EDGEWATER — The rebuild of the Red Line on the Far North Side will be assisted by a custom-built overhead crane system almost the length of a football field.
Crews this week will begin assembling a gantry crane near the Red Line tracks at Ardmore Avenue, where the crane will be put to use installing sections of the rebuilt Red Line, CTA officials said at a recent community meeting.
At 285 feet long, the gantry crane is longer than a Boeing 747 and is nearly the length of a football field minus the end zones. It is being employed to minimize traffic and neighbor disruptions during the reconstruction of the Red and Purple Line tracks in Uptown and Edgewater.
While most construction cranes stretch hundreds of feet in the air, a gantry crane runs horizontally and installs pieces of infrastructure projects. In this case, the gantry will install massive, prefabricated concrete blocks that will form the base of the Red and Purple Line infrastructure in the area, CTA officials said.
The gantry is being assembled near Ardmore Avenue beginning this week, CTA spokesperson Tammy Chase said. It will begin installing portions of the track base in November.
The gantry will install 1,555 pieces of prefabricated concrete track base between Lawrence and Bryn Mawr, the portion of the Red and Purple line tracks and stations being rebuilt. Installation will start at Ardmore and work south.
Each prefabricated concrete base piece is 27 feet wide by 9 feet tall and is 8-11 feet long. The pieces are being trucked into the site from a production plant in downstate Morris.
Ardmore will be closed until February to accommodate the gantry and concrete pieces. Balmoral and Ainslie avenues will also be used as crane and concrete block staging areas, requiring Balmoral to be closed March-August and Ainslie in September and October 2022.
Alley closures will also be required as the gantry moves south from Ardmore, said Kevin Buch, project manager for the CTA’s Red-Purple Modernization Project
Using the gantry and prefabricated materials will cut down on the work that needs to be done on the site, Buch said. The gantry was also custom built to fit in the dense area.
“Anyone who has gone anywhere near this project understands how dense and how little real estate there is to work” with, he said at the community meeting. “By designing a piece of equipment that can operate within those confines … we’re able to operate without impacting the adjacent structures.”
CTA crews will soon move to building track structures after recently demolishing a large portion of the existing eastern-most portion of the Red Line infrastructure in the area.
So far, crews have demolished nine of the 11 viaducts where the CTA spans residential streets, said CTA project manager Michal Williams. The station houses at Berwyn and Lawrence have also been demolished.
Six of the 81 foundational shafts have been drilled, with the shafts averaging 6 feet wide by 70 feet deep.
Work on the $2 billion Red-Purple Modernization Project is scheduled to wrap up in late 2024. Service on this portion of the “L” system will be maintained throughout the project.
“The first six months of this project have been significant,” Ald. Harry Osterman (48th) said. The gantry “will help make this project move along quicker. We appreciate your patience with this project.”
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