Operation will temporarily close main navigational channel
LOUISVILLE, Ky. (Sept 5, 2012) – The Milton-Madison Bridge Project is expected to mark another major milestone next week when a second massive section of the new bridge is lifted into place. The 727-foot pre-assembled section of steel truss will be hoisted onto temporary piers, another in a series of steps to replace the US 421 bridge, connecting Milton, Ky., and Madison, Ind.
The existing bridge remains open during the lift, currently scheduled to begin at 12 a.m. Sept. 10, weather permitting. The span, which was pre-assembled on barges in Milton, will be floated into position and lifted using a method called “strand jacking,” often used to lift heavy structures.
Special hydraulic jacks and bundled strands of steel cable will lift the 2,067-ton span to a
height of 90–95 feet onto temporary piers 4 and 5, immediately north of the first section that was lifted in June.
Because the span lift takes place in the main navigational channel, the river will be closed to commercial traffic for approximately 24 hours. The U.S. Coast Guard will determine when the river can safely reopen. Recreational boaters will also be prohibited from using the area near the lift during this time. A “no wake” zone will be established 1,000 feet upstream and downstream of the bridge, and boats must stay back 500 feet on either side of the bridge. For the safety of the boaters and the workers, this restricted area will be enforced.
Once the span reaches its full height, a “sliding girder” will be placed under the truss, supported by the temporary pier and a concrete pedestal on the existing piers. This massive beam will be used next spring when the completed 2,426-foot bridge slides from its temporary position onto the permanent piers, which are being rehabilitated and strengthened.
The Milton-Madison Bridge Project – a joint effort between the Indiana Department of Transportation and the Kentucky Transportation Cabinet – was named one of the Top 10 bridge projects in the country by Roads & Bridges Magazine and has received several state and national engineering awards for innovation. For more information, visit www.MiltonMadisonBridge.com.