ZERO-FLEET WINCH SHEAVES PHOTOS: BILL BROWNING by B.R. Delaney North Carolina School of the Arts At North Carolina School of the Arts, as in other academic programs, there is a desire to include stage automation in our productions. This desire often leads to challenges. The spring 2006 productions of A Month in the Country and Fathers and Sons were a case in point. To fly a large section of cornice molding we decided to use several deck winches. One of the initial concerns with the automation rig was the noise it would make. To solve this problem we located the winches in a room beside the control booth. This room had no windows; however an 8˝x12˝ pass-through was available for the four required cables to exit vertically from the winches. This is where the challenge arose. The changing fleet angle as cable paid off the drum would cause the cable to walk beyond the limited size of the pass through. THEATRE 42 DESIGN & TECHNOLOGY SPRING 2007 Conquering this challenge would require a "zero-fleet" device. Generally "zero-fleet" winches operate by physically moving the drum so the cable always exits the winch assembly at the same point. Because the deck winches being used were not outfitted to deal with fleet angle changes, some sort of compensator rig would need to be designed and fabricated. Whatever modification we made to counter the fleet coming off the device, we could not introduce an element that created a fleet problem within the device or defeated any existing compensating measures. Early in the R&D process, the idea of having the walking sheave tilt as well as "walk" provided a solution that addressed the fleet problem at the winch itself. If this sheave would be able to pivot on the same pitch diameter that the cable enters (essentially about the axis defined by