NTSB determines probable cause of dredger Waymon Boyd accident

The National Transportation Safety Board (NTSB) issued 10 safety recommendations Tuesday during a public board meeting held to determine the probable cause of the fatal Aug. 21, 2020, hazardous liquid pipeline strike and subsequent explosion and fire aboard the dredging vessel Waymon Boyd.

The Waymon Boyd struck a submerged 16-inch hazardous liquid pipeline carrying propane during dredging operations in Corpus Christi, Texas. A geyser of propane gas and water erupted adjacent to the vessel. Shortly thereafter, propane gas engulfed the dredge and an explosion occurred. Fire damaged the vessel and surrounding shoreline.

A total of 18 personnel employed by Orion Marine Group were working or resting on the dredge and assist boats (tender boats, anchor barges, booster barges and a supply barge) on the day of the accident. Three crewmembers aboard the Waymon Boyd and one on an adjacent anchor barge died in the explosion and fire. Six crewmembers aboard the dredge were injured, one of whom later died from his injuries.

The Waymon Boyd, owned by the Orion Marine Group, was a total loss valued at $9.48 million. The cost of pipeline damage was $2.09 million.

​The Enterprise Products’ pipeline TX219 was struck by the Waymon Boyd’s rotating cutterhead, causing a breach in the line that allowed propane to escape and form a gas cloud that surrounded the dredge.

Although the Waymon Boyd leverman attempted to swing the dredge away from the geyser of water that was carried with the escaping propane, the vessel was less than 200 feet away from the pipeline breach, and the expanding gas cloud enveloped it. Investigators concluded that propane gas released from the pipeline was drawn into the Waymon Boyd’s engine room by the ventilation fans and was ignited, causing the explosion.

The NTSB determined the probable cause of the accident was Orion Marine Group’s inadequate planning and risk management processes, which failed to identify the proximity of their dredging operation to Enterprise Products’ pipeline TX219 and resulted in the absence of effective controls to prevent the dredge’s cutterhead from striking the pipeline.

Contributing to the accident were deficient dredging plans provided by Schneider Engineering and Consulting, which resulted in incomplete and inaccurate information communicated to Enterprise Products by Orion Marine Group during the one-call process, which resulted in insufficient measures to protect the pipeline from excavation damage.

The NTSB identified the following safety issues during its investigation: inadequate project planning and risk assessment, pipeline damage prevention, and pipeline hazard training.