Minneapolis—Attaching sports banners to the Metrodome's wall once kept the stadium's engineers on the run.
As staff engineer Jeff Freeman explains, the Metrodome plays host to three different teams, and each has its own set of banners that ring the stadium. At roughly eight-feet high, the banners cover wall sections from 15 to 52 feet long and weigh up to 15 lb.
In the past, drywall screws left walls with more holes in them than the San Diego Chargers' defensive line. It also took too long to change banners.
Freeman finally tackled the banner problem with 3,300 ft of Dual-Lock fasteners from 3M (St. Paul, MN). These reclosable fastners employ hundreds of mushroom-shaped stems that interlock for a pull-apart (tensile) strength of roughly 40 lb/in 2 . Freeman mounts the one half of adhesive-backed Dual Lock on 2-inch-wide×3/16-inch-thick strips of aluminum, which have been permantently screwed into the wall. The other goes on the backs of the banners, making installation as simple as pressing the banner against the strips. And removing the banner has become as easy as quick tug. Now all Freeman has to worry about are souvenir hunters.