NTSB Releases Preliminary Report Detailing Dredge-Related Explosion In Corpus Christi
The National Transportation Safety Board (NTSB), which is conducting an investigation into an August 21 fire aboard the cutterhead dredge Waymon L. Boyd, has released a preliminary report on the accident, which occurred on the inner harbor of the Corpus Christi Ship Channel.
While not final, and subject to further investigation, the preliminary report offers the clearest picture yet of what led to the explosion and fire aboard the Orion Marine Group dredge.
At about 8:05 a.m. August 21, the dredge “reportedly struck a submerged 16-inch liquid propane pipeline,” according to NTSB’s preliminary report. The Waymon L. Boyd was dredging adjacent to EPIC Corpus Christi Marine Terminal.
After striking the pipeline, a “geyser of gas and water erupted adjacent to the vessel,” according to NTSB. Then, the gas spewing from the ruptured pipeline ignited, triggering a fire that consumed the dredge. According to NTSB, 18 people were working aboard the Waymon L. Boyd and nearby assist vessels at the time of the accident. Four members of the crew died. First responders took six of the surviving 14 crew members to burn units in San Antonio, Texas, the preliminary report said.
The fire aboard the dredge was largely extinguished by 4:10 p.m. that afternoon. The fire reignited later that night but was reportedly extinguished again by 9:30 p.m. The dredge sank overnight.
In the preliminary report, NTSB identified the pipeline as TX219, a pipeline operated by Enterprise Products Operating LLC. NTSB said an Enterprise Products pipeline controller received the low pressure warning at the same time as the incident and closed valves upstream and downstream of the rupture. According to NTSB, an estimated 6,000 barrels of propane was released.
Agencies involved in the investigation include NTSB, the lead federal agency; the U.S. Coast Guard; Orion Marine Group, owner of the dredge; Enterprise Products Operating LLC, the pipeline operator; the U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration; and the Railroad Commission of Texas.
NTSB said the agency has conducted interviews with several Waymon L. Boyd crew members and collected documents related to dredging operations and pipeline marking. NTSB said an August 24 underwater inspection of the pipeline found “evidence of mechanical damage and two wall breaches in the pipeline.” The cutter dredge head from the Waymon L. Boyd has been recovered and “is being transported to a secure location for examination.”
Ongoing work includes efforts to remove the damaged pipeline for further testing, “as well as interviews with additional crew and company officials,” the preliminary report said.
To view the report, go online to www.ntsb.gov/investigations/accidentreports and look for the report titled “DCA20FM026.”