Earlier this year, a sinkhole the size of a tennis court opened up directly under the National Corvette Museum (NCM) in Bowling Green, Kentucky. Fortunately, the incident happened early in the morning and nobody was harmed, but the NCM announced with ‘heavy hearts’ that eight historical Corvettes were swallowed up by the 30’ deep sinkhole that measured nearly 60’ by 40’ wide.
The NCM formulated a local team including contractor Scott, Murphy & Daniel Construction, structural engineer DDS Engineering, Walkers Towing Service, Western Crane Service, Inc., and Alabama/Tennessee-based CraneWorks to assist in ‘Operation Corvette Plus,’ to secure the sinkhole and recover the vehicles.
Once the site was secured and the ‘go ahead’ was given to bring in heavy equipment such as manlifts, excavators and cranes, preparations were made for the cranes to suspend engineers and contractors safely into the middle of the sink area and determine the best method for lifting and removing the vehicles.
The first car planned for removal was the 2009 ZR1 “Blue Devil.” Crews rigged up the ZR1 and did a few test lifts. John Spencer, Manufacturing Integration Manager at the GM Corvette Assembly Plant, helped consult the team on the best points to strap up the car. Then, on March 3, crowds of construction personnel, media, museum visitors and staff cheered as the “Blue Devil” emerged from the depths of the sinkhole, a process that was streamed live with thousands of viewers tuning in all over the world.
Even more cheers erupted when the car cranked up after only a few tries, drove about 20 feet to the doorway of the Skydome, and was immediately put back on display. “It’s incredible to have the car back on display again. It’s what we’ve been hoping for,” said Bob Hellmann, Facilities and Displays Manager. “Now we just want to get the next seven, restore the cars, and get them all back on display.”
Later that same day, the crew resumed the car retrieval process – lifting the 1993 “Ruby Red” 40th Anniversary Corvette.
The next day, March 4, was entirely dedicated toward the removal of the 1962 Black Corvette. This proved to be a complicated task, as a five-ton slab of concrete was partially resting on the front of the car, and plans called for two cranes to simultaneously lift the car and the concrete.
“The team began work early, extracting a portion of the car lift that had become mangled around the car, removing the hood from the ’62 and tying a strap to the engine bay, then drilling anchors into the slab of concrete that appeared to be wedged into the grill. In hooking their lifting devices to the car they discovered that they didn’t have to lift the slab to free the car. Really, all that went better than I expected… that’s my favorite car,” explained Mike Murphy, CEO of Scott, Murphy and Daniel Construction.
The following day proved even more exciting as crews unexpectedly recovered another vehicle sooner than expected – the one-millionth Corvette built locally at the Bowling Green production facility in 1992.
“Initially there was no intention to bring the Millionth out, but as we got in there and saw more this morning, we did feel like this might be our best chance,” said Danny Daniel, President of Scott, Murphy and Daniel Construction.
Daniel explained, “they pulled the car by one wheel from where it was lodged and it swung free into the cavern. They were then able to lift the car and place it to rest, upside down on the bottom of the sinkhole. Finally, the Corvette was hooked up by its two tires for final lifting out of the sinkhole, much like the process to retrieve the 1993 40th Anniversary.”
The NCM now has half of the cars recovered from the sinkhole, and in a few weeks hopes to be adding four more cars for visitors to see. The NCM plans on displaying the cars ‘as is’ once they are recovered, now through August 3, 2014. “We appreciate all of the support and interest from Corvette and auto enthusiasts around the world,” said Wendell Strode, Museum Executive Director. “We still have a long road ahead, lots of repairs to make, but we are confident we will come out better than ever.
From the March/April 2014 Wire Rope Exchange, Industry News.
photos courtesy National Corvette Museum