Stacks by the German cranes (8)
I believe the answer is:
derricks
'cranes' is the definition.
(derrick is a kind of crane)
'stacks by the german' is the wordplay.
'stacks' becomes 'ricks' (ricking is a kind of stacking).
'by' says to put letters next to each other.
'the german' becomes 'der' ('the' in German).
'ricks' after 'der' is 'DERRICKS'.
(Other definitions for derricks that I've seen before include "Cranes" , "Frameworks over oil wells" .)