Method of accurately dredging a desired profile contour

The method of dredging which comprises the steps of:

• (a) providing a cutting tool on one end of a link element which is at one end of a serial system of pivotally interconnected links,
• (b) swinging said system of links to sweep said cutting tool along a path;
• (c) measuring angular movements of each link within two orthogonal planes passing through that pivotal connection of each link which is remote from said cutting tool;
• and
• (d) controlling said tool in response to the measurements of step (c).

The method of dredging which comprises the steps of:

• (a) orienting a buoyant cutter dredger hull by means of radio beacons such that the centerline of the hull is substantially located within a vertical plane which defines the Y,Z plane of an X, Y, Z coordinate system with respect to which the depth coordinates Y and side slope coordinates X of a desired profile for a channel are known,
• (b) anchoring the hull to define a pivot point whose location is fixed with respect to said Y,Z plane while the hull is oriented as in step (a) and swinging the cutter of the cutter dredger downwardly into engagement with subaqueous ground;
• (c) swinging said dredger about said pivot point thereby to swing the cutter in known manner with relation to X, Y, Z coordinate system;
• (d) mathematically simulating the cutting envelope of said cutter as at least one imaginary sphere of fixed radius;
• and
• (e) controlling the sideways translation of said cutter to cause the simulated cutting envelope to move into close conformity with said known side slope coordinates of the desired profile for a channel without exceeding the X coordinates thereof.