A design for a flexible, low-cost rigging block for black-box theaters by Michael J. Shields.

Abstract

Theater rigging greatly expands both scenic movement and storage options when putting on a production. Small, black-box theaters are often built without rigging equipment in them. Temporary rigging equipment can greatly add to the flexibility of these spaces. A rigging block was designed which can be installed in small theaters by attaching to the existing lighting structure. The design was developed to solve problems encountered when using currently available temporary rigging solutions. The block was designed to lift a 200 pound scenic load while providing a safety factor of 10:1. A dual-pulley arrangement allows for flexibility in the placement of rigging positions and better utilization of the available space. Top and bottom pulleys allow for lines to be routed above the level of the lighting grid. The independent swiveling of the pulleys allows lines to enter and exit the block at different angles, adding significant freedom to the rigging system. Calculations were done to assess the forces and torques to which the block might be subjected. Potential materials were evaluated based on their ability to withstand these forces. An eye was kept toward using available off-the-shelf parts where possible in order to reduce costs and to allow for the system to be used by small theaters working with limited budgets.