In-place underwater dredging apparatus of the crater sink type

Underwater dredging apparatus for dredging solid material from an underwater area by pumping a mixture of water and solids from the area and discharging the mixture at a remote location to thereby clear and deepen the area, said apparatus comprising,

• a generally vertically upstanding pipe having a hydraulically driven pump adjacent its upper end, and said upstanding pipe having a lower end located beneath the surface of the water, said pump having a discharge conduit for conducting said mixture to a remote location,
• tubular auger means including a tube and an auger screw rotatably mounted therein and extending generally horizontally and laterally outwardly from the lower end of said upstanding pipe and in direct and positive material delivering communication therewith;
• variable speed hydraulic motor means connected with said auger screw for rotatably driving said auger screw to deliver and meter material at a selected rate directly into said upstanding pipe;
• whereby said pump draws said mixture directly from said tubular auger means, upwardly through said upstanding pipe and discharges it through said discharge conduit to said remote location, said tubular auger means including a plurality of said tubes and auger screws extending in different directions, shaft means extending through said tubes and having said auger screws secured to said shaft means, said shaft means being driven by said hydraulic motor means, a hydraulic fluid power source located remotely from said area, and fluid conduits connecting said source with said hydraulic pump and with said hydraulic motor means.

Underwater dredging apparatus for dredging of solid material from an underwater area by pumping a mixture of water and solids from the area and discharging the mixture at a remote location to thereby clear and deepen the area, said apparatus comprising,

• a generally vertical upstanding pipe having a hydraulically driven pump adjacent its upper end, and said upstanding pipe having a lower end located beneath the surface of the water, said pump having a discharge conduit for conducting said mixture to a remote location,
• tubular auger means including a tube and an auger screw rotatably mounted therein and extending generally horizontally and laterally outwardly from the lower end of said upstanding pipe and in material metering and delivering communication therewith;
• variable speed hydraulic motor means connected with said auger screw for rotatably driving said auger screw;
• whereby said pump draws said mixture directly from said tubular auger means, upwardly through said upstanding pipe and discharges it through said discharge conduit to said remote location,
• an upwardly extending dirty water intake pipe having a closable upper end and having its lower end communicating with said tubular auger means and said upstanding pipe adjacent the juncture of said tubular auger means and said upstanding pipe whereby said dredge water fluidizes the material coming from said tubular auger means and for easier handling by said pump,
• and a clean water intake pipe having a closable upper end above the upper end of said dirty water intake pipe, said clean water intake pipe having its lower discharge end in water delivering communication with said upstanding pipe intermediate the height of the latter and below said pump, whereby clean water acts to purge said pump and discharge pipe prior to dredging solid material, and to clean said pump and discharge pipe after use.