Towboat Flooding Caused by Pre-Existing Hull Fractures
The U.S. National Transportation Safety Board has released a Marine Accident Brief about the January 7, 2019, accident involving the towing vessel Tom Bussler which was transiting upbound on the Tennessee River near Calvert City, Kentucky when she began flooding and quickly sank in the channel.
The vessel was built in 1968, and the probable cause of the flooding was the company’s lack of an effective hull maintenance and repair program which resulted in flooding into the bow voids and engine room through fractures in the hull.
No pollution or injuries were reported. Damage to the vessel was estimated at $297,368, and the vessel was scrapped.
Both the captain and deckhand stated that the bow centerline void had a pre-existing crack slightly above the waterline. The vessel was equipped with two portable sump pumps: one was placed at the bow to dewater the forward voids, and a second pump was placed on the stern to dewater the aft voids. Three voids (centerline forward, port stern and starboard stern) were pumped out daily.
Based on the numerous cracks in the Tom Bussler’s hull found during the post-accident survey, and the documented reports from the crew of water leaking into voids, investigators attempted to determine how long the watertight integrity issues had existed and what actions, if any, had been taken to mitigate them. The vessel had last been drydocked in January 2018, about a year before the accident. No hull repairs related to watertight integrity were scheduled or completed. Throughout 2018, multiple issues with the hull were reported by crewmembers. However, attempts to find the leaks were unsuccessful, and the reported issues were not resolved.
When the vessel was pushing a barge ahead, her bow was protected from the bow wave by the barge ahead, and the pre-existing fractures in the hull therefore remained above the effective waterline. However, at the time of the accident, the vessel was under way in light boat condition, without a barge to deflect water, and the bow therefore was subject to the water build up as it moved through the river
The report is available here.