Abstract: A portable bridge system formed from at least a pair of substantially rectangular bridge platforms positioned in side-by-side relationship including end locking plates for locking the platforms together at the end regions thereof. The invention further includes shear plates integral with, and spaced along, a side edge of the bridge platform for engagement with an adjacent bridge platform to resist transverse shear forces between adjacent bridge platforms.

Abstract: A monolithic cast bridge broadly includes a unitary, monolithic structure (12) having a pair of spaced haunches (14, 16) a span (18) having upper and lower surfaces (20, 22) and a pair of axially extending webs (24, 26). Haunches (14, 16) define support-engaging undersides (28, 30) which are provided for supporting the bridge above a support level (48). The lower surface (22) of the span (18) extends upwardly from each of the haunches (14, 16) to present a maximum rise relative to the haunch undersides (28, 30) at a midpoint (50) of the span (18). The webs (24, 26) are spaced and substantially parallel with respect to each other, and respectively include lower surfaces (52, 58). The lower surfaces (52, 58) are substantially flat and correspond to the haunch undersides (28, 30). A pair of reinforcement cables (64, 66) are advantageously positioned within respective webs (24, 26), and are configured for reinforcing the structure (12) along its longitudinal axis.

Abstract: A roller carriage for portable bridges or bridge parts have a rocker carrier connected by a support stud to the bridge structure while the rocker bodies are connected to the rocker carrier by pins which are formed in one piece and inseparably with the rocker bodies. A pair of rollers are journaled on each of the rocker bodies.

Abstract: A deployable bridge having at least one bridge section which includes a base body; and a road section articulated to the base body for pivotal movement about a horizontal pivot axis oriented transversely to the length of the base body. The road section has a first pivotal position in which the road section lies lengthwise on the base body. The road section has a second pivotal position in which the road section is in a raised state relative to its first pivotal position. There is further provided a pivot shaft mounted on the base body and having a horizontal pivot axis oriented transversely to the length of the base body. A support member adjoins the base body and is articulated to the base body by the pivot shaft. The support member has a first pivotal position in which it is in a flat-lying state. In such flat-lying state the free outer end of the support member projects beyond the outer end of the road section in a direction away from a location situated at midlength of the bridge section.

Abstract: A trough bridge is provided with a plane roadway and upward extending side walls. Top chords are arranged on the upper ends of the side walls. The bridge can be divided along the roadway into an arbitrary number of modules, the length of which may be adapted to the available transport length. The individual bridge modules may be nested in each other for transport such that a stack with a very small transport height results.

Abstract: A bridge laying apparatus for longitudinally displacing a bridge section includes a pinion shaft; a pinion secured to the pinion shaft for moving with the pinion shaft as a unit; a bearing rotatably and axially slidably supporting the pinion shaft; and a hydraulic power cylinder unit. The power cylinder unit includes a cylinder coaxially surrounding the pinion shaft and defining a cylinder chamber; and a hollow piston axially slidably accommodated in the cylinder chamber and being axially driven by a pressure prevailing in the cylinder chamber. The hollow piston surrounds the pinion shaft. There is further provided a coupling arrangement connecting the hollow piston with the pinion shaft for axially displacing the pinion shaft and the pinion into an axially advanced and into an axially withdrawn position.

Abstract: A guide groove provided in an inner lower cord of a bridge section of a portable bridge includes an extruded profile section which is comprised of a vertical strip having an upper end and a lower end, and being composed of, over its entire height in at least a partial cross section thereof, a homogeneous material; and an upper wall section extending from the upper end of the vertical strip and a lower wall section extending from the lower end of the vertical strip. The guide groove has an increased service life when the vertical strip has a thickness in cross section which is reduced at the center portion of the bridge section over at least a part of the length of the bridge section in respect to at least one of the end portions of the bridge section. The guide groove is repairable by a method in which an insertion element is replaced, the insertion element being provided over a part of the length of the bridge section in which the thickness in cross section of the vertical strip is not reduced.

Abstract: A portable, demountable bridge which can be self-launched. The bridge uses a traditional beam system to conform the deck of the bridge. Two hollow, bottom-plated, triangular footings are added as supports for this beam. These footings, buried into the soil of a riverbank or the bank of a chasm, absorb the horizontal forces using the weight of the soil above the bottom plates of the footings. Sets of vertical plane trusses parallel to the axis of the deck and located on each side of the deck at the entrance, help the beam of the deck to support vertical loads, by means of a transversal truss which touches the beam of the deck at its upper chord. Each set of the additional vertical plane trusses are founded on two bottom plated footings buried into the riverbank or the bank of a chasm. The footing near the water uses the soil as a bearing, and the other footing is used as a counterweight. The bridge also uses the soil of the riverbank or bank of the chasm as a protection against floods.

Abstract: The invention relates to a bridge comprising at least one bridge elements. The bridge elements has a base body that has chamfered end surfaces on which roadway plates rest that can be necessarily brought out of a drive-on position into a coupling position by hinged ramp plates in that respectively two bridge elements are moved toward the ramp plates into a drive-on position. The apparatus for laying the bridge has a guide (support rail, holding sheet) for the guide members of the ramp plates so that the bridge elements can be reliably guided together. Moreover, the apparatus has guide rails with which the locking elements (hook, pins) can be centrally actuated.

Abstract: A bridge deploying vehicle includes a deployment arm mounted on the vehicle for pivotal motion. The deployment arm has a length dimension and a frontal end oriented toward a bridge end while the bridge is being handled by the deployment arm. A first roller assembly formed of a plurality of rollers is pivotally mounted on the deployment arm for pivotal motion relative thereto about an axis perpendicular to the length dimension of the deployment arm; and a second roller assembly formed of a plurality of rollers is pivotally mounted on the deployment arm for pivotal motion relative thereto about an axis perpendicular to the length dimension of the deployment arm. The first roller assembly is closer to the frontal end of the deployment arm than the second roller assembly. During handling of the bridge by the deployment arm, the first and second roller assemblies enter an entrance pocket at the bridge end and are guided onto a runner rail mounted on the bridge.

Abstract: A method of constructing a bridge using a two step composite construction process. In the first step, the region to be spanned is bridged with precast prestressed concrete elements that are designed as beams and complete permanent formwork to carry the dead load of the bridge, to provide a high density concrete protective shell giving a greater degree of protection against deterioration from the elements and to provide a very high quality of finish and architectural design, to provide a complete working platform for construction, and to eliminate the need for temporary scaffolding and formwork. In the second step, additional poured in place concrete is cast into the spaces created by the precast elements and serves as beams, post-tensioned to carry the live loads of the bridge.

Abstract: A dismountable bridge comprises at least one bridge section including a top deck and a bottom boom disposed underneath the top deck. The bottom boom includes a mechanism for adjusting the length of the bottom boom. Rigid end supports each have one end hinged to a respective one of the ends of the top deck and have another end hinged to a respective one of the ends of the bottom boom. Tension elements are disposed laterally of the bridge section and are stressed only tensionally. Each tension element has one end hinged to one end of the top deck and another end hinged to an end of the bottom boom opposite to the one end of the top deck. The bridge section can be changed from a transport position, in which the top deck and the bottom boom are collapsed for maintaining a low height for transporting, and into an operating position in which the top deck is remote from the bottom boom at least at one end of the bridge section.

Abstract: A transportable bridge having longitudinal sides, includes plural bridge sections connected in series and presenting first and last bridge sections in the series. Each said bridge section in the series includes a deck slab extending across a width of the bridge and having front and rear transverse ends, and an inverted triangular truss on each longitudinal side of the bridge. Each truss has a lower corner portion and an oppositely disposed top beam. The lower corner portion of the truss is connected to the rear transverse end of the deck slab and additionally to the front transverse end of the deck slab of an adjacent following bridge section in the series of bridge sections. The top beam of the truss of the bridge section is connected to the top beam of the adjacent following bridge section thus forming a trough-shaped bridge having a lateral truss structure. A further deck slab is associated with the last bridge section.

Abstract: A method for building a road bed by providing a plurality of vaulted structures located at a road bed site. A first layer of concrete is applied on the structures for reinforcing the structures. The structures can be comprised of a profiled steel plate or a sheet metal mesh. They may have reinforcement braces comprised of troughs or corrugations provided on an outer surface of the structures which receive the first layer of concrete. The first layer of concrete is allowed to set before a second layer of concrete is applied to the structures and to the first layer to form a concrete casing.

Abstract: A spanning beam structure for clearing breaches by vehicles, having a locking member including at least one pair of locking shafts made fast to a raisable access jib and to a central box, respectively, of the spanning beam while extending longitudinally of the central box along the same axis in the locked position of the access jib and two jaw-like members gripping round to confronting heads of both locking shafts.

Abstract: A bridge or tunnel construction consisting of one or more arch units (10), each unit formed from a pair of reinforced concrete arch segments (11 and 12) interconnected to form the crown of the arch unit with the arch unit or units being overlaid with a compacted interacting soil layer.

Abstract: The invention concerns a bridging system comprising several uniform bridge section in the form of track supports (1). The width of the bridge can be continuously adjusted with telescoping pipes ( 2 ). The stationary ramps ( 3 ) on the track support are slotted like a comb and, once the have been assembled and connected to the pivoted-out lower truss system (4), can accommodate any compression forces and bending moments that occur when traveled. Since each track support is the same shape, the bridging system has a smoothly curving upper roadway edge.The traction component (5) in each track support travels back and forth between pivoting stays (9) provided with connectors (8) and the overall lower truss system can be pivoted into the track support.This bridging system, which consists of modular track supports (1), is outstanding for its compact traveling state and few connectors and can be positioned by appropriate transporting and laying equipment.

Abstract: A portable, demountable bridge to ford rivers and the like, includes a pair of footings for supporting the bridge buried at different heights in the soil on one side of the river. The footing closer to the river receives a load in a downward direction, and the footing further from the river resists an upward force produced by the weight of the bridge and objects on the bridge. Soil located over this further footing acts as a counterweight of the bridge. At least two bridge supporting units are located over the footing closer to the river. Preferably each supporting unit includes two support tubes. A removable first bracket is fixed to each supporting unit, and a second bracket is connected to the first bracket. The panels forming a roadway track for the bridge are connected to the second bracket via a first elongated support. A second elongated support connects to the footing further from the river to the second bracket.

Abstract: A bridge module for a modular bridge comprises a central deck structure (10), to the lateral edges of which are pivoted first and second main girder structures (12,14). These main girder structures can be pivoted from a use position, in which they define lateral deck surfaces (20,22) (which can carry a military vehicle such as a tank) to a storage position in which they are folded beneath the central deck structure (10). In the storage position, the main girder structures intermesh, one with the other, so enabling the bridge module to be packed for transport into a standard ISO container.

Abstract: A bridge includes a bridge element which has a basic bridge body; a folding ramp situated at opposite sloped end faces of the bridge body; a hinge connection pivotally attaching each folding ramp to the bridge body; and a locking device supported by the bridge body for locking the folding ramp to the bridge body in the downfolded position of the ramp in which the ramp forms a common access ramp with the respective sloped end face of the bridge body. The locking device includes a locking pin and an actuating device for moving the locking pin into a locking position or into a withdrawn position. In the locking position the locking pin extends into a locking pin-receiving opening of the folding ramp if the folding ramp is in its downfolded position or into a locking pin-receiving opening of an adjoining basic bridge body in the upfolded position of the folding ramp. The hinge connection includes a double-jointed lever connected to the bridge body and the respective folding ramp by pivotal joints.

Abstract: A separable bridge, particularly useful for military purposes, having bridge modules which can be coupled together and whose roadway elements, diagonal elements and lower chords form a vertically adjustable framework. The lower chords of the bridge modules are shorter than the roadway element of that bridge module, and the diagonal elements are fastened to ends of the lower chords. The roadway elements have a plurality of fastening points for the diagonal elements and the lower chords. These fastening points are located at different distances from an end of the roadway element. The roadway element, the lower chords and the diagonal elements have constant lengths.

Abstract: The bridge includes a plurality of foldable portions or modules (M) interconnectible releasably in sequence longitudinally. Each module (M) includes a central deck member (9) and two lateral deck members (10, 11) articulated to opposite sides of the central deck member (9). Respective longitudinal beams (13-16) extend from the lower faces of the lateral deck members (10, 11) and, together with the homologous beams of the other modules (M), constitute the load-bearing trusses of the bridge in its condition of use.Conveniently, the bridge is constructed by a method of assembly which provides for the use of a load-bearing assembly structure or forestarling (S). This load-bearing assembly structure (S) is assembled in a position of assembly on a first side (B.sub.1) of the gap (R) to be spanned by the bridge and is then advanced until it reaches the other side (B.sub.2) of the gap.

Abstract: A method of erecting a span between two points is disclosed which comprises the steps of securing an elongated, flexible sheath to the two points; inflating the tubular sheath with a gaseous fluid to form an arched tubular span; maintaining inflation of the arched tubular span to effect a constant pressure differential across the sheath; further increasing the upward force gradient on the sheath by support apparatus; utilizing the arched tubular span as support for a plurality of hollow aluminum troughs; anchoring the troughs at the two end points to erect a permanent load-bearing span between the two end points; and, deflating and removing the tubular sheath.

Abstract: A vehicle for laying movable bridges formed of bridge sections which can be coupled end-to-end on the vehicle. The vehicle has at one end a laying device for displacing and laying the assembled bridge. Spaced longitudinally from the laying device is a pick-up device for picking up and supporting a bridge section so as to permit coupling of bridge sections at a same height with respect to the laying device. The pick-up device can support a plurality of the bridge sections in a coupled state, and while so supported, the coupled bridge sections can be displaced relative to the pick-up device in a direction away from the laying device. The pick-up device is spaced from the laying device by a distance which is dimensioned so that at least one bridge section can be inserted between bridge sections supported by the laying device and the pick-up device.

Abstract: A construction kit for a multispan military or army bridge, comprising a plurality of bridge elements (1) which carry track lanes (10, 11), and coupling devices (15, 16) for coupling a plurality of bridge elements together to form a row of such elements, and further comprising a plurality of ramp sections (2, 3) which form drive-on and drive-off ramps on the bridge construction. The construction kit is characterized in that it comprises a crane carriage (4) for lifting a bridge element into a position in which it can be coupled to another bridge element; locking devices for coaction with the locking devices (15, 16) when coupling to bridge elements together; and support-leg pairs (120, 121) which function to support the mutually coupled bridge elements. The whole of the construction kit can be accommodated on conventional trucks or lorries (8). The invention also relates to the actual bridge element, crane carriage, locking devices and support-leg pairs themselves.

Abstract: A system for assembling a crossing structure for the bridging of gaps, comprising at least two sections (1) which are placed end to end to form at least one runway and of which at least the mutually opposite ends (1a, 1b) are equipped with interlocking members (10) of complementary shape comprising a succession of projecting parts (11) and of recesses (12).

Abstract: A laying vehicle for a bridge composed of connectable bridge elements includes a laying beam and a carriage that can be moved on the laying beam and having a swivelling elevating platform on which the bridge elements are disposed. A holding device for the locking of the connected bridge elements is provided on the laying beam. The carriage lifts the whole bridge off the laying beam and moves it, therefore, the bridge does not require rollers or rails for its displacement.

Abstract: The present invention relates to a road excavation and paving system having a main bridge section and ramp sections attached thereto for allowing traffic to continuously flow to and from the old highway and to and from the new highway. The old highway is reconstructed under the main bridge section. Crossovers are necessary to allow cross traffic over the old and new highways. The system has a plurality of movable pads connected by hydraulic pistons to the main bridge section for incrementally moving the system while the old road is being excavated and rebar is being laid on the new surface. After the rebar has been laid down, cement may be poured and the road finished to provide a continuous system for excavating and constructing the new highway. There is a continuous flow of traffic over the system while the old highway is being excavated and the new highway is being built.

Abstract: The bridge includes a plurality of foldable portions or modules (M) interconnectible releasably in sequence longitudinally. Each module (M) includes a central deck member (9) and two lateral deck members (10, 11) articulated to opposite sides of the central deck member (9). Respective longitudinal beams (13-16) extend from the lower faces of the lateral deck members (10, 11) and, together with the homologous beams of the other modules (M), constitute the load-bearing trusses of the bridge in its condition of use.Conveniently, the bridge is constructed by a method of assembly which provides for the use of a load-bearing assembly structure or forestarling (S). This load-bearing assembly structure (S) is assembled in a position of assembly on a first side (B.sub.1) of the gap (R) to be spanned by the bridge and is then advanced until it reaches the other side (B.sub.2) of the gap.

Abstract: A stress laminated timber bridge deck is disclosed. The deck includes a transversely extending laminate of longitudinally extending timbers and a system for prestressing the laminate. The prestress system includes a pair of longitudinally extending stress distribution channels disposed on opposite sides of the laminate, a number of transversely oriented threaded tension rods, and threaded members, threadably engaged with the tension rods, for tensioning the rods. A disc spring assembly is disposed on each of the tension rods and compressed between the respective stress distribution channels and respective threaded members to reduce the effective stiffness of the deck and thereby reduce prestress losses due to wood creep and temperature variation. A method for measuring prestress in a tensioning rod of the deck of the present invention is disclosed.

Abstract: A bridge-laying device is placed, together with bridges or bridge sections (26), on an armored tracked vehicle (7) used by the armed forces in various countries, after removal of the armored turret. The laying device is constructed as a unit on a guide support (10) and placed on the annular part (25) of the turret of the vehicle (7), to which it is screwed. The laying device includes laying support (10) hydraulically mobile in the longitudinal direction, a mobile front laying arm (8) and a swivelling rear jib (16). Articulated supporting legs (12) which support the vehicle during the laying operation are also provided. These supporting legs are raised when the bridge-laying vehicle (7) moves.

Abstract: A movable bridge has a bridge section having an upper face with a roadway thereon and a hinge having a horizontal axis perpendicular to the longitudinal direction of the bridge. There is a lower chord fixed to and extending along the length of the bridge section. The bridge section includes a roadway section disposed in an end region of the bridge section and pivotally attached at the hinge.

Abstract: A ramp for use in loading off road vehicles on pick up trucks. The ramp includes a number of ramp panels joined at lateral edges by hinges for foldably connecting the panels and longitudinal hinge means for foldably connecting support panels at or adjacent to both side edges of the ramp panels so that the support panels fold with ramp panels. In use the ramp panels are coplanar and the support panels are normal to the ramp panels to support a load on the top surface of the ramp panel.

Abstract: A collapsible bridge for military purposes is assembled from a plurality of similarly constructed and interconnected bridge elements, each including two track plates, two girders and several length adjusted diagonal struts and tie rods, interconnected and configured so that the angular orientation of the girders is adjustable in relation to the track places, these adjustments being different for different bridge elements such that either the interconnected track plates or the interconnected girders or both approximate arches.

Abstract: A deployable modular bridge has a central girder; two side girders flanking the central girder; and couplings connecting each side girder to the central girder along the lower zones of the girders parallel to the bridge length. The couplings are arranged symmetrically with respect to a central vertical longitudinal plane of the bridge and permit displacement of the side girders relative to the central girder parallel to the bridge length. Each coupling includes a rail affixed to the central girder and extending parallel to the bridge length. The rail has a guide track formed thereon. Each coupling further includes a roller mounted on a respective side girder and engaging the guide track.

Abstract: A bridging system for clearing a breach comprising at least two identical beams rigidly connectable endwise and including each one at least one supporting structure having treadways at the upper portion and two noses pivoted to both ends, respectively, of the supporting structure so that each nose assumes a position folded back onto the structure and a position extended in prolongation of the latter.

Abstract: A high-capacity lift assembly consisting essentially of a multipurpose platform and a pair of commercially available truck cranes or crawler cranes wherein the lifting capacity of the respective cranes is combined to create an overall assembly capable of lifting an object weighing at least double the capacity of the individual cranes. The invention further includes a drive shaft to interconnect the hoists of the respective cranes to synchronize the rotation of the hoists, a mast and boom mounting arrangement to support the loading forces with the platform and an equalizing beam to distribute the load forces equally between the two truck cranes.

Abstract: A bridge span consisting of a series of end-to-end engageable bridge modules can be launched across a gap from a launch vehicle with the aid of an overhead launch rail consisting of a series of end-to-end engageable launch rail modules, the rail having been previously cantilevered out across the gap from the vehicle. The launch rail carries a cable-driven trolley beneath which the leading end of the bridge span is slung, after the leading end of the rail has been located upon the far bank, and the span then winched out so as to bridge the gap.

Abstract: The automatic-assembly bridge, ramp and the like comprises a base segment which has, on one face, two sets of wheels provided with positioning means for disengaging from the ground when the bridge, ramp and the like is installed, as well as an articulation for releasably coupling to a tractor. A second segment is articulated at one end of the base segment and is constituted by a first track and a second track which can be arranged mutually side by side and can be rotated independently from one another so as to be arranged in a transport position, wherein the tracks of the second segment are superimposed on the base segment, and in an installation position, wherein the tracks are arranged substantially along the extension of the base segment. One of the tracks acts as ballast during the rotation of the other track.

Abstract: A modular lightweight bridge comprises a pair of tubular truss formed spans, each of which include a plurality of modules hinged to one another at locations on the bottom of the bridge for folding the bridge for transport prior to deployment of the bridge. Each span has a unique high strength fabric deck or roadway surface tensioned across the upper side of the truss chord members. The bridge is uniquely captively mounted on a trailer by rollers for transporting the bridge when it is in its folded mode. When the bridge is to be deployed, each span is unfolded by pivoting the modules with respect to one another about vertical axes so that the spans expand longitudinally with respect to the trailer. The spans are then pivoted 90.degree. downwardly about longitudinally extending horizontal axes and the bridge rolled rearwardly from the trailer over the gap to be spanned.

Abstract: A modular overpass that uses interlockable roadway units. These interlockable units include ramp units adapted for fitting together to create entry and exit ramps having a low end and a raised end, cantilever units for attachment to the raised ends of the ramps, and suspended span units for joining the cantilever units. Flexible footings are provided to support the roadway units. The flexible footings comprise a resilient base, a covering cap sealably fitted over the base to define a cavity, and a packable bearing material partially filling the cavity. A system of pilings are used to anchor the roadway units in position. The system can be used to create an overpass over intersections between highways and secondary roads so that highway traffic travels over the overpass and local secondary road traffic is controlled by traffic lights. The modular overpass is shaped to conform to the existing highway surface and is supported on that surface by the flexible footings.

Abstract: A play enhancing game ramp for use in a game wherein opposing players exchange an elastic projectile between each player over a barrier on a playing surface. the preferred ramp for tennis use is employed in sets of three adjacent ramps which each includes a portable base frame, a pair of connected planar ramp sections hinged together and movable between a folded configuration and an unfolded configuration in which the ramp sections form a single ramp lying in a path extending from the predetermined height toward the playing surface, and strut supports connected between the pair of ramp sections and the portable base frame for causing said pair of ramp sections to counterbalance one another. Each of the pair of ramp sections has a top surface which reflects the trajectory of an incident projectile so that it passes over the barrier. The ramp (in alternate embodiments) can also be employed to enhance the play of other games such as badminton and ping pong.

Abstract: An improved dry bridge kit, composed of individual bridge bays of cross-sectional U-shape and of a cross-sectionally H-shaped traversing beam, the improvement comprising that the bridge bays are composed of a central part and of two side parts, the side parts containing hollow parallelipipedic track ways, and being foldable for transport underneath the central part. When launching the bridge, first the traversing beam is assembled and launched and then the individual bridge segments are coupled together and moved over the tranversing beam. The traversing beam remains as a bridge support element.

Abstract: The present invention relates to a system for spreading and depositing a spanning beam from a vehicle wherein, in the transport position of the spanning beam on the vehicle, the outer extreme element of the spanning beam is pivotally supported and maintained at its free end by a mobile support device of the vehicle occupying a raised position while the inner extreme element of the spanning beam rests on the outer extreme element along same and wherein the spanning beam can be raised by winding of the working cable on a winch of the vehicle into a position where the inner extreme element is pivotally supported at its free end by the support device with concomitant release of the free end of the outer extreme element from the device.

Abstract: A mini arched bridge is provided with at leat two hollow pans having integral depending sides and ends forming a unitary structure, each side and end of the pans having comparable holes, a plurality of fasteners passing through the holes in adjacent ends of said at least two pans whereby said pans become a single arched member and placing the ends remote from the connection into the earth on opposite sides of the arc to be bridged.

Abstract: A rapid deployment stationary bridge. The bridge comprises a central girder lanked by two side girders, each of the central and side girders consisting of a plurality of aligned and connected sections.For deployment the central girder is first assembled on one bank of an obstacle by aligning and interconnecting the constituent sections thereof. As the assembly progresses the central girder is launched by gradual advancing it towards the opposite bank. Some time after the commencement of the assembly and launching of the central girder the side girders are assembled by slidably mounting the constituent sections of each side girder in alignment on one side of the central girder and interconnecting them. In the course of their being assembled, the side girders are launched in such a way that the advancement of the side girders lags behind the advancement of the central girder.

Abstract: A bridge apparatus has a relatively light lower beam portion and a relatively heavy upper beam portion. The beam portions are generally equal in length. The lower beam portion is initially placed across the point to be bridged and has sufficient strength to support itself and to support the upper beam portion as the upper beam portion is moved across the lower beam portion. The upper beam portion is placed on top of the lower beam portion and fasteners are used for drawing together the two beam portions to close any gas therebetween and to rigidly connect the beam portions together so the beam portions jointly contribute to bearing the load.

Abstract: A method of erecting a span between two points, comprising the steps of securing an elongated flexible sheath to the two end points; inflating the sheath with a gaseous fluid to form an arched tubular span connecting the two points; erecting a generally rigid frame structure supported by the tubular span, the frame structure arched at the two end points; utilizing the frame structure as support to erect a span between the two points; permanently anchoring the span at the two end points; and, removing the sheath.

Abstract: A rollable temporary roadway is composed of individual supporting elements (2) which are articulately connected by hinge-like joints (7), each of which is formed by a bead (5) and the associated recess of a claw (6). The joints (7) are looped by at least one cable (10), with the cable being guided below the joints. A reeling device (20) for rolling up an installed temporary roadway (1) includes a pipe (21), hub members (22) which can be mounted on the pipe, and a cable arrangement (32, 33, 34).

Abstract: A method of constructing a modular bridge across a span comprises at least a first trestle on the home bank of the span, placing a first module of a modular launching rail on the trestle, connecting one or more subsequent launching rail modules to the launching rail being formed, placing a first bridge module on the launching rail, connecting one or more subsequent bridge modules to the bridge being formed, booming out the launching rail across the span and launching the bridge across the span along the launching rail. A trestle for use in such a method is also disclosed.