Answer: dredgers

AnswerCrossword Clue
DREDGERSTunnel-building machines
DREDGERSGold diggers, at times
DREDGERSFlour-sprinkling devices
dredgersA barge or other vessel designed for dredging harbors or other bodies of water
dredgersDREDGER, one that dredges (to scoop mud with a machine)