Cutter Suction Dredger (CSD)

A stationary hydraulic dredger that loosens soil with a rotating cutter head at the mouth of the suction pipe, then pumps the resulting slurry through a dredge pump and a floating or shore pipeline. It holds position and swings about an anchored spud using winches on side wires, advancing by stepping the spud. CSDs cut compact sand, clay, and soft to medium rock and are rated by installed power; the largest exceed 25,000 kW total. Because the slurry runs straight down the discharge line, a CSD carries no cargo hold of its own.