Forming 27,000 cubic yards of architectural concrete at the San Diego Convention Center provided a real challenge for architect, contractor, and form supplier. Although the job had its share of conventional walls, concrete decks, and pan slabs, it also had large amounts of complex, unconventional column, arch, and beam forming, for which the architect specified steel forms. Twenty-five fin-like structures soaring 100 feet above ground level dominate the longitudinal sides of the structure. Each fin contained integral columns, beams, arches, and slabs that varied in number, size, and location. Within the 25 fins there were 50 arches. The arches required many custom forms to achieve the required contours and depressions in the arch faces. The soffit form, supported on a 200,000-pound capacity shore tower was designed to collapse and strip in a manner similar to a tunnel form. The 125-foot-long diagonal fins, typically 3 feet, 10 inches deep and 6 feet, 6 inches wide, sloped at a 45 degree angle. They were formed with self-spanning all steel plate girder forms that needed no shoring support.