A 12,000-mile superhighway snakes through the United States—underused, underappreciated, and underfunded.
Each year, it carries cargo to and from many of the country’s oceangoing ports as well as to and from 38 states. The inland waterway system is an unsung hero of the nation’s freight transportation system, moving $135 billion annually in raw materials, fuel, construction supplies, and finished goods.
Vanderbilt transportation and logistics engineers believe the time is now for inland waterways to get increased attention. Growing threats from extreme weather events and cybersecurity attacks jeopardize the nation’s supply chains, which rely heavily on rail, plus tractor-trailer and medium-duty trucking. The U.S. can build supply chain resiliency with targeted investments in locks, dams, and inland ports, they say.
“The inland waterway system for many is out of sight, out of mind,” said Craig Philip, director of the Vanderbilt Center for Transportation and Operational Resiliency. “But the inland waterways are a superhighway with untapped capacity.”
Greater use of the system has added benefits: per mile and per ton, shipping by river barge is the least costly, most energy efficient, and safest mode of moving cargo in the domestic U.S. supply chain.
VECTOR is putting the final touches on a case study on resilience strategies for navigable portions and infrastructure of the Cumberland/ Tennessee river couplet system. The research will contribute to a national Port Resilience Guide to be published by the U.S. Department of Homeland Security and the Army Corps of Engineers.
Colonial Pipeline shutdown
A cyberattack that shut down the Colonial Pipeline in May 2021 gave VECTOR researchers a perfect, if disruptive, opportunity to see how much difference the inland waterways could make in gasoline supply.
Quite a bit, it turns out.
Using data from the Corps and Gas Buddy, a crowd-sourced app that provides real-time fuel prices and availability, a civil engineering doctoral student looked at what happened in six southeastern cities.
“Our preliminary findings suggest that there is a statistically significant inverse relationship between a city’s annual waterborne petroleum volumes (adjusted per capita) and the proportion of gas station outages during this year’s disruption of the Colonial Pipeline, especially as the closure stretched on to its second week,” said PhD student Miguel Moravec.
A decade ago, two major petroleum companies added river barge service to diversify their delivery modes to the Nashville region, giving it the largest waterborne fuel volume per capita of the cities studied. In Nashville only 19 percent of stations were reported to be out of fuel by the twelfth day of the disruption while in Knoxville and Chattanooga, which receive less waterborne fuel, reported 32 and 34 percent outages, respectively, on the same day.
Between 42 and 60 percent of the gas stations in three North Carolina cities that rely solely on the pipeline for petroleum product delivery had outages two weeks after the pipeline attack.
Floods and earthquakes
Researchers also are looking at how lock closures, including those from accidents and scheduled maintenance, affect the inland waterway system’s ability to move commodities to and from the Middle Tennessee region. The system, standardized around vessels with a maximum draft of 10 feet and locks with width and length limits, is vulnerable to droughts and floods, too.
Another piece of the supply chain security puzzle includes how an earthquake along the New Madrid fault would impact rivers and inland ports, not to mention rail lines, major highways, and bridge crossings for both. The New Madrid Seismic Zone is a series of large, ancient faults buried beneath thick, soft sediments that run for 120 miles, crossing five state lines, the Mississippi River in three places and the Ohio River in two places. Experts estimate there is 25-45 percent chance of a 6.0 magnitude or greater earthquake striking in the next 50 years. Destruction would cover 20 times the area of a similar West Coast earthquake because of geological differences in the two regions.
“We cannot underestimate the need for multiple transport delivery options that allow essential goods and products to travel across the country,” said Janey Camp, research associate professor of civil and environmental engineering and VECTOR associate director. “This analysis demonstrates that ports, especially inland terminals, continue to be a critical factor in the nation’s supply chain. American cities and states will need to keep this in mind as they plan for long-term, resilient infrastructure investments over time.”
VECTOR’s research on port resiliency will look at the untapped capacity in the system of inland waterways and make recommendations for addressing resiliency of the freight transport system.
“We are not going to build many miles of new freeway and we aren’t going to build any new pipelines. But we have this superhighway of inland waterways,” Philip said. “Unlike the highways, however, waterways could be utilized today in a greater way.”