Henry measures the rigging (8)
I believe the answer is:
halyards
'henry measures the rigging' is the definition.
I can't tell whether this defines the answer.
'henry measures' is the wordplay.
'henry' becomes 'hal' (short for Henry).
'measures' becomes 'yards' (yard is a kind of measure).
'hal'+'yards'='HALYARDS'
Can you help me to learn more?
(Other definitions for halyards that I've seen before include "Ropes for raising and lowering sails or flags" , "Nautical ropes" .)