The basket-handle piece of the Interstate 74 Bridge construction is expected to be completed on Wednesday, May 6.
It may look like a small area to cover, but it’s a multi-step process with some very weighty materials. Project leaders explained that the keystone, which will connect the two waiting pieces of the arch, was delivered in two pieces and assembled at the work site. The keystone weighs about 215,000 pounds.
To install it, a work platform was placed under the gap in the arch. This will allow workers to spread the arches apart before setting in the keystone. The largest crane on site will lift the keystone to the top of the arch while ironworkers set it in place. Once the piece is set, ironworkers and engineers will make adjustments to ensure it has the most stable fit.
To complete this work, the Mississippi River’s navigation channel in the construction area has to be closed to barge and boat traffic for 72 hours. This closure is set to begin at 6 a.m. Wednesday. All recreational boaters are reminded to travel slowly, obey no-wake zones, and avoid the construction area.
“This is a landmark accomplishment for the project and people understandably want to see it,” said Joe A. Larson, Vice President of Lunda Construction Company. “we ask that residents keep everyone’s safety in mind, including our crews working on the bridge.”
Project leaders are asking for the public to avoid the construction area, and instead take advantage of several at-home viewing opportunities.
Here are the places you can watch the construction:
Once the keystone is in place, there is weeks worth of work yet to be done on the arch. First workers will bolt the keystone in place. There are four connections on the keystone, each requiring more than 1,000 bolts apiece.
All of the work is weather-dependent and plans are subject to change.
