The old and new portions of the Wells Street bridge. (Credit: Bernie Tafoya/WBBM Newsradio)

CHICAGO (CBS) – Mayor Rahm Emanuel was dishing out praise Monday morning for the on-time replacement of half of the Wells Street Bridge over the Chicago River.

WBBM Newsradio’s Bernie Tafoya reports the bridge reopened to CTA Brown Line and Purple Line trains in time for the morning rush. It had been closed for nine days to replace the south half of the bridge.

The old south section of the bridge sat on the banks of the Chicago River early Monday as its replacement carried CTA trains into the Loop again for the first time since the work began.

The mayor was on hand to thank the engineers and construction workers who replaced the south half of the bridge, and the CTA and city workers and officials involved in the project. He also thanked the77,000 CTA commuters who ride over the bridge each day on the Brown and Purple lines.

“After 90 years this bridge was up, in nine days we replaced the bridge. I took my train in this morning, as I do twice a week; and it was a great ride, very convenient, got a lot of reading done,” Emanuel said.

CTA President Forrest Claypool thanked commuters for their patience during the bridge replacement work.

“I know the Red Line subway was more crowded than usual. There were obviously longer commutes, but as you can see behind us – as the mayor indicated – it’s worthwhile. This is the price of progress,” he said.

The north half of the bridge will be replaced starting April 26, forcing another nine-day shutdown of the bridge.

The street level of the double-decker bridge will remain closed to cars and pedestrians until the fall.