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.

The present invention provides a system, apparatus, and method for harvesting objects from the bottom of aquatic environments. The invention preferably provides a system, apparatus, and method for utilizing swarms of autonomous harvesting vehicles to harvest polymetallic nodules from the ocean floor.

The present invention is a hydraulic excavation and delivery device capable of hydraulically removing soil overburden from a buried structure, like a pipeline, and delivering an article, such as an electro-mechanical connector for attachment to the buried structure. Hydraulic excavation is achieved by directing a stream of fluid at soil adjacent to and inside an open bottom region of the device to simultaneously dislodge adjacent soil, suspend dislodged soil in the accumulating fluid and form a pit that the device may fit within. Delivery of article is achieved by: (1) loading an article into the tool; (2) advancing the device toward the buried structure by deepening the pit without significant failure (slumping or sagging) of the pit walls until a portion of the buried structure is exposed and within the device; (3) landing the device on the exposed portion of the structure; (4) fixing the article to the exposed portion of the structure; and (5) releasing the article from the device.

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 subsea trencher for arranging at least partly into the seabed a subsea pipeline, includes at least one cart that separately carries at least one trench tool and is configured to run along the subsea pipeline. trench tool is configured to work the seabed underneath the subsea pipeline. A subsea support frame carries heavy subsea equipment connected to the trench tool for operating the trench too. When the subsea support frame is fixed to the cart, the subsea trencher is configured to load the assembled weight of the cart and subsea support frame onto the subsea pipeline as the subsea trencher runs on the subsea pipeline. When the subsea support frame is separate from the cart, the subsea support frame is configured to be suspended above the seabed or arranged beside the subsea pipeline at a distance from the subsea pipeline as the cart runs along the subsea pipeline.

The disclosure relates to a suction generation device for the removal of matter from a submerged surface, including: a housing including a fluid inlet, a suction inlet, an expulsion outlet, and defining a cavity therein; the fluid inlet being configurable to direct a supply of fluid into the cavity and to establish a flowpath from the fluid inlet to the expulsion outlet, the flowpath extending through the cavity, and fluid flow in the flowpath generating a reduction in pressure at the suction inlet to generate a flow of fluid therethrough and into the flowpath; and the fluid inlet includes an array of inlet fluid ports. The disclosure further relates to an operation apparatus for the suction generation device and a method for the removal of matter from a submerged surface.

A subsea trencher for arranging at least partly into the seabed a subsea pipeline, includes at least one cart that separately carries at least one trench tool and is configured to run along the subsea pipeline. The trench tool is configured to work the seabed underneath the subsea pipeline. A subsea support frame carries heavy subsea equipment connected to the trench tool for operating the trench too. When the subsea support frame is fixed to the cart, the subsea trencher is configured to load the assembled weight of the cart and subsea support frame onto the subsea pipeline as the subsea trencher runs on the subsea pipeline. When the subsea support frame is separate from the cart, the subsea support frame is configured to be suspended above the seabed or arranged beside the subsea pipeline at a distance from the subsea pipeline as the cart runs along the subsea pipeline.

A system for performing underwater earthworks, the system including a power pack situated outside the water, at least one submersible operating unit for performing underwater earthworks, wherein the operating unit is connected with the power pack through power supply means, and a control unit connected via data communication means with the power pack and the operating unit and with instrumentation indicating location and depth of the operating unit.

A seafloor haulage system (10), for lifting seafloor materials from the seafloor to the surface, that has a line member (150), preferably synthetic rope, that extends at least partially between the seafloor and the surface and a container (400), preferably a plurality of containers, capable of carrying a load connected to the line member (150). The containers have a steerable element (410), such as a rudder, that enables the container to manoeuvre as it is propelled, typically towed by the line member, through the water.

De-trenching apparatus (100) for extracting a buried line, such as a cable or pipeline, is disclosed. The de-trenching apparatus comprises a channel (112) configured to receive a buried line to be extracted, the channel comprising a first flared opening (114) at a front end of the de-trenching apparatus and a second flared opening (115) at the rear end of the de-trenching apparatus, the first and second flared openings each having a curved surface (111) configured to support the line during extraction, and material removal means for removing material from around the buried line ahead of the de-trenching apparatus.