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 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).

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 subsea clearance apparatus (1) includes a chassis (2), fore and aft skids (3, 4) spaced along a principal axis (P) of the apparatus (1), and a pair of flanks (22a, 22b) with a plurality of tines (5) depending from the flanks (22a, 22b). The tines (5) are spaced transversely with respect to the principal axis (P) and pitched toward the fore of the apparatus (1). In use, the chassis (2) is spaced from the seabed (S) by the skids (3, 4) as the apparatus (1) is propelled therealong such that the tines (5) engage and deflect away from the principle axis (P) obstructions which are larger than a predetermined size and which protrude by a predetermined amount from the seabed (S).

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 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 deep sea mining method includes providing a deep sea mining system for mining matter from a bottom of a body of water, the mining system including: a slurry line coupled with a pump system to transport the slurry from the bottom of the body of water; and a return line in fluid communication with the slurry line and distinguishable from the slurry riser, for transporting non valuable slurry part to the bottom of the body of water, the return line having a return line outlet proximate the bottom. The deep sea mining method further includes spreading the non valuable slurry part over the bottom of the body of water in a controlled 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 jetting system for an undersea trencher has jetting conduits extending onward 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 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.