Abstract: An event construction comprises a public area, such as a grandstand, and a pitch for performing activities, for example sporting activities like football or baseball. The pitch is accommodated on a floor which by sliding elements is set up in such a way that it can be moved in relation to the public area. The sliding elements comprise at least one elongated track which is set up underneath the floor and is connected to the base or to the floor, and also supporting elements which are connected to the floor and can be slid in relation to the track, or supporting elements connected to the base, over which supporting elements the elongated track can be slid. Each track consists of mortar material.

Abstract: A settling unit for separating a liquid and the particles. Such as sand, suspended therein, comprises a basin with an inlet for the liquid mixture containing the particles, and an overflow for discharging the liquid after at least some of the particles have been removed therefrom through settling. With a view to increasing the efficiency, a plate separator is provided at the position of the overflow, which plate separator has a liquid outlet which is connected to the overflow and an outlet for settled particles which is connected to the basin. The gaps defined between the plates can be shut off at their underside by a non-return valve which can be moved into an open position under the influence of the weight of the separated particles.

Abstract: System for positioning a vehicle within a predetermined area, which system is provided with a laser transmitter/receiver and three or more laser reflectors which are located outside and/or inside the predetermined area, the position of the laser transmitter/receiver with respect to the laser reflectors being determined continuously with the aid of a method known per se. The position of a reference point on the vehicle with respect to the laser reflectors is determined continuously with the aid of the laser transmitter/receiver . The vehicle is provided with movable parts with which predetermined work can be carried out and is provided with sensors with which the position of a number of movable parts of the vehicle is measured continuously, which parts are determining for the relative position, with respect to the reference point, of the location where the said work is carried out.

Abstract: Methods of forming cast prestressed concrete elements and structures include a non-corrosive reinforcing element being formed of a plurality of substantially parallel continuous filaments embedded in a matrix of thermosetting resin. These reinforcing elements are tensioned, then concrete cast about the elements is permitted to harden and the tension transferred to the now-hardened concrete in order to prestress the same. The resulting concrete elements and structures have high resistance to alkali induced corrosion of the prestressing elements.

Abstract: A method and apparatus for laying a web in a submerged condition on an entrenchment floor includes wrapping a web onto a drum as said drum is floating on a water surface of the entrenchment, navigating the wrapped drum to a beginning section of the entrenchment, and unwinding the drum as it is floating on the entrenchment while further navigating the drum. Water is pumped from a section of the entrenchment already layed with the web, thus imparting an unwinding force to the drum and giving the web a convex shape along the portion of the web which extends from the drum to the entrenchment floor.

Abstract: A system for generating energy by converting thermal energy into another form of energy by the exchange of water from great depth with surface water, said system comprising a floating installation having a downwardly directed cold water pipe as well as a number of thermal energy converting aggregates, said installation having the form of a pontoon, carrying a platform by means of columns, a number of box-shaped units containing the thermal energy converting aggregates being placed on top of the said pontoon, each unit having a channel with pump and heat exchanger, said channels having their inlets either in connection with the cold water supply or with the environmental water, the connection with the cold water being at the underside of the units and the connection with the environmental water at the upper side of the units, each channel having its outlet at the side of the pontoon.

Abstract: The hammer of an underwater pile driving apparatus is movable upwards and downwards in a housing which, in operation, is filled with a liquid which is present both above and below the hammer, the hammer being driven at least on the upwards direction by a driving liquid which is pressurized by a motor driven pump located on or adjacent the housing and which is the same as the liquid in which the hammer moves.

Abstract: A flexible and pivotable connection for the top of a cold water conduit 8 to a floating device 1-3 provided with means for the conversion of energy based on the temperature difference between surface water and deep sea water supplied by the conduit. The connection supports the top of the conduit by means of flexible cables to a central core 7 guided and fixed in a sleeve 5, 6 of the floating device. The flexible cables 10, 11 partly extend horizontally from the lower end of the core to a top ring 9 of the conduit, and partly from the lower end of the core downwardly towards a lower annular portion 12 of the conduit.

Abstract: A method of and apparatus for driving piles by the impact force delivered by a hammer disposed in a housing from the bottom end of which there extends downwardly a pile sleeve in which a pile anvil is held captive, in which shock absorbing means separate from the hammer are interposed between the bottom end of the housing and the pile anvil for absorbing rebounce forces reaching the top of the pile of lower magnitude to that of the impact force.A pile driving apparatus constructed according to another aspect of the invention comprises a hammer and resilient means in the path of travel of the hammer for transmitting the impact force of the hammer to a pile, and stop means for cutting out the resilient effect of the resilient means on the impact force by delivering a non-resilient blow to the pile.

Abstract: A flexible conduit for carrying cold ocean water at great depths to the surface comprises a plurality of spaced, heavy annular rings 1 of concrete or the like between which are mounted tubes 2 of flexible material which form the walls of the conduit. The tubes may bear the tension load of the rings directly, or they may be suspended from loosely mounted rods 6 or cables 11.

Abstract: A method and apparatus for generating a retropulsive force on a body upon which forces act which try to displace said body. More in particular the invention deals with holding upright an enlongated body such as a pile when in unstable equilibrium or by returning a floating body to its position of origin. The unstable pile is held upright by a weight guided in the pile and supported from a cable guided on the pile at a distance above the weight. The floating body is held in position by a weight guided on a stable pile and supported by cables which are connected with the body and run through guides at the upper end of the pile.

Abstract: The invention relates to a device for accurate subaqueous measurements of the vertical displacements of a reference point e.g. the head of a pile by using a pressure difference recorder at the reference point which measures the difference between an air filled chamber and the water pressure outside said chamber, said recorder being bridged by a tube interconnecting the two pressure regions and having a valve which in the open position interconnects the two regions said air chamber being located above the recorder while the valve has an electromagnetic operating member placed in a circuit with the recorder and a measuring device, the initial pressure in the air chamber being the atmospheric pressure at the water surface.There may be two identical devices each having a switch in the circuit of the recorder which brakes the circuit at the end of the measuring range, the switches of the two devices operating such that when one interrupts the other makes its circuit.

Abstract: Apparatus for under water pile driving comprises a pile hammer and a drive unit connected by high pressure hoses to the hammer. The hammer is guided for relative vertical movement within an auxiliary guide frame on top of which the drive unit is permanently attached, said frame being suspended from a hoisting device.

Abstract: In an apparatus for driving a pile or similar object by the stroke of a hammer, the impact of a hammer stroke is transmitted to the pile or similar object through resilient means comprising a precompressed gas in at least two closed chambers, which may intercommunicate, arranged in series.

Abstract: An elongated hollow tube 2 is secured to the top of a pile driver 1, and the assembled unit is lowered to the head of an anchoring pile 12on the sea bottom via spaced guide rings 13 on a submerged tower 10. The flexible hose string 5 for conveying hydraulic, electric, pneumatic, etc. power and control to the pile driver is accommodated in a loop fashion within the tube 2 via a weighted and floating pulley(s) 7, and feeds out during the lowering of the unit through guide rings 13 spaced on the tower over a pulley 4 mounted on a detachable surface ring 3. The various hoses and cables in the string 5 are maintained in a parallel relation by periodic clamping means 14, and smooth surface reel winding is implemented by periodic spacers 26 secured to the outboard tension cables 15, 16 in the string.

Abstract: An anchoring arrangement including a concrete block 3 provided with countersunk end openings 4, 5 through which piles 6, 7 having limiting abutments 8, 9 are driven into the sea bottom. The block(s) may be supported on a base frame 1. If a floating load tethered by cables 10 raises the block it will successively engage each abutment to thereby evenly distribute the lifting forces.

Abstract: One or more guide elements support a pile at the region where the chance of bending or collapse of the pile is most likely and during the process of pile driving, the guide element is moved along with the pile to eliminate the need for puncheons or the like.

Abstract: A submersible pile driving apparatus includes a drop hammer 7 reciprocably mounted in a guideframe on vertical posts 8. Either the drop hammer or the guideframe is guided on cables 4 secured to a crossbar 5 attached to the pile 6, and the guideframe is suspended from the surface ship by a rigid column of tube sections 10 or the like to which the guideframe has been rigidly connected. The apparatus is provided with a guide sleeve 12 or 13 having a funnel-shaped mouth to center the pile during descent. The overall arrangement maintains even very long piles in a vertical position during driving, and prevents tilting or tipping at the pile head - drop hammer interface.

Abstract: Underwater pile driving is implemented by a pile-driving apparatus 14 releasably coupled to a guide sleeve 5 secured to the top of a pile 10. The assembly may be performed on the surface vessel 1 through an opening 4 in a laterally extending platform 2 with the aid of a crane 13, or underwater. The components are lowered on guide cables 8, 9, and after the driving operation is completed, the coupled apparatus 14 and sleeve 5 are raised together. The striking plate 22 for the pile-driving hammer is carried by the apparatus 14.

Abstract: A pile driving apparatus to be lowered onto the head of a previously submerged pile positioned in a caisson is guided in its descent on cables. The cables are secured to a crossbar attached near the head of the pile. The crossbar must be attached sufficiently close to the head of the pile so that the funnel shaped mouth of the pile driving apparatus is guided onto the head of the pile even if the surface ship has drifted laterally to pull the cables away from the vertical, or if the pile itself is positioned in the caisson at an angle to the vertical.The crossbar is attached to the pile by retractable pins extending through longitudinal slots in the pile, or by extendable pressure pads that engage the circumference of the pile. Means are provided for automatically retracting the pins or pads whenever the crossbar bears against the pile driving apparatus.