To allow for the work, the Chelsea Street Bridge over Chelsea Creek at the Boston/Chelsea line is closed until Thursday, December 1st. Detours are in place.
In the view at left from atop the new structure's south tower, the three fixed spans of the old bridge on the Chelsea side are demolished and gone. The existing piers will be retrofitted with a crane rail system to advance the new truss, seen at upper right, to the channel edge prior to launching the truss and raising it to the up position for marine traffic.
The Chelsea Street Bridge project involves the replacement of a truss-type structure that spans 450 feet and will provide 175 feet of vertical clearance when raised. The new bridge will provide for four lanes of traffic two pedestrian sidewalks. The project is scheduled to be completed in spring 2012.