London Bridge is Falling Down

I find these wooden skeletons scary. I don't know how these Egyptian workers can climb and work on them. These skeletons go up many floors high and all that keeps them from falling apart are a bit of rope. I actually don't understand the physics behind them. How come they don't wobble and shake? How can it handle all these workers? You could give me a thousand bucks and I wouldn't climb on one. You would think by now, the year 2005, they would be using more modern methods instead of wood and rope.