Inside the Tollway
It’s necessary to attack at all angles when rebuilding the Illinois Tollway’s dual-structure Mile Long Bridge in the southwest suburbs of Chicago.
The first of the two new bridge structures is being built for northbound traffic to the east of the existing northbound structure and the Illinois Tollway’s June video offers an update on progress to date.
The logistics of maneuvering in and around the surrounding environmental and man-made obstacles requires precise calculations and coordination to keep the $184.6 million northbound bridge contract on track.
The new bridge is being constructed from the ground, from the existing bridge and from a modular barge built on site using an array of heavy duty cranes, and all the activity was recently captured on drone photos by Chicago Tribune photographer Zbigniew Bzdak.
The barge-mounted crane has a more than 50-ton capacity and the ability to lift the longest beams.
A ground-level rough-terrain crane provides the versatility to lift beams of various lengths and weights from unpaved conditions beneath the bridges.
The 1.2 million-lb. fixed-boom crawler cranes operating from the existing bridge are capable of lifting the heaviest of steel beams being erected over a portion of the Cook County Forest Preserve, as well as the Chicago Sanitary and Ship Canal and the Illinois and Michigan Canal, and can travel and rotate with a full load.
Construction on the new northbound Mile Long Bridge is scheduled to be completed before the end of 2020. Once the northbound bridge is complete, traffic will shift to the new bridge and the old northbound structure will be demolished. Construction will then begin on the new bridge for southbound traffic where the old northbound bridge was located.