NTSB: Barge Deterioration Led To 2019 Triple Towboat Sinking
A deteriorated barge and infrequent monitoring caused the flooding and subsequent sinking of the moored towing vessels Chattie Sue Smith, Mary Fern and Mary-R, along with the unnamed deck barge, the National Transportation Safety Board has determined.
The barge flooded and sank July 5, 2019, pulling the three boats down with it while moored on the right descending bank at the Jersey County Grain Company facility in Hardin, Ill., Illinois River Mile 20.7. The vessels were unoccupied, and no one was hurt.
About 2,800 gallons of diesel were released into the river, but mostly recovered. Damage to the vessels, deck barge and facility totaled an estimated $920,000, the NTSB said in the report released late last month.
Hex Stone Inc. owned the vessels. They were moored with the Teddi B, which did not sink. The 46-foot-long towing vessel Chattie Sue Smith had been operating as a fleeting vessel locally since January 2019, and the Teddi B was operated as a docking facility. The Mary-R and Mary Fern were not operational at the time of the sinking.
The Chattie Sue Smith was built in 1963, and Hex Stone bought it renamed it in 2011. In April 2019, Hex acquired the 55-foot Mary-R, built in 1964, the 54-foot-long Mary Fern, built in 1978, and the 50-foot-long Teddi B, built in 1989. The towboats, all equipped with twin propellers, were moored with a 50-foot-long by 18-foot-wide steel deck barge, also known as a dock barge or work flat. The deck barge was subdivided into four compartments: A bow rake compartment, two full-width midbody compartments and a stern rake compartment.
Mooring lines and wires connected the vessels and barge together, with the Mary Fern and the deck barge tied off to mooring cells with mooring lines. No crewmembers were at the facility.
At 6:54 a.m., the Hardin Fire Protection District was dispatched to Jersey County Grain following a report of four towboats and deck barge sinking in the river. A crewmember aboard a passing towing vessel made the report. The crewmember alerted the nearby Hardin Bridge operator, who in turn contacted the sheriff’s office, which dispatched the fire department. Hex Stone arrived on scene before the fire department. The company’s river operations manager notified the Coast Guard regarding the sinking as well as an environmental response company concerning diesel in the water.
When first responders and Hex Stone personnel arrived, the Chattie Sue Smith was laying on its port side, submerged in the water, and the Mary Fern was taking on water and laying against The Teddi By. About 8 a.m., company employees boarded the Teddi B, started an engine and maneuvered it away from the Mary Fern to prevent both vessels from possibly capsizing. Once they were separated, the Mary Fern capsized and sank in 26 feet of water, near the Chattie Sue Smith. The deck barge sank completely where it had been moored, and the Mary-R was partially submerged to the upper part of the wheelhouse and sitting upright on the river bottom upriver from the Chattie Sue Smith. All three vessels were a constructive total loss.
The mooring cell, which was also a support for the grain elevator, was damaged by the deck barge’s mooring lines as two sheet piles were pulled apart by about 3 feet at the top of the cell.
By the early afternoon, containment booms were deployed around the vessels. The following afternoon, divers arrived on scene and secured as many oil tank vents on the sunken vessels as possible to contain pollution. Altogether, the three sunken vessels had 4,700 gallons of diesel fuel on board.
“Between July 12 and 19, a salvage company recovered the Chattie Sue Smith, Mary Fern, Mary-R, and the deck barge that sank,” the NTSB reported. “An inspection for possible deficiencies that might have caused them to sink revealed no reported signs of water ingress from the three towboats. Aboard the barge, however, several small holes were found on the deck, the sides (about 6–12 inches from the bottom), and the bottom plating. An open watertight hatch (manhole) on the deck of the barge, which provided access to the midbody compartment for power cords and discharge hoses, was found during salvage operations. The barge was equipped with two electrically operated submersible bilge pumps powered from shore, one in each of the midbody compartments. The pumps had 2-inch discharge ports and were designed to be activated automatically by float switches. Both pumps were tested after the sinking for proper function: one pump was found to be inoperable. Closer inspection of the areas of the hole on the sides of the barge showed pitting and several areas that had been previously repaired with an epoxy-like product. The operating company did not have any information about the manufacturer, age or maintenance records of the pump. There were no records of inspections of the towing vessels and the deck barge while docked at the facility.”
Although the company typically had crews board the vessels every two or three days, the last day any company employee had been on the barge and with the towing vessels was July 1, four days before the accident, when the owner of the company said he had been aboard the barge and pumped out water that had accumulated, the NTSB reported, then noted that for the five days before the sinking, every day except July 1 there were thunderstorms with a total of 0.78 inches of rain reported at the nearest weather station, at the St. Louis airport.
“A post-salvage inspection of the deck barge revealed that there were several small holes on the deck that could have allowed rainwater to collect and enter the interior compartments,” according to the NTSB. “Additionally, holes found on the sides and on the bottom of the hull could have allowed river water to enter the barge. Based on a review of its condition, the holes likely had been present for a significant amount of time and were the source of barge flooding. The side and bottom holes would have allowed water to continuously flood the barge’s compartments, which required the automatic bilge pumps to dewater the spaces at frequent intervals. Monitoring the frequency of the bilge pump operation and developing a trend of the volume of water being removed would have indicated the rate of water ingress an assisted in detecting hull leaks not easily visible.”
The NTSB determined that the failure of one of the automatic submersible bilge pumps would have prevented constantly accumulating water from being removed from its compartment, resulting in the space flooding.
“If the barge began flooding in this manner, the barge’s freeboard would have been reduced, thereby submerging other holes that were above the waterline in the side plating and resulting in an increased rate of flooding,” the NTSB determined. “Once the upriver rake of the barge became submerged in the estimated 1–2-mph. current, flooding would have occurred through the open manhole, and the current would have forced it under water. Since the towboats were secured by wires and mooring lines to the deck barge, the flooding and subsequent sinking of the deck barge pulled three of the attached towboats under the surface and nearly the fourth vessel as well.”