What is the purpose of these barns?

[G W Wade]

15 hours ago, Alpo said:

Were they still using them in the '80s?

 

Apparently they are still using a few now, but were they still in common use?

 

The movie that the screenshot and my question came from was made in 1986.

The last one I worked on was in 1967 , but it was a smaller unit (110 ft)   to be used for fertilizer.        GW