I spent a few minutes looking at the engine hoist picture, and it really does keep getting worse. Those are actually propane canisters from forklifts at the base of the whole thing.
Oh jeez. I didn't even see the propane tanks
What gets me about that picture is that ignoring everything the ladder is on, for better support (and stability) the ladders should be turn 90 degrees.
Hmmm. I suspect you're probably right, but I see why he put them like that. Clearly he's thinking about the added surface contact, which I can understand. Makes sense at first. However, that added surface contact increases the risk of the ladders tipping inward. The flipside is that if you rotate them 90° you increase the risk of the 2x8 tipping one way or the other. You have to figure with the way the beam is sagging the contact point is only a fraction of what's "over" the ladder.
Upon further reflection, rotate the ladders 90° and then drop the beam down one step so it's caged in. It'll still fail catastrophically, but it'll perhaps give you another second to run for the hills.