WO2010081911A1

WO2010081911A1 - Pontoon

Info

Publication number: WO2010081911A1
Application number: PCT/EP2010/050585
Authority: WO
Inventors: Stefaan Vandycke
Original assignee: Dredging International N.V.
Priority date: 2009-01-19
Filing date: 2010-01-19
Publication date: 2010-07-22
Also published as: BE1018565A4

Abstract

The invention relates to a pontoon that is adapted for transporting dump material such as rock boulders and stones. The pontoon is on at least two sides provided with a bridge along which dry equipment can be supplied, which pontoon is further provided with anchoring means such as at least one spud pole, that is movable up and down in the vertical direction, as well as means for moving and positioning the pontoon. The pontoon may be used on the one hand for loading and transporting of dump material such as rock boulders and stones, and on the other hand also as positioning platform for a second pontoon. With the pontoon dump material can be dumped into water in an efficient way, in order to form a breakwater for instance.

Description

Pontoon

The invention relates to a pontoon adapted for transporting dump material such as rock boulders and stones. The invention further relates to a method for dumping dump material in water by means of the pontoon, and to the use of the pontoon for loading and transporting dump material.

For many construction works at sea (or in water in general) dump material has to be supplied. A stone breakwater for example is built by dumping rock boulders or stones in sea until the desired height has been reached. The dump material needs to be supplied in large quantities over sometimes long distances. This applies in particular to areas where suitable dump material is hard to find, like in the Middle East. For the transport of dump material, pontoons are frequently used. Pontoons are floating platforms with a typical length of 100 m and more, and a typical width of 30 m and more, and primarily aim at supporting and transporting a load. Most pontoons do not have an engine, and are pushed or dragged by means of a motorized aid vessel. Sometimes however they are provided with a drive.

In a known method for building a breakwater for instance, dump material is supplied by means of a transport pontoon and transferred to the shore. The breakwater is subsequently built up from the shore by taking up the dump material with a gripping tool and dumping it into the sea. The breakwater so to speak grows at the end that faces the sea, whereby the gripping tool uses the already built part as support.

The above described method for dumping dump material in water is time-consuming, and there is a need for an improved method, which is among other things faster and more flexible.

The invention aims to provide such an improved method by providing a pontoon which is arranged for transporting dump material such as rock boulders and stones, and that is on at least two sides provided with a bridge along which dry equipment can be carried, which pontoon is further provided with anchoring means such as at least one spud pole, that is movable up and down in the vertical direction, as well as means for moving and positioning the pontoon. With the invented pontoon a method for dumping dump material in water may be carried out offering several advantages. The method according to the invention comprises on the spot positioning of a pontoon according to the invention, provided with dry equipment, by operating the anchoring means, such as lowering of at least one spud pole until it takes support on the water bottom, or anchoring with 3 to 6 anchors for example, mooring a transport pontoon provided with the dump material on a side of the pontoon, lowering the bridge at said side and carrying the dry equipment to the transport pontoon, and dumping the dump material from the transport pontoon into the water with the aid of the dry equipment. By using the pontoon according to the invention it is no longer necessary to bring to shore a large quantity of supplied dump material. This material may now be dumped in the sea where necessary directly from the transport pontoon, through which the dump material was supplied. This produces a large gain of time. The pontoon according to the invention ensures among other things a precise positioning of the transport pontoon at the height of the works to be carried out. The transport pontoon is known per se and may comprise any pontoon that is arranged to transport dump material such as rock boulders and stones. The transport pontoon may comprise a pontoon according to the invention if desired.

In a preferred embodiment of the method according to the invention the method is characterised in that the pontoon with the anchoring means in unanchored state, such as with at least one spud pole in pulled-up position, is moved by means of the means for moving and positioning the pontoon. By moving the pontoon during dumping of the dump material, and because the transport pontoon is moored to the pontoon and therefore releasably attached to it, the transport pontoon is also moved. Moving hereby happens in a direction in which the construction to be dumped must develop further. In this way it becomes possible to realise a construction considerably faster than was possible hitherto.

The present method and pontoon are preferably applied in waters with restricted depth, in particular in waters with a depth which does not exceed 25 m.

It has advantages to characterise the pontoon according to the invention in that the pontoon comprises a shore side and a water side, both of which are provided with a bridge, and that the bridge on the shore side is provided tiltably on the shore side. Such an embodiment has among other things the advantage that all kinds of dry equipment or materials may be supplied along the bridge. For that purpose the pontoon is moored along the shore and the bridge let down onto the shore. With dry equipment in the context of this application is meant any equipment for manipulating dump material, such as for instance gripping tools, cranes, bulldozers, and the like.

A preferred embodiment of the pontoon according to the invention is provided with a bridge on the shore side which comprises a portal, provided with cables attached to the bridge deck, with which the bridge deck can be moved. This embodiment has the advantage of being able to place the bridge deck in virtually any slope with respect to the deck of the pontoon. In this way a good connection can be made of the bridge with the shore, independent of the degree of loading of the pontoon.

According to the invention, the pontoon is also provided with a bridge at least on another side then the shore side. Preferably this is the opposite side, generally a longitudinal side of the pontoon. The non- shore side is, within the framework of the present application, denoted as the water side. Preferably the pontoon has the characteristic that the bridge on the water side comprises a portal, provided with cables connected to the bridge deck, with which the bridge deck can be moved, and that the portal is tiltably connected to the water side of the pontoon. By means of the bridge on the water side, dry equipment or materials may be supplied to a second pontoon for instance, which second pontoon is moored along the pontoon for that purpose. The bridge on the water side is let down in such a case to the level of the deck of the second pontoon. By providing the bridge on the water side with a portal that is tiltably connected to the water side of the pontoon, the bridge may be brought from a first state to a second state. In the first state the bridge deck is mainly on the deck of the pontoon, so that no components of the bridge stick out outside the pontoon. The portal hereby is directed about vertical or preferably slanting backwards, in other words the portal preferably slantingly extends over the deck of the pontoon. The second state corresponds to a state in which the bridge deck is mainly present on the deck of the second, moored pontoon. This state is reached from the first state by tilting the portal from the backward slanting position to a forward tilting position, whereby at the same time the bridge deck is pulled by the cables, connected to portal and bridge deck, such that said bridge deck undergoes a translation in the direction of the second, moored pontoon.

In a further preferred embodiment the pontoon is characterised in that at least one of the sides thereof is provided with energy absorbing means such as fenders. This can be a shore side or a water side. The energy absorbing means are particularly effective if these have been provided on the water side, at which side a second pontoon is moored, and when moving an assembly of a pontoon according to the invention and a second pontoon, moored to it and provided with dump material, within the framework of this application also indicated with transport pontoon. The energy absorbing means such as fenders in this case not only provide an adequate protection against impact loads, but ensure moreover that the second pontoon can be positioned accurately by moving the pontoon according to the invention.

The means for moving and positioning the pontoon according to the invention can comprise any means arranged for this purpose. It has however advantages if the means for moving and positioning the pontoon comprise at least one winch and tension cable. In particular the pontoon is provided at least on the four angles with a winch about which a cable is led. Each of the four cables is connected to the free end to a fixed point, which point is located outside the pontoon. By now separately tightening or loosening the cables the pontoon may be positioned accurately.

The pontoon according to the invention is preferably applied in a method for dumping dump material in water, which method was already described above. An additional advantage of the pontoon according to the invention is that this pontoon may be used with advantage for loading and transporting dump material such as rock boulders and stones, in other words as a transport pontoon. The pontoon according to the invention is therefore multipurposely usable, in which it differs from the known pontoon.

The invention will now further be clarified by means of the following figures and figure description, without however being limited thereto. In the figures: figure 1 schematically shows a perspective view of a preferred embodiment of a pontoon according to the invention; figure 2 is a schematic view from above of an assembly of another embodiment of a pontoon according to the invention and a transport pontoon; figure 3 is a schematic front view of a bridge on the water side of the pontoon according to the invention; figure 4A is a schematic side view of a bridge on the water side of the pontoon according to the invention in the pulled-up state; figure 4B is a schematic side view of the bridge as shown in figure 4A in the pulled-out state; and finally figures 5 A - 5 C are schematic side views of an assembly of a pontoon according to the invention and a transport pontoon in several mutual positions.

With reference to figure 1 a pontoon 1 according to the invention is shown. In the shown embodiment pontoon 1 comprises a deck 10, which is limited by a shore side 11, a water side 12, a front head side 13 and a rear head side 14. On the shore side 11, pontoon 1 is provide with a bridge 15, and on the water side 12 of a second bridge 16. By means of the bridge 15 dry equipment 31 or materials, such as for example dump material, may be supplied from the shore 51 to pontoon 1 that is moored for that purpose along the shore 51 by means of cables 19, as shown in figure 2. By means of the bridge 16 dry equipment 31 or materials, such as for example dump materials, may be supplied from pontoon 1 to a second pontoon 50 that is moored for that purpose along pontoon 1 by means of cables 29, also shown in figure 2. Pontoon 1 is further provided with two spud poles (17a, 17b), that are movable up and down in vertical direction R, and of means for moving and positioning the pontoon in the form of a number of winches 18, provided with tensioning cables 19 (see figure 2). To pontoon 1 are provided on the shore side 11 (see figure 1) and/or on the water side 12 (see figure 2) energy absorbing means in the form of fenders 30. Furthermore pontoon 1 can be provided with aid supplies such as a workshop 70, a generator room 71, fuel storage 72, and the like.

The bridge 15 on the shore side 11 is tiltably connected to the shore side 11 by means of a hinge connection 20, and further comprises a portal 21. Cables 23, connected with the bridge deck 22 and attached to portal 21, may be tensioned with the aid of pulleys (not shown), as a result of which the bridge deck 22 is pulled up, or can be loosened, as a result of which the bridge deck 22 is let down. The bridge 16 on the water side 12 also comprises a portal 24, that is shown in more detail in figures 3, 4A and 4B. Portal 24 is provided with cables 26, connected with the bridge deck 25 and by which the bridge deck 25 can be moved. The cables 26 run across pulleys 27 and are tensioned or loosened by means of actuators 28. The portal 24 is tiltably connected with the water side 12 of the pontoon 1 in the shown embodiment. This is shown in more detail in figures 4 A and 4B. By providing the bridge 16 on the water side 12 with a portal 24 that is tiltably connected with the water side 12 of pontoon by means of hinge connection 32, the bridge 16 can be brought from a first state to a second state. In the first state, which is shown in figure 4A the bridge deck 25 mainly finds itself on the deck 10 of the pontoon 1. The portal 24 is in this state slantingly tilted backwards (in the direction of pontoon 1), in other words the portal 24 slantingly extends over the deck 10 of the pontoon 1. The second state corresponds to a state in which the bridge deck 25 extends substantially on the deck 52 of the second, moored pontoon 50 (not shown in detail). The second state is reached from the first state by tilting the portal 24 from the backwardly tilted state to a frowardly tilted state, as shown in figure 4B. Tilting is carried out by means of piston 53, which is connected on one side with the deck 10 of pontoon 1, and on the other side with the portal 24. The tilting movement of portal 24 causes a pulling froce to the bridge deck 25 through the cables 26, attached to portal 24 and bridge deck 25, so that this bridge deck undergoes a translation in the direction of the second, moored pontoon 50. To ease the translation, the bridge deck 25 is provided with wheels 54 that can roll over the deck (10, 52) of pontoon 1, respectively transport pontoon 50. It is also possible to bring the portal 24 in the rest state. This state corresponds to a virtually completely tilted back position, as shown in figure 4B (position 55 in dotted line). For completeness may be noticed that bridge deck 25 is provided with tiltable end parts 25 a, and with a guardrail 25b, if desired.

Pontoon 1 is extremely suitable for dumping dump material in water and thereby realising construction works. The method according to the invention comprises positioning a pontoon 1 according to the invention provided with dry equipment 31 (not shown) in the immediate vicinity of the to be dumped construction work. Pontoon 1 is positioned and anchored at least temporarily by letting down the spud poles (17a, 17b) until these take support on the water bottom and are introduced therein, as shown in figure 5 A. In the shown embodiment pontoon 1 is moored along the shore 51 , yet this is not necessary according to the invention. On the contrary, preferably pontoon 1 is positioned (more) remotely from the shore. On the water side 12 of pontoon 1 a transport pontoon 50, provided with dump material 60, is moored. In figure 2 only part of the dump material 60 is shown for clarity. The bridge 16 on the water side 12 is let down so that the dry equipment 31 can be transferred to the transport pontoon 50. Then using the dry equipment 31 the dump material 60 is dumped from the transport pontoon 50 in the water. After the desired quantity of dump material 60 has been dumped the spud poles (17a, 17b) of pontoon 1 are at least partially pulled up so that they come loose of the water bottom, whereupon pontoon 1 is moved by means of the winches 18 and cables 19. Because transport pontoon 50 is moored to pontoon 1 and therefore is releasably connected thereto by means of the cables 29, the transport pontoon 50 is likewise moved during dumping of the dump material. Moving the assembly of pontoon 1 and transport pontoon 50 happens in a direction in which the to be dumped construction work must develop further. In this way a construction work may be realised much more rapidly than is the case up to now.

The assembly of pontoon 1 and transport pontoon 50 may be in several mutual positions as indicated in figures 5 A, 5 B and 5 C. In figure 5 A a situation is shown in which the transport pontoon 50 has been loaded virtually entirely with dump material. The load water-line of transport pontoon 50 is larger than of pontoon 1. The bridges 15 and 16 of pontoon 1 have been let down so that dry equipment (not shown) may be carried from the shore 51 by means of pontoon 1 to transport pontoon 50. Eventually, it is also possible to carry dump material from transport pontoon 50 by means of pontoon 1 to the shore if this is needed. In the shown situation, pontoon 1 and transport pontoon are fixed by means of let down spud poles (17a, 17b). Between pontoon 1 and transport pontoon 50 are provided fenders 30, which allow a mutual vertical translation of pontoon 1 and transport pontoon 50. In figure 5B a situation is hown in which the transport pontoon 50 has been loaded partially with dump material. This situation is reached after a part of the dump material 60 was dumped in the sea. The load water-line of transport pontoon 50 is in the depicted situation approximately equal to the load water-line of pontoon 1. The bridge 16 of pontoon 1 has been let down so that dry equipment (not shown) may be brought from pontoon 1 to transport pontoon 50 and vice- versa. The bridge 15 is provided in upright position, because pontoon 1 has been removed from the shore 51. Because pontoon 1 and transport pontoon 50 are mutually connected by means of bridge 16 and cables 29, and the spud poles (17a, 17b) are provided in pulled-up position the assembly is movable. In figure 5C a situation is shown in which the transport pontoon 50 is virtually empty. This situation is reached after the dump material 60 was dumped virtually completely into the sea. The load water-line of transport pontoon 50 is in the shown situation less than the load water-line of pontoon 1. Pontoon 1 has been moored to the shore 51. The bridges 15 and 16 of pontoon 1 have been let down so that dry equipment (not shown) may be transferred from transport pontoon 50 by means of pontoon 1 to the shore 51. Transport pontoon 50 may in this way be emptied so as to make it available again for loading and transporting dump material 60.

It will be clear that the mutual positions of pontoon 1 and transport pontoon 50 shown in figures 5 A, 5B and 5C merely show a number of possible positions, and that many more other positions are possible. It is for instance possible that the pontoon 1 is used for loading and transporting dump material such as rock boulders and stones. It will also be clear that only some embodiments of a pontoon according to the invention have been shown in the figures and described above, and that many modifications can be made without deviating from the inventive idea.

Claims

1. Pontoon adapted for transporting dump material such as rock boulders and stones, which pontoon is on at least two sides provided with a bridge along which dry equipment can be supplied, which pontoon is further provided with anchoring means such as at least one spud pole, that is movable up and down in the vertical direction, as well as means for moving and positioning the pontoon.

2. Pontoon according to claim 1, characterised in that the pontoon comprises a shore side and a water side, both of which are provided with a bridge, and that the bridge on the shore side is provided tiltably on the shore side.

3. Pontoon according to claim 2, characterised in that the bridge on the shore side comprises a portal, provided with cables attached to the bridge deck, with which the bridge deck can be moved.

4. Pontoon according to any one of claims 1-3, characterised in that the bridge on the water side comprises a portal, provided with cables connected to the bridge deck, with which the bridge deck can be moved, and that the portal is tiltably connected to the water side of the pontoon.

5. Pontoon according to any one of the preceding claims, characterised in that at least one of the at least two sides is provided with energy absorbing means such as fenders.

6. Pontoon according to any one of the preceding claims,, characterised in that the means for moving and positioning the pontoon comprise at least one winch and tension cable.

7. Method for dumping dump material such as rock boulders and stones into water, the method comprising on the spot positioning of a pontoon according to one of claims 1-5, provided with dry equipment, by operating the anchoring means, such as lowering at least one spud pole until it takes support on the water bottom, mooring a transport pontoon provided with the dump material on a side of the pontoon, lowering the bridge at said side and carrying the dry equipment to the transport pontoon, and dumping the dump material from the transport pontoon into the water with the aid of the dry equipment.

8. Method according to claim 7, characterised in that the pontoon with the anchoring means in unanchored state, such as with at least one spud pole in pulled-up position, is moved by means of the means for moving and positioning the pontoon.

9. The use of a pontoon according to any one of claims 1-6 for loading and transporting of dump material such as rock boulders and stones.