New River Gorge Bridge - History
The New River Gorge Bridge was designed by the Michael Baker Company, under the direction of Chief Engineer Clarence V. Knudsen, and erected by U. S. Steel's American Bridge Division. Construction of the bridge began in June of 1974 and was completed on October 22, 1977. The engineering marvel took three years to complete and cost nearly 37 million dollars.
Most of the 22,000 tons of structural steel for the bridge project was fabricated at the American Bridge Division's Ambridge, Pennsylvania plant. All of the structural steel used for the Bridge is USS COR-TEN Steel, which oxidizes with age and gives the Bridge its dark russet color. This special steel blends in well with the surrounding environment and eliminates the need for repainting as the oxidation is a natural protectant.
The first challenge in designing the New River Gorge Bridge was choosing the type of bridge capable of spanning the 3030 foot wide gorge, 876 feet above the river. Several types of bridges were considered including two different suspension bridge designs, an arch truss design, and a continuous truss design. But the design that suited the surroundings of the New River Gorge and dealt with the challenges the gorge presented for construction was a single 1700 foot arch span design. The New River Gorge Bridge would be the longest single span arch bridge in the World.
Due to the chosen arch design and the depth of the gorge, construction required innovative engineering and construction techniques. A four-tower cable-way was erected to span the gorge with airborn trolleys, cables and hoisting machinery to move the massive steel members into place. The two trolleys were capable of transporting 50 tons each which allowed for portions weighing up to 92 tons to be moved into place when they worked together.
Most of the bridge pieces were delivered by railroad to Nallen, WV, then transported by trucks over 19 miles to the construction site. Some pieces were too heavy to be transported by trucks and had to be lifted from the train tracks at bottom of the gorge by the cable-way.
Another innovation was the tie-back system used to support the arch pieces during construction until it could support itself. The last pieces of the self supporting arch were bolted into place in the spring of 1976 at which time the 13 arch towers ranging in height from 26ft to 305ft were put into place. These towers would support the deck trusses and pavement above the bridge where 1000 tons of concrete and reinforcing steel went into the heavy roadway which was necessary as a counterweight cap to the massive arch.
Construction was completed and the bridge was opened on October 22, 1977. The New River Gorge Bridge has been a great asset to West Virginians and tourists alike. It provides access to the magnificent New River Gorge and all the area has to offer.
To commemorate the importance of the New River Gorge Bridge to West Virginia, the Bridge Day festival is held the third Saturday of every October, closing traffic for pedestrians to explore the bridge and allowing BASE jumping for a few hours on that day only. The iconic bridge became the subject of the West Virginia state quarter in 2005, and now Bridge Walk guided tours are available year round on the walkway beneath the road