美國國家運輸安全委員會(National Transportation Safety Board)周三表示，去年在休斯頓航道(Houston ship Channel)，一艘拖船在進行港口輔助機動時速度過快，導致與一艘集裝箱船相撞。
拖船George M和集裝箱船MSC Aquarius于2022年4月14日相撞，當時拖船正在進行船舶輔助機動，集裝箱船正在休斯頓船舶航道向北航行。沒有人員傷亡的報告。大約1000加侖的齒輪油從受損的George M號左舷推進裝置中釋放出來。兩艘船的損失總額超過90萬美元。
George M號和另一艘拖船正在執行港口輔助操作，將MSC Aquarius號?？吭诖a頭。George M被分配到集裝箱船船頭的“前導中心”位置。為了接近MSC Aquarius號的船首，拖船必須在集裝箱船前面進行船頭對船頭的機動。相撞時，George M號上的大副正在操作拖船。這是這位大副第一次在“George M”船上輪崗。
大副本可以要求MSC Aquarius的引航員減速，但在被分配到中導位置后，大副沒有與引航員溝通。引航員不知道拖船的狀況，也不知道需要減速。美國國家運輸安全委員會認為，碰撞的可能原因是“George M”號大副試圖在拖船和集裝箱船以超過港口輔助機動的速度通過時進行艏對艏調整。
Excessive speed during an advanced harbor-assist maneuver led to a tugboat colliding with a container ship in the Houston Ship Channel last year, the National Transportation Safety Board said Wednesday.
The tugboat George M and container ship MSC Aquarius collided on April 14, 2022, while the tugboat was positioning for a ship-assist maneuver and the container ship was transiting north in the Houston Ship Channel. No injuries were reported. About 1,000 gallons of gear oil were released from the damaged George M’s port propulsion unit. Damages to both vessels totaled more than $900,000.
The George M and another tugboat were performing a harbor-assist operation to dock the MSC Aquarius at the terminal. George M was assigned the “center lead forward” position on the bow of the container ship. To make up to the bow of the MSC Aquarius, the tugboat had to maneuver into position ahead of the container ship, bow-to-bow. The mate on the George M was operating the tugboat at the time of the collision. It was the mate’s first rotation on board the George M’s class of vessel.
In maneuvering the George M to the center forward position, the mate approached the container ship as it was transiting at 9.7 knots. While attempting to connect its line to the container ship, the tugboat moved out of the centerline. The mate attempted to maneuver the tugboat back to the centerline but was unable to regain position. The mate’s attempt resulted in two collisions between the vessels.
The mate could have requested the pilot of the MSC Aquarius to slow, but the mate did not communicate with the pilot after being assigned to the center lead forward position. The pilot was unaware of the status of the tugboat or the need to slow. The NTSB determined the probable cause of the collision was the George M mate’s attempt to make up bow-to-bow while the tugboat and container ship transited at a speed that was excessive for the advanced harbor-assist maneuver.
Contributing to the collision was George M mate’s lack of experience operating the tugboat.
“The risk of a casualty during bow-to-bow harbor-assist operations with azimuthing stern drive (ASD) tugboats increases with increasing speed. Hydrodynamic forces around an assisted vessel’s bow increase exponentially with speed, while the amount of reserve propulsion power available to the tugboat operator decreases,” the report said.
“Owners and operators of ASD tugboats that perform bow-to-bow harbor-assist operations should set speed limits for these maneuvers. These limits may vary for different classes of tugboats based on design. Tugboat operators should communicate these pre-determined speed limits to ship masters or pilots in command of the vessels that they are assisting before engaging in these maneuvers.”