The crawler crane operator was moving aft on a spud barge off the Virginia coast when he noticed the tracks rising off the barge deck. He tried without success to move the crane forward.
“The crane continued to travel aft, and he felt the crane tipping over, so he opened the cab door and jumped from the crane as it went over backwards off the barge into the bay,” National Transportation Safety Board (NTSB) said in its recently released investigation report into the cause of the incident.
The crane was working on the spudded deck barge Carolyn Skaves in support of a highway construction project in Willoughby Bay, off Norfolk, Va. It went overboard on Feb. 8, 2022, at about 0725 local time.
The crane operator escaped without injury, but the $2 million crane was a total loss. An unknown amount of diesel fuel escaped into the waterway, although some was recovered.
According to the report, the probable cause of the incident was the lack of a spotter during crane movement despite company policy requiring one, and the failure of a cable system intended to keep the crane from falling overboard.
Ineffective oversight of barge operations from operator Seaward Marine was a contributing factor.
“The company was unaware that the crane operator and other workers were not following the company’s written policy, as they did not directly observe the workers’ performance or have other processes in place to ensure compliance,” the agency said in its report. “With more effective oversight, the company could have ensured that management policies and procedures were followed, thereby improving the safety of its crane barge operations.”
Seaward Marine, which is based in Norfolk, Va., did not respond to an inquiry about the NTSB findings. However, an internal company investigation cited by the NTSB found that the crane operator should have asked a co-worker to serve as a spotter.
“The (company safety) director learned during his investigation that the employees working on the Carolyn Skaves had not always assessed hazards, nor had they always used a spotter for previous crane movements,” according to the NTSB findings.
The crane used aboard the barge was a Liebherr 1300.1SX model mobile hydraulic lattice boom crawler. Crews operated the crane from the aft end of the barge atop a mat of hardwood timbers used to disperse the crane’s weight.
Federal regulations required the use of a centerline cable system that allowed the crane to move forward and backward on the mat. The system was connected to the deck via brackets on the deck forward and aft of the mat.
The wooden mats also had a required “stop mark” painted on the wood slats to indicate safe positions. Turnbuckles on either side that were connected to the barge deck were intended to keep the crane from tipping sideways.
Seaward Marine leased the 180-foot Carolyn Skaves to support construction on the Hampton Roads Bridge Tunnel in Norfolk, Va. Workers arrived on the barge about 0700 on the morning of the incident and completed a pre-work assessment.
The foreman was shoreside for meetings and not present for the assessment, and crew later told investigators the pre-work assessment did not discuss crane movements.
“Had they done so,” the report said, “the workers may have realized a spotter was needed (per written company policy) to monitor the crane’s movement.”
The day’s work involved installing bridge girders, and the task required special crane rigging. The crane operator set about moving the crane further aft to attach that equipment. Before getting started, another worker released the turnbuckles that helped secure the crane on the barge deck.
“After lowering the block to its desired height, the crane operator began moving the crane aft, using the pedals to move each track,” the NTSB report said. “The operator told investigators that as he moved the crane aft, he heard a noise on his left and thought the crane’s steps had hung up on something.
“He quickly looked to his left and right and then looked for the aft stop mark painted on the timber mat near the forward end of his left track,” the report continued. “He stated that he saw that he was beyond the stop mark and released the pedals that he used to move the crane aft.”
At that point, despite his efforts to move forward, the crane continued going aft until it fell off the barge. Diesel fuel from the crane created a sheen roughly 75 feet by 75 feet. Crews used sorbents to recapture some of the fuel.
Investigators determined the cable system failed before the crane went overboard. They suggested noise the crane operator heard just before falling off the barge was the cable striking the crane after disconnecting from a deck bracket.
“A centerline cable system of sufficient strength, per OSHA regulations, would have prevented the crane from being driven off the barge,” the NTSB report said. “Measures to secure the crane on the barge such as the cable system are the last line of defense to keep a crane on board a barge.”
Further, the agency said the crane operator likely lost situational awareness as he moved aft on the wooden mat. Without a spotter present, there was nobody to warn him of the impending danger.
Seaward Marine adopted several new policies as a result of this incident. One such change requires the use of barricades when the crane is disconnected from the turnbuckles. The company also held a meeting with its employees to highlight lessons learned.