US3538875A - Hopperbarge - Google Patents

Description

United States Patent 1 11 3,538,875

[72] Inventor Jfl l Kfllling [56] References Cited Amsterdam, Netherlands [2l] AppLNo. 776,561 2257 885 10/194 N 1 evehng et al. 114/36 [22] 3 404 650 10/1968 Mn 1 114 29 [45] Patented Nov. 10, 1970 1 1 1 er et a [73] Assignee N.V. lngenieursbureau voor Systemen en Primary Examiner-Trygve M. Blix Octrooien Spanstaal Attorneys-Imirie and Smiley Rotterdam, Netherlands a Dutch contracting company [32] Priority Dec. 7, 1967 3 3 1 Netherlands [3]] 67/16647 ABSTRACT: With a hopperbarge, comprising two air cases swinging with respect to each other and together bordering the hold, sealing the lower side of the hold is difficult, because HOPPERBARGF: 1 the lower edges of the air cases, owing to deformation under 2 Claims 5 ws Figs' influence of the load deflect more in the middle than at their [52] US. Cl 114/29 ends- The PP lower edges of the case being arched [511 u u 3631,3550 and elastic means being mounted between them result in a 50 Field of Search ll4/26-38 good sealnil \1 Pia tented Nov. 10, 1970 Sheet Eu wmw' m m m Q w wmhn H M W ATTORNEYS Patented Nov. 10, 1970 Sheet INVENTOR D E" m m N a :rAN

ATTORNEYS HOPPERBARGE With a hopperbarge, comprising two air cases which border together the barges hold and which can each swing round a ships longitudinal axis between a loading position in which the hold is closed at the lower side, and an unloading position in which the hold is open at the lower side, the problem exists that the opposed longitudinal edges at the lower side of the hold deflect from each other under influence of the weight of the load, because the air cases deform. The deflection is largest in the middle. By means of elastic seals between the longitudinal edges it is tried with known hopperbarges to provide effective seal between the deflecting longitudinal edges. This is only partly succeeded, in that the pressure forces between the longitudinal edges, seen over the length of the longitudinal edge are not equable in the loaded position of the barge.

The invention relates to a hopperbarge, comprising two air cases which border together the barges hold and which can each swing round a ships longitudinal axis between a loading position in which the hold is closed at the lower side, and an unloading position in which the hold is open at the lower side, whereby the shape of the opposed longitudinal edges at the lower side of the air cases is such, that they are spaced apart at each place out of their middle more than in their middle during closing the barge. Such a hopperbarge is known. With this barge the two opposed longitudinal edges of the air cases are somewhat arched. During the closing of this known barge the longitudinal edges first bound to each other in the middle. After that the ends of the air cases are drawn with large force to each other by means of hydraulic jacks, whereby the air cases are deformed to such extent, that the longitudinal edges of these cases abut each other over their whole length. When after that the barge is loaded with dredging spoil, owing to their prestress the air cases cannot deform under the load of this dredging spoil in such manner, that the longitudinal edges deflect from each other in the middle. This known hopperbarge requires strong hydraulic jacks and strong drive means for these jacks in order to be able to deform the air cases in the empty position of the vessel to the prestressed position. This known seal is disturbed, however, when, as often occurs during dredging, stones land between the longitudinal edges. If, in order to omit the disadvantage of small stones and suchlike, a strip of elastic material would be mounted between the longitudinal edges, this strip would be, destroyed under influence of the enormously large forces exerted thereon, which are necessary to deform the air cases.

The invention improves the hopperbarge of the last-mentioned kind, in that said hopperbarge comprising seal means is mounted on at least one of the two, longitudinal edges, said seal means consisting of at least one elastically compressible strip, whereby in the empty closed position of the barge the compression of the seal means at each place out of the middle of the longitudinal edges is so much less than that in the middle of these edges as the longitudinal edges, owing to the deformation of the air cases, deflect less form each other at said place than the middles of the longitudinal edges during the loading operation of the barge. With this hopperbarge the seal is equable over the whole length of the longitudinal edges, because the remaining prestress in the elastic means after loading the barge is equably divided over the whole length of the barge. Small stones can penetrate into'the elastic means. Large hydraulic jacks are not per se necessary, because only the relatively flexible elastic means are to be prestressed and no extremely forces are necessary for this.

The mentioned and other features of the invention will be elucidated in the following description with reference to a drawing. Therein show of a preferred embodiment of a hopperbarge according to the invention:

FIG. 1 a section over the line 1-1 of FIG. 3,

FIG. 2 a top view, whereby the barge is somewhat open,

FIG. 3 a top view, whereby the barge is closed and empty,

FIG. 4 a top view, whereby the barge is closed and completely loaded, and

FIG. 5 a characteristic of the applied elastic means.

The hopperbarge according to the invention is mainly built up from two air cases 1 which are pivotably connected to each other by means of two hinges 2 disposed in the ships longitudinal axis. The air cases I enclose the hold 3 between them. All this is so that in the loaded position of the barge the load inclines to swing the air cases 1 from each other into the opened position pointed out with dotted lines in FIG. 1. This is prevented either by means of hydraulic jacks 4 or by means of claws not-shown, which keep the air cases 1 together.

When the oil is exhausted at the piston-rod side of the hydraulic jacks 4, respectively when the above-mentioned claws are brought out of engagement, the barge opens itself. After the load is fallen out of the barge at the lower side, the barge closes itself. In this position the oil outlet from the piston-rod side of the hydraulic jacks can be cut ofi, respectively the above-mentioned claws can be brought into engagement with each other, so that the barge can be loaded then.

The opposed longitudinal edges 5 at the lower side of the barge have a shape as is drawn in exaggerated measure in FIG. 2. The middles M of these edges 5 are positioned closer to each other than the other parts of these edges 5. Over the whole length of each of these two edges elastic means formed by a hollow rubber strip 7 are mounted, the section of which is the same over the whole length in unstressed position of this strip 7. In FIG. 5 the relation between the compression in cm. and the compressure force in kg. per meter is drawn of a hollow rubber strip to be applied said strip having a height and a width of about l0 cm.

In the closed empty position of the barge the strips 7 are compressed in a manner as is shown in FIG. 3 in exaggerated measure. The compression is largest at the place of the middle M of the longitudinal edges 5, whereas this compression decreases independence on the distance from the relating place to the middle. This compression is so that it corresponds with the deflection of the lower edge 5 owing to the deformation of the air cases 1 under influence of the total load. As FIG. 4 shows the strips 7 have a same width over the whole length of the longitudinal edges 5 in the completely loaded position of the barge. The seal pressure is therefore equal over the whole length of the longitudinal edges 5. If under influence of the full load the deformation of each air case 1 is so large, that in the empty position of the barge the deflection in the middle M is equal to 2 cm., each strip 7 is compressed, for instance 4 cm., in the middle M. Then a compression of 2 cm. remains over the whole length of the strip 7 which provides a seal pressure of 2,500 kg./m. over the whole longitudinal edges. In this example the measures pointed out in the drawing are about: a= l0 cm.,b= 12 cm. andc= l6 cm.

I claim:

1. A hopperbarge comprising a pair of load carrying air cases defining the hold of the hopperbarge, means mounting said air cases for swinging movement about a substantially longitudinal axis of the hopperbarge between a load carrying position wherein the hold is closed at the lower side and an unloading position wherein the hold is open at the lower side, means for moving said air cases between load carrying position and unloading position, said air cases having at the lower side thereof opposed longitudinally extending edges which in the unloaded load carrying position of the hopperbarge are in spaced relationship and are in substantially unstressed condition and are of such a configuration that the central portionsof said edges are positioned closer to one another than the remaining portions of the edges, and seal means supported at least by one of said edges, said seal means comprising a relatively flexible plastic strip which in the unloaded load carrying position of the hopperbarge is in prestressed condition and is prestressed to a greater extent in the central portion thereof than in the remaining portions thereof, the stress in said seal means being substantially equal throughout the length thereof when the hopperbarge is fully loaded.

'2. A hopperbarge as defined in claim 1, including seal means supported by each of said edges, each seal means comprising a hollow strip of rubber.

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