A vehicle (6) apparatus for removing material from the seabed is disclosed. The vehicle comprises first thrusters (10) for moving the vehicle vertically and second thrusters (12) for moving the vehicle horizontally. A collector unit (16) removes material from the seabed, and a latching mechanism (42) is adapted to be connected to a riser to enable removed material to be transported to a vessel on the surface.

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.

Cutting wheel system (1) for a dredging device, comprising a cutting wheel (2) and a cutting wheel drive system (8), whereby the cutting wheel comprises at least two cutting element rings (3), which rings are positioned at a distance from each other in parallel planes whereby the cutting element rings have coaxial rotation axes (12,13), whereby a suction tube (7) can be positioned between the two cutting element rings (3), whereby the cutting wheel drive system is arranged to rotate the cutting wheel about the coaxial rotation axes, wherein the cutting wheel system further comprises connecting arms (9) for mounting the cutting wheel in a rotatable manner to the dredging device, wherein the connecting arms are moveable with respect to each other between a closed position wherein the connecting arms engage the cutting wheel from opposite sides of the cutting wheel, and an open position wherein the cutting wheel is released from the connecting arms.

An overflow system for a hopper dredger comprises an overflow tube; an inlet for taking in head water from the hopper; and a collector to collect the flow of head water entering the inlet and guide the flow to the overflow tube. The collector comprises a substantially horizontal top portion which delineates a top of a flowpath for head water into the collector to ensure substantially radial flow into the collector. At least one of the overflow tube and the inlet is adjustable for controlling flow into the overflow system.

A cutterhead for dredging a body of water. The cutterhead comprising a shroud including a top wall, a bottom wall, and two sidewalls each extending between the top and bottom walls. The cutterhead additionally comprises a rotatable cutterbar at least partially received within an interior space presented by the shroud, a first water-jet bar extending along a portion of the top wall of the shroud, and a second water-jet bar extending along at least a portion of one of the two sidewalls. The cutterbar and the water-jet bars are configured to generate a slurry of fluidized material from the water-bed.

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.

An apparatus, system and method for removing and treating contaminated materials on a bottom of a body of water and introducing growth packets to revitalize the treated bottom of the body of water. The structure may comprise a vessel with an open face. The vessel may be lowered down to the bottom of the body of water with the face facing down. As a result, the vessel and the bottom form an isolated space. The structure may comprise at least one agitating device(s) for stirring up the materials inside the vessel so as to form a mixture containing the sediment materials which in turn contain the contaminants. Multiple at least one pipe(s) may be coupled to the vessel for transporting the mixture out of the vessel for processing (filtering, treating with chemicals, etc.) so as to neutralize or eliminate the contaminants in the mixture. Then, the treated mixture can be returned to the inside of the vessel via the at least one pipe(s).

The invention relates to a trench cutter and a method for producing a cut trench in the soil having a cutter frame, at least one pair of cutting wheels which are supported and driven in a rotatable manner on a lower end of the cutter frame, wherein each cutting wheel has a plurality of cutting teeth along its outer circumference, and a supply and/or discharge means for supplying or discharging a cutting liquid to or from the cut trench in the region of the cutting wheels. According to the invention provision is made in that spaced from the supply and/or discharge means a cleaning device is provided for cleaning the cutting wheels during the cutting operation with a cleaning fluid and in that the cleaning device has a plurality of cleaning nozzles which are directed onto the outer circumference of at least one cutting wheel and designed to inject the cleaning fluid to loosen adhering soil material.

A pump apparatus comprises a primary pump having a relatively low pressure fluid input and a relatively high pressure fluid output and means, associated with said primary pump fluid input, operable where the ambient pressure is insufficient substantially to prevent cavitation in the primary pump, to locally increase the pressure at said primary pump fluid input.

In a bubble lift system, a pressurized chamber at an upper end portion of a riser pipe applies a pressure to an upper portion inside the riser pipe to suppress an increase in the volume ratio of bubbles to a fluid mixture rising inside the riser pipe in a shallow water region. The upper end of the riser pipe is not opened to the atmosphere but is inserted into the pressurized chamber under a high pressure to thereby prevent expansion of the bubbles and gas. In addition, a deaerator for discharging bubbles separated by a centrifugal force is also provided in a middle portion of the riser pipe in a shallow water region to distribute the bubbles more evenly inside the whole riser pipe. The bubble lift system and a bubble lift method thus provided are efficient and employable even in a deep water region.