The Knapp Center is a multi-use sport, recreation and convocation facility for Drake University. The main arena roof structure consists of custom-designed bowstring trusses spanning 210 feet to tapered concrete columns. To facilitate the lighting of this structure, a large catwalk system was designed and erected along the bottom chord of the bowstring trusses. The main arena floor was depressed approximately 10' into the existing grade, to reduce the mass of this huge structure. The truss erection was carefully planned during design so that the roof structure could be assembled rapidly and sequentially to keep this project on schedule.