Staff photo by Ken Ritchie
The 600-foot span of the new bridge was successfully positioned between two temporary piers Monday in a process that took several hours. Walsh Construction Co. is using the firm VSL International to lift the span, which weighs 1,776 tons. The lift is scheduled to take place as early as this afternoon (Tuesday).
The span will be lifted 85 feet into the air at a speed of 13 feet an hour.
According to a press release from the bridge project team, "After the truss has reached the full height of the lift, a massive, 125-ton beam, called a sliding girder, will be slid under the truss, supported by the temporary pier and a specially designed concrete pedestal on the existing piers.
"Eventually, this beam will be used for sliding the new 2,400-foot bridge from the temporary piers to the permanent piers, which are being rehabilitated and strengthened."
The positioning drew dozens of people to the riverfront Monday. "I told the people at home it wouldn't get done unless I'm here," Dale Yates of North Vernon joked. He and his wife brought their camper to stay at the city campground until the span is in place.
Juanita Helton of Madison sat on the concrete wall along the river in the temporary shade of a small tree. "I used to work in construction, so I just wanted to come down and watch them," she said.
The original plan had been to start the lift Monday and leave the bridge span hanging overnight and finish it today, a project spokeswoman said. But that plan was changed and it was decided to not start the lift until it can be completed in the same day.
Much of the work Monday was to attach cables to the span for the lift, which the spokeswoman said was being done very slowly.
With the new span in place, the difference in design between the old and the new can be seen. The existing bridge is not symmetrical, with the span the new one will replace being flat along the top instead of curved like the new one.
The longer span over the shipping channel will be lifted onto temporary piers in August, and the rest of the bridge will be built on-site instead of being assembled on barges on the riverbank. When the new bridge is all done, it will be slid over to the existing piers.
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