Tightening Bridge Bolts – All 200,000 of Them

The Bridge Project’s main span is a steel structure that has many bolted connections with various bolt diameters and lengths. One of the final tasks before construction is complete is inspecting and performing quality assurance (QA) testing on all of the bolts along the main span. That involves tightening each one with a torque wrench like the 36-inch-long one pictured above that gives the worker extra leverage. The process takes weeks, as there are more than 200,000 bolts along the main span.

Each of the 36 bridge segments has approximately 5,000 bolts that attach the floor beams and edge girders. In addition, there are more than 3,000 bolts that attach the end girders on both sides of the main span. Tightening these bolts and plates acts as a replacement for welding the many steel pieces together.

Since these bolts are above salt water, each one is made with all-weather steel then coated in zinc to prevent corrosion. Further protection from the elements is added when they are painted. In the future, QA testing on these bolts will occur as part of regular maintenance inspections.