Installing a production rigging system involves sequential decisions, each carrying forward the consequences of those that preceded it. Structural verification, hardware assembly, motor programming, and load monitoring form an interdependent chain where a failure at any link can produce catastrophic results. Understanding the regulatory and technical standards that govern each phase is essential for rigging crews, production managers, and venue engineers involved in contemporary entertainment events.

Pre-Installation Structural Verification and Point Load Documentation

Before any rigging hardware is attached to a venue structure, the load capacity of each proposed attachment point must be verified by a qualified person. ANSI E1.2-2018, Entertainment Technology — Design, Execution, and Use of Rigging Systems in the Entertainment Industry, Section 7 requires that for complex rigging operations, a qualified person confirm that the structure is capable of supporting the proposed loads. This confirmation must reference actual structural data, not assumptions. Venue-provided point load ratings are the starting point; where such ratings are unavailable or unverifiable, OSHA’s General Duty Clause requires that a licensed structural engineer evaluate the structure before any production load is applied.

ASCE 7-22, Minimum Design Loads and Associated Criteria for Buildings and Other Structures, Section 2.3 defines load combinations that structural engineers use to evaluate combined dead, live, and dynamic loads. For rigging, the relevant load combination is dead load plus live load (the suspended production equipment) plus any dynamic load factor applied for chain motor acceleration. IBC 2021 Section 1604 establishes minimum structural load criteria for building elements and requires that structural members and connections have adequate strength to resist all applicable load combinations with appropriate safety factors. A qualified person performing pre-installation review must confirm that the total load applied to each venue structural member — including the rigging hardware, motor, batten or truss, and all suspended equipment — remains within the IBC-compliant design capacity of that member.

Hardware Assembly Sequence and Connection Verification Standards

The sequence in which rigging hardware is assembled and connections are verified directly affects the safety of the completed system. ASME B30.26-2015, Rigging Hardware, Section 2-1.3 requires that shackle bolts be fully threaded into the bow, that the pin be secured (moused with wire or a cotter key, or locked by a nut and cotter pin where the manufacturer requires it), and that no shackle be used in a side-loading configuration unless rated for that use. The common practice of “finger tight plus a quarter turn” for shackle bolt installation is not a substitute for following the specific manufacturer instruction sheet for each hardware item; torque requirements and locking methods vary by manufacturer and product line.

Wire rope sling installation must follow ASME B30.9-2014, Slings, which prohibits the use of U-bolt wire rope clips with the U-bolt bearing on the live end of the wire, a configuration known colloquially as “saddling a dead horse.” Sling angle has a direct and quantifiable effect on working load: at a 60-degree included angle (30 degrees from vertical), the tension in each leg of a two-leg sling is 1.00 times the load; at a 120-degree included angle (60 degrees from vertical), the tension in each leg rises to 1.155 times the load; at a 150-degree included angle (75 degrees from vertical), leg tension reaches 1.932 times the load, meaning a 2,000-pound load applies nearly 4,000 pounds of tension to each sling leg. ASME B30.9 provides sling angle correction factors and requires that the effective working load limit for any sling configuration account for these angle-induced reductions in capacity.

ANSI E1.43 Load Cell Technology: Monitoring Principles and Event Deployment

ANSI E1.43-2016, Entertainment Technology — Load Cell Use in the Entertainment Industry, published by ESTA, establishes standards for using load cells to measure tension or compression forces in rigging systems. Load cells installed in-line with rigging chains or wire rope provide real-time data on actual loads at each pickup point, allowing verification that installed loads match the design loads specified in the rigging plan. Discrepancies between designed and measured loads may indicate hardware placement errors, trim imbalance, or unanticipated dynamic loads from equipment attached to the rig.

ANSI E1.43-2016 requires that load cells used in entertainment rigging be calibrated at intervals recommended by the manufacturer and that calibration be traceable to NIST (National Institute of Standards and Technology) standards. Pre-event baseline readings should be recorded after rigging is complete at working trim but before any additional equipment is loaded onto the system. Monitoring during the event should include periodic logging of load readings at predetermined intervals and real-time alerting when loads approach a preset warning threshold, typically set at 80 percent of the equipment’s rated capacity. Where motorized rigging systems are used for dynamic production elements, continuous load monitoring with automatic motor cutoff triggered by overload conditions is the current industry best practice and is addressed in ANSI E1.6-1-2012.

Chain Motor Programming, Travel Limits, and ANSI E1.6-1 Overload Protection

ANSI E1.6-1-2012, Entertainment Technology — Powered Hoist Systems — Part 1: Design, Manufacture, and Use, governs the design and operational requirements of electric chain hoists used in entertainment rigging. The standard requires that powered hoist systems incorporate upper and lower travel limit switches that halt motor travel before the load block contacts the motor housing (two-blocking) or reaches the floor. Soft limits, which are programmable electronic stops, provide primary travel restriction; hard limits, which are mechanically triggered switches, serve as backup protection. ANSI E1.6-1-2012 Section 5.5 requires that overload protection devices prevent the motor from lifting loads exceeding 110 percent of rated capacity, with automatic cutoff before structural damage can occur.

Motor control system programming must be performed by a qualified person who has reviewed the rigging plan and understands the load at each pickup point. Variable speed control reduces dynamic load factors during acceleration and deceleration: at slow speed, a well-maintained chain hoist introduces dynamic multiplication factors approaching 1.0; at full speed, factors of 1.3 to 2.0 are common depending on motor characteristics and load mass. OSHA’s General Duty Clause requires that known hazards, including two-blocking and overload conditions, be abated by feasible means; ANSI E1.6-1-2012 compliant motor control systems with properly programmed limits represent the recognized standard of feasible abatement. Motor control operators must be trained on the specific control system in use, including the override procedures that apply when a safety limit has been tripped and must be cleared.

Flying Units and Personnel Hoisting: OSHA and ASME Requirements

Theatrical flying systems that carry performers present a distinct category of rigging risk: failure is likely to cause death or serious injury to the person being flown, and the system must be designed with corresponding safety margins. OSHA 29 CFR 1926.552 governs personnel hoists used in construction, requiring that the design factor for the lifting medium be not less than 10 to 1 for wire rope, and mandating dual braking systems, automatic slack rope devices, and operator training. Where theatrical flying systems are installed as permanent building equipment, ASME A17.1, Safety Code for Elevators and Escalators, may apply by local jurisdiction.

ANSI E1.6-1-2012 Section 5.7 specifically prohibits the use of a standard entertainment chain motor for personnel hoisting unless the motor has been specifically designed and rated for personnel use with appropriate design factors and safety systems. Motors rated for personnel use must carry visible markings indicating that personnel rating, and operators must verify that marking before using any hoist to fly a performer. Pre-use inspection for flying systems must include verification that the arrest mechanism is functional, that all connections along the lift line are secure, and that the travel limits are correctly programmed for the specific rigging height and performer weight. Rigging crew should conduct a loaded test cycle with a sandbag equal to or greater than the performer’s weight before any performer is attached to the system.

Trim Verification, Acceptance Inspection, and Pre-Show Checkout Protocol

After rigging installation is complete, a systematic acceptance inspection verifies the integrity of the entire system before any equipment is loaded or personnel work beneath suspended loads. ANSI E1.2-2018 Section 10 describes the inspection process for completed rigging systems, which must include visual examination of all connections, confirmation that travel limits function correctly, verification that load cells (if installed) are reading within expected range, and confirmation that all rigging hardware is within its rated working load limit for the configuration in use. This inspection must be conducted or directly supervised by a Level 2 or Level 3 competent person as defined by ANSI E1.2-2018.

Pre-show checkout differs from acceptance inspection in scope and timing. While acceptance inspection occurs once after initial installation, pre-show checkout occurs before each performance and focuses on changes that could have occurred since the previous show: equipment additions or removals, trim height adjustments, hardware that may have worked loose, and motor control programming that may have been altered. The pre-show checkout list should be documented and signed by the person who conducted it. OSHA 29 CFR 1926.502 requires that fall protection systems be inspected before each use by a competent person; applying an equivalent standard to the entire production rigging system is consistent with the hazard severity involved and with the level of care expected under OSHA’s General Duty Clause.

References

• ANSI E1.2-2018. Entertainment Technology — Design, Execution, and Use of Rigging Systems in the Entertainment Industry. ESTA/ANSI.
• ANSI E1.6-1-2012. Entertainment Technology — Powered Hoist Systems — Part 1: Design, Manufacture, and Use. ESTA/ANSI.
• ANSI E1.43-2016. Entertainment Technology — Load Cell Use in the Entertainment Industry. ESTA/ANSI.
• ASME B30.9-2014. Slings. American Society of Mechanical Engineers.
• ASME B30.26-2015. Rigging Hardware. American Society of Mechanical Engineers.
• ASCE 7-22. Minimum Design Loads and Associated Criteria for Buildings and Other Structures. American Society of Civil Engineers.
• IBC 2021. International Building Code. Section 1604: General Design Requirements. International Code Council.
• ASME A17.1-2019. Safety Code for Elevators and Escalators. American Society of Mechanical Engineers.
• OSHA 29 CFR 1926.502. Fall Protection Systems Criteria and Practices.
• OSHA 29 CFR 1926.552. Material Hoists, Personnel Hoists, and Elevators.
• OSH Act Section 5(a)(1). General Duty Clause.