Happy turning barge right, one managed easily (8)
I believe the answer is:
pushover
'happy turning barge right one managed easily' is the definition.
I can't tell whether this definition defines the answer.
'happy turning barge right one' is the wordplay.
'happy' becomes 'up' (I've seen this in other clues).
'turning' is a reversal indicator.
'barge' becomes 'shove' (I've seen this before).
'right one' becomes 'r' (I can't explain this - if you can you should believe this answer much more).
'up' backwards is 'pu'.
'pu'+'shove'+'r'='PUSHOVER'
Can you help me to learn more?
(Other definitions for pushover that I've seen before include "Topple - easy opponent" , "upset" , "breeze" , "customer offering little resistance" , "Child's play, piece of cake" .)