Why transport to wharf? (4,3)
I believe the answer is:
what for
'why' is the definition.
(for what reason)
'transport to wharf?' is the wordplay.
'transport' indicates anagramming the letters (letters are transported elsewhere).
'to'+'wharf'='towharf'
'towharf' is an anagram of 'WHAT FOR'.
(Other definitions for what for that I've seen before include "Beating" , "reprimand?" , "Punishment that may be given" , "it's a question of purpose" .)