This Architectural Drawing is AutoCAD 2d drawing of The structure shown forms part of a truss designed by An architectural engineer to support the roof of an orchestra shell in AutoCAD, dwg file. A full shell is 42' wide at the downstage wall, 30' deep from the plaster line and consists of eight movable towers with four ceiling clouds. The ceiling clouds are permanently hung on battens, and are flipped down to a horizontal position when in use.