Road and Bridge Construction – the Lake Barkley Bridge

For nearly 90 years, the old Lake Barkley Bridge, also known as the Henry R. Lawrence Memorial Bridge, was the only way to cross the Cumberland River in Kentucky for people traveling east to west. Since 1932, the Henry R. Lawrence Memorial Bridge had witnessed its share of historical events, like when the Barkley Dam flooded the Cumberland River, causing it to become Lake Barkley, and the bridge was raised to account for the new water level. Sadly, the 20-foot-wide Henry R. Lawrence Memorial Bridge had become functionally obsolete, as today’s average vehicle is nearly half the width of the bridge itself. Therefore, it was time for the bridge to make history one final time.
 

No Wile E. Coyote

The old bridge and its steel truss, weighing more than 300 tons, made it the perfect candidate for implosion. Steel bridges are often demolished by implosion rather than disassembling the bridge piece by piece, especially when time is of the essence and it’s imperative not to drastically impact marine traffic. In the days leading up to the blast, copper-wrapped, linear-shaped charges were placed at strategic points throughout the steel. These charges offer the ability to slice through material in a straight line, as opposed to the dynamite used by Wile E. Coyote and other cartoon antagonists of the past. The charges are then connected by a detonation cord, which serves as a high-speed, exploding fuse. Exploding at a rate of more than 13,000 miles per hour, the charges are detonated almost simultaneously across the entire length of the bridge.

Gone in a Flash

After a competitive auction at the Cadiz Rotary Club, the Baker family came out on top, bidding $16,500 to flip the ceremonial ignition switch and implode the old bridge. Following a quick countdown and a warning blast to humans and animals alike, the switch was flipped and the Henry R. Lawrence Memorial Bridge was gone in a flash. PCL’s Transportation Infrastructure Group quickly went to work using a 300-ton barge-mounted crane to pull each steel segment out from the lake bed. The segments were then placed on a hopper barge and sent to a local scrap yard.

A Living Legacy

Though now resting peacefully in a scrap yard, the legacy of the Henry R. Lawrence Bridge will live on. A donated piece of railing, a wooden table made with steel from the old bridge, and the ceremonial blast itself together raised nearly $20,000 for the Rotary’s Youth and Senior Service Fund and the Education Committee.  

The new Lake Barkley Bridge is 3,805 feet long and includes a breathtaking 550-foot-long main arch span, known as a basket handle tied arch. Once complete in December 2018, it will carry four lanes of US68/KY80 over the lake. 
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