The bucket dredger is one of the mechanical dredgers. 

A bucket dredger is a stationary dredger that is equipped with a continuous chain of buckets, which are carried through a structure,the ladder. This ladder is mounted in a U-shaped pontoon. 
The drive of the bucket chain is on the upper side. The bucket dredger is anchored on six anchors. 
During dredging, the dredger swings round the bow anchor by taking in or paying out the winches on board. The buckets, which are filled on the underside, are emptied on the upper side by tipping their contents into a chute along which the dredged material can slide into the barges moored alongside. 
The chain is driven by the so called upper tumbler at top of ladder frame, which is connected either via a belt to the diesel or directly to an electro motor or hydro-motor.