What Should Be on Your Shackles? Understanding Markings for Theatrical and Arena Rigging Shackles.
Whether you are flying a lighting truss in an arena or suspending a scenic element from a grid in a proscenium theatre, shackles are one of the most frequently used rigging components in the entertainment industry. But using just any shackle is not enough—it has to be the right shackle for the application, and more importantly, it must be clearly marked with the correct information. These markings are not decorative; they are safety-critical. Without them, you cannot verify whether a shackle is strong enough, traceable, or even manufactured for lifting.
In the United States, the most widely referenced standard that mandates shackle marking requirements is ASME B30.26, titled “Rigging Hardware.” This standard outlines the minimum information that must be permanently marked on every shackle intended for overhead lifting. Additionally, ANSI standards developed by ESTA (Entertainment Services and Technology Association), such as ANSI E1.6-2 and ANSI E1.43, further support these requirements for entertainment-specific rigging applications. This post will help you understand exactly what needs to be on a shackle, why it matters, and how to comply whether you’re in a theatre, arena, or touring venue.
Required Shackle Markings per ASME B30.26
ASME B30.26-2015 states that every new shackle must be permanently marked by the manufacturer in two places: the body and the pin. These markings must be forged, cast, or die-stamped into the metal. Simply printing or painting this information is not sufficient because markings must remain legible throughout the life of the shackle, even with regular use, transport, and cleaning.
On the shackle body, the required markings are:
- The manufacturer’s name or trademark
- The rated load, commonly called the working load limit (WLL)
- The size of the shackle, usually the diameter in inches or millimeters
Simply labeling the shackle “China” does not comply with this standard.
On the shackle pin, the required markings are:
- The manufacturer’s name or trademark
- Either the grade of the material, the material type, or the load rating
If any of these markings are missing or illegible, the shackle must be removed from service. This is a clear and non-negotiable requirement. Shackles without markings are considered untraceable and unverified, and therefore not compliant with U.S. safety standards.
Why These Markings Matter
Shackle markings serve three critical purposes. First, they confirm that the shackle is rated for lifting and capable of bearing specific loads. Second, they provide traceability, so you can identify the manufacturer and verify product specs if needed. Third, they allow inspectors and riggers to quickly assess the suitability of a component for a given lift.
In the event of a rigging failure, the first question asked in an investigation will be about the hardware. If the shackle has no markings, it will be treated as uncertified hardware. This can result in liability issues, insurance exclusions, and violations of OSHA’s General Duty Clause.
Theatrical Rigging Systems
In theatres, shackles are frequently used to connect pipe battens to lift lines, attach scenery to overhead structure, or suspend trusses and chain motors from grids and rigging beams. Most theatres use a mix of wire rope lift lines, counterweight systems, dead-hung battens, and motorized hoists. In these systems, shackles may be located 50 feet in the air, backstage, or even buried in a wall pocket.
Because these applications often involve flying scenery over performers, technicians, or audience members, the stakes are high. As a result, many venues—especially those employing ETCP Certified Riggers or operating under IATSE contracts—treat ANSI E1.6-2 as a binding standard.
ANSI E1.6-2, titled “Entertainment Technology – Design, Inspection, and Maintenance of Electric Chain Hoists for the Entertainment Industry,” reinforces the ASME standard by requiring that all hardware used in hoist systems be clearly marked with traceable identification and the working load limit. Although E1.6-2 is focused on electric chain hoists, the principles apply to all rigging hardware used in the overhead load path.
Inspections conducted in theaters should always include verification that each shackle is marked correctly and legibly. The absence of required markings is grounds for immediate removal of the hardware from the system.
Arena Rigging Systems
In arena rigging, speed, efficiency, and repeatability are essential. Touring productions roll into new venues daily, building their entire rig from scratch each time. Shackles are used to connect steel, distribute loads across multiple points, secure motor chains to structure, and create drop lines for lighting and sound systems. A single tour might carry hundreds of shackles, each of which must be correctly sized, rated, and marked.
Arena rigging environments are also harsh. Road cases, forklifts, docks, and weather exposure all take a toll on rigging gear. It is common to see shackles that are painted, dirty, or scratched, which can obscure or damage the original markings.
In this environment, supervisors and head riggers must enforce high standards. This often includes requiring that all shackles:
- Are clearly marked with manufacturer, WLL, and size
- Have pins marked with grade or material
- Are free from overpainting, welding, or unauthorized modifications
- Are rejected immediately if markings are missing or altered
The fast pace of an arena load-in does not excuse poor compliance. In fact, it makes marking verification even more critical. A single unmarked shackle at the top of a point could jeopardize the entire rig.
Inspection and Field Practices
To maintain compliance, here are some best practices for theatrical and arena riggers:
- Never grind, sand, or blast shackles in a way that removes or distorts markings
- Do not paint over markings. If you need to color-code shackles, use tape or tag systems that do not obscure required info
- Take photos of markings during the inspection process to document compliance
- Maintain a rigging inventory that includes load ratings, serial numbers, and manufacturer details
- Educate crew members about what markings to look for and how to report missing or suspect hardware
Shackles may be small components, but they carry big responsibility. The markings on a shackle are the only way to confirm it is rated and suitable for overhead use. Whether you’re hanging soft goods in a high school theatre or running steel at a 40,000-seat arena, markings are your first line of defense against rigging failure.
In the entertainment industry, we cannot afford to guess. Only use shackles with clearly marked WLLs, manufacturer IDs, and size or grade. Follow the guidance of ASME B30.26 for all applications, and consult ANSI E1.6-2 and E1.43 for entertainment-specific rigging. If you cannot read the markings, do not use the hardware. It is that simple.
References
American Society of Mechanical Engineers. (2015). ASME B30.26-2015: Rigging Hardware. New York, NY: ASME.
Entertainment Services and Technology Association. (2013). ANSI E1.6-2 – 2013: Entertainment Technology – Design, Inspection, and Maintenance of Electric Chain Hoists for the Entertainment Industry. ESTA.
Entertainment Services and Technology Association. (2016). ANSI E1.43 – 2016: Entertainment Technology – Performer Flying Systems. ESTA.
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