Continuing our nine-part Meet the Bridge Builders video series, this week’s episode takes a behind-the-scenes look at a truly innovative engineering solution to one of the challenges that arose during the construction of the main span.
The main span is made up of a grid of edge girders that run the entire 2,000-foot length of the main span on the north and south sides of the new bridge, and 140-foot-long, 10-foot-high floor beams that cross between the two sides at 50-foot intervals. When a floor beam was placed between the edge girders, the bolt plates used to connect them were not lining up due to a very slight bowing of the edge girders from the weight of the concrete road deck.
To get the bolt plates to line up, the contractor SFI used huge steel braces that – when tightened – rotated the edge girders into place. These braces were given the name “super wrenches” because they rotated the girders in the same fashion that a crescent wrench turns a washer or bolt. Making the use of the super wrenches all the more impressive was that they were deployed 200 feet in the air.