Good news arrives on bridge: Contractors are aiming to have drivers on two lanes of the new bridge in 11 months
Drivers in Hastings get good news this week: The Highway 61 bridge over the Mississippi River here will, if all goes as planned, be completed six months earlier than previous projections.
After high water and a state government shutdown prompted significant delays in the project, Minnesota Department of Transportation officials said the project wouldn't be complete until May 2014.
Now, it looks as though the bridge could be finished at the end of 2013.
The change is due in large part to an agreement worked out between the contractors, MnDOT, the Army Corps of Engineers and the shipping industry. The agreement was needed to shut down the river to barge traffic while the main span for the bridge is floated in place.
That span is being assembled now at the staging area near the lock and dam in Hastings.
At 545 feet, the span is the longest tied arch bridge with a free-standing rib in the western hemisphere. The only one longer is the Kaiserlei bridge in Germany, which spans 722 feet.
"It's pretty impressive," said project manager Steve Kordosky as he surveyed the span construction Monday morning.
Barring any unforeseen delays, one lane of traffic in each direction will be routed onto the new bridge at the end of May in 2013, less than one year from now. Once traffic is on the new bridge, the old bridge will be dismantled, and crews will be able to construct the final piece of the project, the two northbound lanes over downtown Hastings. Crews can't build those now because the current bridge is in the way.
Now that the agreement to shut down the river is in place, Kordosky and Joel Myers from Lunda Construction can focus on getting that span moved from its current location into the river, and that will be no easy task. When both steel arches and the floor system are assembled by the end of August, they will weigh 6.5 million pounds, or 3,250 tons. Then they will be moved in place over the span of about a week, likely between Aug. 25 and Sept. 5.
Slowly, the four corners of the span will be lifted, and the shoring towers that are holding the span in place right now will be disassembled. The main span will then be rolled down to the water's edge, a distance of about 200 feet, using a platform vehicle with a number of wheels below it. The vehicle will roll on special steel plates on the ground until it reaches the ramp to the barge.
That's when the agreement with the shipping industry takes effect. Lunda and Ames, the contractors for the project, will then shut down the river to barge traffic for 48 hours as the span is loaded on to two enormous barges that are almost as long as a football field (260 feet) and 72 feet wide.
The span will be gently loaded on to the barges, and the barges will then be towed out of the shipping channel where they will sit for a few days.
Meanwhile, all those barges heading upstream will be forced to take a 48-hour break, and it is figured that most will stay on Lake Pepin. Kordosky said he has heard that between 20 and 30 barges will be affected at that time of year.
Once the span is out of the way, shipping traffic will resume. It will be open for about 60 hours to allow those barges to get up to St. Paul, get loaded again with grains and to come back through Hastings. Once they clear the lock and dam here on their way down south, the traffic will be shut down again and the span will be floated downstream.
The barges will make their way to the construction site and four massive jacks, mounted on the piers, will lift the span in place. The jacks are about five feet tall and about as big around as a garbage can. Each is capable of lifting 900 metric tons.
As he recounted all the steps that await the project, Kordosky simply said:
"It's a daunting task."
The subcontractor in charge of moving the span into the river is a firm from the Netherlands called Mammoet. They operate across the world, specializing in heavy lifting.
They have worked on projects ranging from a radio telescope in Sardinia to the Media City swing bridge in Manchester, England.
They have been involved with the construction of three large swing bridges in New York City since 2004. They accomplished a very similar task there with one of the bridges, the Willis Avenue Bridge. It weighed 2,500 tons and was floated down the Hudson river by the contractor.
The decks are poured for both the south approach and the north approach to the bridge.
The south approach, in downtown Hastings, used about 3,200 yards of concrete, or about 320 trucks' worth.
The north approach, near Hub's Landing, used about 2,500 yards of concrete, or about 250 trucks' worth.
The concrete has come from Cemstone, and most of it has come from the plant right in Hastings.
The arches are being manufactured by a business in Eau Claire, Wis., called PDM Bridge. Each rib has seven pieces to it, and about 15,000 bolts will be used to assemble the two ribs.
Small access doors are going to be built into the arches. The secure doors will give MnDOT bridge inspectors the chance to walk inside the structure during inspections. The arches themselves vary in height from more than eight feet tall on the outside to about six feet in the center.
The bridge is 104 feet wide.
There are four lanes of traffic and a 12-foot-wide pedestrian and bike path.
The arches have been painted gray so far. They will be terra cotta when finished. The light poles, cables and railings will all be silver.
The vehicle that will move the span from the construction site into the river is a marvel of engineering, in and of itself. They are called self-propelled modular transporters. The 32-axel vehicle that will be used in Hastings will move slowly toward the river -- most travel at under one mile per hour when loaded. For more information, and photos of a SPMT, visit http://en.wikipedia.org /wiki/Self-propelled_modular _transporter.
The Mammoet website features some photos of bridges moving down rivers, just like what will be happening here. To see those images, go to www.mammoet.com, click on "News and Media", then on "Civil references." You'll see a few photos there for "Bridge for the Big Apple."
The total cost for the bridge project is estimated to be $120 million.