It's a replay of the project that went ahead without too many hiccups last month on the south side of the river and though the objective is the same, moving a half-million pound new structure into place, it's still about getting it right, down to the 1,000 points of connection that have to fit, with only 1/16th of an inch wiggle room.
A ballet of beams and bolts will take place 24 hours per day for the next nine days on the 91-year-old bridge.
"Now I guess the big challenge is to make sure both sides meet," said AECOM Senior Vice President Denise Casalino, Aecom Senior Vice President. "They will."
Casalino is overseeing a $41 million project that involves disconnecting the north end of the bascule, or see saw bridge, and floating in on a barge its 500,000-pound replacement.
As in March, two out of every three weekday morning rush Brown Line trains will be routed via the Red Line subway to Roosevelt. Unlike in March, those subway-bound will say "Roosevelt" up front and stop on the inner platform at Fullerton, which is the Red Line track. Brown Line trains not headed for the subway, one out of three, will stop at the Merchandise Mart. At Fullerton, those brown line trains will stop on the outer platform.
"Some customers were confused and we did notice, especially at Fullerton, a lot of crowds there with customers not sure which train they should board, so we wanted to make it easy for them" said CTA's Brian Steele.
There will be no express Purple Line service, and riders of the Pink, Green and Orange Lines can expect their trains to stop short of the Loop especially on weekends.
"Now I've got to re-route, which mean my extra travel time is 30 minutes and I'm afraid I'll get lost," said commuter Romance Martin.
But the changes are for a cause, the revamping of a key piece of Chicago's infrastructure.
"I really pushed the city to do the full replacement and not just do piece-meal," Casalino said.
The last trains stop at 10 p.m. Friday night and will be affected until rush hour on Monday, May 6.
For more information, visit http://www.transitchicago.com/wellsbridge/.