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What Goes Up Should Not Come Down

Using the right equipment and following the rules in rigging loudspeakers correctly and safely...

By Craig Leerman May 16, 2017

EAW Anna line arrays reinforced by Otto subwoofers at the CMA Music Festival.

To most of us working in professional production, rigging refers to flying loudspeakers, truss, lighting and scenery in the air.

It’s a black art performed by a secret society of stagehands called “riggers” who somehow have managed to defeat the laws of physics and get things to stay aloft. Rumor has it that these riggers even have their own handshake and a secret underground temple where they sacrifice old shackles into a volcano to ensure a good rigging season next year (or something like that).

The fact is that rigging pertains to anything not placed directly on the ground, including things like a loudspeaker on a tripod stand. It’s also not a magical art full of secrets, as every one of us in entertainment production can learn a little about proper rigging practices by reading books and articles, as well as asking riggers (who may have a secret handshake but will always answer your questions).

But reading and asking questions will only provide a basic amount of knowledge on the subject. The Occupational Safety and Health Administration (OSHA) in the U.S. (and other such governmental bodies in other countries) want to see “competent” and “qualified” persons performing rigging, and that requires knowledge along with training and experience in the job.

A competent person is described by OSHA as one who is capable of identifying existing and predictable hazards in the surroundings, which are dangerous to employees and has authority to take prompt corrective measures to eliminate them. Meanwhile, a qualified person is defined as one who by possession of a recognized degree, certificate or by extensive knowledge, training and experience, has successfully demonstrated the ability to solve problems relating to the subject matter and the project.

A qualified person is the one who designs a rigging system to fit a particular application, and a competent person is the one who installs and monitors the rig, and inspects its components.

Becoming competent requires knowledge, training and experience. Today, the knowledge part is pretty easy as you can go on the internet and research the topic in general as well as visit the websites of manufacturers to learn about the specific safety, rigging, operating and maintenance instructions for their own products. (In audio this is primarily loudspeakers.) Books are another valuable way to gain knowledge of the subject, and a great one is Entertainment Rigging by Harry Donovan.

Training programs from manufacturers, rigging companies and/or rigging schools can provide valuable lessons on how to do things correctly while also offering hands-on training. Working with a production company, labor agency or local union can result in the experience needed to be a competent rigger. The Entertainment Technician Certification Program (ETCP) from trade association PLASA offers two rigging certifications, one for theatres that mainly deals with installed fly rail type systems and one for arenas that’s primarily focused on truss and chain motor type systems.

Safety First

Not all working at a gig may be at the level of competent or qualified, but everyone should be focused on safety. Anyone on a production crew who sees a problem with rigging (or any other safety issue, for that matter) can call “stop” and point out the issue so it can be addressed and corrected to prevent an accident or injury.

To avoid problems a competent person should inspect all rigging hardware, stands and equipment before each use and periodically do a major inspection for signs of wear, abuse and general adequacy, as well as perform any manufacturer recommended preventive maintenance on schedule.

Never exceed the “Safe Working Load” (SWL), the “Working Load Limit” (WLL) or “Maximum Rated Load” (MRL) of any rigging, support or hoisting equipment. These terms all mean basically the same thing, the maximum static weight the piece of rigging equipment will safely hold continuously, when used as intended. Note the term “static load” – it’s a load that is not moving. One that moves, i.e., a loudspeaker array swinging in the wind, puts additional stresses on rigging equipment.

Use only loudspeaker cabinets designed by the manufacturer to fly and follow all manufacturer recommendations concerning their individual products. Make sure all hardware is designed for overhead use and only use items as they are intended. Never modify any rigging hardware as it may affect the weight loading capacity of the item.

In addition, only finger tighten shackle bolts, never use a tool. If you’re worried that a pin might vibrate out, mouse (secure) the pin in place with twine or wire. Always load a shackle pin to end, never from side to side.

Factor in enough time to do rigging correctly and make sure the crew isn’t tired – rushing and fatigue cause accidents. Double check everything before it goes up in the air. Follow the rules and don’t cut corners when it comes to rigging. Once items leave the ground, they better be rigged properly or gravity will demonstrate why it’s the most powerful force in the universe!

Since we’re focused on the audio side of things, let’s look at some of the common methods of supporting loudspeakers.

Tripod Stands

The most common way of doing a small show is to place loudspeakers on tripod-type stands. As noted earlier, check them before use to make sure they’re in working condition. Pay extra attention to the clamping collars and the braces on the legs because these items seem to get damaged more than others.

In use, the tripod legs should be extended to their largest footprint to provide maximum stability. Make sure the top of the stand is correctly sized for the loudspeaker socket or the cabinet can tilt and its center of gravity will not be directly over the pole. Do not exceed the weight loading for the stand. Position it where the legs won’t be a trip hazard – a fall could cause a person injury as well as possibly knock over the stand (and loudspeaker).

Use fixed leg tripod stands only on firm level ground. If outdoors and the ground is a little soft, place a square of plywood under each leg to spread out the load and keep the stand from sinking into the dirt.

Saddle-style sandbags can be used with tripod stands to add a bit of weight to the bottom for increased stability. The sandbag should straddle the leg, not hang from any bracing. To avoid crew injury, larger loudspeakers should be hoisted onto stands by two people.


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About Craig

Craig Leerman
Craig Leerman

Senior Contributing Editor, ProSoundWeb & Live Sound International
 
Craig has worked in a wide range of roles in professional audio for more than 30 years in a dynamic career that encompasses touring, theater, live televised broadcast events and even concerts at the White House. Currently he owns and operates Tech Works, a regional production company that focuses on corporate events based in Las Vegas and Reno.
http://www.techworksvegas.com

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