Vehicle lifted pieces for workers on track (7)

'workers on track' is the definition.
(workers in a railway yard)

'vehicle lifted pieces' is the wordplay.
'vehicle' becomes 'dray' (type of cart).
'lifted' says the letters should be written in reverse (going up in down clue).
'pieces' becomes 'men' ('man' can be a synonym of 'piece').
'dray' reversed gives 'yard'.
'yard'+'men'='YARDMEN'

'for' is the link.