[A930Rocket]

Red has it right. Pump jacks have been around for a long time. From the video above, you can see they are using 2x4's for poles and 2x's for walk boards. That's a big no no and probably an old video (I hope). I've seen them at an angle and all sorts of stuff. I've climbed regular scaffolding 40' or so and that was enough for me.

They are usually tied on top of the roof via the bracked you see at the top of the aluminum poles.