Apparatus for removing sludge from an underwater deposit comprises a blade having a cutting edge that points forwards and a blade surface to the rear of the cutting edge that faces the interior of a housing. Nozzles are positioned and oriented to direct jets of water onto the blade surface to fluidize sludge that has been cut by the blade. The jets have a component of motion in the rearward direction relative to the blade surface, whereby the fluidized sludge is effectively contained within the housing and high collection rates can be achieved. The apparatus can be adapted for horizontal use over the surface of a sludge deposit or for movement in any direction through a bulk sludge deposit.

The present invention relates to apparatuses, methods, and systems for removing sediment from waterway bottoms and pumping the sediment through pipelines. More particularly, the present invention relates to apparatuses, methods, and systems for sediment control and altering the average effective depth in a section of rivers, streams and channels for maintaining the navigability of waterways and coastal restoration. The apparatus and method of the present invention including a means for preventing and removing blockages of water flow in the pipelines.

The invention relates to a dredging method for dredging a navigation channel for guaranteeing a nautical depth of a navigation channel. The method comprises performing agitation for mobilizing sediment and displacing the mobilized sediment to a collector which is embedded in the bottom of the navigation channel, the collector being a trench in the navigation channel wherein the trench has, when not being filled with sediment, a bottom level positioned substantially deeper than the nautical depth of the navigation channel. The method also comprises, in a step different from said performing agitation dredging, after solidification of the sediment collected in the collector, removing the solidified sediment from the collector so that the collector again has a bottom level positioned substantially deeper than the nautical depth of the navigation channel.

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 cleaning device for ponds (1) for interaction with at least one pond filter for removal of solids (2) from the pond (1) has a sediment swirling device (3) with a pump (11) which sucks in a swirling medium and discharges the latter through at least one ejector channel (4, 5) in the area of sedimented solids (2). The cleaning device is self-floating and is provided with a motion drive (14) and a location determination device for the purpose of directional control.

An apparatus (1) for underwater dredging includes a pipe (10) and a dredging head (2). The pipe (10) has a first aperture (11) and a second aperture (12) each disposed at opposing ends of the pipe (10). The pipe (10) also has at least one first sidewall aperture (13). The dredging head (2) is circumferentially arranged on a sidewall of the pipe (10) and has at least one input (20), at least one output (21) and a plenum chamber (22). The at least one output (21) is in fluid communication with the at least one first sidewall aperture (13). A first obstruction mechanism (23) is configured to selectively deter reverse fluid flow into the dredging head (2). The first obstruction mechanism (23) is configured to be selectively transformable between: a first, obstructing, configuration in which at least reverse fluid flow through the dredging head (2) is deterred; and a second, open, configuration in which fluid flow through the dredging head (2) is permitted. A method of underwater dredging is also described.

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 device for removing granular material by suction is presented, the device comprising a suction head. The suction head comprises a lower end, an outlet for removing granular material from the suction head, and side walls, extending from the lower end to the outlet. The suction head further comprises one or more nozzles, configured to emit a pressurized fluid for fluidizing granular material, and one or more side inlets for the inflow of fluidized granular material into the suction head. The side inlets are located in a side wall, and the side inlets combined extend over at least 2% of the circumference of the lower end. A method for removal of granular material by suction from a granular material mass is also presented. The nozzles on an outside and the nozzles on an inside of the suction head provide a helical flow in the same direction.

Subsea blower device comprising at least one nozzle, at least one propel arranged to provide the nozzle with water, further comprising a chassis with belts for movement of the device along the seafloor. The device typically has at least one arm pivotally attached to the chassis so that the position of the arm in relation to a horizontal plane is adjustable, while the nozzle is attached to the arm.

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.