The National Transportation Safety Board (NTSB) recently published findings regarding a tugboat accident that took place on Oct. 12, 2023, in Tacoma, Wash. The incident involved an articulated tug and barge (ATB) that collided with the fender system of the Hylebos Bridge, resulting in the fender system being “damage beyond repair.”
The tugboat Olympic Scout was assisting the ATB Montlake/Sodo as it traveled outbound on the Hylebos Waterway. The captain of the Montlake/Sodo requested the bridge operator to open the Hylebos Bridge. While waiting for the opening, the ATB drifted off course, causing its bow to move left of the channel's center. Attempts by the captain to realign the vessel were hindered by drag from the Olympic Scout on the ATB's port side.
The report indicated that the distance between the Montlake/Sodo's bow and the bridge was 1,276 feet at the start of the transit. The channel width between the bridge's fenders was 150 feet, while the combined width of the Montlake/Sodo and Olympic Scout was 104 feet, leaving a 23-foot clearance on either side. The NTSB concluded that the speed of the ATB and the limited distance to the bridge did not allow sufficient time for the captain to adjust the vessel's alignment before the collision with the fender system.
"Because of the short distance to the bridge and the speed of the ATB, there was insufficient time to correct the lineup before the Olympic Scout struck the fender," the report stated. Investigators noted that slowing or stopping the ATB earlier could have allowed more time for safe navigation through the bridge opening.
The Hylebos Bridge itself remained undamaged, but the fender system was rendered unusable and required replacement. A marine surveying and consulting firm reported that the fender system's poor condition contributed to the extent of the damage incurred during the contact. "The damage caused by the [Olympic Scout contact] resulted in more damage than would have occurred had the fendering structure been sufficiently strong," the firm noted.
The findings highlight the need for maintaining marine infrastructure and ensuring navigational practices prioritize safety to prevent similar occurrences in the future.
Marine Investigation Report 24-26 is available online.
