Largest bridge slide in North America ready to take place - wave3.com-Louisville News, Weather & Sports

Largest bridge slide in North America ready to take place

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Source: Milton-Madison Bridge Project Source: Milton-Madison Bridge Project

From Milton-MadisonBridge Project

MILTON, KY - It'sthe largest bridge slide of its type in North America. The new Milton-MadisonBridge, which spans nearly a half-mile and weighs some 30 million pounds, willslide 55 feet laterally from its temporary piers and onto refurbished permanentpiers.   

Theslide, scheduled to begin Wednesday morning, April 9, could take up to 16 hoursbefore the bridge rests in its final location – on top of the refurbished piersthat held the old Milton-Madison Bridge in place beginning in 1929. The CoastGuard will close the river during the slide.

"We're making history in Indiana and Kentucky," said Karl Browning,commissioner of the Indiana Department of Transportation. "Through hard workand creative engineering, we've been able to rebuild this bridge quickly andcost effectively."

Pulling a half-mile structure weighing 30 million pounds a distance of 55 feetin a matter of hours is an engineering marvel, though simple in concept.

Polished steel sliding plates are secured on top of the refurbished piers.Steel cables and hydraulic jacks controlled by computers will be used to pullthe bridge. A total of eight jacks are mounted on the piers. Industriallubrication is put on the sliding plates to grease the skids. Then, through aseries of grabs and pulls, the bridge is slid into place. Each grab and pull isexpected to move the bridge 2022inches – up to 10 feet per hour.

Once the bridge is in its final position, additional work has to be completedbefore it can reopen, including inspections, welding and bolting it in place,reconnecting the driving surfaces, installing expansion joints, pouringconcrete, configuring drainage and re-striping.

"Everyone is a winner on this project," said Mike Hancock, secretary of theKentucky Transportation Cabinet. "We're showing the rest of the country how twostates, by strategically working together, can deal with aging infrastructurein creative ways that improve safety and better the quality of life for theircitizens."

All schedules aretentative because weather and other factors can alter the schedule. Ifall goes as planned, the bridge will reopen to traffic about a week after theslide.

Thenew steel truss bridge is 2,428 feet long and 40 feet wide with two 12-footlanes and 8-foot shoulders – twice as wide as the old bridge. A 5-foot-widecantilevered sidewalk will be added to the structure in the coming months afterthe slide. 

The Milton-Madison Bridge Project – a joint effort between the IndianaDepartment of Transportation and the Kentucky Transportation Cabinet – hasreceived numerous awards. It was named one of the top 10 bridge projects in thecountry by Roads &Bridges magazine, received a 2012 Best of What's New Award from Popular Sciencemagazine and received several state and national engineering awards forinnovation. For more information, visit http://www.MiltonMadisonBridge.com or followthe project on Twitter