Apparatus and method for removing coatings from the hulls of vessels using ultra-high pressure water

A method for removing surface coatings from a metal vessel hull, which comprises:

• providing a rotating nozzle for directing an ultra-high pressure water stream against the hull of a ship, said rotating nozzle being mounted to the body of a steerable, motorized platform, said platform being supported by a plurality of magnetically tractive wheels, said nozzle comprises a inner member having a plurality of equidistant, radially arranged orifices each connected to a supply of high pressure water, an outer sheath extending longitudinally over said inner member, a conical area defined by the inner walls of said outer sheath and the exterior surface of said inner member, whereby said conical area forms a chamber for suctioning water and coating particles removed from said vessel hull during the cleaning process;
• providing ultra-high pressure water and power to said motorized platform via a conduit;
• and
• steering said motorized platform via a steering means to move said motorized platform supporting said ultra-high pressure nozzle over the hull of the ship while said ultra-high pressure water stream removes said surface coatings.

An apparatus for removing coatings from the ferro-magnetic hulls of ships, comprising:

• body means having a frame means and a cowling means;
• seal means on said cowling means for providing sealing contact between said apparatus and said hull;
• motor means;
• steering means;
• a plurality of magnetically tractive, steerable motive means connected to said motor means, wherein said motor means drives said plurality of magnetically tractive steerable motive means;
• ultra-high pressure water jet means attached to said body means, said ultra-high pressure water means directed toward said ship hull and comprising at least one rotatable nozzle having a rotatable symmetrical housing having a central axis, proximate and distal ends and further having a central conduit for the passage of pressurized water and a plurality of orifices in said housing distal end wherein each of said orifices is connected to said central conduit by a radial port, wherein the orifices have a central axis which is oblique to the central axis of said housing and wherein the passage of the water through said orifice forms an annular stream of water, the thrust of said annular stream imparting a rotational force to said housing, and said oblique angle of said orifice central axis directs the stream of pressurized water to a working surface wherein said annular streams cooperatively score said working surface;
• and
• conduit means passing through said cowling means and communicating with
• a) said ultra-high pressure water means for the passage of ultra-high pressure water, and
• b) with said motor means.