On August 21, 2020, about 0802 central daylight time, the US-flagged dredge
Waymon Boyd struck a submerged 16-inch liquid propane pipeline 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 vessel 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, valued at $9.48 million, was a total loss. The cost of pipeline damage was $2.09 million. The cost of physical damage to the EPIC facility was $120,000.
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We determined that the probable cause of this 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 accident occurred because the Waymon Boyd’s rotating cutterhead struck Enterprise Products’ pipeline TX219, breaching the pipeline, which allowed propane gas to escape, surround the dredge, and ignite within the engine room, causing the explosion. Inadequate planning and risk management by the dredging company, Orion Marine Group, meant that not enough controls were in place to mitigate the risk of the cutterhead breaching pipeline TX219.
We also found that the engineering drawings for the dredging project were deficient, which led to the Orion Marine Group project engineer misinterpreting information within the drawings and communicating incomplete and inaccurate information during the “one-call” (“Call Before You Dig”) process, which dissuaded Enterprise Products from protecting pipeline TX219 in accordance with the company’s damage prevention program.
Pipeline protection measures specific to dredging, such as greater collaboration between pipeline operators and dredging companies, sharing GPS coordinates of pipelines, improved marking requirements, and tolerance zones for dredging, could have prevented this accident.
As a result of this investigation, we made recommendations to the companies involved in the accident to implement or update policies and procedures for dredging near pipelines. We also made recommendations to a federal regulator and industry organizations about developing additional guidance and training specific to pipeline protection for marine dredging projects and establishing tolerance zone guidance for marine construction and dredging projects near pipelines.