"What are these carriages used to transport? In the UK, they maximise neither aerodynamics nor capacity. Look too clean for coal, doors at 45degrees to the horizontal…"
A: "The wagons are basically hoppers filled from the top, and empty down towards the rails, so they’re emptied on a special section of rail that has a conveyor or similar underneath it."
#4... What box? you see something I can't?
#2 Ive seen lots of adze, I live where they are made culturally. There are lots of different shapes depending on the purpose of it the region it was manufactured.