I think those are pumps in the foreground, possibly for a sewage lift station. The red valve handle is either for a fire sprinkler system, or controls the flow to the sewage lift station.

It's a load control center (switches for equipment). These buildings were never very rain tight, thus the pitched top to keep out as much water as possible.

Looks like my garage!

That device is an old Westinghouse 3 phase electric motor. I would say 20 - 25 HP.