Walter Brough, P.Eng., project manager for JTI, oversaw the design and testing phase. AOC provided several resin samples, which JTI sent to a testing lab to obtain the physical properties of the combination of fiberglass, Hardwire and resin. Using that information, Brough and his team conducted a computerized stress analysis to determine the necessary tube thickness and what layers were required to limit deflection. JTI selected the K022-AA resin because it is fire-resistant (critical in an architectural application) and corrosion-resistant (important in the museum’s coastal environment). Inclusion of the Hardwire steel wires increases the strength-to-weight ratio of the tubes while maintaining flexibility: The tip of each tube will move a maximum of only eight inches in 146 mph winds.
The team at JTI fabricated the tubes using hand lay-up, alternating layers of fiberglass and Hardwire in a sandwich construction to create the 3/8-inch thick tubes. JTI built custom 40-foot-long mandrels to accommodate the project. Even then, technicians had to slide the tubes out of the mandrels and continue making the ends of the longest tubes on specially created extensions.
One of the biggest production challenges was dealing with varied weather conditions. “This project spanned several months,” says Jason Brough. “In our Alabama plant, we would find ourselves dealing with drastic temperature changes from one day to the next.” AOC worked closely with JTI to help the company promote the resins based on environmental conditions and stay on the tight production schedule.