact, as captured by a security camera aboard Cathlamet (WSF/NTSB)
The vessel was still moving forward after the impact, and it risked hitting a cluster of anchored watercraft next to the terminal. The quartermaster instructed the master to "back out" three times, after which the master put both engines astern and halted the ferry's motion.
According to NTSB, the master stopped making rudder commands about 30 seconds before impact and did not take any action to avert the accident or minimize damage, like backing down or sounding the general alarm. In interviews with investigators, he had no recollection of the moments leading up to the accident.
The master’s work/rest history showed that he had been sleeping 5 to 6 hours a night in the days before the casualty, and he told the Coast Guard that he had had a hard time sleeping because of the heat (Seattle was experiencing a heat wave at the time). The quartermaster told investigators that the master was “always tired in the morning.”
According to NTSB, the evidence was consistent with a "microsleep," a brief period of sleep caused by fatigue.
“Fatigue affects all aspects of human performance, including decision-making, alertness, and reaction time,” NTSB investigators concluded. “Mariners should understand the performance effects of sleep loss and recognize the dangers of fatigue, such as microsleeps."
The NTSB also found that Cathlamet's quartermaster was not monitoring the master as the ferry neared the dock, as is required by company policy. Instead, he was located towards the aft end of the wheelhouse and was focused on reading a company memo. If he had been watching closely, he could have taken over the helm when the master was asleep. NTSB marked this down to "complacency," and noted that extra vigilance is required to prevent complacent attitudes for "repetitive operations, such as ferry transits."
The day after the casualty, the master retired from Washington State Ferries, surrendered his Merchant Mariners' Credential and ceased providing information for the investigation, according to NSTB.