Bridge and Pontoon Arrangement.
This invention relates to a bridge and pontoon ar¬ rangement based upon one or more transportable units pro¬ vided with wheels and preferably designed so as to have a significant buoyancy in water.
There are previously known many designs of such units or modules which possibly in the form of pontoons may be used for building provisional bridges. There are inter alia examples of such transportable units in the form of amphibious vehicles provided with henged ramps, e.g. as described in Swedish Patent 191891, British Patent 1544611 and German Patent Application Publication 2641257. The designs described therein are obviously special vehicles for military purposes and are exclusive¬ ly intended to be components in provisional bridge struc¬ tures. These are highly specialized equipment which among other things have been provided with their own drive means, a driver's compartment, hydraulic means for swinging out ramps, and so on. Such amphibious vehicles having special designs in order to constitute pontoons in provisional bridges apparently will be so expensive that only military uses thereof may be thought of. This also applies to the particular design described in Published German Patent Application 2941374 which - it is right - is somewhat sim¬ pler than the above mentioned, previously known designs, but also here there is described an arrangement which is intended exclusively as a pontoon in provisional bridge structures.
On the other hand there is known from U.S. Patents 1400345 and 2395039 a type of load vehicle comprising in the prinsiple a tank the upper side of which is substan¬ tially plane so that it may constitute a load surface for other goods than liquid load which may be carried in said tank. The present invention in short is directed to a combined utilization and adaption of this type of load
vehicle for building pontoon bridges and the like, under a large variety of conditions. Thus, it has been found that a load vehicle unit in the principle as described in the above two U.S. patent specifications, may be uti¬ lized with advantage for the building of pontoon bridges and the like, when it is provided with certain special additional structure.
What is of interest here is to satisfy the need for temporary or provisional pontoons, barges or bridges for the crossing of rivers and water, including marshes and the like, possibly clefts and other depressions in the terrain, which cannot normally be crossed with common wheeled or other vehicles.
The utilization of a special load vehicle unit of the above type for the purpose stated here, is inter alia based upon the following two circumstances: the load vehicle unit comprises a tank having a large volume which gives the unit a significant buoyance in water, the structure inherently involves a structural strength which may be considered to constitute a "bridge span" between the end portions of the unit. The combination which according to the present in¬ vention constitutes the novel and specific features of a bridge and pontoon arrangement as indicated initially above, thus in the first place consists therein that each transportable unit is formed by a load vehicle being de¬ signed also for common road transport of goods and compri¬ sing a rear wheel set and possibly a front wheel set as well as a tank for liquid loads, with a middle portion of the tank lowered in relation to one or both end por¬ tions of the vehicle, whereby the upper side of the tank is substantially plane and has such a height from the ground that it constitutes a load surface for other goods than said liquid loads, said load surface or plane com-
prising at least one longitudinally movable member which may be displaced completely or parly outside the load surface in order to form a ramp which allows driving on and off, either in relation to the ground or to a connec¬ ted load vehicle unit of the same type.
The invention shall be explained more closely in the following with reference to the drawings, in which: Fig. 1 shows an arrangement according to the invention in the form of a semi-trailer floating in water, Fig. 2 shows a similar load vehicle unit (semi-trailer) as in Fig. 1 , but raised with supporting legs on the ground and with an accompanying ramp at one end, Fig. 3 shows a length of a longer bridge structure com¬ prising several load vehicle units, of which two have been shown completely in the figure, Fig. 4 shows somewhat more in detail the ramp at the right-hand end of Fig. 2, Fig. 5 shows the load vehicle unit from the rear and with two separate ramp members sunk into the truck body (the tank) , Fig. 6 shows a ramp member from beneath, Fig. 7 shows a relatively flexible intercoupling of two load vehicle units, and Fig. 8 shows a more rigid coupling between two units.
In Fig. 1 there is shown a load vehicle unit 60 which in the principle may be of a similar design as the ones found in U.S. Patents 1400345 and 2395039, but are provided with certain additional structure in order to make possible the use contemplated here. Thus, the load vehicle unit 60 comprises a tank 63 the middle portion of which is lowered in relation to the end portions, and having an upper side 64 being designed so that it may con¬ stitute a load-supporting surface. Moreover, there is shown a wheel set 61 here consisting of a boggi having three pairs of wheels.
The unit 60 is here illustrated in a floating posi¬ tion, the water surface being designated W and with solid ground or a bottom B underneath. Because of the buoyance caused by the tank 63, the unit 60 will be able to float on water even with a significant load as indicated with arrows 66 on the load surface or plane 64. In this con¬ nection it is obvious that the liquid load in the tank 63, for example an oil charge as indicated with hatching at the lowered middle portion of the tank in Fig. 1, must be taken into account when calculating the carrying capacity and the stability for such a pontoon or barge floating in water. With a semi-trailer as the load ve¬ hicle unit and having dimensions for common roads and transport requirements, for example an oil charge of 9 tons in the botton of the tank will result in a re¬ maining buoyancy for carrying approximately 7 tons of deck cargo with sufficient stability, provided that the center of gravity of the deck cargo is not higher than about 0,8 m above the deck.
The oil charge as indicated with hatching in the tank 63 in Fig. 1, may for example be a necessary amount of reserve fuel for the operation concerned in which such units are involved, for example transporting off-road in connection with construction works or military movements.
At both ends of the unit in Fig. 1, or more closely at each of the four corners thereof, there is mounted a supporting leg 67 and 68, respectively, which suitably may be in the shape of a hydraulic telescoping cylinder which is provided with a foot plate 69 at the lower end as shown at the supporting leg 67 in Fig. 1. This is a device which may be of a design as known per se and therefore does not require any closer description here. What is essential is that each of the supporting legs may be extended or adjusted individually to the desired length, for adaption to irregularities at the terrain site concerned, possibly the bottom of a river or the like.
These supporting legs 67 and 68 in the first place serve to give an additional supporting force when buil¬ ding bridges, when there may be a need for increasing the carrying capacity over and beyond that which results from the buoyancy of the tank 63. In such case there will be established a combination of a floating bridge or pontoon bridge and a bridge structure having conven¬ tional foundations.
However, as will be understood the supporting legs may also be used for other purposes, namely for suppor¬ ting the load vehicle unit when standing on solid ground, possibly to form a provisional bridge crossing a cleft
or other depression in the terrain.
The latter use may be considered to be illustrated by Fig. 2 of the drawings, in which the load vehicle unit 70 is supported by means of supporting legs (only one supporting leg 78 is shown at the right-hand end of the unit in Fig. 2) , the foot plate of which lies against the ground B. Also the wheel set 71 may be in engagement with the ground B. At the right-hand end of unit 70 there is shown a ramp 75 which from the load surface 74 runs down to ground level. The ramp 75 has a (not shown) coupling to the unit 70 at 76 and besides is provided with a central support 77. Such a central support is more or less needed depending upon the loads to which the ramp 75 is subjected during leading and un¬ loading of cargo, possibly vehicles to be transported on or driven across the load surface 74.
It is an essential feature according to the inven¬ tion that the ramp 75 constitutes a longitudinally mo¬ vable-part of the load surface 74 itself, so that this movable part normally is in a state or rest in which it is more or less incorporated in the upper side of the tank 73 and thereby constitutes a portion of the load surface or plane 74.
In Fig. 2 the ramp member 75 has been pulled out from the load surface 74 in its full length, but it is obvious that in other situations this longitudinally movable part may be pulled only partly out from the end of unit 70, so as to form a horizontal extension of the load surface 74 for the purpose of being connected to another load vehicle unit of the same type.
A more detailed description of a practical design of a ramp part is given below with reference to Figs. 4-8.
When coupling together load vehicle units as dis¬ cussed with reference to Figs. 1 and 2, into a longer pontoon or floating bridge as already mentioned above,
it is necessary to have coupling devices at the ends of these units. In this connection it is a possibility to design the ramp structure in such a manner that this by itself also provides for the desired coupling between the load vehicle units. However, there may also be pro¬ vided separate means or mechanisms for the coupling, and such structures may be of more or less conventional de¬ sign for similar purposes.
In Fig. 3 as in Figs. 1 and 2 there is shown sche¬ matically and simplified a section of a longer bridge structure based upon load vehicle units as shown in the principle in the preceding figures 1 and 2. In the bridge of Fig. 3 there are shown two complete load ve¬ hicle units 80 and 90 as well as an end portion of a further unit 100 at the outermost right of the figure. Between units 80 and 90 there is shown a connection ramp 85 which constitutes a longitudinally movable part of the load surface 84 on unit 80. In a similar way there is shown a ramp 95 between unit 90 and unit 100. A further ramp 115 is shown at the outermost left in the figure. This ramp may belong to unit 80 or it may be¬ long to an additional load vehicle unit (not shown) which constitutes an extension of the bridge further to the left.
This bridge structure may be considered to be of the combined type indicated above, since it is built in water the surface of which is designated W and where the bottom is designated B. Accordingly the bridge will have a carrying capacity stemming in part from the buoyancy of the tanks 83, 93 and so on and in part from the sup¬ porting legs shown, being extended into engagement with the bottom B. As it appears from the figure there will thus be formed a continuous roadway which from the left side to the right of the figure, consists of the ramp 115, load surface 84, ramp 85, load surface 94, ramp 95 and unit 100. There are indicated two vehicles 88 and
99 being in the course of crossing the bridge.
The coupling devices for interconnecting the load vehicle units into a continuous bridge as for example shown in Fig. 3, in particular cases may be designed so as to form a rigid connection between the units, but usually the coupling will be effected in such a manner that there is provided a certain flexibility in the inter¬ connection. This is the case irrespective of whether the longitudinally movable ramp parts completely or par¬ tially constitute the coupling devices.
The ramp parts as for example shown at 75 in Fig. 2 as well as at 115, 85 and 95 in Fig. 3, may either be formed as one piece in the complete width of the required roadway, or as known per se they may consists of two parallel parts each of which forms the roadway for the wheel set at either side of the vehicles being of inte¬ rest for the crossing of the bridge. As far as the total width of the load vehicle units is concerned and thereby the width of a resulting pontoon bridge, a prac¬ tical normal version may have a width of 2,4 m across the deck or load surface, but it is obvious that the struc¬ ture may be made wider, for example for military purposes if this should be desirable.
Fig. 4 shows somewhat more in detail than Fig. 2 an example of an embodiment of a loading ramp arranged at an inclination for driving or bringing a load from ground level up to the load surface 74 on a load vehicle 70. As shown the supporting leg 78 is extended into engagement with the ground. Here the ramp 75 may be regarded as composed of two halves 171 and 172 at either side of a transverse horizontal hole 177 for a bolt serving to mount the central support 77 swingably with respect to the ramp. At the upper end where there is shown a coup¬ ling 76 to the load vehicle unit 70, the ramp has a fur¬ ther transverse and horizontal hole 176 for a bolt to cooperate with corresponding holes or coupling means at
the end portion of the load vehicle unit. At the oppo¬ site end of the ramp 75 there are shown two similar holes 178 and 179 having a certain mutual spacing. The function of these two holes shall be explained more closely below, in particular with reference to Fig. 8.
As will appear from Fig. 5 the ramp may consist of two ramp members 75a and 75b being arranged in parallel and each along a side of the load surface 74. The upper surfaces of these ramp members lie generally flush with the surface of the load plane. Accordingly there are provided recesses or pockets in the load plane or sur¬ face, respectively in the actual tank, in order to ac¬ commodate these ramp members. Suitable means may be pro¬ vided for facilitating the mentioned longitudinal move¬ ment of the ramp members when these shall be manipulated from their state of rest in order to form an inclined ramp as in Fig. 4 or possibly for use in the inter¬ connection of several load vehicle units, for example into a- pontoon bridge.
As will further appear from Fig. 5 the ramp members 75a and 75b have an inverted ϋ-shaped cross-section, which in a practical design may consist of a steel pro¬ file 300 x 400 mm. In the state of rest in which the ramp members 75a and 75b are completely retracted into the load surface, they may be locked in this position by means of locking mechanisms as known per se.
In Fig. 5 there are also indicated wheels 71 and a supporting leg 78 as mentioned above. In this embodi¬ ment the supporting legs are located outwardly on the side walls of the tank, but for the purpose of obtaining a smaller total width of the vehicle, it may be possible to build in such supporting legs within the contour or ground plan of the tank.
In the embodiment of Fig. 6 the two halves 171, 172 of the ramp have an articulated connection with each other centrally by means of a bolt 177b in the previous-
ly mentioned hole 177, which at the same time connects the central support 7*7 to the ramp. Here the ramp mem¬ ber is shown from underneath and with the central support 77 swung completely into the ϋ-profile of half member 172. Moreover, as shown the above holes 176, 178 and 179 penetrate both side flanges of the U-profiles.
Figs. 7 and 8 show two different possibilities for interconnecting two load vehicle units using ramp mem¬ bers as discussed above. Thus, here one or two such ramp members are adapted to be incorporated as essential elements in the coupling devices for this interconnection. Accordingly, this constitutes a substantial supplemen¬ tary function of the ramp members in addition to their primary function with respect to driving on and off, either in relation to the ground or to and from respec¬ tively, a connected load vehicle unit of the same type.
The coupling shown in Fig. 7 serves to connect two load vehicle units 70a and 70b to each other in a rela¬ tively flexible way, for example in order to form a pon¬ toon bridge. The articulated design of the ramp members as shown in Fig. 6, are employed here. The holes 177 and 179 are in Fig. 7 brought into coincidence with cor¬ responding holes at the end of the two units 70a and 70b so that bolts (not shown) may be used for connecting ramp half member 172 to unit 70a and unit 70b, respectively. These have correspondingly shaped recesses into which the two ends of the ramp half members enter. These re¬ cesses suitably have such tolerances in relation to the ramp that there will be clearance for a certain mutual movement between the members in the vertical direction, for example vertical movements when a vehicle crosses the pontoon bridge. The other half 171 of the ramp mem¬ ber in Fig. 7 is shown in its state of rest retracted into the load plane or tank of unit 70a.
A more rigid interconnection by means of the same ramp member is shown in Fig. 8. Here the ramp half mem-
ber 172 has been pulled just a little distance out from unit 70a, so that anchoring takes place with hole 178 and possibly one of the other holes, for example hole 177. The outermost right-hand end of this ramp member then projects as a rigid beam for connection to the other unit 70b by means of the hole 179. Thereby the two units 70a and 70b can only have small angular move¬ ments in relation to one another, whereas the connecting method according to Fig. 7 also allows vertical trans¬ lation movements between the units. The space between the units will also be substantially larger when connec¬ ted as in Fig. 7, compared to the coupling of Fig. 8. The former of these two connecting methods may for example be suitable on an irregular road or ground, whereas the latter connection may be adapted for more smooth, solid underlayers or when a floating structure is concerned, for example a pontoon bridge.
It will be understood that with the structural features described here there will according to the invention be obtained a very advantageous combined uti¬ lization of the particular load vehicle unit, i.e. at one hand for common land or road transport of goods, including liquid loads, and on the other hand for the building of provisional bridges according to the pontoon principle, possibly for use as a single pontoon when crossing bridges and the like.