Just two months from now, one lane of traffic in each direction will be running on the new Highway 61 bridge in Hastings.
Steve Kordosky, the project manager from the Minnesota Department of Transportation, said this week that the bridge is right on schedule.
He expects the shift to occur in late May or right around the first of June.
Once traffic is routed onto the new bridge, work will begin immediately to demolish and remove the portion of the current bridge that is in downtown Hastings. That piece needs to be removed so that crews can finish the final two lanes of the new bridge.
Demolition of that piece of the current bridge is expected to last about a week. Work would then begin to finish the new bridge.
All four lanes of the new bridge, two in each direction, would open to traffic on or before Dec. 13, 2013. The contractor has a financial incentive to finish up to 30 days prior to that deadline.
Kordosky expects to see evening and weekend work on the bridge this summer.
"It will require long hours and weekend shifts this summer," he said. "They have a lot of work to do to get that ... approach done."
Kordosky said that a portion of Second Street downtown will be closed for a few days while part of the current bridge is demolished in early June.
Sensors will be used downtown to monitor vibration activities so that the buildings there don't endure too much shaking.
"What could make that task take longer is if the vibrations resulting from the demo are too great," Kordosky said. "There's a threshold that has been established with the historical society. We may end up saw cutting that existing structure and remove it piece-by-piece, rather than using hydraulic hammers to knock it down."
The new bridge
Crews are busy constructing the deckwork to support the concrete that will be poured on the main span for the new bridge in April.
About 2,100 cubic yards of concrete will be needed for the roadway across the 545-foot main span of the bridge. That's equivalent to about 200 concrete trucks.
The pour is expected to occur around April 10 to April 15.
The infrastructure is in place for the anti-icing system on the bridge.
The pressurized system will be designed to automatically sense weather conditions that would lead to ice. It will react on its own, spraying environmentally friendly potassium acetate on the bridge deck through a network of small sprayers.
The cars traveling over the bridge then help disperse the chemical evenly across the entire deck. A pumphouse to run the systems will be built over the coming months near Hub's Landing.
The steel cables that run from the arch to the bridge deck are now in place. There are 36 cables on each side, each with a diameter of 3.75 inches.
In testing, it was determined that the destructive force necessary to shred each cable is about two million pounds.
Footings and piers are all completed for the new bridge over the railroad just north of the bridge. Once the decking crew finishes work on the main span of the bridge, they will move to the railroad bridge and deck that.
The current bridge
While the demolition of the piece of the bridge that is downtown will only take a few days, the rest of the bridge will take much longer to haul away.
Work on that will likely occur beginning in about August. It will take about three months.
That said, it is possible that the contractor will decide to tackle the project over the winter and spring, so this schedule is flexible.
Traffic north of the Highway 61 bridge will see a lot of changes in the coming months. Among the most significant projects will be the construction of a U-turn near The Point at the top of the hill.
That work will take about five days to complete, and during that time, southbound Highway 61 will be down to one lane.
"I would expect pretty significant afternoon delays on southbound 61 for about a five-day period, starting about mid-April," Kordosky said.