Rigging 101, Part 1: A Question of Balance
Whether you worked on the stage crew for your high school play or you’re a full-time professional stagehand in a big city opera house, chances are you’ve used counterweight rigging. The system of ropes, weights, and pulleys can seem both commonplace and mysterious, especially if you’ve never been formally trained in its use.
It’s commonplace. Counterweight rigging systems have been installed in performance spaces for more than 100 years, and many new performing arts centers still choose counterweights over motorized rigging systems. They haven’t gone the way of Kodachrome film and Sony Betamax yet—and it may be many decades before they do.
It’s a mystery. The workings of this familiar system can seem like an unsolvable word problem in math or an experiment in a physics lab. If high school physics was a long time ago for you, it’s time to brush up on the basics.
It’s simpler than it seems. Counterweight rigging operates on a simple principle: The load over the stage is counterbalanced by an equal amount of steel weights—called “counterweights”—backstage. When properly counterweighted, the system is easy to operate. When the set is out of balance, the system has the potential to be very dangerous.
The physics you need to know involves gravity, the most fundamental and familiar of physical properties. The key is to counterbalance the load with the counterweights. Essentially, the weight of the batten (pipe) and its load—your scenery—must equal the weight of the steel stage weights that you place on the arbor (the carriage that holds the weights) backstage.
When the load is in proper balance, you can move the load easily by pulling on the hand line.
- If you have to struggle to move the load, the set is out of balance.
- If the line set moves by itself or takes virtually no effort to move, it is also out of balance.
Here’s where gravity comes in. The heavier side of the system will always move downward. As it does so, it brings the lighter side up. The more the system is out of balance, the faster it will do this.
Don’t be a hero. If you don’t feel confident about your ability to judge the balance between the load and the arbor, don’t operate the line set. Ask for help from someone who is trained to use a counterweight rigging system—and find out how you can get trained to use the system correctly. Look for classes offered at USITT, the semi-annual conference for theatre technology education, or contact Sapsis Rigging and schedule a session at your site, led by one of the world’s leading professional riggers.