An explosion and fire aboard a barge was the result of a lack of effective maintenance and safety management of the vessel by the Bouchard Transportation Company, the National Transportation Safety Board (NTSB) said in a report released Thursday, May 9.
The subsequent accident brief states the October 20, 2017, explosion aboard the articulated tug and barge (ATB) Buster Bouchard/B No 255 (pictured) some three nautical miles off Port Aransas, Texas, was caused by the ignition of flammable vapour that formed in a void space. The vapour was from crude oil that leaked into the void space from the number one port cargo tank through a corroded bulkhead.
Two barge crewmembers who were on the bow were killed in the explosion while about 2,000 barrels of crude oil were discharged from the barge into the water or were consumed in the ensuing fire.
The barge sustained more than US$5 million in damage and was scrapped after the accident. The tug was not damaged.
NTSB investigators documented cracks in the area of the original bulkhead that were not repaired prior to the explosion. These cracks compromised the integrity of the cargo containment of the number one port tank.
The NTSB's report noted US Coast Guard inspectors who examined the barge prior to the accident failed to identify unsafe conditions, which allowed the vessel to continue to operate at an increased risk to the crews, the environment, and the port facilities.
Further, the American Bureau of Shipping (ABS) failed to act on its surveys that also highlighted discrepancies regarding the substandard performance and hazardous conditions of B No 255.
The NTSB also found no indication of collaborative communications between ABS and the coast guard regarding deficiencies discovered by either organisation prior to the explosion. The lack of communication between ABS and the coast guard prevented a coordinated effort to evaluate the structural condition of the tank barge.
The NTSB concluded in its report that the ineffective inspections and surveys by both the coast guard and the ABS and failure to correct unsafe conditions contributed to the accident.
Based upon the findings of its investigation, the NTSB issued safety recommendations to both the ABS and the coast guard seeking the establishment of joint policy and procedures to share information including results from findings from audits, surveys, examinations, inspections, and all other applicable activities related to vessel safety.
The NTSB also issued one safety recommendation to Bouchard Transportation to evaluate its safety management system with a third party to identify deficiencies.