What is this trailer for?

[blown motor]

I see these often enough on I90 in NY state and the odd time on the QEW in Ontario. What are they hauling? It looks like the back of the trailer would open but not easily.

[cuda hunter]

Worksite trailers.
Probably oil field office.
Doesn't look like a bunk house or maintenance trailer.   

[blown motor]

Worksite trailers.
Probably oil field office.
Doesn't look like a bunk house or maintenance trailer.   

If they're worksite trailers they sure get hauled around a lot. It's not unusual for me to see two or maybe even three on a 40 minute stretch of I90. And this is in NY state, certainly not oil field offices.

[cuda hunter]

After looking closer at the doors I would agree not oil field offices.
I would say they are remote laboratories with the type of doors they have.
Those are lockable doors from the outside.
Could these be bio labs? 
 

[blown motor]

Well I googled my picture and found the answer.

[cuda hunter]

Interesting. 
A very specific use. 
Only for aluminum coils.  Now I want to see the aluminum coils.

Are the coils for cars?  Or are they for the building process?
Apparently they need a lot of coils if you see the trucks that often.