A ditch forming apparatus having: a frame; a primary ditch forming assembly having: a) a first subassembly for penetrating and separating subjacent ground material; and b) a second subassembly for directing separated ground material away from a ditch being formed; and a ground treatment assembly to facilitate delivery of ground material to the second subassembly and having a ground engaging component that is turned around a first axis. At least one of: a) a vertical height of the first axis relative to the frame; b) a variable vertical force generated between the at least one ground engaging component and frame; c) a fore and aft position of the first axis relative to the frame; d) a speed of turning of the at least one ground engaging component around the first axis; and e) a direction of turning of the at least one ground engaging component around the first axis, can be changed.

A vibratory plow has a lift bracket. The lift bracket couples to an upper link by an upper spring having an upper energy absorptive member. The upper spring and upper energy absorptive member are configured to limit upper link movement relative to the lift bracket in a first direction. The lift bracket is coupled to the upper link by a lower spring having a lower energy absorptive member; the lower spring and lower energy absorptive member are configured to limit upper link movement relative to the lift bracket in a direction opposite the first direction. The upper link is coupled to a shaker box which is attached to a plow blade. The shaker box is configured to travel from a baseline position a first distance greater than two inches in the first direction before the upper spring compresses enough that the upper energy absorptive member dampens shaker box movement.

A bit assembly includes a base block and a bit holder having a forward body portion and a shank. The bit holder includes a diametrically expanding retainer circumferentially disposed around a shank of the bit holder adapted to maintain the interference contact between the bit holder and the base block as the diameter of a bore of the base block increases from use. The bit assembly also includes a sealing gasket that forms a force fit between a washer disposed about the shank of the bit holder and the base block.

Disclosed herein are walk behind grinding tools with horizontally aligned guides and grinding drum. One embodiment relates to a grinding tool with a pair of guides on opposing sides of a blade set of a grinding drum, where the pair of guides is configured to limit a grinding depth of the grinding drum. At least a portion of a guide curvature is generally concentric with a mill curvature, and a guide radius is less than a mill radius. Another embodiment relates to a grinding system including a grinding tool with a vacuum shroud hingedly attached to a front of a main body of a grinding housing, and a vacuum including a vacuum tube in fluid communication with the vacuum shroud. Another embodiment relates to a method of forming a grinding tool.

A subsea plough includes a plough share coupled to a chassis, boulder clearance and spoil clearance members, and front and rear support surfaces. In a first configuration, a maximum span of the boulder clearance member in an extended position is greater than a span of the spoil clearance member. The plough may be reconfigurable to include a backfill member. A method of use of the plough is provided in a boulder clearing only mode, and optional modes of simultaneous boulder clearing and trenching, second pass trenching, and backfilling a trench to bury a flexible elongate member in a seabed.

An earth working implement has a main frame, a main blade supported on the main frame transversely to the forward direction, and two wing blades pivotally supported at opposing ends of the main blade for movement between forward and rearward projecting orientations. A tilt actuator controls angular orientation of the main blade relative to the main frame about a lateral axis. Two rear wheels support the rear end of the frame for rolling along the ground. A hitch arm extends forwardly from a pivotal connection of the main frame for connection to a towing vehicle so as to vary in angular orientation relative to the main frame independently of the main blade. Furrow openers in a laterally spaced apart row are movable relative to the main frame between a working position protruding below the cutting edge of the main blade and a raised storage position.

An earth moving implement for forming a ditch when towed across ground includes a frame, a tow arm connecting the frame to a towing vehicle, wheels supporting the frame for rolling movement along the ground, and a blade assembly comprising a plurality of earth moving blades. The blades include two main blades arranged to be configured to extend rearwardly in opposing lateral directions from a blade apex of the blade assembly such that the earth moving blades diverge rearwardly from the blade apex, and two outer blades supported on the main blades respectively. The orientation of the outer blades relative to the main blades and of the main blades relative to the frame can all be adjusted while the bottom cutting edges remain level with one another to readily vary cutting width and the lateral direction of earth movement by the blade assembly as desired.

A ditch cutting and excavation spoil removal apparatus creates ditches and land contours while simultaneously removing excavation spoil from the banks of newly created ditches. The apparatus includes an excavation spoil collection box and an adjustable plow saddle that supports a plowshare. The spoil collection box has a vertically adjustable rectangular frame with an open front and bottom. The pivotally mounted plow saddle may be tilted upward and downward through the bottom of the excavation box frame for adjustment of the plowshare and, correspondingly, the depth of the ditch being cut. Excavation spoil is collected in the spoil collection box as the apparatus is moved along the ground surface and is removed by raising the spoil collection box.

A method and apparatus for installing a monitoring cable or other utility near an existing pipeline. An electromagnetic signal may be induced on the pipeline, either directly, or by transmitting a signal from a vehicle carrying a sensor array. The sensors disposed on the vehicle communicate with a processor to determine a distance and orientation of the vehicle relative to the pipeline. The signal may be electromagnetic, acoustic, capacitive, or the like. A plow or other digging tool may be on the vehicle or a secondary vehicle. Such a digging tool opens a trench and installs the cable along a path disposed next to the pipeline within an acceptable distance range from the pipeline. The vehicle may be remotely or automatically operated.

An apparatus for forming a trench in a sea floor and/or displacing material on the sea floor is disclosed. The apparatus comprises a body and front skids mounted to the body for engaging the sea floor and supporting the body. The front skids are adjustable between a first mode, in which the front skids engage the sea floor, and a second mode, in which the front skids engage the sea floor adjacent the trench and at the trench walls.