Abstract: A dredging head assembly for deploying on the bed of a body of water, is provided, the assembly comprising a cutter housing having a cutting opening for extending over a section of the bed from which material is to be removed; a cutting assembly disposed within the cutter housing, the cutting assembly operable through the cutting opening in the cutter housing to loosen material from the bed; and an outlet opening in the cutter housing for removing water and entrained material from within the cutter housing under suction; wherein the cutter housing comprises a plurality of holes therein, in use water being drawn into the cutter housing through the holes under the action of reduced fluid pressure within the cutter housing. A dredging assembly comprising the dredging head assembly and a method of dredging are also provided.

Abstract: A fill device for use with a water reservoir tank in an earth reduction system, the fill device comprising a ring having a top surface and a bottom surface, a pipe having a first end connected to the top surface of the ring and a second end for connection to a water supply, a skirt affixed to the bottom surface of the center ring, an opening surrounded by a plate and defining a tortuous path and positioned below the first end of the pipe and the skirt, and a check valve support with a check valve mounted below the opening and the plate.

Abstract: 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.

Abstract: 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.

Abstract: A system to generate pressurized air for hydro-excavation includes an exhaust silencer configured to hold water and an exhaust manifold disposed through the silencer, where the exhaust manifold is configured to be in fluid communication with an internal combustion engine in order to receive exhaust gases to heat the exhaust silencer. In addition, the system includes a steam turbine configured to be driven by steam generated in the exhaust silencer, a primary steam line secured proximate to an upper end of the silencer to connect to the steam turbine, and an air compressor driven by the steam turbine to generate pressurized air. A secondary steam line is in fluid communication with the primary steam line and the air compressor to generate a mixture of the steam and pressurized air for use in hydro-excavation.

Abstract: A drag head of a trailing suction hopper dredger, comprises a visor which is dragged over the bottom in a dragging direction and herein loosens soil, and a suction conduit which connects to the visor and which discharges the loosened soil. The drag head is provided with cutting bodies for loosening the soil, with the proviso that the cutting bodies comprise conical bits. Harder soil can be dredged efficiently with a trailing suction hopper dredger equipped with the drag head.

Abstract: The present invention provides a system and method to efficiently and effectively dredge in the presence of hard rock. An additional aspect of the present invention is to provide a system that induces cavitation bubbles and/or a vortex flow within a dredging cutter head by use of water jets mounted within a cavity of the cutter head. The cavitation bubbles and/or vortex flow produced by the water jets urge comminution of hard rock encountered during dredging operations, providing a more effective and efficient dredging of waterways than conventional approaches.

Abstract: An excavation system utilizes a vacuum truck having a vacuum system in combination with a small backhoe to which an excavator assembly is affixed to the backhoe extendable and articulating arm whereby manipulation of the excavator assembly can be controlled by an operator positioned in the backhoe operator cab. The vacuum assembly and the excavator assembly are operatively attached by an elongated, at least partially flexible vacuum hose operatively attached to the vacuum truck pump to permit material that is excavated to be transported from the excavator assembly to the vacuum assembly for storage or disposal.

Abstract: A suction mouth (10) for mounting on the front of a subsea mining tool and to be pushed into sediment. The suction mouth comprises a hollow body (12) having an entrance opening (14) and an exit opening (16), wherein the body converges from the entrance opening towards the exit opening. The entrance opening has a lower lip (20) and an upper lip (22), and the upper lip comprises an extension (22a) projecting forwardly and upwardly relative to the lower lip to form a canopy over the entrance opening. The suction mouth (10) may include a valve (30) on the body downstream of the entrance opening which is operable to selectively provide a further entrance opening into the body. Where such a valve is present, the consistency of the material sucked in can be regulated.

Abstract: The present invention relates to an underwater excavation apparatus and a method of excavation with the same. The apparatus of the invention performs the excavation by both mass flow and jet flow. Mass flow excavation takes place at a pressure that is lower than the jet flow excavation performed by the apparatus, and the volume flow rate of the mass flow excavation is greater than the volume flow rate of the jet flow excavation performed by the apparatus. The outlet for jet flow excavation is provided within the outlet for mass flow excavation of the apparatus.

Abstract: This invention is titled “Vibrating Agitator Attachment for Toyo Dredge Pumps” and is for use with Toyo submersible dredge pumps. The invention is for use in subsea dredging operations. The invention is easily attachable when needed and detachable when not needed. It uses vibrating technology to move an agitator unit, which touches the seafloor, in the X, Y and Z planes in a rapid and powerful motion. The agitator unit has “blades” with vertical surfaces and pointed at the bottom for easy penetration in hard clay. These “blades” are attached to the bottom of a jet ring that uses pressurized water spraying through jet nozzles aimed at the pointed edge of the vertical surface blades. The vibrating motion moves the horizontal column of water between the vertical blade surfaces agitating the seafloor material, and breaking it loose for removal by the Toyo dredge pump. The idea of using vibrating technology with a Toyo dredge pump is new.

Abstract: A mobile digging and backfill system for removing and collecting material above a buried utility. The system comprises a mobile chassis, a collection tank mounted to the chassis, a water pump mounted to the chassis for delivering a pressurized liquid flow against the material for loosening the material at a location, a vacuum pump connected to the collection tank so that an air stream created by the vacuum pump draws the material and the fluid from the location into the collection tank, and at least one backfill reservoir mounted to the chassis for carrying backfill for placement at the location.

Abstract: The present invention relates to an underwater excavation apparatus. The apparatus of the invention utilizes mass flow for disturbing or excavating an underwater location and for extracting or sucking excavated material from the underwater location to another location. Restriction of spoil and/or direct spoil is provided for the apparatus and comprises a baffle provided within a cavity of a housing having an open base for the extracting or sucking of excavated material. An outlet for disturbing or excavating and an inlet for extraction or suction are located within the housing while an inlet for disturbing or excavating and an outlet for extraction or suction are located external to the housing.

Abstract: A mobile digging and backfill system for removing and collecting material above a buried utility. The system comprises a mobile chassis, a collection tank mounted to the chassis, a water pump mounted to the chassis for delivering a pressurized liquid flow against the material for loosening the material at a location, a vacuum pump connected to the collection tank so that an air stream created by the vacuum pump draws the material and the fluid from the location into the collection tank, and at least one backfill reservoir mounted to the chassis for carrying backfill for placement at the location.

Abstract: A mud removing device includes a case which is merged into water and has an opening and a space. At least one at suction tube and multiple injection tubes respectively extend and connect to the case. The injection tubes are located around the opening of the case and one end of the injection tubes reaches to the periphery of the opening. A working station introduces high pressure water to flush the mud located below the opening of the case and at least one the suction tube sucks the mud which is collected to the working station. The case has weights and the working station can be carried by a floating carrier. The working station has a crane which has a cable to hang the case.

Abstract: An apparatus and associated method of soil working is provided for performing one or more of soil fracture, soil excavation and soil treatment. The method comprises the steps of: supplying a source of pressurized gas; supplying a source of fluidized material; positioning a nozzle adjacent the soil; directing a stream of the pressurized gas through the nozzle at the soil being worked; and entraining a stream of fluidized material in the gas stream prior to the stream reaching the soil.

Abstract: A method for rehabilitating a land area comprises the step of using an excavating machine to extract dirt desired to be dispersed over the land area from another area, such as a ditch. The extracted dirt is mixed with water to form a slurry. The slurry is pumped to a high-pressure spray nozzle, and is then sprayed in a thin layer over the land area desired to be rehabilitated. The slurry can also be pumped to the land area at a controllable depth to achieve a desired land profile thereat.

Abstract: An underwater trenching system is mountable on a side of a barge to be propelled by the barge along a waterway, the bed of which contains a trench with a laid pipeline. To remove the excess sediment from the trench the trenching unit delivers pressurized water and air to the trench. A sparge assembly with jet nozzles directs jets of water, breaking up the formation that has built up around the pipeline. The airlift assembly creates a turbulent flow to lift the disturbed sediment and remove it from the created trench.

Abstract: The invention relates to a drag head (1) of a trailing suction hopper dredger, comprising a visor (2) which is dragged over the bottom in a dragging direction and herein loosens soil, and a suction conduit (5) which connects to the visor (2) and which discharges the loosened soil. The drag head is provided with cutting bodies for loosening the soil, with the proviso that the cutting bodies comprise bits (20). Harder soil can also be dredged with the drag head by applying bits (20). The invention also relates to a method for dredging at least partially hard bottoms under water with a trailing suction hopper dredger equipped with the drag head.

Abstract: A method for removing soils, particles or fluids from the seabed or from great sea depths, includes positioning a platform or a vessel above an offshore location, lowering a riser from the vessel or platform to the seabed or great depth, the riser being vented to the atmosphere, sucking soils, particles or fluids with inflow of fluid into the riser and removing them from the riser via an outlet in the riser, the outlet being at a level well below the water surface, by use of a pumping system with a flow return conduit running to a selected location, while keeping the level of the fluid in the riser at a level between the outlet and the surface corresponding with a pressure in the lower end of the riser substantially lower than the sea water pressure at the end of the riser.

Abstract: The present invention relates to a draghead (1) for a trailing suction hopper, comprising a visor (2), revolvable around a first axis (6) for removing soil, and a suction line (31) connected to the visor (2) for the removal of the loosened soil, characterised in that the draghead (1) is provided with a pressure plate (21), which comprises a number of mainly disc-shaped penetrating bodies (22) on the soil-facing side of the pressure plate (21), in such a way that their circumferential edge (23) is capable of transferring forces to the soil.

Abstract: An excavation technique for a stratum capable of excavating a submerged stratum such as a layer containing an underground resource by using laser irradiation in liquid is provided. In this technique, a laser beam transmitted through laser transmission means 20 is irradiated in liquid 90 in form of a laser beam having a wavelength with high absorptance of the liquid 90 by laser-induced bubble generation means 35, generating a bubble flow 36, thus excavation of a submerged stratum may be carried out by using a laser-induced destruction effect. Moreover, a laser beam 41 having low absorptance of the liquid 90 is irradiated by laser irradiation means 39 and passed through the bubble flow 36, thereby applying a thermal effect to a stratum to destroy rock and excavate the stratum. The destruction effect and the thermal effect also may be cooperatively worked.

Abstract: An earth reduction tool configured to connect to a vacuum source of an earth reduction system for moving material comprising an elongated body defining a first end for connecting to the vacuum source, an opposite second end, and an elongated vacuum passage extending through the elongated body between the first and the second ends. The tool also has an elongated air passage extending from the body second end to at least a point intermediate the elongated body first and second ends, the air passage having an open first end and an open second end proximate the elongated body second end that is in fluid communication with the elongated body vacuum passage second end, wherein when the vacuum source pulls a vacuum through the elongated body vacuum passage, air is drawn up into the vacuum passage from the air passage open second end.

Abstract: An apparatus to gather and relocate benthic life and life supporting material for use in combination with a seabed or aquatic bed dredger, plough, mole or other seabed disturbing apparatus comprising a means of gathering the benthic life and life supporting material in, on or above the seabed in front of and in the path of the draghead or said seabed disturbing apparatus, thereby preventing entrainment or damage to the benthic life, and a means of releasing the benthic organisms and life supporting material via a directional exit duct, away from the work area.

Abstract: A sediment removal system and method provides a versatile and controllable device for removing sediment from water in a focused manner that avoids generating unwanted turbidity. A suction pump draws water and sediment through a suction conduit and the injection of air into the suction conduit by air nozzles enables sediment to be removed from greater depths. The inclusion of water nozzles on an inlet opening enables hardened sediment to be dislodged such that it may be drawn into the suction conduit. A GPS receiver mounted to the suction conduit enables the location of the removal process to be tracked and a knife valve prevents backflow out of the suction conduit. The capturing of solid sediment by retention containers and the capturing of water containing suspended sediment by a tank enables the sediment and water to be transported to an appropriate location for treatment or disposal.

Abstract: A compact mobile vacuum boring, mud recovery, excavation and surface cleaning method comprising a device which will create a vacuum condition within a vacuum container and the vacuum container may be mounted on an incline slope to provide space beneath it to locate a water storage container. A vacuum conduit may be used to transport liquid or solid particles into the vacuum container. The vacuum conduit may be mounted adjacent to an articulated boom with one or more elbows and arms and the boom arm may have multiple utilities and tools attached. The vacuum tank may be mounted at a slope sufficient to assist emptying it's contents by gravity. An air filter housing may be adjacently mounted above the vacuum tank for efficiency and compactness. A dispensing device may be added to dispense a liquid or a solid from the vacuum container without eliminating the vacuum environment within the vacuum container, and said vacuum container having the ability to fill, store and dispense its contents simultaneously.

Abstract: An underwater trenching system is mountable on a side of a barge to be propelled by the barge along a waterway, the bed of which contains a trench with a laid pipeline. To remove the excess sediment from the trench the trenching unit delivers pressurized water and air to the trench. A sparge assembly with jet nozzles directs jets of water, breaking up the formation that has built up around the pipeline. The airlift assembly creates a turbulent flow to lift the disturbed sediment and remove it from the created trench.

Abstract: A sediment removal system and method provides a versatile and controllable device for removing sediment from water in a focused manner that avoids generating unwanted turbidity. A suction pump draws water and sediment through a suction conduit and the injection of air into the suction conduit by air nozzles enables sediment to be removed from greater depths. The inclusion of water nozzles on an inlet opening enables hardened sediment to be dislodged such that it may be drawn into the suction conduit. A GPS receiver mounted to the suction conduit enables the location of the removal process to be tracked and a knife valve prevents backflow out of the suction conduit. The capturing of solid sediment by retention containers and the capturing of water containing suspended sediment by a tank enables the sediment and water to be transported to an appropriate location for treatment or disposal.

Abstract: A cutter head for dredging soil, which is mountable to the ladder of a suction dredger for dredging soil, and connectable on a suction pipe for removing loosened soil, the cutter head comprising a cage-shaped support construction which is mountable to a drivable rotation shaft extending mainly in extension of the ladder and which has a circumferential surface provided with a number of cutting tools for penetrating the soil, the cutting tools comprising a number of disc-shaped penetration bodies of which the disc planes extend substantially perpendicular to the rotation shaft, so that they can transfer forces to the soil via their peripheral edges.

Abstract: A mobile digging and backfill system for removing and collecting material above a buried utility. The system comprises a mobile chassis, a collection tank mounted to the chassis, a water pump mounted to the chassis for delivering a pressurized liquid flow against the material for loosening the material at a location, a vacuum pump connected to the collection tank so that an air stream created by the vacuum pump draws the material and the fluid from the location into the collection tank, and at least one backfill reservoir mounted to the chassis for carrying backfill for placement at the location.

Abstract: A tool for excavating an object comprises a jetting system having a nozzle arranged to receive a fluid and abrasive particles via an abrasive particle inlet, and arranged to impinge the object to be excavated with a jetted stream of the fluid mixed with the abrasive particles, the tool further having a recirculation system arranged to recirculate at least some of the abrasive particles from a return stream, downstream of the impingement of the jetted stream with the object to be excavated, back to the jetting system via the abrasive particle inlet, the abrasive particle inlet having an entrance window in which a device in a path fluidly connecting the return stream with the entrance window keeps the abrasive particle inlet free from objects of the same size or larger than the size of the window while allowing passage of the abrasive particles.

Abstract: Subsea excavation and suction device includes a suction head with an inlet opening at an outer, free end and an outlet opening connected to a suction hose arranged at a distance from the inlet opening. The suction head is mounted on a hydraulic controller arm and at the inlet opening is provided with mechanical and hydraulic devices to disintegrate solid material (sediment). The hydraulic device includes a number of jet nozzles, while the mechanical device includes bars. The cross-sectional area of the inlet opening is larger than the cross-sectional area of the outlet opening.

Abstract: An apparatus for soil excavation having a vacuum hose, a vacuum holding tank and at least one air lance and/or water jet, in which a soil beneficiating agent is introduced into the soil during one or more of the steps of the vacuum excavation process.

Abstract: Provided herein is a device useful for recovering valuable metallic objects which are located in a submerged location, such as beneath the sand or mud off the shore of a beach or riverbank. A device according to the invention first locates a metallic object using a conventional metal detector comprising a coil that is disposed about the end of a pickup conduit. Once a metallic object is located, the operator causes the sand, mud and other debris in the vicinity of the end of the pickup conduit to be admitted into the device and filtered through a recovery basket which comprises a mesh or screen. Valuable objects so located and collected are readily recovered by the operator of the device by opening a door portion which is integral to the recovery basket. By its configuration, the weight distribution of a device according to the invention is such that it may be used for extended periods by an operator without undergoing fatigue.

Abstract: A method of forming a trench in the bed of a body of water, the bed having an initial undisturbed upper surface, comprises suspending a pressure line from a vessel floating on the body of water, the pressure line terminating downwardly in a downwardly directed nozzle. The nozzle is positioned a small distance above the bed, and water is pumped under pressure on board the vessel and is discharged via the pressure line and nozzle downwardly against the bed surface with the water pumped at an overpressure between 0.01 bar and 20 bar and at a flow rate of 0.25 to 20.0 cm per second. The distance of the nozzle above the surface of the bed is not more than ten times the diameter of the water jet defined by the nozzle, preferably about six times the diameter of that water jet.

Abstract: A utility pole installation system, comprising a hydrovac unit having a chassis and a utility pole positioner mounted on the chassis. The hydrovac unit has an internal combustion engine mounted on the chassis, and a hydrovac boom mounted on the chassis. A hydraulic power supply mounted on the chassis is powered by the internal combustion engine and used to power both the hydrovac boom and the utility pole positioner.

Abstract: This invention relates to apparatuses and methods for subsurface mining, and more particularly to apparatuses and methods for relocating (including dredging, mining, filling, reverse-layering, replenishment) subsurface strata.

Abstract: Apparatus for dredging shellfish from the bottom of a body of water includes a source of pressurized water, at least one water jet arranged to receive water from the pressurized water source and direct it at shellfish-containing sediments, sorting plates for receiving the shellfish-containing sediments excavated by the at least one water jet and separating the shellfish from the sediments, a collection chamber for receiving the separated shellfish, and dual lifting compartments, one of which is connected to the pressurized water source for lifting shellfish from the collection chamber and entraining the shellfish for transport to the surface, and the other of which is arranged to received pressurized air for increasing the transport speed and lifting power while cushioning the shellfish as they are transported to the surface.

Abstract: An apparatus for forming a trench in a seabed for burying a line generally consisting of a main frame, at least one buoyancy tank mounted on the main frame, a pair of endless track assemblies, each engageable in gripping relation with a side of the line for propelling the frame along the line, a pair of jet legs mounted on the main frame and communicable with a source of fluid under pressure, for ejecting high velocity streams of fluid to dislodge portions of the seabed when the track assemblies grip the line and propel the main frame along the line to form a trench and allow the line to fall therein.

Abstract: A hand-held wand is disclosed for exposing buried objects such as utility lines or the like. The wand comprises an elongated, hollow tube having upper and lower ends with first and second water supply conduits being positioned adjacent the exterior surface of the tube. The lower end of the first water supply conduit has a digging nozzle mounted thereon. The lower end of the second water supply conduit extends upwardly into the lower end of the tube to create a vacuum or suction within the lower end of the hollow tube to remove muddy water from the hole being dug. A two-way valve is connected to the upper ends of the first and second water supply lines for alternately delivering water to the water supply conduits. The intake side of the two-way valve is in fluid communication with a source of high pressure water. The upper end of the hollow tube has a mud take-off hose connected thereto which may be utilized to convey the muddy water to a location remote from the hole being dug or to a container.

Abstract: A hand-held tool for a diver has a hollow tube to vent pressurized gas from an interconnected source through an opening in the tube. The vented pressurized gas aerates material of a seabed, and an anchoring system disposed adjacent to the tube is effortlessly inserted in the aerated material by a single diver. The hand-held tool permits an improved method of inserting the anchoring system as compared to the time consuming, strenuous, and noisy hammering procedure that usually requires more than one diver to successfully embed an anchor in the seabed. Different sources of pressurized gas for aerating the material may include a portable gas cylinder, diver's air tank, or hose from a remote source, such as a compressor. Quick-change connectors can be used to quickly and easily connect and disconnect components to supply more gas or add different components that will help insert different anchoring systems.

Abstract: A soil excavating apparatus for use in combination with a cleaning/vacuuming machine having at least one high pressure fluid supply in the vacuum line. A soil excavating apparatus is disclosed for use in combination with a cleaning/vacuuming machine having at least one high pressure fluid supply in the vacuum line. The apparatus includes a spray head secured to the vacuum line first end, and disposed substantially thereabout. The spray head is in fluid communication with the pressurized fluid supply. A plurality of inboard spray nozzles are disposed substantially thereabout. The spray head is in fluid communication with the pressurized fluid supply. A plurality of inboard spray nozzles are removably secured to the spray head and extend therefrom. The spray nozzles are angularly oriented to direct the pressurized fluid towards a center line of the vacuum line.

Abstract: A reduction system using water pressure and vacuum excavation and including a water supply tank, water pump, vacuum pump, slurry collection tank, a system for tilting the collection tank, handheld reduction tool, and a drive system. The reduction tool, or wand, is used to deliver high pressure fluid, such as water, to the ground in order to loosen soil directly in front of the tool. The tool includes diametrically opposed nozzles which are angled with respect to one another such that pressurized water delivered from the nozzles is directed in a fashion to slice the ground in a generally spiral or helical fashion as the tool is pressed downward into the ground. As the soil is loosened by the pressurized water delivered from the nozzles, the loosened soil is sucked away to form a hole in the ground, and such loosened soil (a slurry when mixed with the water) passes upwardly through the tool in a vacuum air-flow created by the vacuum pump and is deposited in the slurry collection tank.

Abstract: A vacuum boring and mud recovery system comprising a vacuum container, a vacuum producing device to create a vacuum within said container, a conduit to vacuum solid particles and liquids into the vacuum container and a dispensing device to dispense the liquid or solid particles from the vacuum container without eliminating the vacuum environment within the vacuum container. Vacuum container contents are stored within the container while simultaneously dispensing the solid particles and or liquids. The vacuum container system may also have a separating device disposed within it to separate solids and liquids by category. The vacuum container system is a continuous operation vacuum container which can simultaneously fill, store and dispense solid particles and liquids with the added ability to simultaneously separate the solids and liquids before they are dispensed from the vacuum container. This is accomplished without eliminating the vacuum environment within the vacuum container.

Abstract: An apparatus and method for dredging under water ground layers includes the steps of providing a dredging device composed of a mechanical dredging component having a part operative to contact the under water ground layers and exert a dredging action; and at least one water jet effective to inject water under pressure in an area where the mechanical dredging component is operative; mechanically impacting the underwater ground layers with the part to fracture the underwater ground layers and form fractured material; and injecting water under pressure from the at least one water jet simultaneously with the mechanical impacting to remove the fractured material so that an improved break-away pattern of material is obtained and reduced wearing of said part.

Abstract: An improved underwater excavation apparatus achieves efficiency and control of movement through provision of a hollow body having at least one inlet and at least one outlet, at least one pair of impellers coaxially displaced one from the other and rotatably mounted in the hollow body, and a mechanism for driving the impellers in contrary rotating directions. The underwater excavation apparatus comprises a pair of horizontally opposed inlets communicating with a single outlet, the outlet being disposed vertically downwards substantially midway between the two inlets, in use. The excavation apparatus may, therefore, be substantially “T” or “Y” shaped. The mechanism for driving the impellers may include at least one drilling motor.

Abstract: A hydrovac wand is provided with a crossfire nozzle arrangement that reduces thrust to the wand operator, and that has a spray pattern that eliminates spray back. A pair of jets erode a hole while two other jets push the debris back to a suction hose. Two high pressure swivels are provided at the end of the wand to allow the wand to rotate in all directions without binding. Boom controls are placed on the wand to maximize digging rates.

Abstract: A placer gold separating method includes subjecting placer gold-and gold ore-containing sand and gravel layers accumulated on the bottom of the water of a river and placer gold- and gold ore-containing sand and gravel layers formed deep in the ground to excavation or suction excavation by utilizing a water pressure difference. This causes a mixture of the excavated or suction excavation placer gold- and gold ore-containing sand, gravel and water to flow horizontally by the action of a pressure fluid. The placer gold and gold ores are separated by utilizing a specific gravity difference while the mixture is flowing. A placer gold mining boat used to practice this method is provided thereon with a combination of a suction excavation component, a mixture transfer component, a component for separating placer gold by utilizing a specific gravity difference, and a component for discarding the remaining mixture from which the placer gold has been separated.

Abstract: An ocean plow device and accompanying method which incorporate a passive plow blade and a jetter tool working in conjunction with one another to lower drawbar and increase cable deployment speeds. In order to avoid cavitation due to sand dilation, in one embodiment of the plow device, the jetter tool includes nozzles oriented in a downward and backward direction relative to the plow device which creates a flow pattern to turbulently remove surface soil in front of the jetter tool in a rapid manner. The jetter tool is pivotally suspended from a point in front of the passive plow blade, such that the jetter will be free to find its own equilibrium position. That is, the pivotal mounting enables the jetter tool to rotate upward in harder soils and become fully extended in softer soils in order to reach the equilibrium position. The passive plow blade behind the jetter tool provides a constant burial depth for the cable and also provides protection from side loads encountered during deployment.

Abstract: A vacuum excavation system which incorporates a low consumption air lance, a highly efficient multi-stage vacuum generation system effectively isolated from the waste stream and the air source, and a highly portable material collection system. The air lance includes a cylindrical main body which narrows to a flat taper nozzle at the digging end, and a tee-shaped handle with a swivel type air fitting at one end, while the vacuum generation system is a multi-stage ejector fitted onto a collection drum and consisting of successive venturi tubes with pressure equalizing check valves on the second and higher stages, the material collection system consisting of the drum and hoses or pipes connected to the drum through a separate opening.