Abstract: In an excavator equipped with an offset boom, an offset command value generating device of a rotation control device offsets a second boom arranged on a distal end side in a rotation direction relative to a first boom arranged on a proximal end side when an acceleration start judging device judges that a rotation operation is started, and offsets the second boom in a reverse rotation direction when a deceleration start judging device judges that a rotation deceleration operation is started. Accordingly, when a rotation acceleration is performed using a reaction force generated in the offset, clearances between members of a work machine can be contracted in advance in the rotation direction, while when the rotation deceleration operation is performed, these clearances can be contracted in advance in the rotation reverse direction, thereby reducing an impact in the acceleration and deceleration.

Abstract: A dewatering apparatus for removing water from the interior volume of a closed, loaded clamshell dredging bucket. The dewatering system comprises at least one conduit adapted for support from a clamshell type dredging bucket. The conduit has a first end adapted for placement within the interior volume defined by a closed dredging bucket, and a lower second end disposed to allow communication between the space surrounding the exterior of the dredging bucket and the interior volume thereof. The conduit is positioned so that the first end thereof is disposed within an upper layer of retained water contained in the interior volume of a loaded clamshell dredging bucket when the same is moved to the closed position and lifted above the dredging area with a load of sediment and water therein. The upper layer of water is drained by gravity through the conduit and the lower end thereof for removal from the interior volume of the clamshell dredging bucket.

Abstract: A grab bucket, in particular motor-driven underwater grab bucket, has first and second half-scoops. The scoops can be moved relative to on another from an open position into a closed position by a hydraulic cylinder. The opening angle of the half-scoops is monitored by a sensor which is connected to a control and monitoring device. The sensor is integrated in the hydraulic cylinder and generates an actuating-travel signal which corresponds to the actuating travel of the hydraulic cylinder.

Abstract: The planting of individual sea grass plants or small bunches of sea grass plants is known in the prior art. In the prior art these plantings are made either manually or with appropriate machinery. This invention deals with the digging, transporting and planting of large slabs of sea grass. The process comprises the steps of digging a slab of sea grass, transporting the slab of sea grass to a new location, digging a furrow with the same apparatus that is used to dig the slab of sea grass and depositing the slab of sea grass in the furrow.

Abstract: A hydraulic circuit for a working machine is provided which prevents a decrease in the working speed of a clamshell bucket upon expansion of an expansion arm, so that improvement of the operability can be achieved. A hydraulic circuit for a working machine is configured such that a clamshell bucket is attached to a tip end of an expansion arm and the expansion arm and the clamshell bucket are operated by pressure oil supplied from a common pressure source. The operating pressure is reduced for driving the expansion arm to the expansion side based on the operating pressure for opening the clamshell bucket. By the configuration, the clamshell bucket can be opened rapidly, and improvement of the operability is achieved.

Abstract: An apparatus for recovering oil has a bucket for skimming and collecting water and oil floating on the surface of the water. The bucket has a base plate having apertures for draining water collected by the bucket. The apertures have a preselected diameter and length to allow separation of the oil and water utilizing differences in specific gravities and viscosities of the oil and water so that the oil can be discharged from the bucket into an oil recovery tank after the water drains out of the bucket through the apertures but before the oil begins to drain out of the apertures.

Abstract: The method relates to the recovery of fine sand on floating production equipment in the form of a floating grab-bucket type excavator or floating bucket chain dredger. In this case, the dredged material is dewatered and transported to shore via floating conveyor belts. The dredged material is transferred to dewatering screening machine having a dewatering deck with a dewatering coating. Below the dewatering deck the screening machine has a blind bottom covering the entire surface area, whereby in the direction of conveyance the end zone is provided with a discharge. The discharge is directed at a hydro belt separator, which has a revolving endless conveyor belt with a washing trough as the separation bed, and an ascending part leading away from the washing trough. The running direction of the conveyor belt is in the direction of the ascent, whereby the dredged material is transferred at the discharge of the screening machine to the washing trough of the hydro belt separator.

Abstract: A monitoring device for motor-driven underwater grab bucket dredges contains a bucket gear suspended on a cable. The device ensures reliable monitoring and controlling of the operating condition of the bucket gear 4. There is at least one sensor connected to the grab bucket gear for sensing a measured value. There is a computer connected to the sensor for representing the measured value detected by the sensor.

Abstract: A slope excavation control system for a hydraulic excavator and a slope excavation method using a hydraulic excavator include an external reference 80 which extends horizontally in the direction of advance of a target slope face. A vertical distance hry and a horizontal distance hrx from the external reference to a reference point on a target slope face, and an angle of the target slope face are set by using a setting device. When a front reference provided at a bucket end is aligned with the external reference and an external reference setting switch is depressed, a control unit calculates a vertical distance hfy and a horizontal distance hfx from a body center of the excavator to the external reference, then calculates a vertical distance hsy and a horizontal distance hsx from the body center to the reference point of the target slope face by using the distances hsy and hsx as modification values.

Abstract: A semi-submersible machine moves on rotatable endless belt tracks over diverse surfaces and has two tools on articulated booms for remediation of roadside drainage ditches, retention ponds and other shallow water bodies. One tool is a cutter bar for cutting vegetation at a plurality of angles and positions above or under water, and the other tool is a rotatable pair of opposing clawlike jaws for raking or scouring soil above or under water to restore percolation performance, and to remove loosened vegetative matter without removing soil and water. The vehicle is submersible to a depth of forty inches, and can traverse a slope of thirty degrees while its tilting control platform remains above water and level, thereby maintaining stability of the vehicle.

Abstract: A water based dredge includes a grizzly with a sieve and a pair of bi-directional rakes. The rakes translate relative to the stationary sieve to slide waste or recoverable material off of the grid and onto a refuse barge or material processing apparatus, respectively. A grab deposits dredge material onto the sieve and an operator determines whether the material includes waste such as clay or the like or recoverable material such as rocks, dirt, or sand. If the operator determines that the dredge material is waste, the rakes will be actuated for movement from a first direction to thereby push the waste off of the grizzly and onto a refuse barge. If the operator determines that the dredge material includes recoverable material, the rakes will be operated in a second direction so the recoverable material is slid from the grizzly and into a crusher or other appropriate processing apparatus.

Abstract: A bucket for power shovels is disclosed having a first bucket half and a second bucket half. Each bucket half includes a pair of spaced side walls and an end wall extending between the side walls which together forms a scoop for each bucket half. The bucket halves are pivotally secured together so that the scoops face each other and are movable between an open position in which the scoops are spaced apart from each other and a closed position in which the scoops space each other and form a load carrying chamber. The side walls of the bucket half overlap each other upon closure to minimize the spillage of the load out through the sides of the bucket during a scooping operation. Furthermore, a flap valve is mounted to an upper side of at least one of the bucket halves to allow water and air to freely escape from the interior chamber of the bucket as the bucket is lowered. This valve, however, prevents spillage of the load from the interior of the bucket.

Abstract: A marine dredging device comprised of scoop buckets hinge-connected to a soil receiver chamber with deployable silt curtains. The silt curtains are deployed to close off the aperture between the scoop buckets and prevent the extrusion of soil. Introduction of pressurized air lowers the water level in the soil receiver chamber to provide a void for dredged soil.

Abstract: A lake rake (1) or other aquatic tool that is drag-line operated in a body of water (4) between a first earth-anchored vehicle (9) with a motorized winch (8) at a distal position (15) and a second earth-anchored vehicle (11) with a motorized winch (10) and a loading means (12, 13) at a proximal shore (16) of the body of water. The lake rake or other aquatic tool is pulled with a positioning line (5) by the winch on the first earth-anchored vehicle against selective braking resistance of a drag line (6) operated by the winch on the second earth-anchored vehicle to position the lake rake or other aquatic tool in a raised position relative to the body of water at a desired position proximate the first earth-anchored vehicle. There the lake rake or other aquatic tool is dropped to a bottom (17) of the body of water by release of tension between the two winches.

Abstract: The invention relates to an apparatus, suitable for deployment from small vessels, for obtaining samples of materials from the sea bottom and, more specifically, to a multi-bucket sampler particularly suited for, but not restricted to, gathering samples from bottoms comprising hard or compacted materials and/or having coarse matter, such as gravel, distributed therein. In one embodiment the sampler comprises, in general, a dual bucket assembly pivotally attached to a frame, cover means for the buckets, and an actuator for pivoting the buckets from an open position wherein the buckets can penetrate the bottom to a closed position wherein the buckets are urged against the cover. The apparatus is designed to achieve maximum penetration of the seabed and to prevent washout of the materials collected upon recovery. The dual buckets provide sample duplication which may be used to assess local variability of bottom conditions.