The CTA viaduct for Dempster Street is nearly in place. Workers fine-tuned its alignment before lowering it onto steel supports that rest on a concrete foundation.RoundTable Photo

Chicago Transit Authority’s Purple Line viaduct replacements at Dempster and Grove streets that began June 22 were completed June 26. CTA trains had been shut down at 8:30 p.m. on June 22 to remove the old viaducts and make final preparations for the installment of new retaining and foundation walls. The new viaduct was lifted above Dempster Street at about 6:00 p.m. on June 23, and it took a few more hours to fine-tune its alignment and lower it into place. The Grove Street viaduct was swung into place later. CTA trains started running again on June 25. With the earlier installation of the Greenleaf viaduct on June 8-10, the project is now complete.