A favorite destination of adventurous tourists and locals is in danger of being closed.

The Grand Auglaize Bridge, one of the longest wire suspension bridges in the state, received a downgrade to being in “Poor Condition” after an integrity study was conducted in 2018, by the Missouri Department of Transportation (MoDOT).

The Grand Auglaize Bridge, better known to locals as the “Big Swinging Bridge” (because of a smaller suspension bridge 1,000 ft. away) hangs over the confluence of the Lake of the Ozarks and the Grand Auglaize Creek. By road, it is off Highway 42, on Lake Road 42-18, a gravel road, also known as Swinging Bridges Road, southwest of Brumley, Mo. in Miller County.

The 500 ft. x 12.1 ft. wire suspension bridge was built in 1920 by Joseph Dice and is a favorite destination for brave hikers, photographers and history buffs. Many enjoy fishing off the architecturally unique structure or hiking across on a dare.

According to MoDOT Area Engineer Bob Lynch, the Grand Auglaize Bridge was rated as in Poor Condition, with a 3-ton weight limit, (the average car weighs approximately 2-tons). The 3-ton weight limit was put into place in 2017. Prior to 2017, it had a weight limit of 5-tons. The 3-ton limit is the lowest weight rating that can be given to a bridge in Missouri before it is taken out of commission.

The bridge is still open to the public and is still safe, although maybe not for the faint of heart. The bridge unnervingly moves with the weight of the car, and wooden planks make unsettling creaking-noises, as if you may plunge down into the river at any moment!

VIDEO OF FLOODING AROUND THE SWINGING BRIDGES IN 2015:

2020 Inspection

According to Lynch, it is required that Missouri bridges be inspected every two years, whether or not they are on the state system. The county has to pay for the next inspection, due in 2020. MoDOT requires the inspection be done by an engineer that specializes in this type of bridge. Along with the condition of the bridge, they will calculate the costs for maintenance, repairs, or replacement.

“It is in the county's hands now,” Lynch said.

The Cost

“Unfortunately, the county just does not have the funds to pay for that type of inspection, or to repair the bridge,” Miller County Commissioner Tom Wright said. “We hope some type of funding will turn up, so we don’t have to close it. We are open to ideas.”

According to Wright, MoDOT shut down a swinging bridge on A Road, immediately after a bad inspection, and it took three years for the county to get it repaired and back open to traffic. “That would be an incredible inconvenience to the people that live in the area and we would lose a valuable piece of Lake history,” Wright said.

The county allocates approximately $280,000 annually for bridge repairs and Wright suspects the costs to repair this bridge will be much higher. The state park is on one end of the bridge, limiting the available amount of land, if a new structure is recommended to be built.

The county has already replaced four big swinging bridges with Off System Bridge Replacement and Rehabilitation (BRO) funds. According to Wright, they have replaced the wood flooring on the Grand Auglaize Bridge, as well as conducted routine maintenance. “Some of the cables are the concern right now,” Wright explained. Original towers, cables, railings, and floor beams are present on the bridge.

“There is possible funding for this bridge through the state, as a historic site,” Wright said. The Grand Auglaize Bridge is one of the largest of the remaining Dice Bridges (built by Joseph Dice) with the highest level of historic integrity. There is also a chance the Missouri State Parks system could take it over as a footbridge, if it is closed, since it connects to the Lake of the Ozarks State Park. Wright is waiting to hear back from the Department of Natural Resources. “It depends on their budget,” Wright said.

“Hopefully, the next inspection will give us an idea of costs and what can be done to restore the bridge,” Wright said.

The Bridge

According to historicbridges.org, the bridge is hung on massive steel wire cables that connect two towers. The cables create a catenary chain (the curve produced when a flexible wire hangs from two fixed supports). Vertical suspender cables connect the bridges deck to the catenary chain. These suspender cables get shorter toward the middle of the bridge, creating the deck's arch.

The arch makes it hard to tell when another car may be crossing the one-lane bridge. If two cars cross at the same time, one of the cars must back up to their starting point and wait for the other to cross. The arch is important, since it allows the deck to flatten with heavy loads, making it stronger.

The Builder - A True Craftsman

According to historicbridges.com, the bridge is tribute to Dice’s skills, since his bridges have, in many cases, including the Grand Auglaize Suspension Bridge, lasted longer than new bridges built by corporate consulting engineers with AASHTO regulations and high-tech engineering computer programs. These programs are utilized to determine the correct curve through a complex mathematical formula. The curve is the most important factor in the strength of this type of bridge.

According to Missourilife.com, a 1980 history of the US Army Corps of Engineers reported that no one who worked with Dice ever saw him ask for advice or figure his curves with a pencil and paper. Instead, he simply strung twine between tall trees on opposite banks to find the basic curve. When the curve looked right to him, he marked the length of the twine, noted the heights, and proceeded to build his bridge. Several decades later, no main cable has ever snapped. Dice and his ball of twine hold a perfect record!

When a vehicle rolls onto the Big Swinging Bridge, Dice’s engineering still allows the vertical cables to respond with a bit of give. That downward movement causes the bridge to rock a little from end to end and sets off a wave of motion on the bridge’s deck. Just like water in front of a boat, the deck in front of the vehicle rolls up and forward. And just like with water, cars moving with the bridge’s wave don’t feel the up-and-down motion… but drivers who stop do feel it.

Respect the Load Limit

“Regular traffic can safely go across,” Lynch said. “Anything larger than a passenger car could be an issue. No dump trucks.” According to Lynch, this bridge has always had a weight limit on it. “There are poorer structures in the state,” Lynch added. “There are more than 900 bridges with a poor rating across the state, that the state still says are safe to drive on. We ask people to respect the load limits, especially in poor conditions. High winds, or over-the-limit-weight vehicles could cause further damage.”

Miller County has three suspension bridges besides the Grand Auglaize Bridge, including the Mill Creek Bridge, located 1,000 ft. from the Grand Auglaize Bridge, on Lake Road 42-18 in Brumley and the Kemna Bridge in St. Elizabeth. The Mill Creek Bridge was built in 1910, has a 15-ton weight limit, and was reconstructed in 1978. Both of those bridges are rated to be in good condition and open for travel.

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