The engineering analysis, personnel qualifications, rescue planning, and rigging load plan described in the preceding articles in this series represent the pre-production framework for safe event rigging. This article addresses what happens when rigging work begins on site: the physical installation, the monitoring of actual loads during and after installation, the training and certification framework for event riggers, and the integration of moving and flying production elements into the event’s rehearsal process. Each of these elements presents distinct safety considerations that must be addressed through deliberate planning and qualified execution.

Pre-Rig Scheduling

Event organizers should always consider the possibility of a pre-rig: scheduling rigging work prior to the general mass crew call (Event Safety Alliance, 2013). The rigging process requires a clear floor and a quiet environment; the presence of other production crews working simultaneously creates both distraction and hazard. Scheduling rigging a few hours earlier than the load-in time for other production departments, or even on a prior day, contributes to safety and in many cases to cost efficiency. A pre-rig allows rigging work to proceed without other workers inadvertently entering the area beneath high riggers and without the pressure of other departments waiting to begin their own work.

Rigging Team Composition

A rigging team typically includes at least two high riggers and one ground rigger; generally at least two rigging teams are required for an efficient load-in. Bridle rigging points can require three high riggers and can take many minutes to complete if there are building obstructions such as catwalks, handrails, ductwork, conduit, lighting infrastructure, or dropped ceilings (Event Safety Alliance, 2013).

Large-scale productions often require four or more rigging crews for efficient installation and removal. The tempo of the entire load-in day is typically set by the pace at which riggers complete the installation. Experienced organizers and producers understand that properly staffing the rigging department reduces end-of-day time pressure and therefore reduces the conditions that lead to rushed, unsafe work. If a rigging installation requires 60 man-hours of labor, six riggers will complete it in ten hours while ten riggers will complete it in six hours — a gain of four hours for approximately the same cost. This calculation only holds, however, if there are enough qualified and competent rigging personnel in the locality; many markets cannot supply a large rigging crew without importing resources from outside the region (Event Safety Alliance, 2013).

Managing Onsite Changes

Even carefully prepared rigging plans require modification during installation. If changes are required, the production rigger and the responsible venue representative must be consulted, and the change may require additional consultation with the structural engineer of record and the original rigging plan author. Whenever the configuration departs from what was analyzed and approved in pre-production, a new structural analysis is required before proceeding. Proceeding with an unapproved configuration on the basis that the change “seems minor” is a common contributing factor in rigging incidents; the production rigger’s responsibility to receive written approval for any variations from approved engineering documents is specifically noted in the ESG (Event Safety Alliance, 2013).

Determinate and Indeterminate Loads

A simple straight truss supported at two points is a “determinate” load: as long as the truss is level, the point loads at each support can be determined with reasonable confidence. Indeterminate loads are created when additional support points are added, such as a center hoist on a long continuous truss. Any single element supported by three or more rigging points can have significant differences between actual point loads, even with careful analysis and leveling, because it is very difficult to balance loads between multiple points on a single continuous element. The only reliable method to verify indeterminate loads on the supporting structure is through real-time load measuring devices (Event Safety Alliance, 2013).

This distinction is important for structural safety. An engineer designing a system for three rigging points must make assumptions about load distribution between those points. If actual field conditions result in load distribution significantly different from the design assumption, one or more rigging points may be carrying loads that exceed the structural capacity of the supporting attachment. Load cells that provide real-time readouts allow the production rigger to verify that actual loads match design assumptions and to adjust the rigging configuration if they do not.

Real-Time Load Monitoring

While loads can be estimated by totaling the specification weights of supported elements, this method is often inaccurate; only by actually weighing the loads at the rigging points can an accurate figure be determined. Load verification is typically performed during equipment preparation in the shop, in pre-production, during rehearsals, or during initial dates of a tour. As event rigging becomes more complex, the need for accurate real-time load information increases (Event Safety Alliance, 2013).

Dynamometers are mechanical or electronic scales that display applied load at the device. Mechanical dynamometers require a person to read them up close at their installed location, which may be impractical in an operational event environment. Electronic dynamometers, or “load cells,” are devices inserted into the suspension system that produce an electronic readout of load data which can be monitored from a remote location. This allows the production rigger to monitor loads during lifting operations and during show conditions from the production desk or other convenient position. Some load cell systems can stop entire groups of motors if one fails or if a load threshold is exceeded; they can also monitor dynamic loads and record load data over time (Event Safety Alliance, 2013).

When Load Monitoring Is Required

Any truss system that moves during the event should be actively monitored by a load monitoring system. Indeterminate loads should be monitored, as should loads generated during load-in and load-out when configuration changes can significantly alter load distribution. In time, it may be possible to monitor every rigging point with load cells as standard practice. Load cells are particularly valuable where suspended elements are subject to external loading from wind (Event Safety Alliance, 2013).

Guy line systems on temporary outdoor structures create static loads that reduce the structure’s overall load capacity, and those loads increase or decrease in windy conditions. Load measuring devices on guy lines can identify overloading due to wind and provide essential information for implementing the event safety plan. Chapter 19 of the ESG addresses structures and guy lines in detail.

Automation and High-Speed Winch Loads

Productions that use specialized winches for moving effects must treat those systems as a distinct and particularly high-risk category of rigging load. Automation winches can increase point loading dramatically during operation. When moving elements start and stop, they create momentary increases in loading. In an emergency stop of a high-speed winch, the rapid increase in point loading can exceed twice the static load value. Automated winches must never be used without qualified professional consultation, and those loads must be monitored with measuring devices (Event Safety Alliance, 2013).

Rigging Training and Certification

Entertainment rigging knowledge is primarily acquired through experience, which has historically meant that the qualification bar for “rigger” was set inconsistently across markets and production contexts. In response to this challenge, the entertainment industry developed national certification programs to create a consistent, verifiable standard of rigging knowledge and competency.

The Entertainment Technician Certification Program (ETCP) offers certification programs for both theatre riggers and arena riggers. These are separate certification tracks that reflect the different technical environments and rigging systems encountered in each setting. The ETCP program has become widely accepted in the United States as the certification standard for entertainment riggers; many venues now require ETCP certification of riggers working in their facilities. Event organizers are encouraged to verify venue certification requirements well in advance of the event during the planning phase (Event Safety Alliance, 2013).

Certification through ETCP demonstrates that a rigger has met a defined standard of knowledge and competency, but it does not substitute for site-specific training and briefing. Even ETCP-certified riggers must be briefed on the specific rigging systems, fall protection equipment, and emergency procedures applicable to each venue and event before beginning work.

Integration of Moving and Flying Units

Following load-in, all persons who will be in areas where flying of any object will occur need to be briefed on and familiar with what elements will fly and when. Under the leadership of the person in charge of performer integration, an event organizer, promoter, or stage manager, all persons should attend a structured rehearsal sequence (Event Safety Alliance, 2013).

The first phase of this rehearsal proceeds under full white work lights and in silence: all moving and flying units are demonstrated in the exact sequence in which they will be executed during the performance, first at half speed where possible, and then in real time. The rigging crew must also demonstrate how they can stop any unit at any time. The second phase repeats this demonstration under full work lights and in silence, but now with talent and all personnel in the positions they will occupy during the performance. Each person must be given time to ask questions, express concerns, and be taught the process to stop the motion of any flying unit at any time, including during the performance. The third and final phase runs the moving and flying units under full show conditions: show lighting, other moving scenic elements, full audio, and full effects (Event Safety Alliance, 2013).

Following this rehearsal sequence, a meeting must be held at which questions can be asked and answered by anyone involved in the event. The STOP protocol introduced in the context of rigging installation applies with equal force here: every person in the performance area must understand that calling “STOP” during a flying or moving unit operation will immediately halt all motion, and that they have both the right and the responsibility to call “STOP” if they perceive a hazard.

Conclusion

Safe rigging installation at live events requires more than technically qualified personnel following an approved plan. It requires deliberate scheduling that protects the quality of the rigging work, team staffing that prevents time pressure from compromising safety, real-time load monitoring for systems where design-assumption load distributions cannot be verified by calculation, industry certification that establishes baseline competency standards, and a structured rehearsal process that ensures every person in the performance area understands the motion elements and can stop them. These are not additional best practices layered on top of the minimum requirements; they are the operational expression of the engineering and planning framework that precedes them.

References

Event Safety Alliance. (2013). The event safety guide (version 1.1). ESA. https://eventsafetyalliance.org

Entertainment Technician Certification Program. (n.d.). ETCP certification programs for arena and theatre riggers. ETCP. https://etcp.plasa.org

Occupational Safety and Health Administration. (n.d.). 29 CFR 1926.32: Definitions. OSHA. https://www.osha.gov

American National Standards Institute / Entertainment Services and Technology Association. (2013). ANSI E1.6-1: Entertainment technology — powered hoist systems. ESTA.