Bundles to haul on board (7)
I believe the answer is:
sheaves
'bundles' is the definition.
(I know this)
'haul on board' is the wordplay.
I cannot quite see how this works, but
'haul' could be 'heave' (I've seen this before) and 'heave' is located in the answer.
'on board' could be 'ss' (I've seen this in other clues) and 'ss' is present in the leftover letters.
No letters remain.
This explanation may well be incorrect...
'to' is the link.
Can you help me to learn more?
(Other definitions for sheaves that I've seen before include "Bundles of grain stalks" , "He saves (anag.)" , "loads of paper" , "Bundles of corn tied together" .)