NTSB cites use of single barge couplings in high water for breakaway
Two barges carrying sand and gravel struck a fireboat and bridge pier in downtown Nashville, Tenn., after coming loose from their tow on the Cumberland River.
The incident, reported at 2250 on June 6, 2017, happened while the towboat James H. Hunter pushed upriver with a three-barge string to a nearby terminal during high water. National Transportation Safety Board (NTSB) investigators traced the initial failure at mile marker 191.1 to the port steering coupling between the face-up barge and the middle barge.
The leading cause of the allision, according to the NTSB, “was the practice of using single barge couplings (one each on the port and starboard sides instead of two) in high-water conditions, which resulted in the parting of a steering coupling after rudder input to counteract the strong current.”
James H. Hunter was operated by Hunter Marine Transport at the time but is now part of Hines Furlong Line. According to the NTSB report, Hines Furlong has developed new safety procedures that include doubling up rigging at the couplings — even for short voyages.
James H. Hunter got underway from the company’s fleeting area at Cumberland River mile marker 176 about five hours before the incident. A nearby river gauge measured 26 feet — considered high water. The vessel initially had six barges in tow but dropped off three before continuing upriver toward a terminal east of downtown Nashville.
The pilot was minutes into his watch shift, traveling through the heart of the city, when the head of the tow moved to starboard ahead of an upcoming turn to port. The captain, now off watch, remained in the wheelhouse during the incident.
“The pilot counteracted by putting the steering rudders to port,” the NTSB report said. “Seconds later, the pilot and the captain noticed that the port steering coupling between PBM 403 (the face-up barge) and PB 2013 (the middle barge) parted.”
The face-up barge remained connected to the towboat, and the middle barge remained tethered to that barge via the starboard coupling. During the incident, the starboard coupling between the middle barge and lead barge also severed. At this point, all three barges remained in contact with one another, but only on one side.
“PB 2013 and (lead barge) PBM 141 ended up perpendicular to the bank and began to top over on each other after contacting the bank,” the report said. “Then, about 2252, the two barges (now loose) struck the dock and the port side of a fireboat moored there, knocking the dock and the fireboat loose before drifting and striking the upriver pier of the bridge on the left descending bank.”
Other towboats operating nearby responded to the incident. Charlie Everhart first secured the drifting fireboat, the city of Nashville’s Fire Boat No. 9, then assisted James H. Hunter, which was drifting downriver with all three barges. Two of Charlie Everhart’s crewmembers climbed onto PBM 403 to reconnect it with the middle barge.
Towing vessel Charles B. Holman came from about a mile upriver. It secured PBM 141, released the coupling connecting it with the middle barge, then towed the lead barge to its destination at the Pine Bluff Materials fleeting facility, the report said. James H. Hunter then towed its two remaining barges to the facility.
After the accident, the pilot said he adjusted the rudders to counteract the current setting the tow toward the bank. He did not recall how much rudder he used and the vessel did not record the setting. The captain, who witnessed the maneuver, said the pilot steered “a little hard and broke one side.”
“Considering the length of the tow and the effect of the current (estimated to be 5 mph) against the side of the tow (underwater profile), a large rudder input could have put excessive load on the single steering coupling, exceeding its breaking load limits,” the report said.
Hunter Marine Transport, which operated the 3,600-hp towboat, did not have specific procedures in place during high water. The vessel’s new operator has since developed voyage risk assessment and bridge transit protocols.
Investigators speculated the single couplings were in place because the tow was traveling only three miles from one fleeting area to another. However, the NTSB said the captain and pilot on the towboat were not familiar with that section of river.
Total damage from the incident was about $300,000, mostly to the dock that broke away with Fire Boat No. 9. That vessel, as well as James H. Hunter and its three barges, sustained only superficial damage.