The US National Transportation Safety Board (NTSB) has released its preliminary report on an incident earlier this year wherein four people were killed after a dredger caught fire in the Port of Corpus Christi in Texas.
On Friday, August 21, 2020, at about 08:05 local time, the US-flagged, non-propelled cutter suction dredger Waymon L. Boyd reportedly struck a submerged 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 work boats, anchor barges, booster barges, and a supply barge.
A total of 18 personnel employed by Orion Marine Group were working on the dredger and assist boats on the day of the accident.
Four crewmembers on Waymon L. Boyd were initially declared missing but were later found dead during subsequent search and rescue/recovery operations.
Local first responders located the victims and took six of the 14 surviving crewmembers to burn units in San Antonio, Texas.
The fire aboard the dredger was extinguished by 16:10. However, at 20:30, the fire temporarily re-ignited and was reported to be out by 21:30 p.m.
The dredger sank overnight.
The damaged pipeline was a liquid propane line operated by Enterprise Products Operating 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 the pipeline. 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 US Coast Guard declared the accident a major marine casualty.
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 August 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.
