Compared to the usual sheet metal deck, this one is as firm as Mother Earth.

JLG? Rentals? The plant's equipment yard has a full compliment of rental lifts, of nearly every type known to man.

Crane? Yup, looks like it. I can already hear the wailing about the cost - but these folks didn't miss a trick in putting up this place as cheaply as possible. Now they get to pay the price.

Junction boxes being readily accessible? They were, sort of - before they put the production line in under them. Heck, the box is still in plain sight laugh