Engineers left account of progress made? (6)
I believe the answer is:
report
'account of progress made?' is the definition.
'engineers left' is the wordplay.
'engineers' becomes 're' (Royal Engineers).
'left' becomes 'port' (left side of a ship - opposite of starboard**).
're'+'port'='REPORT'
(Other definitions for report that I've seen before include "School student's assessment" , "Account, of news say" , "Bulletin" , "Announce; rumour" , "Article" .)