Madison-Milton Bridge Project
First section of old bridge coming down July 17
Wednesday, July 10, 2013 11:00 AM
The main span of the old Madison-Milton bridge is scheduled to be demolished on July 17, the first in a series of blasts to bring down the 2,427-foot-long steel structure. The blast will require the temporary closing of the new bridge that carries U.S. 421 across the Ohio River.
This illustration shows the section of the old Madison-Milton Bridge that is scheduled for demolition next week if weather permits. (Staff photo illustration by Ken Ritchiefirstname.lastname@example.org)
Weather permitting, the approximately 700-foot-long span over the main navigational channel is scheduled to be demolished in the morning. A 1,000-foot safety perimeter will require the adjacent new bridge to be temporarily closed for a few hours.
An FAA no-fly zone of 2,000 feet will also be in effect prior to and during the blast. More information will be provided in the coming days as to the specific timing of the blast and temporary bridge closure.
Once the safety perimeter is secured, sirens will sound at intervals prior to the blast. Local authorities will strictly enforce the perimeter, and any spectators entering that zone once cleared will postpone the demolition.
Authorities said noise and vibration levels caused by the blast are expected to be well below levels that would cause any type of damage to structures. Special measures and protective materials are being used during the blast to protect the original bridge piers, which are being strengthened and reused.
Similar precautions will also be taken to protect the new bridge, which sits 15 feet downstream from the old bridge. Traffic was switched from the old bridge to the new bridge last month.
Using many small explosive charges placed at critical locations on the bridge, subcontractor Advanced Explosives Demolition Inc. (AED) will detonate the charges in intervals to control the direction of fall. The blast itself is expected to last a few seconds. In the days leading up to the blast, AED will precut the truss in strategic locations to allow the bridge to drop straight down into the Ohio River.
In coordination with the U.S. Coast Guard, the Ohio River will be closed to traffic for 24 hours to allow for the demolition and retrieval of the truss bridge from the water. Pieces of the truss will be retrieved from the river, placed on barges, taken to the shore for further dismantling and eventually sold for scrap. Divers are on call to ensure all pieces are removed from the river.
The 1929 bridge will be demolished in a series of three blasts about seven days apart over the next few weeks. The public will be notified prior to each blast.
Once the old truss is removed, work will begin on widening the original piers to accommodate the new 40-foot-wide bridge which is currently sitting on temporary piers. The new bridge will be slid into its permanent position on top of the original piers.
During the bridge closure, drivers can follow the signed truck detour to the nearest crossing, either 26 miles upstream at the Markland Locks and Dam Bridge or the Kennedy Bridge in Louisville, 46 miles downstream. Motorists detouring to Interstate 65 should be aware that the Kennedy Bridge is also under construction, and check www.kyinbridges.com for traffic updates.