Abstract: A signalling device for scuba divers uses their compressed air supply to drive a piston (42, 51, 72) against a diaphragm (22, 48, 49, 57, 63, 90) to generate sound in water against the diaphragm. A bistable valve 34, 52) switches pressurised air alternately to opposite ends of the piston (42, 51, 72) to cause it to reciprocate and repeatedly impact against the diaphragm (22, 48, 49, 57, 63, 90). Air is exhausted from the cylinder (11, 54, 70) through ports (27, 28, 29, 30, 110, 111, 73, 74), the ports being valved by movement of the piston.

Abstract: A pair of truss brackets are secured to the roof of an underground passage adjacent to opposing ribs of the passage. The truss brackets each include a roof engaging surface and a truss supporting arm member extending from the roof engaging surface. A pair of U-bolts are supported by the arm members of the truss brackets. Each arm member extends horizontally from the truss bracket to an enlarged end portion of the arm member. The U-bolt is horizontally movable in a vertically hanging position on the arm member and is restrained by the enlarged end portion from disengagement from the arm member. The U-bolts are pivoted on the truss brackets to a horizontal position for connection to truss members which are connected to each other and tensioned to apply an uplifting force to the roof. As the truss members are connected and tensioned, the U-bolts are retained for a range of horizontal movement on the arm members to facilitate adjustments in the position of the U-bolts on the truss brackets.

Abstract: Porous pipe formed of particles of vulcanized rubber dispersed in a binder resin such as polyethylene are stabilized to reduce degradation by ultraviolet light by dispersing in the binder resin an effective amount of an ultraviolet stabilizer such as 0.1 to 10% by weight of carbon black.

Abstract: A deployable spill containment boom which, when not in use, is stored along a shoreline. Attached to one end of the deployable boom is a floatation device. The boom is deployed into a moving waterway by means of a cable to which the boom is attached. The deployment cable runs through a pulley attached to an anchor permanently located on the bottom of the river. The other end of the deployment cable is attached to a winch system located on shore on a "take-up" reel. During an oil spill, the system is actuated by a radio signal. The take up reel reels in one end of the deployment cable and a "supply reel" pays out the cable through the anchored pully cable. The deployable boom is then pulled away from the shoreline. Since the boom floats it remains on the surface of the water while the cable is deployed The deployment cable winding operation causes the boom to be extended out into the river. The end of the boom with the floatation device extends into the river to the location above the anchor.

Abstract: A method for the remediation of soils contaminated with hydrocarbons utilizing a selective liquid additive. The method includes the steps of collecting the contaminated soil; reducing the collected soil to finely-divided particles: applying a controlled amount of the selective liquid additive as a spray onto the contaminated soil particles; and aerating the soil particles as the additive is being applied. After treatment, the decontaminated soil is rendered environmentally safe.

Abstract: A method of operation of marine locks includes the steps of supporting a first column of water within a lock chamber upon a vertically movable first floor, supporting a second column of water within a balance chamber upon a vertically movable second floor, supporting the first and second floors upon a confined volume of compressed air communicated between the lock chamber and the balance chamber and causing the first floor to rise or fall by application of upward or downward hydraulic pressure on the first floor while causing the second floor to move in the opposite direction by application of contrary hydraulic pressure on the second floor. Lock systems to perform the new methods are disclosed.

Abstract: A collar for a friction rock stabilizer and a friction rock stabilizer incorporating such collar. The collar is shaped having a domed outer surface to allow improved alignment between the collar and a mine bearing plate used between the collar and the mine surface when the stabilizer tube is inserted in a bore in a mine roof or wall.

Abstract: The present invention includes landscaping structures such as a retaining wall comprising a plurality of composite masonry blocks, the composite masonry block comprising a block body having an irregular trapezoidal shape and comprising a front surface and a back surface, an upper surface and a lower surface, and first and second sidewalls. Both the first and second sidewalls have a first and second part, the sidewall first part extends from the block front surface towards the block back surface at an angle of no greater than ninety degrees in relationship to the block front surface, the sidewall second part surfaces adjoins and lies between the sidewall first parts and the block back surface. The block also has a flange extending from the block back surface past the height of the block.

Abstract: A submersible mobile caisson having ice crush resistance for adapting semi-submersible mobile offshore drilling units and mobile offshore oil well production rigs, which are ice crush sensitive for use in ice bearing offshore ocean waters, is provided. The caisson comprises a floatable generally four sided structure composed of front and rear outer walls, and opposing side outer walls, with the rear outer wall having a removable entrance door. Inner walls are positioned in a spaced apart, opposing relationship with each of the outer walls, and so that the inner and outer walls define a perimeter structure and the inner walls define a cavity which is located within the perimeter structure. The perimeter structure has a plurality of ballast compartments which permit the caisson to float or be sunk so as to rest on the ocean floor. A drilling/production moon pool system is also provided in the perimeter structure.

Abstract: A trench shield assembly (12) having first and second shield walls (14, 16) maintained spaced apart by a plurality of spacer struts (30) at the front end of the shield walls and an archway (32) secured at the rear end of the shield walls. Each shield wall is constructed from a plurality of beams (18) that are stacked on top of each other and secured together. Each beam includes a central web (20) and first and second face flanges (22, 24). When stacked and secured, the first face flanges define a first exterior skin (26) of the shield wall and the second face flanges define a second exterior skin (28) of the shield wall. The ends of the spacer struts project through transverse passages (44) defined in the shield walls. Stops (46) formed on the spacer struts, at a location spaced from the ends of the struts, limit the degree of insertion of the struts into the transverse passages. A locking plate (50) is secured to each projecting end of the struts to prevent withdrawal of the struts from the passages.

Abstract: A pile cutter for breaking up reinforced concrete piles. The pile cutter includes a pair of hydraulic cylinders which operate cutting teeth when the hydraulic rams are retracted. The use of only two cylinders, and the cutting of the pile when the rams are retracted minimize the weight of the pile cutter and the space occupied by such.

Abstract: A water jet system for trenching of a cable or a pipe below the floor of a river, lake, gulf or ocean bottom. Two opposed water jet legs are carried on a carriage forward of venturi tubes for disposing of the trenched bottom. The carriage includes a hydraulically powered track system for advancing along the length of the cable or pipeline. The water jets are a plurality of nozzles mounted in a rotating tube at different angular directions. When the nozzle tube rotates within the housing and the nozzles pass by different openings at different heights, the jets' high pressure water shoot forth. The high pressure action of the streams of water loosen the sediment below the floor of the body of water, which is subsequently carried away by air or water action through venturi tubes which are positioned behind the jet legs. The jet legs and carriage are positioned, controlled and powered from a work vessel on the surface of the water.

Abstract: The invention concerns a prop headboard (10) which is used in conjunction with an elongate mine prop. The headboard supports a preload bag (50) inflatable with a settable grout. The headboard is composed of a headboard member (12) and a pot (34). The headboard member includes a pressed steel sheet (14) having relatively higher end regions (16) and a relatively lower central region (22). The central region is formed with an opening (24). The headboard member also has bag retaining formations (30) which receive opposite ends of a preload bag located on the headboard member. The pot is engaged in the opening in the central region and receives the upper end of an elongate prop, thus supporting the headboard member on the prop with the headboard member extending transversely to the prop.

Abstract: A yieldable grout compactor for a cable roof support fixture adapted to be insertable in a uniform diameter borehole or in a stepped borehole in which the grout cartridge and compactor are insertable so as to have the cable perform the piercing and mixing function with respect to the grout material while the compactor is slidable on the cable caused by a sufficient degree of force to permit the grout to surround and anchor the cable. Compactor sleeves are sized with respect to the axial cable length and the internal and external diameters are sized to yieldably permit fixture installation and grout securement of the cable in a manner to obtain a secure anchor for the cable in the back of the borehole.

Abstract: Bioremediation systems and methods are disclosed in which petroleum contaminated soil (PCS) are treated and recycled to below acceptable contaminant levels. The system comprises a treatment cell at a location removed from the original site of the contaminated soil and having a capacity to receive and treat PCS from numerous sources concurrently. The system includes a treatment water infiltration system and an air circulation system which, in combination, supply the required oxygen and nutrients to enhance the growth of naturally occurring, hydrocarbon-consuming microbial organisms as well as optimizing the hydrocarbon consuming activity of those organisms. The pH, system temperature, and growth inhibiting toxin concentration are all controlled in the systems and methods of the present invention to thereby further enhance microbial growth and hydrocarbon consumption.

Abstract: A method for remediating a hydrocarbon-contaminated region of a subterranean body of groundwater to destroy or reduce the initial concentration levels of hydrocarbon contaminants. A plurality of mutually spaced wells are provided intersecting the groundwater region, and the existence of acceptable continuity and well interflow paths for the said region is determined by generating a test flow of a solution of hydrogen peroxide from one of the wells and monitoring pH changes at each other of the wells as a function of time to detect a pH drop of at least 0.2. Subsequent to detecting the pH drop, a treating flow of the hydrogen peroxide solution is provided from one or more of the wells. A system to enable the foregoing is also disclosed.

Abstract: A method and compositions using a first ferrous iron containing solution with the iron concentration in excess of theoretical requirements to treat a contaminated site to reduce hexavalent chromium to trivalent chromium and coprecipitate trivalent chromium with other heavy metals and using a second solution of silicate containing a destabilizing salt to form a relatively impermeable gel in the contaminated site thereby fixing metals and organics to the extent that there should be no detectable ground water contamination.

Abstract: Saturated sand or silt is densified at depth by applying a radially propagated lateral translation force within a region of the soil, while water is actively withdrawn from such region toward the point of application of such force. A densification device incorporating the foregoing principle has a mechanism which imparts to the region surrounding the device cyclic lateral displacements which act axi-symmetrically to the longitudinal axis of the device; and, a filtered cavity and pumping mechanism for withdrawing water from the region surrounding the device.

Abstract: The present invention relates to a block interlock offsetting key for use in the construction of a mortarless retaining wall wherein a plurality of blocks are stacked in offset rows or courses, the blocks of the wall being provided with top and bottom grooves. The block interlock offsetting key is able to interlockingly engage the bottom groove of a block and the top groove of an underlying block so as to offset the blocks a predetermined distance with respect to each other.

Abstract: A grid composite for protecting men and longwall mining equipment during longwall shield recovery includes a regular polymer geogrid structure formed by biaxially drawing a continuous sheet of select polypropylene material which is heat bonded to a polyester fabric. The grid composite is secured over caving shields of longwall mining equipment during a longwall mining operation. The polymer grid composite is ideal for waste containment structures, backfill barriers, and silt barriers in construction and mining applications. In waste containment and backfill barriers, the grid composite is used to form a containment structure. It principle function is to contain waste material usually consisting of a liquid with some percentage of solids.