cutter hopper dredger

Google the words: hopper dredger

The hopper dredge is basically an ocean-going ship equipped with a suction pump and supporting machinery, drag arms, drag heads, pipelines etc. to remove unconsolidated sediments from the channel bottom or ocean floor and hydraulically transport them to bottom-dump hoppers within the ship hull. These hoppers are then emptied over the spoil area by opening the bottom dump hopper doors. Some of these dredges are equipped to unload the spoil by pumping. The US Army Corps of Engineers operates a number of hopper dredges and has a lot of good info on dredging, you might do a google on them and link to various sites within the Corps of Engineers.