Longest U.S. Suspension Pedestrian Bridge to Open
The longest suspension pedestrian bridge in the U.S., located in Gatlinburg, Tennessee, is set to open in a couple of weeks, running 680 feet across a valley in the Great Smoky Mountains. The ground falls away 140 feet below, roughly around the structure’s midpoint.
What has been dubbed the SkyBridge, which belongs to Skylift Park, will open May 17. The bridge was designed and installed by ERi (Dayton, Ohio) for Boyne USA (Boyne Falls, Michigan).
Suspension Pedestrian Bridge
According to CNN, the span features glass panels along the center of the walkway to allow visitors to see the ground beneath them. Skylift Park also features a chairlift that takes passengers up 500 feet, from Gatlinburg to the top of Crockett Mountain. Once the bridge opens, visitors will be able to take the chairlift up to the bridge, enjoying the view. Plans also include an observation area and snack shop, as well as a bar and gift shop.
ERi selected Hayward Baker Inc. for the design and installation of the bridge’s micropiles.
“Reinforcing steel, typically an all-thread bar, is inserted into the micropile casing,” HBI notes on ERi’s blog. “High-strength cement grout is then pumped into the casing. The casing may extend to the full depth or end above the bond zone with the reinforcing bar extending to the full depth.”
The resulting micropile resists compressive, uplift/tension and lateral loads, and meets the testing requirements of ASTM D 1143 (compressive), ASTM D 3689 (uplift/tension) and ASTM D 3966 (lateral).
Once the micropiles were installed, focus shifted to preparing the foundations for concrete. The subsurface assembly of each side consists of two bases, 44 threaded rods and other hardware. Threaded rod placement was imperative, as “the top of each assembly would also have a template to help ensure that everything was held perfectly in place while the concrete cured,” notes ERi. The steel rods are 2 inches in diameter, each weighing roughly 50 pounds.
The concrete forms for the abutments, installed by general contractor Mike Walston, of MCW Construction, were made from lumber, and heavily reinforced. According to ERi, with everything accounted for, the bridge weighs more than 1 million pounds.
Though the developer behind the SkyBridge claims that this is the longest suspension pedestrian bridge in North America, that title can arguably go to the pedestrian suspension bridge at Kelowna Mountain, in Canada, which the park claims runs over 800 feet long.
"The Gatlinburg SkyLift is an instantly recognizable landmark in the downtown area, and we wanted to preserve its history and all treasured memories in our expansion," said park general manager Randy Watson.
Since the wildfires that occurred in November 2016, visitors have been unable to disembark the SkyLift toward the top of the ride. Once the bridge opens, however, visitors can visit all the park attractions for one price.
Editor's Note: Corrected steel rod dimensions at 8:08 a.m, on May 2, 2019.