A worker crosses the Checkered House Bridge in Richmond, Vt. The historic Vermont bridge is going to be updated with an unusual technique: Engineers will cut the 350-foot bridge in two lengthwise, push the two sides apart, widen them and put it back together.RICHMOND, Vt. – After more than a year of planning using computers, laser levels and measuring devices accurate to a fraction of a millimeter, it took engineers with tape measures and construction workers with sledgehammers to finally bring the 83-year-old Checkered House Bridge into the 21st century.
On Monday, workers cut the historic 350-foot U.S. Route 2 bridge in two lengthwise by unbolting the braces holding the trusses together and began the process of pushing the sides apart to widen the span by 12 1/2 feet.
As far as anyone involved in the project has been able to determine, it’s the first time such a technique has been tried on such a large bridge. Officials say the wider bridge is needed to accommodate modern traffic that frequently includes bicyclists, pedestrians and farm equipment. The span is scheduled to reopen a year from now.
Despite the preparations, the hardest push was the first. After workers moved one 300,000-pound truss about 2 inches downstream on the Winooski River on Monday, crews spent hours trying to free a single spot at the base of the bridge where, despite the specialized rollers it was laid on and pressure from hydraulic jacks, it remained stuck.
“I’m really not surprised. It’s such a large structure and such an old structure that there have to be points, friction points, that it hangs up on,” said Dale Gozalkowski, of the Albany, N.Y.-based engineer firm Clough Harbour & Associates, who helped design the project and watched Monday as it was put into action.