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.

The hydro excavation remote dig system provides for a primary and secondary dig tube attachments that permit a vacuum truck to be used for a remote dig setup. Specifically, the attachments include various attachable handles, corrugated tubing that connects to a reinforcement bar device with releasable clamps to maintain the corrugated tubing in an elongated state during use, a debris box with an integrated safety valve, and a dig tip.

A method for recovering rare-earth mud including steps of: (A) penetrating a mud gathering pipe into a layer containing rare-earth mud under the seafloor, (B) preparing a slurry containing a rare earth by loosening rare-earth mud in the mud gathering pipe, and (C) transferring the slurry through a mud raising pipe. A rare-earth mud recovery system including: a mud gathering pipe configured to penetrate into a layer containing rare-earth mud under a seafloor; a stirring device configured to loosen rare-earth mud in the mud gathering pipe; and a mud raising pipe connected to the mud gathering pipe.

A device for the removal of a layer of sludge and/or sand from the bottom of a wetland includes: a diving bell with an open bottom and a lower free edge; a unit for driving the diving bell with its lower edge into the layer of sludge to be removed; a dredge pump installed in the space of the diving bell and provided with an inlet for pumping up the sludge and/or an outlet to which a pipe is connected for pumping the pumped up sludge and/or sand to a collector; and a compressor for pumping gas under pressure into the space of the diving bell during dredging. The diving bell is also provided with a gas outlet for the compressed gas, the gas outlet being adjustable in height in the diving bell because the outlet is attached to a float that can float on the sludge.

A self cleaning collecting apparatus and method are provided for the collection of seafloor material. The collecting apparatus, which operates on a seafloor, has a plurality of rotating discs in front of a slurry suction pipe with clearing members located between adjacent discs. Any oversize material lodged in the discs during collection is dislodged by the one or more clearing members and prevented from entering the slurry suction pipe, thus preventing blockages caused by oversize material congesting the slurry suction pipe.

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 dredge head assembly is disclosed. The assembly includes: a shroud having a generally open bottom end and a top end; a screen structure covering the generally open bottom end of the shroud; a suction pipe with a first end connected to the top end of the shroud and a second end configured to be operatively connected with a pump which induces suction; a handle connected to and extending from the shroud and having at least one grasping portion; and one or more vacuum relief valve assemblies, each comprising a valve, at least one opening configured to be in communication with water, and an actuation mechanism positioned to be accessible to a diver. Dredging systems and methods of dredging are also disclosed.

A cutter head arranged to rotate about an axis of rotation for removing material from a water bed comprises a base ring positioned respect to the axis of rotation; a hub positioned with respect to the axis of rotation; a plurality of arms extending between the base ring and the hub, the arms comprising a plurality of cutting tools; and a plurality of skirts, each skirt extending from one of the plurality of arms to the hub to form a closed surface between the arm and the hub from a distal end of the cutter head toward the base ring and ending with a side configured to be parallel to a backplate, leaving an open channel between the skirt and the backplate.

The present application relates to a suction dredger for use on an underwater hard soil layer and relates to the technical field of bridge construction equipment. The present suction dredger includes a mud suctioning mechanism, a mud-breaking mechanism, and a blockage-prevention assembly. The mud suctioning mechanism includes a pressurizing assembly and a suction dredging pipe. The suction dredging pipe passes through the pressurizing assembly and the two ends thereof at least partially extend past the pressurizing assembly. The side wall of the section of the suction dredging pipe located in the pressurizing assembly is provided with multiple pressurization holes that are inclined upward in the direction from the outer wall to the inner wall. The pressurizing assembly is used for, via the pressurization holes, forming low pressure in the suction dredging pipe. The mud-breaking mechanism includes at least two mud-breaking assemblies. The mud-breaking assemblies are provided on the bottom of the mud suctioning mechanism and are used for crushing the underwater hard soil layer to assist the suction dredging pipe in suctioning mud. The blockage-prevention assembly is provided on the bottom of the suction dredging pipe. The blockage-prevention assembly is used for preventing the suction dredging pipe from experiencing blockages during the suction process. The suction dredger for use on an underwater soil layer provided in the present application solves the problem in the prior art that when a suction dredger works on an underwater hard soil layer, suction results are poor and blockages are common.

A cutter head arranged to rotate about an axis of rotation for removing material from a water bed comprises a base ring positioned respect to the axis of rotation; a hub positioned with respect to the axis of rotation; a plurality of arms extending between the base ring and the hub, the arms comprising a plurality of cutting tools; and a plurality of skirts, each skirt extending from one of the plurality of arms to the hub to form a closed surface between the arm and the hub from a distal end of the cutter head toward the base ring and ending with a side configured to be parallel to a backplate, leaving an open channel between the skirt and the backplate.