Steinle Construction Engineers (SCE), the structural division of VanDemark & Lynch, Inc., was recently contracted by American Signcrafters, New York, to design a sign support structure for a new sign to be erected on top of the 22-story Brandywine Building in Wilmington, Delaware. An extremely accelerated completion schedule was required, and with SCE’s help the sign was fabricated, permitted, installed and lit within 2 months.
This type of sign requires significant structural support to withstand hurricane force winds. To accommodate the focused loads created by the sign support system, the sign would also require additional bracing and strengthening of the roof structure. Fortunately, the new Citi sign was replacing the recently removed DuPont sign and some of the required support structure was already installed. SCE’s Structural Engineers met at the site with American Signcrafters’ and building representatives where they reviewed existing conditions and obtained original building structural drawings. The analysis confirmed the new sign could be supported by the remaining structural frame. SCE recommended RC Fabricators be contracted to fabricate and erect the steel support structure. With American Signcrafters and RC Fabricators, SCE designed a vertical assembly of structural steel tubes to hold the new sign. This design would allow the construction and preassembly of the 23 feet high by 28 feet wide, LED-lighted sign at American Signcrafters’ offsite facility, while RC Fabricators assembled the support structure.
SCE worked with the City of Wilmington to submit plans and obtain permits for the new structural sign while the design and coordination of the installation was occurring.
The next hurdle would be installing the sign on top of the building at an elevation of 260 feet. Several options for transporting the structural steel assembly to the roof were considered before a decision was made. Using the elevator to bring up small sections was ruled out due to the extended assembly time and impact on a nearby falcon’s nest.
SCE recommended lifting the pre-assembled sign up to the roof, as one piece, using either a crane or a helicopter. However, a helicopter could not be found that would be able to make the lift within the necessary timeframe. Additionally, the possibility that winds might further delay the lift was a concern. RC Fabricators located a crane that could make the lift. Because the City of Wilmington required the building be empty and the adjacent streets be closed, the final assembly and lift was scheduled for a Saturday.
American Signcrafters delivered the pre-wired sign assembly early Saturday morning, and attached it to the pre-fabricated, structural steel frame delivered by RC Fabricators. At noon, with the streets blocked off by City Police, and the building empty, the crane lifted the complete assembly to the roof. It was then bolted to the prepared roof frame and the electrical connections were made to power the sign. The lift and installation of the sign was completed in about 2 hours.
SCE was able to meet their client’s needs, including tight schedule by using experienced structural engineers familiar with both structural fabrication/erection procedures and local permitting requirements, and by communicating effectively with the entire team.