The National Transportation Safety Board (NTSB) determined that a lack of requirements for crewmembers to regularly check below-deck compartments likely led to the January 2023 capsizing of the dredging vessel WB Wood near New Orleans.
No one was hurt in the incident, which happened at about 0050 on Jan. 16, 2023, on the Lower Mississippi River about 10 miles from New Orleans. But about 5,500 gallons of diesel oil and 100 gallons of hydraulic oil were released from the vessel, and WB Wood was considered a total loss, the NTSB said. Damage to the 135-by-35-foot dredging vessel, built in 1983, was estimated at $1.5 million.
Its one crewmember was rescued by a good Samaritan towing vessel.
The NTSB determined that the vessel sank because of undetected flooding from a through-hull pipe that was missing its overboard check valve and subsequent progressive flooding from watertight bulkheads.
“Vessel crews should regularly check tanks and voids that are adjacent to the vessel’s hull to identify hull integrity issues (such as potential corrosion and steel wastage, and watertight integrity deficiencies) that can lead to flooding,” the NTSB wrote in its report. “The presence of water can indicate an issue with watertight integrity or wastage and should be addressed.”
Procedures such as setting up regularly scheduled checks should be in place for preventing and addressing the potential for water ingress and flooding, the NTSB said, and bilge alarms that can detect water at a low level in voids and other spaces also could ensure early detection.
WB Wood was owned by Avondale, La.-based Wood Resources LLC. Numerous phone and email messages seeking comment from CEO John Herron about prevention steps taken since the incident were not returned.
On Jan. 15, 2023, WB Wood was anchored near mile 85 on the Lower Mississippi, having spent the past nine days pumping sand from the riverbed to a pit on the right bank about 800 feet away. During dredging operations, the crew consisted of a leverman and deck hand.
When a shift change occurred at about 1600, nothing out of the ordinary was noted. As per company requirements, the night leverman did a routine visual inspection of the vessel and did not note any problems with the suction pump, ladder or any associated piping and equipment. He did not check any compartments or spaces in the hull beneath the main deck.
The NTSB found that a daily inspection checklist included checks for engine oil levels, fuel levels, leaks in suction and discharge pipes, ladder cracks and other conditions but did not require checks of hull tanks, compartments or hatches for leaks or watertight integrity.
The night leverman later told investigators that during dredging work that night, at about 2240, he noticed the dredge was listing to starboard. He took the dredge out of gear and raised the ladder off the river bottom but not out of the water, then went to the main deck to determine the cause of the listing.
“When he opened the watertight door leading down to the starboard storage space, he saw that the space was completely full of water (up to the door threshold). He did not see an oil film or smell fuel. He recalled that, at the time, there was river water on the main deck aft, but water was not entering the storage space through the watertight door,” the NTSB report said.
The leverman called his supervisor, who told him to pump the space out, which he started doing. He told investigators that at that point, the problem “wasn’t that big of a deal yet” but that just before midnight, when the deck hand rode a skiff to pick up a gas-powered dewatering pump from a nearby barge, the flooding was becoming a bigger issue.
When returning to the vessel with the pump, the night deck hand saw “a massive amount of water across the back deck and the boat was leaning toward the starboard stern.” The two men resumed pumping but soon the pumps could not keep up with the water coming in.
By 1242, the leverman told investigators, the dredge was going to “go over” and that everything was “creaking really bad.”
The captain of Omaha, a nearby towing vessel that had been summoned to help, said the entire starboard side of the dredge was underwater as he approached and that soon the lights went out and WB Wood began to roll over.
When that happened, the night leverman, alone on the boat awaiting a torch kit the deck hand had left to get, jumped into the river without a lifejacket. Omaha’s deckhand pulled him on board to safety.
The non-propelled WB Wood remained afloat, upside down, and a boom was deployed to contain any pollution.
The NTSB report noted that during its first job after an April-May 2022 dry-dock period, WB Wood experienced flooding in three aft spaces but no one ever found out why that had happened. The report said the night leverman and deck hand tested negative for alcohol and drugs after the capsizing.
Investigators found water marks, corrosion, wastage holes and rust scale along the bottom 10 inches of the transverse bulkhead, forward of the aft starboard void space, indicating that water normally pooled there. •