Heartless harassed men on board lose control (2,2,6)
I believe the answer is:
go to pieces
'lose control' is the definition.
(to go to pieces is to lose control or composure)
'heartless harassed men on board' is the wordplay.
'heartless' suggests removing the centre.
'harassed' becomes 'got to' (get to can mean to harass or annoy).
'men on board' becomes 'pieces' (men can mean chess pieces).
'gotto' with its centre taken out is 'goto'.
'goto'+'pieces'='GO TO PIECES'
(Other definitions for go to pieces that I've seen before include "Fall apart" , "Break up entirely" , "Crack up" , "lose it?" , "Have a breakdown" .)