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.

A seabed trenching plow has a chassis, a sled and a towing assembly. The towing assembly has a pair of wings extending laterally from each side of the chassis. The wings are aligned on an axis transverse to the chassis and adapted for connection to a towing line. The transverse axis is forward of the center of gravity of the plow and rearward of the sled, affording an over the stern releasable and retrievable trenching plow of sufficient weight and strength to excavate a three meter trench in a single pass. To assess the protective capabilities of the trench, a threshold signal indicative of a desired composition of seabed-trench soil is compared with a real-time data signal indicative of the actual to produce an alarm signal when the real-time data signal is not protective-capability compliant with the threshold signal.

An apparatus for forming a trench along the bed of a body of water for burying a line lying along such bed including a support structure designed to straddle such line, means for propelling such structure straddling such line and means disposed on such structure including a pair of transversely spaced excavator devices cooperable in forming a trench along the bed of such body of water for receiving such line, each provided with a set of circumferentially spaced, pressurized fluid ejecting nozzles, rotatable about an axis.

The invention relates to a device (10) for dredging a watercourse or body of water, comprising: a watercraft (105) which supports a grinder, the grinder (110) for grinding plants found in the watercourse or body of water comprising an inlet (115) for plants and an outlet (120) for ground plants, and a floating receptacle (125) which is connected to the outlet of the grinder in order to collect the scraps of ground plants.

An intelligent dredging system for a high-piled wharf and a control method thereof are provided, and the system includes an intelligent monitoring-decision control subsystem and a decentralized high-pressure water disturbance subsystem. The intelligent monitoring-decision control subsystem is composed of a high-precision pile-foundation sediment siltation warning device, a tidal monitoring device and a control terminal. The decentralized high-pressure water disturbance subsystem is composed of a water spraying device, a cable and a multi-loop power distribution device.

The invention relates to a manoeuvrable trailing dredging vessel comprising; a vessel propulsion member coupled with a propulsion shaft provided with a single gear for driving the propulsion member, a drive system having a central drive shaft coupled with the vessel propulsion member for providing power to the vessel propulsion member, a transmission device having at least a trailing transmission shaft provided with a trailing pinion and a sailing transmission shaft provided with a sailing pinion,
wherein the central drive shaft is coupled with the single gear of the propulsion shaft through one of the trailing transmission shaft and the sailing transmission shaft.

A seabed plow capable of over-the-stern release and retrieval is usable in any of boulder clearing, trench cutting and backfill modes. In its boulder clearing mode, the plow uses its skid in torquing configuration followed by moldboards to push boulders out of the path to be trenched. In the trench cutting mode, the plow uses the skid in the same configuration with its share and moldboards for initial trench depth and the same share and moldboards with moldboard extensions for increasing trench depth in subsequent passes. In the backfill mode, the plow uses its skid in trench-straddling configuration following a blade with a passage designed to discharge fragmented spoil directly onto the pipe being covered. Thus, a single plow can be reconfigured for all modes for release and retrieval to and from a relatively small vessel without use of heavy lifting equipment.

A surface layer improvement system for on-site remediation of contaminated sediments includes: a stabilizer spray unit that performs underwater spraying of a stabilizer to a remediation target region; and a disturbing and mixing unit that induces bioturbation by mixing the stabilizer with the contaminated sediments in water. The disclosure performs the remediation of the contaminated sediments by spraying the stabilizer to the remediation target region of a water bottom floor through the stabilizer spray unit and performing on-site incorporation of the stabilizer sprayed through the disturbing and mixing unit.

A seabed trenching plow has a chassis, a sled and a towing assembly. The towing assembly has a pair of wings extending laterally from each side of the chassis. The wings are aligned on an axis transverse to the chassis and adapted for connection to a towing line. The transverse axis is forward of the center of gravity of the plow and rearward of the sled, affording an over the stern releasable and retrievable trenching plow of sufficient weight and strength to excavate a three meter trench in a single pass. To assess the protective capabilities of the trench, a threshold signal indicative of a desired composition of seabed-trench soil is compared with a real-time data signal indicative of the actual to produce an alarm signal when the real-time data signal is not protective-capability compliant with the threshold signal.

This invention relates to hydraulic engineering construction and can be used for deposit cleanup of river beds and channels. The object of the invention is to expand the arsenal of usable means for deposit cleanup and deepening of river beds, develop a method and create a device that uses the speed of the river current in the most effective way. The technical result of the claimed method is simplification and optimization of one existing method for cleanup of river beds and channels, increasing its functionality. The proposed method implements a movable water flow-restricting device with flow-guiding elements that creates a concentrated stream and directs it to a washout zone, bound by side walls, roof and washout surface.