On 11 March 2017, the towing vessel ‘Steve Plummer’ was pushing three loaded barges on the Cumberland River in Nashville, Tennessee. As the tow passed beneath the CSX Railroad Bridge at mile 190.4, the second and third barges allided with the bridge’s upstream guard pier. No injuries or pollution were reported, however, the two barges sustained damage and the guard pier was destroyed, as a result. The NTSB issued an investigation report on the incident.
Findings
- Investigators researched industry and Coast Guard guidance for installed towing vessel hp requirements per typical loaded river barge. Industry discussion varied from 175 to 240 hp per 2,000-ton barge in normal- to medium-high river conditions, using an experienced operator. The Coast Guard’s Towing Vessel Center of Expertise stated that there are no regulatory vessel-hp-tobarge requirements or guidance, but both Coast Guard and industry have widely used 250 hp per loaded barge as “best practice” on inland rivers.
Based on these hp-to-barge ratios, the 700-hp Steve Plummer pushing three barges (carrying a total of 3,934 tons of cargo) was within the industry norm for an experienced operator. Although the Cumberland River was rising from recent rain, at the time of the accident the river was within its normal range.
- The Steve Plummer pilot was familiar with the route, having made the transit almost daily in both directions for the previous 3 months without incident. He said that, on the day of the accident, the current was swift at 3 mph and his 3.5-mph speed was the maximum forward speed that the tow could make. The Steve Plummer tow had little additional power and thus limited maneuvering ability when passing through the bridge’s right descending bank channel span.
- The company stated that the number of barges the Steve Plummer towed depended on the river conditions, weather, the area of transit, and the pilot’s level of comfort. The Steve Plummer could tow four barges during slack-water conditions, typically towed three barges during normal river conditions, and towed one or two barges during high-water conditions. The company stated that it left the barge number decision to the individual tow pilots.
Although not required in company guidance, a pilot could check with a more senior pilot (if conditions warranted) about reducing the tow size to allow for more control in high-water conditions. The accident pilot did not check with a more senior pilot before the transit. After the allision, the company reduced the tow size to a maximum of two barges through the CSX Railroad Bridge.
Probable cause The National Transportation Safety Board determines that the probable cause of the Steve Plummer tow’s allision with the CSX Railroad Bridge was the pilot’s decision to tow three loaded barges during rising river conditions with swift currents, which overwhelmed his ability to maneuver the tow through the bridge. Explore more by reading the full report:
