The NFL Draft came to the “Music City” for the first time in 2019. To welcome visitors and provide a scenic backdrop to the stage on Broadway, the Draft’s lead production company sought to hang a 4,000-pound three-dimensional sign from the main span of the historic John Siegenthaler Pedestrian Bridge—a 318-foot steel truss constructed in 1908.
Benesch’s familiarity with the bridge goes back to 2017, when we completed our finite element modeling analysis of the structure’s main steel trusses. Equipped with this prior knowledge and through an on-call contract with lead firm Civic Engineering & IT, Inc., Benesch was tasked with evaluating the feasibility of hoisting and attaching the NFL Draft sign without impacting the bridge’s structural integrity.
Using innovative finite element modeling, Benesch was able to model the unique loads upon the structure resulting from the sign lift and installation, including the addition of a potential 11,400-pound horizontal wind load reaction at the center support. The analysis accounted for all phases of construction (lifting, mounting and dismounting) of the sign and its final mounting position—creating a variety of vertical member load scenarios to consider.
The evaluation was completed on an accelerated schedule, allowing for the sign to be installed on time. Following the successful completion of the structural review, the sign was brought in by barge on the Cumberland River and lifted into place utilizing temporary beams and cable hoists mounted atop the bridge; the team pillars were set up on the bridge deck.