A method of dredging which comprises suspending dredging apparatus 200 from a vehicle 360. The sediment agitating apparatus comprising a chassis 210, and mounted on the chassis are an extractor, sediment agitating apparatus and respective pumps 220, 230. The dredging apparatus 200 is disposed above, but not in contact with a waterbed 340 to be dredged of sediment 350. The sediment 350 is agitated then extracted with the extractor. The dredging apparatus 200 is moved around the water and the extracted sediment 400 is deposited underwater and above the dredging apparatus 200, so that the sediment 400 is transported and deposited away from an area being dredged by the natural movement of the water. Apparatus and use of the apparatus are also described.

Systems and methods include a wing tool configured to be operable from work vessel(s), the wing tool including thrusters capable of fluidizing sediments from a first seabed location and moving it to a second seabed location, the second seabed location including a trench or differently shaped collection sump previously made by the wing tool and/or an extraction pump. The extraction pump operates from a second work vessel having sufficient capacity to pump fluidized sediments from the trench. Certain systems include a separation unit that separates sand from silts and clays and water from collected sediment. Systems and methods for reclamation of reservoirs, moving sand waves, for pre-trenching and/or recovering marine pipelines and cables, for removing cover from marine archaeological sites and for disposing of contaminated bottom materials in an environmentally acceptable manner.

A jetting system for an undersea trencher has jetting conduits extending aftward of its trench-cutting jetting swords. Jetting conduit nozzles direct liquid radially from their jetting conduits into the trench after the trench is excavated by the jetting sword cutting nozzles. The jetting conduits direct sufficient liquid into the trench to maintain the mix of trenched soil and water in the trench along the length of the conduits at not more than a super-critical density, extending the distance in which the product being laid in the trench is able to descend in the trench and increasing the likelihood that the product will be buried at the intended trench depth.

A method of dredging which comprises suspending dredging apparatus 200 from a vehicle 360. The sediment agitating apparatus comprising a chassis 210, and mounted on the chassis are an extractor, sediment agitating apparatus and respective pumps 220, 230. The dredging apparatus 200 is disposed above, but not in contact with a waterbed 340 to be dredged of sediment 350. The sediment 350 is agitated then extracted with the extractor. The dredging apparatus 200 is moved around the water and the extracted sediment 400 is deposited underwater and above the dredging apparatus 200, so that the sediment 400 is transported and deposited away from an area being dredged by the natural movement of the water. Apparatus and use of the apparatus are also described.

A multi-stage seafloor mining system that has at least concentration stage, a reclamation stage, and a haulage stage. The system includes a concentrating system (50) that processes seafloor materials, a reclaimer machine (300) that collects the processed seafloor materials, and a mechanical haulage system (40) that receives the processed seafloor materials collected by the reclaimer machine (300) and conveys discrete parcels of the processed seafloor materials to a surface vessel (100).

A method and apparatus for generating a slurry from the surface of the subsea floor, separating that slurry into multiple slurries, and pumping the desired slurry to the surface.

Apparatus for collecting solids settling at the bottom of a liquid reservoir, the apparatus including: a plurality of suction head assemblies, each suction head assembly including a hollow suction head configured to cause agitation of solids settling in or around the suction head and draw the solids entrained in a liquid flow into one or more outlets of the suction head; a manifold including a body having one or more inlets coupled to the one or more outlets of each suction head to permit the collected solids entrained in the liquid flow to pass into the manifold and one or more discharge ports configured to expel the collected solids entrained in the liquid flow from the manifold; and a pumping arrangement that draws in liquid and entrained solids from the suction head assemblies via the manifold and discharges the liquid and entrained solids via a discharge pipe.

A dragging apparatus has a carriage body. The carriage body has at least one attachment portion. The attachment portion is configured to connect the carriage body to a drag barge. At least one ripper shank is disposed on the carriage body. The ripper shank extends downwardly from the carriage body. A method for operating a dragging apparatus includes providing a barge and a dragging apparatus, and then lowering the dragging apparatus to a floor or bottom of a body of water to agitate the floor or bottom.

A method of dredging a bottom of a body of water is provided. Winching stations are positioned around the perimeter of an area to be dredged and a cable from each winching station is connected to a float. The cables pass through a variable resistance pulley assembly attached to a submersible assembly having a cutter and a submersible pump and are tensioned to suspend the submersible assembly. The cutter and submersible pump are activated and the winches are controlled to move the submersible assembly in a dredging pattern. When an obstacle is encountered the resistance of the pulley assembly is decreased and sufficient tension is applied to the cables to lift the submersible assembly toward the float.

A dragging apparatus has a carriage body. The carriage body has at least one attachment portion. The attachment portion is configured to connect the carriage body to a drag barge. At least one ripper shank is disposed on the carriage body. The ripper shank extends downwardly from the carriage body. A method for operating a dragging apparatus includes providing a barge and a dragging apparatus, and then lowering the dragging apparatus to a floor or bottom of a body of water to agitate the floor or bottom.