WO2007081198A1

WO2007081198A1 - Pontoon, dock and method for a dock

Info

Publication number: WO2007081198A1
Application number: PCT/NL2006/000411
Authority: WO
Inventors: Peter Blonk
Original assignee: Van Der Stoel, Jan Marius; Mulder, Doekle Siebren
Priority date: 2006-01-10
Filing date: 2006-08-04
Publication date: 2007-07-19
Also published as: CN101410291A

Abstract

According to the invention, there is provided an apparatus and method for bringing a vessel to be dismantled to quay level and keeping it so. The apparatus comprises a closable dock into which a vessel can be sailed. The apparatus further comprises a quay bordering the dock, and a pontoon introducible into the dock. The pontoon is displaceable between a first position and a second position. In the first position the pontoon is remote from the water surface. In the second position the pontoon in the dock is nearer to the water surface. Further, the apparatus comprises a position control for controlling the position of the pontoon in the dock, a trim control for controlling the angle of inclination of the pontoon, and a water level control for controlling the water level in the dock.

Description

PONTOON, DOCK AND METHOD FOR A DOCK

The invention relates to an apparatus and method for dismantling a vessel.

At the end of its life, a vessel is dismantled and scrapped. Dismantling of the vessel is done when the vessel is out of water. For the purpose of dismantling, the vessel is usually sailed to Asia, for instance India or Bangladesh, where the vessel is dismantled. This is done by sailing the vessel onto the beach ('beaching'). Next, workers dismantle the vessel on site on the beach. This entails the disadvantage of the relatively high transportation costs of sailing or bringing the vessel to Asia. Another disadvantage is that the vessel is dismantled on the beach, without adequate processing of hazardous or environmentally unfriendly waste products, such as asbestos and oil. This entails a threat to the workers and the local environment. Beach demolition of vessels annually leads to many, sometimes deadly, accidents. Alternatively, the vessel can moor at a quay, where it can be dismantled with the aid of quay cranes. This entails the disadvantage that during dismantling of the vessel, the waste products end up in the water, thereby polluting the water. Further, this requires relatively heavy cranes. Not only are such cranes costly, but also they require a firm foundation of the quay, which renders quay dismantling more difficult still.

The invention contemplates an apparatus and method for dismantling a vessel , whereby the above disadvantages are obviated. It is an object of the invention to provide a dock for environment-friendly dismantling of a vessel. According to the invention, there is provided an apparatus and method for bringing a vessel to be dismantled to quay level and keeping it so, the apparatus comprising: a closable dock into which a vessel can be sailed; a quay bordering the dock; a pontoon displaceable between a first position in which the pontoon is remote from the water surface and a second position in which the pontoon is nearer to the water surface of the dock.

When the pontoon is in the first position in the dock, the vessel can sail into the dock, above the pontoon. Next, the dock can be closed. Alternatively, the pontoon can be outside the dock in the first position, and the vessel is then sailed above it. Next, pontoon and vessel are moved into the dock together, after which the dock can be closed.

By augmenting the buoyancy of the pontoon, the pontoon moves up. The vessel above the pontoon moves up along with it. In this way, the pontoon can be brought into the second position, in which the pontoon is nearer to the water surface, so that the vessel ends up in a substantially dry position. By subsequently raising the water level in the closed dock, for instance by pumping more water into the dock, the pontoon with vessel can be brought to the level of the quay, where it can be dismantled. Parts that have already been separated from the vessel can then be readily placed on the quay to be processed further there. Or the vessel can be moved partly onto the quay to be dismantled there.

The pontoon forms a liquid- tight working floor for cutting parts of the vessel loose. This prevents the water in the dock becoming polluted with waste matter released during dismantling of the vessel. Possibly, the pontoon may be provided with drains for draining waste matter.

As the vessel is approximately at quay level during dismantling, there are no heavy quay cranes required anymore to lift parts of the vessel onto the quay. The vessel or a cut-loose part thereof can now be pulled onto the quay in a simple manner, for instance using a winch. There, the vessel or a cut-loose part thereof can be processed further. Since no heavy quay cranes need to be used anymore, not all walls of the dock need to be made of weighted design to bear the quay cranes. Merely the wall or a part of the wall where the vessel or a part of the vessel is put on the quay may be weighted. As a consequence, in the case of a new dock to be built, savings on the foundation of the walls of the dock can be gained. Usually, the vessel or parts of the vessel will be put on the quay on the side opposite to the entrance of the dock, and only this short stretch will be designed with a heavy foundation. The long sides of the dock can then remain unweighted. This makes it possible to make a new dock to be built of considerably cheaper design. Possibly, the long sides of the dock can also be dug walls. The pontoon can be moved between the first position and the second position by adjusting the buoyancy. The buoyancy of the pontoon is adjustable by providing the pontoon with multiple compartments. These compartments can then be filled with water to a greater or lesser extent.

Also, the water level in the dock can be controlled between a lower level and a higher level. When the water is at a lower level, for instance at the level of a body of water with which the dock is in communication, the vessel can sail into the dock. Next, the water level in the dock can be raised to a higher level in order to bring the pontoon with vessel to quay level. During the change of the water level from the lower level to the higher level, the pontoon can move along in vertical direction. This change of water level in the dock takes place independently of the water level in the surroundings of the dock. When the door is closed, the dock forms a closed basin which cannot be influenced by tides, blowing up or wave formation. Owing,,to the absence of these weather influences, it is possible to bring the pontoon and/or the water level in the dock to a specified level and to keep it there. The invention also provides a dock arranged for cooperation with the submergible pontoon. Furthermore, the invention provides a system for dismantling vessels, which comprises an apparatus and a dismantling unit, which apparatus comprises a dock and a pontoon.

Another aspect of the invention is a method for dismantling a vessel. This method comprises bringing the pontoon in a first position, sailing a vessel into the dock, when pontoon with vessel above it are in the dock, bringing the pontoon from the first position to the second position. In the second position, the pontoon is nearer to the water surface in the dock. The method further comprises raising the water level in the dock until the vessel is approximately at quay level. Furthermore, the vessel can be dismantled. This can be done by shoving the vessel partly onto the quay and cutting a part loose there, or by cutting a part of the vessel loose on the pontoon and then bringing the cut-loose part onto the quay.

The invention will be further elucidated with reference to an exemplary embodiment represented in a drawing. In the drawing:

Fig. 1 shows a diagrammatic top plan view of an embodiment of the dock;

Fig. 2 shows a diagrammatic longitudinal cross-section of a detail at the door of the dock;

Fig. 3 shows a diagrammatic transverse cross-section of the dock;

Fig. 4 shows a diagrammatic longitudinal cross-section of the dock with pontoon in the first position; and

Figs. 5 to 10 diagrammatically show a number of successive steps of the method for bringing a vessel to quay level in accordance with the invention.

It is noted that the drawings are only diagrammatic representations of a non-limiting preferred embodiment of the invention. In the figures, the same or corresponding parts are represented with the same reference numerals.

Fig. 1 shows an exemplary embodiment of a system for dismantling a vessel according to the invention. The exemplary embodiment shown is simple and efficient. The system comprises a dock 1, a pontoon 2, a quay 3 and a dismantling unit 4. Fig. 1 further shows the vessel 5 to be dismantled. The dock 1 is in communication with a body of water 6. The dismantling unit 4 is arranged to separate at least a part of the vessel 5 from other parts of the vessel 5. The separated part of the vessel 5 can then be removed to an area 7 next to the dock 1, where it can be processed or stored. The dismantling unit 4 comprises one or more cranes which are mobile on a, possibly raised, platform and with which a cut-loose section of the vessel can be dismantled.

The water level in the dock 1 is independent of the water level in the surroundings of the dock 1. In Fig. 2 it can be seen that the dock 1 can be closed with a door 14, thus forming a closed basin. The water level in the closed dock 1 can be raised or lowered independently of the water level of the body of water 6. Thus, it may be that the water level in the dock 1 is higher than the water level of the body of water 6. By making use of a closable dock 1, dismantling of the vessel 5 can take place in a protected environment, that is, in an environment not subject to any influence of, for instance, tides, blowing up or wave formation.

In Fig. 2, the pontoon 2 is in the first position I. In the first position I, the pontoon 2 is submerged, being remote from the water surface. In this example, the pontoon 2 in the first position I is near the bottom 9 of the dock 1. Arranged on the pontoon 2 are supporting profiles 10 to support the vessel. The water level 11 in the dock 1 is at the low level, which is equal to the level of the body of water 6 with which the dock 1 is in communication if the door 14 of the dock is open.

As the vessel 5 is approximately at quay level during dismantling, there are no heavy quay cranes needed anymore to lift parts of the vessel 5 onto the quay. As a consequence, the walls 8 of the dock 1 can be made of less heavy design. In this exemplary embodiment, as shown in Fig. 3, the walls 8 are designed as sheet piled walls, but natural walls are also possible. Only the quay 3, shown in Fig. 4, which is on the side opposite to the entrance 18 of the dock 1, should be made heavier to enable it to receive the parts of the vessel 5. If the vessel 5 or parts thereof are put sideways onto the quay 3, the quay of a long side of the dock 1 is of weighted design.

In Fig. 4, the pontoon 2 in the first position I is near the bottom 9 of the dock 1. The door 14 of the dock 1 is open, so that the water level 11 in the dock 1 is equal to the water level of the body of water 6, and a vessel 5 can sail into the dock 1. Further, it can be seen in Fig. 4 that the pontoon 2 comprises multiple compartments 13. These compartments 13 can be separately filled with water. The compartments 13 can be closed off with respect to each other. It is also possible, however, to provide the pontoon with cross partitions not extending throughout the width of the pontoon. Thus, more or less independent compartments are created which are still in communication with each other, while the cross partitions obviate sloshing of the water in the pontoon. By filling the compartments 13 with water to a greater or lesser extent, the buoyancy of the pontoon 2 is adjustable. A position control controls the buoyancy of the pontoon 2.

Preferably, the length and width dimensions of the pontoon 2 correspond substantially with the length and width dimensions of the vessel 5, as can be seen in Fig. 1. The pontoon 2 then forms a liquid-tight working floor which ensures that during work on the vessel 5 no waste matter ends up in the water of the dock 1. As a result, the water of the dock 1 remains unpolluted. The pontoon 2 may be provided with drains through which the waste matter can be caught in the lateral tanks of the pontoon 2. The waste can then be disposed of in an environmentally friendly manner.

Figs. 5 to 10 diagrammatically show a number of successive steps of the method for bringing a vessel 5 to quay level. In Fig. 5, the pontoon 2 is in the first position I, remote from the water surface of the dock 1. The compartments 13 are filled with water and the buoyancy of the pontoon 2 is minimal. The water level 11 is equal to the level of the body of water 6 adjoining the dock 1. The body of water 6 is, for instance, a sea, lake or river. The dock 1 has a door 14 which is open in Fig. 5, so that the vessel 5 can enter through the entrance 18.

When the vessel 5 has sailed into the dock 1, the door 14 of the dock 1 can be closed, as shown in Fig. 6. Possibly, the vessel can also be sailed backwards into the dock. In that case, the deckhouse 17 is on the side of the quay 3 of the dock 1. The pontoon 2 can be moved to a second position II by augmenting the buoyancy of the pontoon 2. By pumping out compartments 13, the buoyancy is augmented and the pontoon 2 moves upwards. Along with the upward movement of the pontoon 2, the vessel 5 moves up along with it. The pontoon 2 can move from the first position I to the second position II in a continuous movement, with the compartments 13 being pumped out gradually. However, the pontoon 2 can also halt in an intermediate position. In the intermediate position, an upper surface 15 of the pontoon abuts against the vessel. In this intermediate position, for instance the deckhouse 17 of the vessel 5 can be dismantled when the vessel has been sailed backwards into the dock 1.

The buoyancy of the pontoon 2 is preferably at least equal to the empty weight of the vessel 5 to be dismantled. The empty weight is defined as 'lightweight displacement tonnage¹.

In a position, for instance an intermediate position or the second position, the buoyancy of the pontoon 2 is kept constant by a position control.

The position control controls the buoyancy of the pontoon 2 in the particular position and ensures that the position of the pontoon 2 in a vertical direction is kept approximately constant. Furthermore, the pontoon 2 comprises a trim control for controlling the angle of inclination of the pontoon. The trim control ensures that the angle of inclination of the pontoon remains approximately equal. Preferably, the angle of inclination is approximately zero, so-called even keel or zero trim. For instance, if the pontoon 2 is in the second position and a part 16 of the vessel is cut loose and moved onto the quay 3, the vessel 5 becomes lighter. As a result, the buoyancy of the pontoon 2 increases. The position control then ensures that the buoyancy of the pontoon 2 is kept constant by letting more water into the compartments, so that the buoyancy of the pontoon 2 decreases again and the horizontal position of the pontoon 2 remains unchanged. The buoyancy of the pontoon 2 can be further augmented by letting water out of the compartments 13. As a result, the pontoon 2 will rise further until the pontoon 2 is in the second position II, as shown in Fig. 7. The pontoon 2 is then nearer to the water surface 11 of the dock 1 and the vessel 5 is then practically dry. Preferably, an upper surface 15 of the pontoon 2 in the second position is above the water surface, so that a dry working floor is obtained.

However, in the second position II, the vessel 5 is not yet at quay level because the water level 11 in the dock 1 is lower than the quay 3. In a next step of the method according to the invention, the water level 11 in the dock 1 is raised until an underside of the vessel 5 is approximately flush with the quay 3, so that the vessel 5 or a part 16 of the vessel can be simply moved onto the quay 3. In Fig. 8 it can be seen that the water level 11 in the dock 1 is higher than the water level of the body of water 6 outside the dock. This is possible because the dock 1 forms a closed basin once the door 14 has been closed. To raise the water level 11 in the dock 1, it is necessary to pump water into the dock 1. To this end, the dock 1 can be equipped with one or more pumps. For raising the water level 11 in the dock 1 and keeping the water level 11 at a desired level, use can be made of a water level control. Once the vessel 5 is at approximately the same level as the quay 3, it can be partly pulled onto the quay, for instance by means of a winch, as can be seen in Fig. 9. The position control of the pontoon 2 then ensures that the pontoon 2 still remains horizontal, despite the fact that less weight is going to bear on the pontoon 2, by filling a number of compartments 13 with water. In Fig. 9 it can be seen that a number of compartments 13 on the side of the door 14 have been filled with water.

The part 16 of the vessel 5 that is on the quay 3 can then be cut loose from the vessel 5, as shown in Fig. 10. The separated part 16 of the vessel 5 can be processed further by a dismantling unit 4 or be stored in the area 7. Bringing the vessel 5 or a part 16 of the vessel onto the quay 3 can be done by means of trolleys on which the vessel 5 or a part 16 of the vessel rests. These trolleys are generally known and are not described in more detail. The further transport of a cut-loose part 16 of the vessel 5 to the dismantling unit 4 also proceeds by means of the known trolleys.

The invention is not limited to the exemplary embodiment described here, and other exemplary embodiments are possible. For instance, the vessel may be moved onto the quay in its entirety and be dismantled there, instead of being dismantled while still on the pontoon. This can lead to a higher production in dismantling vessels.

Also, the vessel may already be cut into parts while the pontoon is still in the first position. The vessel is then sawn into parts with a chain. As cutting up the vessel now takes place in the water, the water of the dock is polluted. The water that is in the dock can then be purified when the vessel is out of the water. The pontoon can then be raised in the same manner, now with a cut-up vessel resting on it. When the pontoon is at quay level, the parts of the vessel can be brought onto the quay.

The apparatus can also be used for maintenance on a vessel. By making use of the apparatus according to the invention for vessel maintenance, the hull of the vessel is simpler to access from the quay, which facilitates the transport of components. This is in contrast with the situation where maintenance is performed in a dry dock and one is limited by the space in the dock. Moreover, the pontoon forms a liquid-tight working floor on which waste matter can be simply removed without polluting the water in the dock.

Both a new dock to be built and an existing dock can be equipped with a floating pontoon according to the invention. The dock can be equipped with one or more pumps for raising the water level in the dock. Further, the dock can be equipped with a water level control to change the water level in the dock and/or to keep the water level constant. The sidewalls of the dock can be natural walls or sheet piled walls or other non-weighted walls. The quay wall situated opposite the entrance of the dock, on the other hand, can be weighted.

For the pontoon, both an existing pontoon and a new pontoon to be built can be used. The pontoon can be equipped with a rail system to facilitate dismantling and/or forward displacement of the vessel or of cut-loose parts of the vessel. Furthermore, the pontoon can be equipped with a position control and/or a trim control and means for letting water into and/or out of the compartments. The pontoon according to the invention can then be readily used in an existing dock. The length and width dimensions of the pontoon favorably correspond approximately to the length and width dimensions of the vessel. For a new-built dock, the requirements to be met by the dock to be newly built can be reduced.

Such variants will be clear to those skilled in the art and are understood to fall within the scope of the invention as set forth in the appended claims.

Claims

1. An apparatus for bringing a vessel to be dismantled to quay level and keeping it so, the apparatus comprising: a closable dock into which a vessel can be sailed; a quay bordering the dock; a pontoon introducible into the dock, which is displaceable between a first position in which the pontoon is remote from the water surface and a second position in which the pontoon in the dock is nearer to the water surface.

2. An apparatus according to claim 1, wherein the buoyancy of the pontoon is adjustable.

3. An apparatus according to claim 1 or 2, wherein the pontoon comprises multiple compartments.

4. An apparatus according to one or more of the preceding claims, wherein the buoyancy of the pontoon is at least equal to the empty weight of the vessel.

5. An apparatus according to claim 4, wherein the pontoon has a buoyancy that is sufficient, in the second position, to allow the pontoon and a vessel resting on it to float in the dock.

6. An apparatus according to one or more of the preceding claims, further comprising a position control for keeping the pontoon in position in a vertical direction.

7. An apparatus according to claim 6, wherein the position control controls the buoyancy of the pontoon.

8. An apparatus according to claim 6 or 7, wherein the position control is arranged to bring the pontoon from the first position to an intermediate position, in which intermediate position the pontoon abuts against the vessel , and to bring the pontoon from the intermediate position to the second position.

9. An apparatus according to one or more of the preceding claims, further comprising a trim control for keeping an angle of inclination of the pontoon partly unchanged.

10. An apparatus according to one or more of the preceding claims, wherein the pontoon in the second position is movable along with the water level in an at least partly vertical direction.

11. An apparatus according to one or more of the preceding claims, further comprising a water level control for controlling the water level in the dock.

12. An apparatus according to claim 11, wherein the water level control is arranged to vary the water level between a lower water level and a higher water level or vice versa, which higher water level is such that the pontoon is approximately at the same level as the quay of the dock.

13. An apparatus according to claim 12, wherein the lower water level corresponds to the water level of a body of water with which the dock can be in communication.

14. An apparatus according to one or more of the preceding claims, wherein the dock has an entrance via which the vessel can be sailed in and which entrance can be closed.

15. An apparatus according to one or more of the preceding claims, wherein the dock is arranged with a pump for raising the water level in the dock relative to the water level outside the dock.

16. An apparatus according to one or more of the preceding claims, wherein the dock is arranged with pull means for pulling the vessel or a part of the vessel onto the quay.

17. An apparatus according to claim 16, wherein the pull means comprise a winch.

18. An apparatus according to one or more of the preceding claims, wherein the pontoon is provided with a rail system for guiding the vessel and/or parts thereof.

19. A method for bringing a vessel to be dismantled to quay level and keeping it so, the method comprising:

- bringing a pontoon situated in the dock in a first position, in which first position the pontoon is remote from the water surface, the vessel being sailed above the pontoon;

- bringing the pontoon from the first position to a second position, in which second position the pontoon is nearer to the water surface in the dock;

- raising the water level in the dock to a higher level where the vessel is approximately at quay level; - dismantling the vessel.

20. A method according to claim 19, wherein bringing the pontoon from the first position to a second position comprises augmenting the buoyancy of the pontoon.

21. A pontoon arranged for cooperation with a dock, for forming an apparatus according to one or more of claims 1-18.

22. A dock arranged for cooperation with a pontoon, for forming an apparatus according to one or more of claims 1-18.

23. A system for dismantling vessels, comprising an apparatus according to one or more of claims 1-18 and a dismantling unit for dismantling at least a part of a vessel situated in the apparatus.