Hell on board, when these start coming in (6)
I believe the answer is:
shells
'these start coming in' is the definition.
The definition suggests an adverb but the answer is not.
'hell on board' is the wordplay.
'on' indicates putting letters inside.
'board' becomes 'ss' (I've seen this in other clues).
'hell' put within 'ss' is 'SHELLS'.
'when' is the link.
Can you help me to learn more?
(Other definitions for shells that I've seen before include "Carapaces or military missiles" , "Collect them on the seashore" , "Hard outer coatings or metal casings" , "Racing boats" , "Hard protective structures" .)