Saturday, June 02, 2007

Pillow Posts -- Day 12

The best part of today was probably the rigging class; we got to learn how to run a no-counterweight fly system. For those of you who don't know, there are three major ways to suspend things in a theatre, if you want to be able to adjust their heights above the stage: a simple pulley system, a counterweight system, and a motorized system.

Motorized systems are really easy to use--you plunk a giant motor above the stage, and then you just press a button and the motor takes care of all the lifting. Motors used to have the problems of being expensive, slow, noisy and stupid--if they hit something and you don't shut them off, they just keep going. However, a lot of that is being fixed with newer models, and Ben thinks that most new theatres will be entirely motorized within five to ten years.

Counterweight systems work by balancing the weight of whatever is above the stage with weight loaded onto a "weight arbor". In the simplest version, called a "single-purchase" system, if the item you're suspending above the stage weighs 50 pounds, then you put 50 pounds on the arbor. If the item weighs 500 pounds, you put 500 pounds on the arbor. Once the system is in balance, even a child can operate a well-maintained counterweight system alone (not that you'd really want to let a kid do that). If you have trouble with the concept of a counterweight system, imagine a seesaw with children of exactly the same weight on either end. Their weights will cancel out, and the seesaw won't move under the influence of gravity, but if you apply the slightest force to either side of the seesaw, it will start to move.

The most basic fly system uses no counterweights; the ropes are attached directly to the pipes, and the system operators have to carry that much weight. This, of course, is what we have. Each pipe in our theatre is suspended by either five or three ropes, and is raised and lowered by teams of five or three people, respectively. This means that if a pipe weighs 50 pounds, each of the five people operating it must lift 10 pounds each. Unfortunately, pipes weigh more like 120 pounds (with nothing else on them), which is 24 pounds per person (not including friction, which is significant) for just the pipe, and it just gets worse from there. Not only that, but the five operators have to be well-synchronized, or the pipe will slant because some ropes will move faster than others. Our first training session made it clear that raising and lowering pipes in our theatres is going to require a lot of practice and a lot of muscle.

I've said this before, but I'm going to say it again--I'm amazed at the caliber of theatre that you can put on using technology which is quite literally centuries old. I'm also excited that I'm getting the opportunity to learn how to do things in a way which is a bit less sophisticated; as I mentioned earlier, we're fast approaching the day when technicians might go years without manually operating a fly rail, and I think it's good for everyone to get back to basics now and then; you gain a better appreciation and understanding for the more advanced technology you get to use. Additionally, if there were a sudden nuclear holocaust and we were required to rebuild from scratch, it would be nice to know how to build simple theatres. Not that you'd really be building theatres right after a nuclear holocaust anyway, but you'd get around to it at some point.

The rest of rigging class was more fun--we got to climb into harnesses and dangle high up in the air in the Duke theatre. It was fun for me because I enjoy rock climbing and being high, but some people were a little freaked out.

No comments: