CHICAGO, IL – The west wall has been braced with steel tubes. This will allow the west wall to stand on its own while the first truss is removed. Truss 1 has purlins that tie into the west wall and to Truss 2. These purlins will be removed as part of the removal of Truss 1. The purlins assist with the stabilization of the west wall. The steel tubes will provide this stabilization during the removal and installation of Truss 1.