A TIGHT CHANNEL AND A TIGHT SCHEDULE.
The I-35 bridge was over 2,000 feet long and crossed the Mississippi River in the middle of Minneapolis. On August 1, 2007, it collapsed in the middle of rush hour, claiming the lives of 13 people and injuring over a hundred more. In immediate response, civilians from all over the region took action to help in the rescue efforts. Within three hours of the bridge’s collapse, the rescue mission was complete. Minnesota DOT swiftly called for a replacement bridge with a far safer, superior design.
The Minnesota DOT selected the Flatiron‑Manson Joint Venture to design and build the replacement. The project kicked off the just days after the bridge’s collapse and the entire team was given just 15 months to open the new bridge. Glosten was contracted to design the crane barge to support the bridge segment lifts. The navigation locks on this upper part of the Mississippi are only 56 feet wide, which is too narrow to fit a single barge large enough to support the crane. The team opted to assemble a raft of two smaller barges connected with a grillage to perform the lift.