Personnel supporting sport in Dortmund area (4)
I believe the answer is:
ruhr
'dortmund area' is the definition.
'ruhr' can be an answer for 'area' (I have seen 'Industrial area' mean 'ruhr' so perhaps 'area' could also mean 'ruhr'). I'm not sure about the 'dortmund' bit.
'personnel supporting sport' is the wordplay.
'personnel' becomes 'HR' (Human Resources).
'supporting' says to put letters next to each other (in a down clue, some letters go below others).
'sport' becomes 'RU' (rugby union).
'hr' after 'ru' is 'RUHR'.
'in' is the link.
Can you help me to learn more?
(Other definitions for ruhr that I've seen before include "Ger. industrial region" , "Herman industrial area" , "German industrial zone, river" , "Dortmund area?" , "industrial valley" .)