Whether standing on the inside or outside, it's almost impossible to miss the precast work on the United Center, future home of the Chicago Bulls and Blackhawks. The interior precast contractor, J. W. Peters & Sons, Burlington, Wis., had its work cut out as 1,468 precast pieces were produced. The pieces range in size from 2x3-foot wall panels to a 12x30 foot camera platform. Other pieces included risers, stairs, vomitory walls, and columns. Many of the precast riser pieces are attached to the structural beams below with pin connections. Ends without pin connections are free, and sit on a bearing pad that is placed between the precast piece and the structural beam. Vomitory walls and other precast pieces are connected with steel welded plates. The walk-ways that circle the facility are cantilevered of the raker beam, requiring that the tolerances between the walk-way tubs be perfect. The building's facade has almost 1,200 pieces of precast, kept in place by steel-imbedded cantilevered plates. Despite the fact that J. W. Peters & Sons have made precast seating and tub pieces for several other stadiums, new tub and seating forms had to be purchased for the United Center because the sizes were different. Work began on the 950,000-square-foot facility in April 1992 and is scheduled to be completed in August.