I feel like an idiot, but... [UPDATED]

... can some Beijing person tell me what on earth this thing is?


I see it from time to time in the Beijing subway. (This picture is from the Tuanjiehu station on line 10 today.) It's about three feet tall and has the general look of a bomb-disposal robot. Today was the first time I had a camera on hand and didn't see any subway officials around, and so felt free to take some pictures. Side view:


Free Atlantic subscription for the first person to send me an (accurate) answer. Sorry, there are so many things that leave me puzzled.

UPDATE: Contest over and problem solved! Thanks to two near-simultaneous entries, each of them a winner, I now understand that this is indeed an anti-explosive device! In the words of one winner, "The big blue iron ball-like thing you saw in the subway is an anti-explosion device - when the police find explosives, they can put them inside this ball-thing. It's designed to keep the explosion safely inside." I feel safer already.  Thanks to all.   (One of the winners was the famous Chinese blogger Isaac Mao; the other, source of the description, is Harvard-bound Beijing area university student Ella Shengru Zhou.)