Dredging system and methods of dredging

A dredging method for excavating material from the bed or bank of a body of water or other liquid and removing it in slurry form comprising:

• moving a generally vertically disposed continuously rotating disc, having cutting knives mounted thereon adjacent openings through the disc through which material cut is moved, in a horizontal path of travel against the vertical wall of a swath of material to be excavated at a level in which the swath to be cut is disposed substantially at or below the top of the disc;
• moving material cut through said openings while said disc is rotating and discharging it;
• at the end of said path of travel rotating the disc through approximately a 90.degree. arc downwardly, while cutting and discharging material, about an axis to dispose the disc generally horizontally and the knives downward thereof;
• moving the disc in a straight line path downwardly while continuing to cut and discharge material a distance approximately the thickness of the next swath to be removed, and then rotating the disc upwardly through approximately an additional 90.degree. arc in the same direction of rotation while cutting and discharging material, to again dispose the disc generally vertically, but in end-for-end reversed position.

A dredging method for excavating material from the bed or bank of a body of water or other liquid and removing it in slurry form through a conduit to a remote location comprising:

• moving a generally vertically disposed continuously rotating disc, connected to said conduit and having at least one cutting knife mounted on its work face adjacent an opening through the disc through which material cut is propelled from its work face through the disc, in a sidewise horizontal path of travel against the vertical wall of a swath of material to be excavated;
• moving material through said opening while said disc is rotating and collecting it for discharge;
• at the end of said path of travel rocking the disc through approximately a 90.degree. arc downwardly, while cutting and collecting material, to dispose the disc generally horizontally and the knife downward thereof;
• moving the disc in a substantially linear path downwardly, while continuing to cut and collect material, and then rocking the disc upwardly through approximately an additional 90.degree. arc in the same direction of rocking while continuing to cut and collect material, to again dispose the disc generally vertically, but in end-for-end reversed position;
• and applying a suction to move the collected material through said conduit.

In a dredging system for excavating material from the bed or bank of a body of water or other liquid and removing it as a slurry and including:

• a floatable vessel having sides and front and rear ends;
• a cutterhead supporting, longitudinally forwardly extending boom and suction conduit assembly mounted thereon;
• a suction creating means carried by said vessel;
• a housing mounted on said assembly and defining a material collecting compartment;
• a suction conduit, connected with the suction creating means, leading from said compartment to deliver slurry therefrom to a location remote from the housing;
• the improvement comprising:
• a sidewisely disposed rotary disc supported for rotation about an axis generally transverse to said longitudinal axis and having an inner face closing one side wall of said housing, and an outer knife mounting face extending generally parallel with the boom, the disc having at least one opening removed from its said axis and extending through the disc from its outer face to its inner face;
• and a knife mounted at said opening having an edge extending generally parallel with the outer face of the disc generally radially along the opening to the inner face of the disc and the material collecting compartment of said housing;
• motor means for rotating the disc about its axis at a cutting speed;
• means for moving the disc downwardly through about a 90.degree. arc from a position in which it is disposed in a generally vertical plane, while cutting and discharging material;
• means for thereafter bodily moving the disc downwardly in approximately a straight line path while continuing to cut and discharge material;
• means for rocking the disc upwardly through about a 90.degree. arc while continuing to cut and discharge material to return the disc to generally vertical position;
• and means for moving said boom and cutterhead in a sidewise excavating path of travel while the disc is disposed in generally vertical position.