(WASHINGTON) — On Friday, Aug. 21, about 8:05 a.m. Central Daylight Time, the U.S.-flagged, non-propelled, 152-foot-long cutterhead suction dredge Waymon L. Boyd reportedly struck a submerged 16-inch liquid propane pipeline during dredging operations adjacent to EPIC Corpus Christi Marine Terminal, located on the Inner Harbor of the Corpus Christi Ship Channel in Corpus Christi, Texas. A geyser of gas and water erupted adjacent to the vessel. Shortly thereafter, the gas plume ignited, and fire consumed the vessel and surrounding shoreline.
Several other vessels assisted Waymon L. Boyd during dredging operations, including workboats, anchor barges, booster barges and a supply barge. Eighteen personnel employed by Orion Marine Group were working on the dredge and assist boats on the day of the accident. Four crewmembers died. Local first responders located the victims and took six of the 14 surviving crewmembers to burn units in San Antonio, Texas. No members of the public were injured in this accident.
The fire aboard the dredge was extinguished by 4:10 p.m. local time. However, at 8:30 p.m., the fire temporarily reignited and was reported to be out by 9:30 p.m. The dredge sank overnight.
The damaged pipeline (TX219) was a 16-inch liquid propane line operated by Enterprise Products Operating LLC, and was installed in 1968. An underwater segment of the pipeline was in close proximity to the area where Orion Marine Group was conducting dredging operations. At the time of the accident, the Enterprise Products pipeline controller received a low-pressure alarm on pipeline TX219. Enterprise Products technicians subsequently closed valves upstream and downstream of the incident location to isolate the pipeline. The estimated release of propane from the pipeline was about 6,000 barrels.
The U.S. Coast Guard declared the accident a major marine casualty. The National Transportation Safety Board (NTSB) is the lead federal agency for the safety investigation. The Coast Guard, Orion Marine Group (owner/operator), Enterprise Products Operating, LLC (pipeline operator), the U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration, and the Railroad Commission of Texas were named as parties to the investigation.
Investigators have interviewed several of the surviving crewmembers and company personnel, and collected documents regarding the dredging operations, crew training, and pipeline marking and damage prevention requirements. On Aug. 24, an underwater inspection found evidence of mechanical damage and two wall breaches in the pipeline. Waymon L. Boyd’s cutter dredge head has been recovered and is being transported to a secure location for examination. On-scene work will continue with the removal of the damaged pipeline for further examination and testing at NTSB’s laboratory, as well as interviews with additional crew and company officials.
– National Transportation Safety Board preliminary report