NTSB examination: The towing ship causes the collapse of the dock

The incident

ON 25 April 2023, at around 0004 local time, the towing ship Ovide J Passed two loaded raw oils to the chalmette -Raffinerie -Raw Öldock near Mile 89 on the lower Mississippi river in Chalmette, Louisiana, when the taxboard load barge contacted the dock. This led to the collapse of about 150 feet of the dock into the water. No injuries or pollution were reported, but the pipelines, bridges and piles of the dock were damaged in detail with estimated repair costs of 7 million US dollars.

analysis

In the early morning of April 25 Ovide J Passed two loaded crude oils to the chalmette refinery raw oil dock when the taxboard ships contacted the number. 3 Delphin transfer platform, which collapses the dock.

The experienced auxiliary captain had planned almost 20 times this place this year, even at the beginning of this week. He explained: “If I had to do it again, I would do it again. I wouldn't change anything. ” The Ovide JThe approach was at a controlled speed (less than 0.5 miles per hour) and in a flat angle. The tow was not separated as a result of the contact, and the onboard recording showed no torn movement, which indicates no major influence on the towing vessel. The Fender Hölzer or the stack of the Bonge EMS 348 contact did not damage.

In an inspection report from 2017, a major deterioration of several horizontal brackets between Delphin no. Determined. 3 piles that determine a severe deterioration of two stacks and shift of all stacks towards the coast. A visual structural inspection of 2021 resulted in damage such as separate joints and corrosion on the dolphin no. 3 transfer platform. Although a complete inspection was recommended, the dock owner had not acted on the recommendation at the time of collapse, which occurred about 1 year and 5 months after the inspection of 2021.

The observed deterioration showed that the structural integrity of the dock had been severely affected. The collapse, which resulted from apparently low contact with low effective docking, indicates that the dolphin no. 3 The transfer platform could not maintain the forces of a typical dock. The Dock owner was aware of the structural problems before the collapse, but had not taken any steps to tackle them. Since the collapse, the Dock owner has initiated measures to monitor the integrity of the dock more precisely.

Probable cause

The National Transportation Safety Board notes that the likely cause of the breakdown of a section of the challmetten refinery raw oil dock during the dock of the Ovide J Towing was the degraded state of No. 3 Delphin transformer platform structure.

Download the report here