It's spelled "ton" in the U.S., "tonne" in most other places I think.
Both words come from French tunne. It's either 2000lbs. or 2240lbs (~1000kg), depending on if it's a short or long ton(ne).
I agree it might fit in better if it were a bit grimier, but the warehouse doesn't look all that grimy to me. The only real giveaway is that there's a light out, so... yeah. Also, sometimes equipment is kept in good condition for maintenance reasons when everything else looks bad.