NASHVILLE, Tenn. (Feb. 26, 2020) – We just celebrated National Engineers Week and recognized Nashville District’s engineers as the region’s problem solvers, committed to serving a higher purpose, and building on a strong legacy as pioneers of progress.
There is no better example of this legacy than the historic efforts of the Nashville District and Tennessee Valley Authority to tame the Cumberland and Tennessee Rivers, commonly referred to as the Twin Rivers.
When British Army Engineer Lieutenant Thomas Hutchins first mapped the Twin Rivers in 1769, the Cumberland and Tennessee Rivers were wild, fluctuating streams.
In their natural state, the Twin Rivers were impassable, strewn with rocky shoals, rapids, and sand and gravel bars. Wooden hulls were always damaged, and after accidents, boatmen would usually only salvage the damaged cargo. The often and always flooded communities along their banks and left uncontrolled were a deterrence to commerce and industry.
In April of 1824, Congress passed the General Survey Act, charging the U.S. Army Corps of Engineers to prepare surveys, plans, and estimates to improve channels.
Surveys for improvement of the Tennessee River were prepared in 1832. From 1871 to 1933 the Chattanooga Engineer District developed the Tennessee River. Special engineer districts were formed to develop the Tennessee River at Muscle Shoals and to construct Wilson Dam.
In order to develop the Cumberland River for navigation, Lt. Col. John Barlow left Chattanooga and took command of the Nashville District in 1888.
One year later, Charles Locke, an assistant engineer, supervised a party of 17 men and two flatboats on a survey of the lower Cumberland for locks and dams, which generated a report that led to the construction of seven locks measuring 60-feet wide by 250-feet long, very small compared to today’s much larger navigation locks.
Col. Henry Robert, who published the first edition of Robert’s Rules of Order 20 years before arriving in Nashville, replaced Barlow as commander of the district in 1891. Under Robert’s direction, the canalization got fully underway with construction of Lock and Dam A and Lock and Dam 1, the two projects closest to Nashville.
Using wood coffer dams, primitive hand tools, A-frames and even animals to haul in supplies and stone blocks on tracks from nearby rock quarries, engineers constructed 15 navigation locks in the late 1800s and early 1900s to tame the Cumberland River for steamboats moving people and commerce throughout the region a century ago.
To improve navigation and add hydropower as a project purpose, the modern multi-purpose dams on the Cumberland River and its tributaries, constructed from the 1940s through the 1970s, replaced the need for the Corps of Engineers to maintain and operate the old locks and dams.
A similar change happened along the Tennessee River as Army engineers worked in the late 1800s to build canals to navigate through the Tennessee Valley. In the late 1800’s and early 1900’s, the region led the nation in grim categories like illiteracy, lowest per capita income, infant mortality and availability of electricity and running water.
Projects along the Tennessee River made power accessible to the region. This led to an increase in commerce, which led to increases in literacy, reduction of poverty and ultimately allowed the region to experience a much higher standard of living than ever before, and engineers enabled that.
Three historic projects related to the Tennessee River spearheaded the commitment of engineers – construction of Muscle Shoals Canal, Wilson Dam, and Tennessee-Tombigbee Waterway.
The Corps constructed the Muscle Shoals Canal in the late 1800’s. Covering 14.5 miles, it would bypass the great shoals and allow steamboats from Florence, Alabama, to carry cargo upriver to Chattanooga, Tennessee.
During the project, workers excavated 50,000 cubic yards of rock and earth per year, while quarrying, cutting and laying thousands more yards of stone. As if the Shoals weren’t treacherous enough, in 1881, famed outlaw Jesse James actually hijacked the payroll being delivered to the workers, forcing a good number of workers to quit the project.
A captain in 1889, George Washington Goethals, who later served as the chief engineer of the construction of the Panama Canal, led the Muscle Shoals Canal project. He later said that his work here was much more daunting than anything he experienced while building the Panama Canal. The work done at Muscle Shoals was such a success that it peaked the interest of Henry Ford and Thomas Edison in the 1920’s to become an industrial hub in the South. Corps engineers made it possible for ships to continue eastward to Chattanooga.
The Corps constructed Wilson Dam from 1918 to 1927, establishing a standard for the nation for future waterways improvement. It was the largest mass concrete lock and dam built at the time, and included the first federal hydroelectric project as the first Corps of Engineers multipurpose effort.
The project amazed and inspired President Franklin D. Roosevelt to create the Tennessee Valley Authority in 1933 to revitalize a region and provided a blueprint for development of water resources nationwide.
The massive structure, 137 feet in height and more than 4,500 feet long, a world record, required the excavation of nearly 1.5 million cubic yards of earth and rock and consumed 1.3 million cubic yards of concrete. At 94 feet, its lock lift established another world record and remains the highest on the system. At peak construction, more than 4,000 men labored at the site. The project highlighted the ability to harness the power of the river, tame the river from flash flooding, and use its power to energize communities that did not have access to power in the past.
The creation of the Tennessee-Tombigbee Waterway is another engineering marvel in the region. It took over 100-million dump truck loads of soil to connect the Tennessee and Tombigbee Rivers, opening a new passageway to the Gulf of Mexico in 1985.
The Mobile District constructed the southern 195 miles of the Tennessee-Tombigbee Waterway, including nine locks and dams. The Nashville District excavated the northern 29 miles of the project, including the massive 27-mile divide cut, which connected the waterway with Pickwick Lake on the Tennessee River.
The Corps excavated nearly 310 million cubic yards of soil during the 12-year project. In comparison, 210-million cubic yards of earth were removed from the Panama Canal. In the end, the two districts, 125 prime contractors and 1,200 subcontractors worked on the overall waterway. The 10 locks and five dams required a total of 2.2 million cubic yards of concrete and 33,000 tons of reinforcing steel.
The Nashville District dedicated the 27-mile divide section of the Tennessee-Tombigbee Waterway May 6, 1984. This project showed how engineers put vision, to plan, to execution and ultimately merged the waters of 23 states and linked them to the Gulf of Mexico. These three projects pioneered progress in the region and help to pull a region out of poverty.
Today the Nashville District continues to pioneer progress along these river systems with its engineering marvels.
At the Kentucky Lock Addition Project, the Corps is building a new 110-foot by 1,200-foot navigation lock at the TVA project. This 1.2 billion dollar project is about 40 percent complete. Over the last year 10 million-plus pound concrete shells were placed onto the riverbed that will be part of the downstream cofferdam and permanent lock wall.
Completion of the downstream cofferdam will make it possible to place about 800,000 cubic yards of concrete to complete the lock in the next big contract. With efficient funding the project is on track for completion in 2024.
At the Chickamauga Lock Replacement Project, also a TVA project, the Nashville District is currently executing the lock chamber contract for the new 110-foot by 600-foot navigation lock, which includes 285,000 cubic yards of reinforced concrete. A conveyor system is placing concrete inside the coffer dam from the batch plant, a distance of about 900 feet in about a minute and a half.
When the new larger lock is completed, it is expected to keep open 318 miles of navigable river miles upstream of Chattanooga and speed up the process of locking through with ability to process up to nine jumbo barges in one lockage.
The $792 million dollar project is approximately 35 percent complete; with efficient funding the project is also on track for completion in 2024. Congress announced Feb. 10 that the Chickamauga Lock project would receive $101.7 million in fiscal year 2020. These funds will be used to exercise all remaining options on the current $240 million Lock Chamber construction contract, which will extend on-site work to June 2023 and result in a fully functioning lock inside of the cofferdam. The lock will go into operation during the follow on contract that we anticipate awarding by the end of FY 2021.
The Nashville District’s engineers and workforce continue to operate 10 dams and 28 hydropower units in the Cumberland River system to produce hydroelectricity, to manage flood risk, to support navigation, and to provide recreation opportunities for the public. The team provides collaborative water resource engineering solutions, world class public infrastructure management, and environmental stewardship for the Cumberland-Tennessee River Systems.
The Nashville District has a proud heritage of servitude, and continues to demonstrate commitment as pioneers of progress, playing a crucial role in the growth and welfare of the nation by solving some of our toughest water related and infrastructure engineering challenges.
The public can obtain news, updates and information from the U.S. Army Corps of Engineers Nashville District on the district’s website at www.lrn.usace.army.mil, on Facebook at http://www.facebook.com/nashvillecorps, and on Twitter at http://www.twitter.com/nashvillecorps.