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 hand held supersonic air knife with a supersonic variable flow nozzle yields a continuously variable power mass flow rate (CFM) and pressure over a selectable power range, responsive to rotations of the nozzle exterior sleeve or outer nozzle member. The maximum power position identified as one end position and a second end position as the lowest power. The exterior sleeve can be rotated to any axial or circumferential position between start (low) and end (high). The result will be an intermediate power position. Any intermediate position will also be a supersonic nozzle of varying parameters between the start and end positions. Thus, a variable flow supersonic nozzle is provided by the manual sleeve rotation by an operator or a remotely controlled positioning of the sleeve.

A trenching assembly lays a continuous pipeline in a trench dug in a bed with uneven bathymetry, the trenching assembly including a trench digging device having a main body; at least four ground contact units, each unit having a height adjustment device, to position each ground contact unit with respect to the main body independently. A trench cutting tool digs in the bed includes a cutting depth adjustment device, for positioning the cutting tool with respect to the main body. A detection device detects bed bathymetry. A control device simultaneously allows cooperation between the detection device, the height adjustment device of each ground contact unit, and the cutting depth adjustment device. A command device cooperates with the control device to adjustment each ground contact unit and the cutting depth adjustment device, to obtain a trench having a height difference lower than a predefined tolerance and a predetermined burial depth.

The present invention provides an improved pipeline burying apparatus that uses specially configured jetting nozzles that intake sea water surrounding the nozzle. The apparatus provides a frame supporting spaced apart left and right inclined pipe sections that are configured to be placed on opposing sides of the pipeline to be buried. Each inclined pipe section is fitted with a plurality of jetting nozzles that are positioned on one of the inclined pipe sections, in vertically spaced apart positions and in horizontally spaced apart positions. At least some of said jetting nozzles include a nozzle body having an outer surface and a main, central longitudinal fluid flow channel with a central channel axis. A fluid inlet end portion of the nozzle body has an externally threaded portion that enables connection to an internally threaded portion of a selected one of the inclined pipe sections. A discharge end portion of the nozzle body extends outwardly from an inclined pipe and the threaded portion. A plurality of lateral channels each intersect the main channel at an acute angle. In one embodiment, the main central longitudinal channel has an inlet section with an inlet section diameter, a discharge section having an outlet section diameter and a connecting section that is in between the inlet section and the outlet section.

A plough for inserting a cable into a trench in the seabed is disclosed. The plough comprises a plough share for forming a trench in the seabed and a drawbar for enabling attachment of tensile members to the plough. The drawbar is moveable relative to the plough share between a first position, in which the plough is adapted to be towed by a towing cable to move the plough share relative to the seabed to form a trench, and a second position, in which the plough is adapted to be supported by the towing cable to enable the plough apparatus to be deployed to the seabed. A cable path receives the cable and an attachment part of the drawbar is moveable relative to the plough share between the second position and a third position, to enable the cable to be received in the cable path from above the plough.

Generally, the present invention relates to a method for burying a pipe in a seabed. A dredging-excavator is usually needed when wanting to bury a pipe or a pipeline in a seabed. This can be difficult to implement and increase costs. The present invention comprises a pressurized water supply, and at least one nozzle connected to the pressurized water supply, wherein the nozzle is arranged on one side of the pipe to be buried to eject a pressurized water jet into the seabed to increase water content of the seabed below the pipe, so that the density of the seabed locally decreases below the density of the pipe allowing the pipe to supersede the seabed, and ejecting the water until the pipe has descended at the desired depth into the seabed.

The present invention provides an improved pipeline burying apparatus that uses specially configured jetting nozzles that intake sea water surrounding the nozzle. The apparatus provides a frame supporting spaced apart left and right inclined pipe sections that are configured to be placed on opposing sides of the pipeline to be buried. Each inclined pipe section is fitted with a plurality of jetting nozzles that are positioned on one of the inclined pipe sections, in vertically spaced apart positions and in horizontally spaced apart positions. In one embodiment, the main central longitudinal channel has an inlet section with an inlet section diameter, a discharge section having an outlet section diameter and a connecting section that is in between the inlet section and the outlet section.

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.

There is disclosed an excavation apparatus (5), such as an underwater excavation apparatus, having means for producing, in use, at least one vortex, spiral or turbulent flow in a laminar flow of fluid, e.g. water. The excavation apparatus (5) comprises a rotor (10) having a rotor rotation axis (A), wherein, in use, flow of fluid past or across the rotor (10) is at a first angle (?) from the axis of rotation (A). The excavation apparatus (5) comprises the rotor (5) and means or an arrangement for dampening reactive torque on the apparatus (5) caused by rotation of the rotor (10), in use. The turbulent flow is provided within, such as within a (transverse) cross-section, of the laminar flow.

Pipe burial apparatus are disclosed that include sets of rotary nozzle cutters configured to straddle a pipe that is to be buried and a nozzle array connected to a nozzle supply pipe in a manner that places the nozzle supply pipe in a cutting path of a rotary nozzle cutter. The nozzle supply pipe may be actuated to alternatingly move the nozzle array between a position straddling the pipe being buried and a cutting position that is below the pipe being buried.