GB2098139A

GB2098139A - Vessel with depending pipe for dumping material

Info

Publication number: GB2098139A
Application number: GB8212961A
Authority: GB
Original assignee: Aannemers Combinatie Zinkwerken BV
Current assignee: Aannemers Combinatie Zinkwerken BV
Priority date: 1981-05-08
Filing date: 1982-05-05
Publication date: 1982-11-17
Also published as: FR2505287A1; DE3217034A1; DK193282A; DK156769C; NL188938B; NL8102244A; DE3217034C2; GB2098139B; CA1174990A; NO821493L; NL188938C; NO154339C; NO154339B; IT1150888B; IT8221109A0; FR2505287B1; DK156769B

Abstract

The depending pipe 9 is made from flexible, water-pervious material, e.g. net material and may be provided with rings 13 supporting the material so that the distance between said supporting rings is equal to or smaller than the diameter of the supporting rings. The pipe is composed of a plurality of sections 10 coupled with one another with the aid of flanges 11, 12 arranged at the ends of the sections. The material is fed from a hopper 5 and exits from a bottom chute. Around the chute are driving members for positioning the bottom pipe end. When not in use, the pipe is pulled up into the vessel. <IMAGE>

Description

SPECIFICATION Vessel The invention relates to a vessel comprising a hollow member hanging down from the underside of the vessel intended to shed through it material on the subaqueous ground.

In many cases it is desirable to pour material, for example, stones at given places of a subaqueous ground to protect the ground and/or objects such as pipelines and the like deposited on the ground. As a matter of course it is desirable to acquire a maximum effect by a minimum amount of dumping material, which can, of course, only be achieved when the dumping material is poured as accurately as possible at the place concerned.

For dumping the material there are sometimes used vessels which permit of gradually pushing the material off the deck of the vessel or vessels having a dividable structure so that the cargo of the vessel can be poured out by opening the vessel. Such methods may yield satisfactory results at depths which are not too large, but in the case of greater depths undesirable spread of the dumping material on the ground surface will often occur. In order to eliminate this drawback it has been proposed, in the case of greater depths, to use vessels provided with rigid pipes. However, several disadvantages are inherent to the use of a vessel equipped with such a rigid pipe. Since a vessel equipped with such a pipe is particularly intended to shed dumping material at a greater depth such a pipe must have a great length.

This requires a relatively heavy and complicated device for moving the pipe up and down in its direction of length, since it will frequently not be acceptable and with regard to the water gauge often not be possible to leave the pipe projecting from the vessel's bottom during the displacement of the vessel from one location to another.

Besides, such a pipe having a closed wall meets heavy resistance in the water so that it will be difficult to maintain the vessel at the place concerned, when the material is being dumped, orto displace it accurately along the intended path.

Moreover, all efforts exerted on the pipe have to be absorbed by the fastening structure between the vessel and the pipe, which requires a very sturdy construction. The movements of the ship are, in addition, transferred to the pipe, which may produce undesirably heavy forces in the system as well as undesirable displacements of the lower end of the pipe.

According to the invention the hollow pipe is made from flexible, water-pervious material.

In practice it has been found that by using such a hollow member of flexible, water-pervious material the disadvantages inherent in the above-described uses of the pipe can be avoided.

The forces transferred through the hollow member to the ship may thus be relatively small, since the wall of the hollow member is pervious to water.

Moreover, the hollow member can be readily hauled up or lowered, since it is made from flexible material and can, therefore, be folded, so to say, in the form of bellows. By correct construction of the flexible member it can be ensured that during dumping of the material the ship's movements are appreciably damped along the length of the hollow member so that the usual movements of the ship are substantially not transferred to the lower end of the hollow member. As a result, the lower end of the hollow member can be brought nearer the ground surface or the object to be protected without the risk of contact between the lower end of the hollow member and the ground or the object concerned respectively, which would give rise to damage of the hollow member and/or of the object to be protected.

The invention will now be described more fully with reference to an embodiment of a construction according to the invention shown schematically in the accompanying drawing.

Figure 1 schematically shows part of a ship with a bunker placed on it, with which communicates the top end of a hollow member.

Figure 2 shows on an enlarged scale part of the hollow member.

Figure 3 is a sectional view of the member of Figure 2 taken on the line Ill-Ill in Figure 2.

Figure 4 is an elevational view of the lower end of the hollow member.

Figure 5 is a bottom view of the part of Figure 4.

Figure 6 is a representation like Figure 1,the bunker being moved into an elevated position and the hollow member being partly drawn up.

Figure 7 is a representation corresponding to Figure 6, the hollow member being completely drawn up.

Figure 1 schematically shows part of a ship's hull 1,which comprises a main deck 2 and a lower surface 3. In the ship's hull is arranged a vertical pipe 4. Above the pipe is arranged a bunker 5, which in the position shown in Figure 1 bears on the main deck 2 by means of a bunker supporting frame 6.

With the bunker are coupled a few setting rams 7 extending vertically upwards, with the aid of which the bunker is displaceable in a direction of height, as will be explained more fully hereinafter.

On the main deck 2 is arranged a crane (not shown) which may be displaceable or not displaceable along the main deck for loading the bunker 5 with dumping material. This dumping material may be taken from the hold(s) of the vessel 1 itself or from lighters or the like lying alongside the vessel.

As a matter of course, other charging devices than a crane may be used for supplying dumping material to the bunker.

With an outlet stub 8 on the underside of the bunker communicates the top end of a pipe 8A, which is surrounded by the top end of a flexible, hollow member 9, which extends in the position shown in Figure 1 downwards through the pipe 4 towards the subaqueous ground.

The hollow member 9 comprises a plurality of cylindrical nets 10, each of which is provided at the top and bottom ends with a flange 11 and 12 respectively (Figure 2). Between the flanges 11 and 12 rings 13 extend at equal intervals parallel to the flanges 11 and 12 and are connected with the net 10.

The distance between a flange and the most adja cent ring 13 and the distance between two neighbouring rings 13 are chosen so that said distance is equal to or smaller than the largest diameter of the hollow member 9 comprising the successive nets 10.

The size of the meshes of the net is chosen in accordance with the material to be dumped so that no undesirable amounts of this material can move across the meshes of the net.

The lower flange 12 of the net 10 is connected with the adjacent flange 11 of the next-following net 10 preferably with the aid of quickly fixable and releasable connecting members, which are not shown in detail.

As is shown in Figures 4 and 5, the lower end of the hollow member 9 is provided with a bottom flange 14, to which is fastened the top end of a shoot 15, which constitutes the lower end of the hollow member.

Around the shoot are arranged four or more driving members 16 to 19, which can be put into and out of operation from the vessel.

With the aid of these driving members (see Figure 5) the lower end of the hollow member 9 can be subjected to a force directed to the left or to the right and, respectively directed upwards or downwards, as the case may be, in conjunction so that the lower end of the hollow member 9 can be maintained in a desired position or, respectively, moved into a desired position. By using four driving members of the kind described the control of the lower end of the hollow member can even be ensured when one of the two parallel driving members 16 and 18 and/or one of the two parallel driving members 17 and 19 fails to operate.

It is furthermore shown that the lower flange 14 is suspended to the lower ends of the hoisting cables 20. As is shown in detail in Figures 2 and 3 these hoisting cables are passed through and coupled with cable guides 21 shown only schematically fastened to the flanges 11 and 12 and to the rings, said guides being preferably constructed so that they can be readily opened and closed to remove the cables from the guides orto rearrange them therein respectively.

The top ends of the hoisting cables 20 are connected with winches 22 arranged on the vessel, particuarly on the frame 6.

Figure 1 shows furthermore that to the opening 8 of the bunker is furthermore fastened a downwardly extending pipe 8A, which extends in the top part of the hollow member 9.

The vessel 1 is preferably equipped with driving means with the aid of which the vessel can be displaced both in its direction of length and in transverse direction. Said driving means can be controlled with the aid of a computer or the like in a manner such that the vessel is maintained accurately in a predetermined position or moves accurately along a given track. In this manner it can be ensured that for dumping material on the sea floor and/or on an object lying on the bottom the lower end of the shoot is also maintained at the given area or moves along the given track. In this case the shoot hangs down in the manner shown in Figure 1 and will be in the stretched state. The material to be dumped can then be brought into the bunker 5 and from the bunker be passed through the pipe 8A and the interior of the hollow member 9 towards the end of the hollow member.By suitable choice of the mesh size of the net of the hollow member 9 it can be avoided that undesirably large amounts of dumping material pass across the meshes of the net-shaped material. Water can, however, pass freely through the meshes of the net-shaped material so that the lateral forces exerted through the hollow member on the vessel will be relatively slight.

By correct choice of the weight of the flanges 11, 12 and the rings 13 it can be ensured that the hollow member hanging down from the vessel during operation has such a resilience constant and inertia that at the occurrence of movements these motions of the ship are dying out along the length of the hollow member so that they will substantially not be transferred to the lower end of the hollow member.

Therefore, during operation the lower end of the hollow member can be fairly closely approached to the ground or the object to be covered with dumping material without the risk of the lower end of the hollow member coming undesirably into contact with the ground and/or the object to be covered.

Since by said construction the hollow member has a low weight and will experience little resistance in the water during operation, it may unobjectionably be constructed in a large diameter so that the hollow member according to the invention permits of using dumping material of large size, for example, stones without the risk of clogging of the hollow member.

Owing to the above-described disposition of rings and flanges at relative distances smaller than the diameter of the pipe it is avoided, as has been found in practice, that the passage is undesirably diminished due to torsion of the hollow member about its longitudinal axis.

After the job has been finished or when the hollow member has to be inspected, the bunker 5 can be lifted with the aid of the rams 7 into the position shown in Figures 6 and 7, in which the pipe 8A is completely above the main deck. Then by actuating the winches the hoisting cables 20 can be hauled up so that the flanges 11, 12 and rings of the hollow member are progressively drawn against one another, the parts of the net being folded in bellowslike fashion as is illustrated in Figure 6. Thus standing on the main deck of the vessel one can check the state of the hollow member and if a given part of the material of the hollow member is damaged, said part can be readily taken away by releasing the flanges concerned and be replaced by a new part. Finallythe hollow member can be completely drawn in on the pipe 8A as is illustrated in Figure 7, in which position also the shoot 15 and the driving members secured thereto can be checked.

From the foregoing it will be obvious that by using the construction according to the invention a particularly simple and efficient structure is obtained, which provides surprising advantages with respect to the constructions hitherto used.

In order to ensure a very uniform supply of material to the hollow member 9 a dosing system, for example, a vibrating chute may be arranged between the hollow member 9 and the bunker 5.

Claims

1. A vessel comprising a hollow member hanging down from the vessel intended to dump material through the hollow member on the subaqueous ground characterized in that the hollow member is made from flexible, water-pervious material.

2. A vessel as claimed in Claim 1 characterized in that the hollow member is made from net-shaped material.

3. A vessel as claimed in Claim 1 or 2 characterized in that the hollow member of flexible material is provided with rings supporting the material so that the distance between said supporting rings is equal to or smaller than the diameter of the supporting rings.

4. A vessel as claimed in anyone of the preceding Claims characterized in that the hollow member is composed of a plurality of sections coupled with one another with the aid of flanges arranged at the ends of the sections.

5. A vessel as claimed in anyone of the preceding Claims characterized in that hoisting cables are coupled with the lower end of the hollow member and connected with winches disposed on the vessel.

6. Avessel as claimed in Claim 5 characterized in that the hoisting cables are releasably coupled with the rings in the hollow member.

7. Avessel as claimed in anyone of the preceding Claims characterized in that the lower end of the hollow member is provided with driving members for displacing said lower end of the hollow member.

8. A vessel as claimed in anyone of the preceding Claims characterized in that the top end of the hollow member is connected with the outlet opening of a dumping bunker.

9. A vessel as claimed in anyone of the preceding Claims characterized in that in the top of the hollow member is arranged a shoot through which the dumping material is guided into the hollow member.

10. A vessel as claimed in Claim 8 or 9 characterized in that the bunker together with the hollow member connected herewith is arranged on the vessel so as to be displaceable in a direction of height.

11. A vessel as claimed in anyone of the preceding Claims characterized in that a dosing system is provided for supplying material to the hollow member.