Abstract: A process is provided for the preparation of dibasic propellant charge powder by a solvent-free process, in which a continuous flow of raw powder mixture moist with water is kneaded at an elevated temperature in a set of shearing rollers, to which the raw powder mixture is continuously supplied and at one end of which the gelatinized mass is continuously removed and immediately continuously granulated. The resulting granulate is continuously delivered to an extruder by means of which it is moulded into powder strands which are worked up into the finished powder by cutting and an end treatment. The process requires only small quantities of powder within the kneading equipment and thus provides a safe and efficient continuous manufacturing facility.

Abstract: An extrudable plastic bonded explosive molding powder is provided and conns about 20 percent by weight ethylenevinyl acetate copolymer and 80 percent by weight PETN.

Abstract: A manifolded, multiple-pin die apparatus and method processes potentially explosive material to form longitudinally perforated cylindrical pellets for use as gun propellants. A main entrance passage formed in mating manifold blocks gradually changes in cross-sectional configuration from circular to figure-eight, and then branches in a gently curved manner. The divergent branches formed then further branch in the same manner and feed circular cross-section passages leading to extruding dies wherein a series of die pins extend axially through a discharge passage. Each die comprises a central core member supporting an outer shell via radial ribs which are configured to form flow passages of hour-glass configuration. No change of flow direction in the entire apparatus exceeds fifteen degrees.

Abstract: A masonry structure is made by setting up a prefabricated wire support structure having the shape of the structure to be made, assembling a first row of bricks on the lowermost horizontal section thereof, masking a plurality of brick of that row with an open top removable mortar molding form which is placed around a plurality of bricks and covering the tops of the bricks by filling the form with mortar and leveling it to provide a mortar filling layer between adjacent bricks of the run and a continuous mortar layer above the bricks.

Abstract: Concrete moulding apparatus (10) is provided which has a mould (19) through which concrete is extruded from a hopper (17) by the action of a pusher plate (22) reciprocating in the hopper (17) towards and away from the mould entrance (20). The pusher plate (22) is arranged to pivot during reciprocation to cause excess material forced towards the mould entrance (20) to be squeezed upwardly back into the hopper (17).

Abstract: A method and apparatus for protecting a mixing apparatus for producing strand-shaped explosives and propellants in a twin-shaft screw extruder, the housing of which is formed of housing parts connected to a clamping device acting under hydraulic pressure. In order to compensate for excessive pressure and to prevent abrupt opening of the mixing chamber, the torque developed at the screw shafts is continuously monitered and fed to a control and storage device together with temperature and pressure values measured at the end of the screw shaft in the material being processed. If one of the measure values exceeds a permissable limit, a signal is produced to change the operating condition of the screw extruder, particularly to stop and withdraw the extruder from the housing, to halt the drive motor of the extruder shafts and to open the extruder housing by relieving the clamping device.

Abstract: To pour and set concrete slabs the form deck is chained to a light truck and the combination is supported between joists. The truck can be lowered while the slab is curing, and raised again before the combination is again lowered to be "flown" to another location.

Abstract: A water-filled pressure chamber (7) loaded by conventional pumps at pressures of several thousand bars is used to isostatically press explosive charges. Inside this pressure chamber (7) is a compression mold (6) having an inner/outer mold (1) consisting of several components. Explosives in the mold are subjected through an elastic sleeve (3) to liquid pressure (p), so that the interior pressure in the chamber will be nearly isostatic. Following pressure relief, Dimensionally accurate and homogeneous precision explosive charges are obtained.The present invention also includes the process using the pressure chamber. The invention increases manufacturing output and quality of explosive charges so produced.

Abstract: A form structure for making a primary concrete covering wall on the surface of the wall of a tunnel which extends behind a shield type tunnel excavator advanced, wherein a form structure for casting concrete to make the covering wall is assembled with a plurality of arcuate form assemblies respectively including form segments and timbering members for reinforcing the cast and set concrete. The form segments of each assembly are detachably coupled to the timbering members. The form structure is disassembled after the cast concrete is set by detaching the form segments of the respective assemblies from the timbering members to leave the members on the primary covering wall of the set concrete, whereby the primary covering wall can be held in stable state simultaneously with completion of the primary covering wall on the tunnel wall surface.

Abstract: Apparatus for forming a concrete panel for constructing a wall of a building in which a reinforcing column of concrete is integrally formed therewith. The apparatus has a hopper in which cement is poured. Depending from the hopper is an inverted U-shaped channel member with depending walls for forming the column. Projecting outwardly from the bottom of the depending walls are flanges. Outboard of the flanges are runners which slide over rails for advancing the apparatus over a rectilinear path.

Abstract: The present invention provides a means by which chemically or thermally gassed emulsion explosives can be packaged in symmetrical cartridges, such as cylindrical paper packages having crimped ends. After formation, the gassed emulsion explosive is formed into a continuous strip of generally constant width and height. The strip then is passed through a cooling bath to cool the emulsion explosive to a predetermined temperature. A desired length of emulsion then is cut from the cooled strip, and the cut length is wrapped with a paper packaging material to form a cartridge of emulsion explosive.

Abstract: The present invention relates to nitrocellulose single-base propellent powders which exhibit good resistance to aging and to moisture. The powders according to the invention characteristically contain zinc carbonate whose particle size distribution is between 2 and 50 micrometers as an additive. The zinc carbonate is incorporated in the powder during the blending. The powders according to the invention find their preferred applications as propellent powders for ammunition intended for warships or for aircraft or as powders intended for gas generators for pyrotechnic devices.

Abstract: A method of and apparatus for casting uncured solid propellant in solid propellant rocket motors includes a casting bayonet having annular slits formed in the exit end thereof that improve the fluidity and self-leveling behavior of the uncured propellant. Both of these effects eliminate or reduce the trapping of air in the cast propellant, thus providing a better product.

Abstract: A tunnel having an inner surface and extending along an axis is lined with pumpable concrete having a predetermined hardening time and by a form having an annular inner wall and an axially movable front wall. Substantially equal sized batches of pumpable concrete are successively injected into the space through the movable front wall through a plurality of angularly equispaced ports therein. The batches are injected axially backwardly through the ports at such a rate that succeeding batches are injected through each port at a time interval that is substantially smaller than the concrete hardening time. The front wall is displaced forward at such a rate and the batches are sized such that each batch spreads over a predetermined axial and a predetermined angular distance, such that the latter is greater than the former.

Abstract: A deformable molded fiber product is formed by a method of felting, pressing and drying the compressed product having a uniformly spaced series of low density ridges on one surface. These ridges provide the molded fiber product with sufficient flexibility so that is may be subjected to a hot swaging like process to change its dimensions. A method of forming detents by hot pressing is also shown. The process is particularly useful in forming combustible nitrocellulose shell casings from a single pulp molding operation.

Abstract: Shield tunnelling method and assembling and disassembling apparatus for use in practicing the method. A shield having shield jacks is actuated for drilling a hole in the ground. Inner forms and outer forms are assembled into a plurality of tubular units coaxially jointed in the hole so that an annular concrete lining space is defined between the inner forms and the outer forms, the tubular units having a leading tubular unit.The shield jacks are applied against inner forms of the leading tubular units for thrusting the shield during actuating of the shield to further drill the hole. A concrete is injected into the annular concrete lining space to form a concrete lining. The concrete lining within a predetermined length of tubular units is set for providing adhesion to the inner forms, in contact with the concrete lining, against a reaction force of the jack thrust for the shield.

Abstract: A solid grain block is housed in a casing with interposition of a heat protection layer and defines a combustion chamber, and a separation zone is formed between the solid grain and the heat protection layer of the rocket motor bottom structure by means of a skin detached from said layer and adhering to the solid grain, at least one of the two parts constituted by the detached skin and the heat-protection layer of the rocket motor bottom structure being provided with projections or teeth to ensure a minimum spacing of the detached skin with respect to said layer and to give easy access to the gases into the separation zone.

Abstract: A rectangular shaped device for making abode bricks including an L-shaped rod mounted perpendicularly to the rectangular shaped device to provide stability and a T-shaped planar insert having a means for adjusting so that different size abode bricks can be made. The form is used at the desired position to make an adobe brick of the adobe structure. The setting of the rectangular shaped device next to the just previously formed adobe brick leaves a gap. The gap is filled when an adobe brick is formed above the gap. Also, the form is combined with a plurality of forms to make a gang mold. The gang mold is used to make a course of adobe bricks. This method of on site adobe brick building forms an uniform integrated adobe structure.

Abstract: In the production of explosive or detonating cords which are covered with plastic, a preliminary cord, which contains the explosive substance, is guided through the opening of an extrusion nozzle and is injection molded with plastic. Measuring sensors in the supply duct for the plastic monitor the temperature and/or the pressure in the supply duct. If permissible limit values are exceeded, a die piece and a spindle sleeve of the arrangement are driven out from a stationary block in opposite directions. The spindle sleeve divided in the lengthwise direction is separated by auxiliary drives from the cord. A plug is withdrawn from the wall of the supply duct by means of a further auxiliary drive in order to relieve pressure stressing. In addition, the preliminary cord is withdrawn from the danger region by reversal arrangment. Furthermore, when the protection arrangment is in the release state an additional cooling takes place.

Abstract: A method of making a primary concrete covering wall on the surface of the wall of a tunnel which extends behind a shield type tunnel excavator. A form structure for casting concrete to make the covering wall is assembled with a plurality of arcuate form assemblies respectively including form segments and timbering members for reinforcing the cast and set concrete. The form segments of each assembly are detachably coupled to the timbering member. The form structure is disassembled after the cast concrete is set by detaching the form segments of the respective assemblies from the timbering members to leave the members on the primary covering wall of the set concrete, whereby the primary covering wall can be held in stable state simultaneously with completion of the primary covering wall on the tunnel wall surface.

Abstract: A circular slit plate having slits therein that are symmetrically positioned and originate near the center of the plate and extend radially toward the outer diameter thereof is used to deaerate solid rocket motor propellant and to provide a uniform propellant flow distribution during rocket motor casting.

Abstract: A method of making solid rocket propellant that facilitates tailoring of a variable burn rate. The method comprises molding binder and fuel and/or oxidizer to produce, for example, a molded strip of solid rocket propellant material. The molded solid rocket propellant material is formed into a desired shape by, for example, filament winding. In a preferred aspect, the solid rocket propellant is cured prior to being encased in a rocket motor casing. This improves rocket propellant to rocket engine casing bonding. Yet another aspect of this invention is a method of making solid rocket propellant comprising forming binder and oxidizer into separate strips and combining the binder and oxidizer strips to form solid rocket propellant material.

Abstract: In a process for the production of a `water-in-fuel` or `melt-in-fuel` emulsion explosive a density-reducing agent is introduced and dispersed in the emulsion at an elevated temperature whereat the emulsion is essentially liquid, the explosive is cartridged and then subsequently cooled by means of a refrigerated fluid so that the continuous phase solidifies and stabilizes the dispersion of the density-reducing agent in the explosive. Preferably, when the density-reducing agent comprises gas bubbles the explosive is subjected to an elevated pressure before it is cartridged in order to ensure that the sensitivity of the explosive will not be impaired by disturbance of gas bubbles by any pressure drop which might occur during cartridging.

Abstract: A concrete slab and beam forming system including first and second shoring towers that are adjustable in height and which can be adjusted to provide for concrete beams of different depths. The forming system also includes a first plank with an integral facing, and second and third planks having integral facings which are pivotally attached at opposite ends of the first plank and which rest upon adjacent shoring towers in a first position in which the facings of all the planks are substantially coplanar. The planks are provided with bolts for releasably securing the second and third planks in that first position and operable to allow the second and third planks to be pivoted to a second position in which the facings of the second and third planks are substantially perpendicular to the facing of the first plank.

Abstract: A method and apparatus for forming wet concrete employing a slip form having a radially expandable elastic outer shell comprising pouring concrete around the exterior surface of the outer shell and applying a fluid under pressure to the interior surface of the outer shell. The pressure of the fluid is pulsated so that the outer shell expands and contracts to reduce the friction between the outer shell and the concrete. The reduction in friction allows the form to be moved longitudinally along the concrete with reduced tearing of the surface of the concrete.

Abstract: To pour and set concrete slabs the form deck is chained to a light truck and the combination is supported between joists. The truck can be lowered while the slab is curing, and raised again before the combination is again lowered to be "flown" to another location.

Abstract: A process and apparatus for producing plastic-bound propellant powders and explosives in crystalline form, with the apparatus including an extruder comprising a casing with a feed opening, optionally a solvent supply opening and one or two extruder shafts with kneading and conveying segments. For processing the plastic binders, which polymerize photochemically or under X-rays, a casing section transparent for the rays is provided, with polymerization within the extruder being initiated by UV/VIS or X-radiation sources arranged around it and the radiation intensity and/or the wavelength of the radiation are controlled as a function of the pressure difference over a given path in a compression zone of the extruder, in such a manner that the propellant or explosive strand or strands leave the extruder in a dimensionally stable and cuttable manner.

Abstract: An elongated flexible bag is fitted inside templates that have aligned openings therein corresponding in shape to that desired for a solid rocket motor propellant bore. With the bottom sealed, the bag is filled with a multiplicity of solid pieces each having a cross section substantially less than that of the bag. When filled, suction is applied to the bag by a vacuum needle to exhaust air therefrom until the bag is very tight on the solid pieces contained therein. The vacuum needle is then withdrawn, the hole made thereby is sealed, and the templates are removed from the bag. After use in loading a solid rocket motor with propellant, the bag is cut open, the solid pieces are removed, and the bag is peeled out of the bore in the propellant.

Abstract: An elongated flexible bag is fitted inside templates that have aligned openings therein corresponding in shape to that desired for a solid rocket motor propellant bore. With the bottom sealed, the bag is filled with a multiplicity of solid pieces each having a cross section substantially less than that of the bag. When filled, suction is applied to the bag by a vacuum needle to exhaust air therefrom until the bag is very tight on the solid pieces contained therein. The vacuum needle is then withdrawn, the hole made thereby is sealed, and the templates are removed from the bag. After use in loading a solid rocket motor with propellant, the bag is cut open, the solid pieces are removed, and the bag is peeled out of the bore in the propellant.

Abstract: A traveling mold for forming a pre-cast, box-like concrete structure has movable frame means for supporting the mold. Inner and outer wall forms of the traveling mold are movable, vertically and transversely, away from a formed reinforced concrete wall section, after the wall section has hardened sufficiently to be self-supporting. A method for forming a pre-cast reinforced concrete building structure having a floor and at least one upstanding wall, using the traveling mold, is also described.

Abstract: A method of constructing a reinforced concrete structure (e.g. a cement building or pipeline) wherein an inflatable form is placed on a precast foundation and confined thereto by wrapping the exterior of the inflatable form with a layer of chain link fencing fabric. For large structures, a plurality of adjacent inflatable forms (preferably pneumatically interconnected) is employed wherein either the exterior interstitial spaces between adjacent forms are occupied by lightweight spacer means or structural walls and support means are present to further anchor the chain link fencing fabric. The inflatable form can then be highly pressurized such as to prestress the chain link fence and a uniform layer of fiber reinforced cement is applied to the form. The resulting thin walled structure exhibits excellent structural properties virtually free of form deformation and cement sloughing.

Abstract: A machine for building a dome or sphere has an extruder that extrudes part of a wall of a dome or sphere from fluid material which hardens on extrusion as the extruder travels around a center axis. A ramp allows the extruder to gradually ride up onto the initial wall so that another partial wall of the sphere can be formed. The extruder continuously moves along its own produced track in a spiral path to ultimately form a dome or sphere, as desired.

Abstract: A low vulnerability ammunition (LOVA) propellant is prepared with a polyurethane binder and a mixture of nitramines consisting essentially of RDX and at least 7.5 wt. % HMX (based on combined oxidizer binder matrix weight). Dilution of RDX with HMX enhances precure extrudability of the propellant grain. Polymerization and extrudability is provided without slumping prior to total cure given a NCO:DIOL:TRIOL equivalent ratio of from about 110:15:85.

Abstract: A marine operations structure for use in arctic seas having steel/concrete composite ice walls positioned to permit multi-year ice ridges to be broken up with lower vertical forces imposed on the structure than heretofore possible. The structure provides for simultaneous contacting and fracturing of both surface ice floe and multi-year ice ridges by proportioning of the ratio of the annular dimension of a first sloped surface to the radius of the structure within the range of about from 0.15 to 0.30. The structure is fabricated by modular construction techniques which lowers total construction costs. The structure is in the form of a sixteen-sided polygonal sloped walled marine structure with internal ballast tanks for providing gravity founding of the structure on the sea floor. Modular drilling equipment is provided for and supported by the structure for use through two rectangular shaped moon pools extending vertical throughout the central core of the structure.

Abstract: A molded explosive member having mating means molded along the periphery to permit interlocking of adjacent members is disclosed. The molded member from an explosive material comprising a mixture of from 30 to 70 wt. % pentaerythritol tetranitrate (PETN) powder, about 1 wt. % graphite, and 70 to 30 wt. % foamable polystyrene beads heated in a closed mold, in the absence of moisture in contact with the PETN powder, graphite, and polystyrene beads, to a temperature of from about 90.degree. to 104.degree. C. to foam the polystyrene beads and mold the explosive material into the desired shape. The amount of PETN powder in the mixture is varied to adjust the desired amount of pressure generated during detonation of the molded explosive member.

Abstract: A multi-story concrete building is constructed concurrently, that is, the steps for constructing the same are carried out simultaneously on different respective stories. To achieve this end, vertical formwork members for forming the columns and bearing walls for one story are erected. Then decking formwork is erected for forming a concrete slab to serve as the floor for the next story thereabove. Formwork spacers are affixed to the tops of the vertical formwork members and these spacers provide mounts, extending through the thickness of the slab to be formed, for mounting the vertical formwork members for the next story. The vertical formwork members for the next story are then erected. Fresh concrete is poured into at least the vertical fromwork members and is permitted to cure and solidify into the vertical support members for that story. Other formwork members are erected above the next story while concrete is concurrently poured and formwork is stripped on different respective stories.

Abstract: A formwork apparatus for concrete placing comprises: a center frame assembly having upper and lower ends; first and second form panels for molding concrete walls, each having a supporting member mounted on an outer surface thereof, the first form panel pivotally connected at its supporting member to the upper end of the frame assembly so as to be pivoted about a substantially horizontal axis, the second form panel pivotally connected at its supporting member to the lower end of the frame assembly so as to be pivoted about an axis parallel to a pivot connecting the first panel with the frame assembly; a first fixing mechanism for fixing and releasing the first panel to and from a cured concrete wall; a second fixing mechanism for fixing and releasing the second panel to and from the concrete wall; a first drive mechanism for pivoting the frame assembly around the first panel when the first panel is fixed to the concrete wall so that the second panel is brought to a position upper side of the first panel; and a

Abstract: A method and apparatus for pressing powder material in which powder is dosed into a die (48) and with the aid of at least one press means (14) is compressed to a ready detail, pressing continuing until a desired final position of the press means or a desired press force has been achieved.The actual value for the position of the press means (14) is sensed when desired press force has been achieved, or the actual value for the press force is registered when the final position has been achieved. The registered actual value is compared with a predetermined criterion value and the pressed detail is accepted or rejected depending on the size of the deviation between actual and criterion values.

Abstract: A method is described for the sectional erection of a superstructure of prestressed concrete for a bridge with a launching girder carrying the formwork for the superstructure and being movable from one concreting section to the other. The process is characterized by a movement of the launching girder to the next concreting section while the previously concreted and prestressed superstructure is supported via bearings by the launching girder, which in turn is supported by the bridge supports via further bearings.

Abstract: The application discloses improvements in hollow charges for linear cutting or demolition purposes wherein a bar formed from a composite of explosive material and a first pliant material has a V-shaped groove with a liner formed from a composite of particulate metal and a second pliant material. The metal may be copper and preferably the first and second pliant materials include the same constituents. The charge may include a casing having a spacing portion having an engagement surface for presentation to a work surface, which engagement surface is parallel to the outer edges of the liner and spaced therefrom to maintain an optimum stand-off distance. The casing may further include a groove filling portion of low density material which may be integrally constructed with the casing from a flexible material such as expanded polyethylene.

Abstract: A composite rivet comprises an integral mandrel from which material is sheared to form a head on the blind side of a workpiece.

Abstract: An apparatus for forming a multisided upright concrete wall with inner and outer form set-ups including an arrangement for stripping said inner form set-up which has a multisided form wall from the cast concrete entirely which comprises at least one wedge means dividing at least one side of the form wall into two portions and wedged in between the two portions in a first direction during casting, and means for moving the wedge means in a second direction opposite to the first direction after casting and bringing the two portions to be nearer relative to one another, whereby the inner form set-up contracts and therefore entirely is spaced apart from the cast concrete.

Abstract: There is described a process for the continuous or semi-continuous fabrication of propellant powders for the production of a powder having reproducable characteristics, in extremely safe conditions, thus overcoming the disadvantages found in the existing batch processes. In accordance with the invention, raw nitrocellulose is homogenised and stored under water in large tanks, from which it is fed in a controlled manner to a continuous centrifuge which removes water and alcoholises the nitrocellulose gradually. The alcoholised nitrocellulose is fed continuously to a stage where it is mixed with solvents and additives to form a gel which is compacted and extruded into filaments. Granules are made from the filaments and are transported in small batches to a preliminary drying step which removes that larger part of the solvents, in suitable vessels in a programmed manner.

Abstract: An erosion control system is disclosed which includes a seawall for protecting dunes or bluffs located adjacent a body of water. The seaward side of the seawall is notched or concave to direct incoming waves upwardly and outwardly, away from the base of the seawall and the bluff. The landward side is also notched or concave. This side is backfilled with soil which acts on the back surfaces of the seawall to lock the seawall into place. The erosion control system also includes a drain field that is installed below the bluff, behind the seawall. The drain field is in communication with the body of water via pipes extending through the seawall. The drain removes water from the bluff, thus decreasing the hydrostatic pressures within the bluff. This stabilizes the bluff itself and the seawall by decreasing the forces associated with hydrostatic pressure.

Abstract: A building form into which concrete may be poured to form a column or similar structure includes a plurality of stacked form units having interconnected expandable and contractible joints. The application of a vertically upward force to the joints of the uppermost form unit causes all the units to move together, first laterally outwardly and then upwardly to strip the form from the column. The form thereafter may be moved to another location where the joints of the form units may be contracted to provide a form for pouring another column. The joints include movable portions which are cammed outwardly or inwardly depending on the direction of vertical movement of a central, vertically movable portion.

Abstract: A method is described for the sectional erection of a superstructure of prestressed concrete for a bridge with a launching girder carrying the formwork for the superstructure and being movable from one concreting section to the other. The process is characterized by a movement of the launching girder to the next concreting section while the previously concreted and prestressed superstructure is supported via bearings by the launching girder, which in turn is supported by the bridge supports via further bearings.

Abstract: A propellant charge is manufactured by spooling a strand of propellant onto a form member. In accordance with one embodiment of the invention, the form member is a spool composed of propellant, and the spooled propellant, including the spool, is loaded into a charge housing.

Abstract: The present invention relates to the field of compound pyrotechnic products.The invention relates to a three-step, solvent-free process for the manufacture of compound pyrotechnic products containing a thermosetting binder obtained by reaction of a polyhydroxylated prepolymer with a diisocyanate, which process is characterized in that:in a first step the said prepolymer is mixed with an energetic charge and with a quantity of diisocyanate representing 50 to 90% of the required stoichiometric quantity,in a second step the remainder required to attain the said stoichiometric quantity is added and, after mixing, the pasty mixture thus obtained is extruded,in a third step the crosslinking of the thermosetting binder is completed hot.The invention makes it possible to obtain industrially, by extrusion, small-diameter pyrotechnic products containing a thermosetting binder without restriction on the "pot life" period. The invention is particularly suitable for the production of compound propellent powders for arms.

Abstract: The manufacture of extended, inaccessible holes for underground ducts, conduits and the like is performed by a closed construction process, wherein the preferably remotely-controlled excavation is performed and following that a structure is installed which is employed as the product duct, conduit or the like. The installed structure is provided by injection of an injection material under pressure into an annular space between a form following the excavating apparatus and the ground to manufacture at least one endless inner wall for the hole which then serves as the underground duct, conduit or the like. The novel apparatus of this invention correspondingly comprises a form following the required excavation mechanism conformed to form an annular space between the form and the ground, that form having a form front closing the form and at least one inlet therein for injection of an injection material into the annular space.

Abstract: A minimum hazard visual screening cloud-forming product is made by forming slurry of fine spheres of titanium dioxide composition, of submicron diameter, together with a volatile surface-wetting agent liquid, in the form of a liquid hydrocarbon, extruding and severing the extended slurry mass into a desired container shape, in particular, a hollow cylindrical shape, and drying the mass. An HE explosive mass is inserted into the resulting compacted hollow cylinder, enabling bursting of the compacted mass.