NTSB: Survey didn't detect hazard before Louisiana pipeline strike
The tug DeJeanne Maria sank after hitting the submerged line in the Gulf of Mexico
The following is a marine accident brief from the National Transportation Safety Board (NTSB):
(WASHINGTON) — On April 15, 2019, at 0044, the towing vessel DeJeanne Maria struck the end of a submerged dredge pipeline on the Mississippi River in Pass A Loutre, 2 miles south of Pilottown, La., while pushing two spud barges to the Gulf of Mexico. Following the contact, the three crewmembers abandoned the vessel to its barges and were rescued by a good Samaritan vessel. DeJeanne Maria later sank. There were no reported injuries, but 70 gallons of diesel fuel were discharged, and damage to the vessel was estimated at $650,000.
The National Transportation Safety Board determines that the probable cause of the contact between the towing vessel DeJeanne Maria and a submerged dredge pipeline end was the last bathymetric survey not detecting the hazard, which had been brought to just below the surface due to an unsuccessful lift the day before.
Three water depth surveys were conducted in the area of the end of the submerged pipeline: in October 2018 after the pipeline was originally laid, in December 2018 when R S Weeks disconnected to temporarily relocate, and again on April 14, 2019, following the unsuccessful attempt to lift the pipe from the river bottom to reconnect to R S Weeks. DeJeanne Maria,with a draft of about 6 feet, was transiting through Pass A Loutre in the area only a day after the April 14 survey. That survey showed water depths of 6.8 to 10 feet, which was adequate for DeJeanne Maria and its two barges. The damage to the side of DeJeanne Maria was consistent with striking the bell end of the submerged pipeline, which, after the strike, was found to be only 5 feet below the river’s surface.
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