An insulated excavation tube preferably includes a non-conductive tip tube, a non-conductive connector tube, a first vacuum tube, a second vacuum tube, a flange member and a handle. One end of the first vacuum tube is retained in one end of the non-conductive tip tube. A distance is maintained between an end of the first vacuum tube and an opposing end of the non-conductive tip tube to provide electrical and vibration isolation. An opposing end of the first vacuum tube is retained in one end of the non-conductive connector tube. One end of the second vacuum tube is retained in the non-conductive connector tube. A gap is maintained between the opposing end of the first vacuum tube and the one end of the second vacuum tube. The flange member is attached to an opposing end of the second vacuum tube. The handle is attached to the second vacuum tube.

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 system for uncovering a trench. The system comprises several subsystems, including a work machine and a frame for providing a seal with the surface to be trenched with a saw blade contained therein. The blade is supported on a hub which is slidably movable relative to the frame by operation of a linear actuator, which may be a hydraulic cylinder or the like. The vertical location of the blade within the frame is continuously adjustable to create a deeper or shallower trench. A monitoring system is provided to monitor the vertical location from an operator station.

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.

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.

A method of moving an underground pipeline including the steps of: driving a casing into a soil proximate to the pipeline; deploying a pivoting wand from the casing about a pivoting axis, the pivoting wand having a plurality of cutting nozzles that are coupled to a fluid conduit having a longitudinal extent in the casing relative to a longitudinal axis; pressurizing the fluid conduit to thereby send fluid through the cutting nozzle to soften the soil in a direction in which the wand deploys; rotating the pivoting wand; conducting the softened soil up through the casing to form a cavity in the soil proximate the pipeline, the cavity in the soil having a shape reflective of the movement of the pivoting wand in the rotating step; positioning a lifting device beneath the pipeline. And, lifting the pipeline with the lifting device thereby drawing the pipeline toward or into the cavity.

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.

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.

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 (α) 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.