BILGE SHORE FOR SHORING A SHIP IN A DOCK

Abstract: Bilge shores (3) are provided on either side of the conven­ tional keel blocks (2) on the dock bottom. The bilge shores (3) comprise a height setting device the setting of which is such that in unloaded condition said bilge shores (3) project above the keel blocks (2). The bulge shores (3) are likewise provided with a biasing member whose operation is initiated when the ship (4) rests on keel blocks (2) and bilge shores (3), the bias being such that a lateral movement of the ship (4) relative to the keel blocks (2) is substantially resisted.

Description: Title: A method and an apparatus for shoring a ship in a dock by means of specific bilge shores. The invention concerns a method and an apparatus for shoring a ship in a dock which for that purpose is provided on the dock bottom with keel blocks having on either side thereof bilge shores adjustable in height. These conventional bilge shores comprise in general a substructure placed on the dock bottom, a movable superstructure and a height adjustment device connecting the superstructure to the substructure, while said height adjustment device ensures that the superstructure is pressed against the underside of the ship. This height adjustment device is substantially a mechanically-pneumatically, hydraulically or electrically operating device, whether or not remote-controlled. For docking a ship, this ship is positioned above the keel blocks arranged in longitudinal direction, and in the centre of the dock, after which the water is pumped out of the dock or in case of a floating dock the dock is lifted. The ship now beds down on the keel blocks which, according as the water level relatively to the ship becomes lower, are increasingly loaded by the weight of the ship. When all keel blocks support sufficiently, the superstructures of the bilge shores arranged on either side of the keel blocks are brought against the bottom of the ship by means of the height adjustment device. Possibly, the bilge shores may be previously set at the proper height. However, various drawbacks go with the use of these prior art bilge shores. For instance, the height adjustment devices being under water pressure for the remote-controlled bilge shores, may refuse uncontrollably or become unreliable in operation, as a result of which for instance one or more bilge shores are adjusted too high or too low, which may cause substantial damage to the ship. In case of non-remote-controlled bilge shores, the dock has practically always to be pumped out between times in order to set said bilge shores at the proper height. This is very time-consuming and expensive. It is an object of the invention to provide a specifically resilient bilge shore which lacks the above drawbacks, to which effect according to the invention the height adjustment device comprises a resilient construction provided between the superstructure and the substructure and a biasing member for biasing the resilient construction. In particular, the resilient construction comprises a resilient material, e.g. in the form of springs or a so-called rubber fender. Such a resilient construction has the advantage that no remote control is necessary any longer. Moreover, the super structure is very simple and the chance of an incorrect operation is substantially excluded. When further ensuring that the bilge shores according to the invention in unloaded condition are higher than the keel blocks, i.e. no ship rests on the bilge shores yet,the ship to be docked during the pumping out or during the lifting of the dock, will first touch the bilge shores and subsequently bed down on the keel blocks. During this procedure first the resilient bilge shores are compressed until the weight of the ship is taken up by the keel blocks. According to the invention it is of relevance as a matter of fact that first the bilge shores are compressed in order to provide a certain amount of spring pressure at a given compression of the resilient construction, in order to maintain the equilibrium of the ship after it rests on the keel blocks relatively to its longitudinal axis. This feature fixes the minimum height of compressed bilge shores, so that also the maximum height of the bilge shores with unloaded resilient construction is fixed, i.e. is considerably higher than the height of the keel blocks. By now applying a bias to the resilient construction, the height of the bilge shore is restricted, while the required maximum spring pressure in compressed state of the bilge shores is not altered. This result has the advantage that a ship of larger draft can be docked, for the height of the bilge shores is a measure for the admissible draft during the docking. By using a resilient construction in the form of e.g. a simple spring, the bilge shore according to the application will be operating substantially without failure and whence will not cause damage, in contrast to the prior art bilge shores. When during docking, e.g. by pumping over ballast from starboard to port, the weight distribution of the ship is changed, the ship will further compress the resilient bilge shores placed on port side due to the larger weight on port side. This compression causes on port side a larger and on starboard side a smaller counter-pressure of the resilient bilge shores, so that a new equilibrium condition is produced. By providing according to the invention a stop element for the superstructure, the compression is blocked at a maximum permissible magnitude, so as to prevent the ship from heeling over in an unacceptable manner in case a change in weight takes place that is larger than the maximum spring pressure. Some embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 shows an arrangement in a dock of the resilient bilge shores arranged on either side of the keel blocks, while in the rest position the superstructure of the bilge shores project above the keel blocks; Fig. 2 shows a ship resting on the bilge shores and keel blocks, which ship may roll within given limits by the resilient bilge shores; Fig. 3 is a diagrammatic view of a first embodiment of a bilge shore; Figs. 4 and 5 are diagrammatic views of a bilge shore the top surface of the superstructure of which rests against the underside of a flat ship, a ship with rise of floor, respectively; Fig. 6 shows a second embodiment of a bilge shore; Fig. 7 shows a third embodiment of a bilge shore. Fig. 1 shows a diagrammatic arrangement of a dock 1 on the bottom of which there are arranged keel blocks 2 with on either side thereof compressible bilge shores 3. The bilge shores are designed in such a manner that they project above the keel blocks in initial position along e.g. a distance d. When, after the docking of the ship 4,the dock is pumped out or in case of a floating dock, the dock is lifted, the bottom of the ship will first come to rest on the bilge shores, which subsequently are compressed to such extent until the ship comes to rest on the keel blocks. The compressible bilge shores 3 are designed in such a manner that, after having being compressed along the distance d, they provide a sufficient spring pressure for maintaining the ship in equilibrium relative to the keel blocks. This spring pressure is normally so large that the bilge shores are capable of also resisting within certain limits a rolling S (Fig. 2) of the ship relatively to its longitudinal axis, as a result of e.g. a displacement of a weight from star board to port and vice versa. Three embodiments of a bilge shore will now be described in more detail, with reference to Figs. 3-7. The embodiment indicated in Fig. 3 shows a bilge shore 3 comprising a substructure 5 to be placed on a dock bottom, a movable superstructure 6 in the form of e.g. a beam which is adapted to rest against the underside of a ship, anda resilient construction 7 in the form of springs connecting the superstructure to the substructure in order to move the superstructure up and down substantially in the vertical plane relatively to the substructure. For limiting the height of said bilge shore and to ensure that the spring pressure provides a sufficient counterpressure along a relatively short compression distance d, see Fig. 1, there is providedabiasing device comprising a plurality of vertical supporting beams 8 the one ends of which are attached to the substructure 5, while the other ends thereof are provided with a vertical guide slot 9 extending in axial direction of the supporting beam, through which slot extends the one end of a horizontally positioned cam 10 which is attached with its other end to the upper beam 6. The top end of the guide slot 9 defines the extent of the bias in the springs 7. The bias can be made adjustable by e.g. mounting the vertical supporting beams 8 slidable in vertical direction on the substructure 5. In order to minimize the damage to a ship to be docked, the top of the beam 6 is provided with a layer of flexible material 11, e.g. rubber. This beam 6 can also be placed at an angle relative to the horizontal in order to support flat ships and ships having a rise of floor, as diagrammatically shown in Fig. 4 and Fig. 5, respectively. As already indicated in the above, the resilient construction is capable of resisting rollings S within certain limits. To prevent the ship from exerting an excessive pressure on the springs 7, due to an excessive list of the ship, the bilge shore is provided with a stop 12 on which the top beam 6 comes to rest after the maximum permissible compression has been reached. It is clear that the length of the guide slot 9 is such that this extends two beyond the stop 12. Fig. 6 shows a second embodiment of a bilge shore 3, provided with a substructure 13 in the form of a block e.g. a block of concrete, a box-shaped superstructure 14 which is telescopically slidable relatively to the block 13, and a resilient construction 15 in the form of a e.g. a rubber fender or a different resilient element or cushion which is mounted in the box-shaped super structure and rests on the block 13. For adjusting a bias in the rubber fender 15, the block 13 comprises a slotted hole 16 through which extends a pin 17 coupled to the box-shaped structure 14. The place of the slotted hole is decisive for the bias in the cushion 15. By providing a stop pin 18 in the block 13, the compression can be limited to a maximum permissible compression value. On the box-shaped structure 14 there are provided a plurality of rubber strips 19 for protecting the underside of a ship to be docked. The bilge shore shown in Fig. 7 is substantially identical to the embodiment shown in Fig. 3, on the understanding that this employs as biasing device a chain 22 coupled between the substructure 20 and the superstructure 21 for biasing the springs 23. Furthermore, a stop 24 is present for limiting the compression of the superstructure 21. Likewise for preventing damage to the underside of a ship to be docked, a layer of flexible material 25 is applied to the superstructure 21. Various alterations can be made without departing from the scope of the invention. For instance, it is possible to construct the resilient construction in such a manner that the spring graph, at a given compression, obtains rather suddenly a higher value. In this case, the stops 12, 18 and 24 are not necessary.

Claims: * CLAIMS * 1. A method of supporting a ship in a dock by means of keel blocks and of bilge shores adjustable in height and placed on either side of said keel blocks, characterized in that the bilge shores (3) adjustable in height have a resilient construction (7; 15; 23) for causing said bilge shores in initial position to project above the keel blocks (2) while the ship to be docked first touches the bilge shores, compressing the same subsequently until the weight of the ship is taken up by the keel blocks, while the compressed bilge shores, due to the spring pressure thereof, substantially resist a lateral movement (S) of the ship resting on the keel blocks. 2. A bilge shore for performing the method, comprising a substructure placeable on a dock bottom, a movable superstructure adapted to be pressed against the underside of a ship, and a height adjustment device connecting the substructure to the movable superstructure, characterized in that the height adjustment device comprises a spring-tensioned biasing device (8,9,10; 16,16; 22). 3. A bilge shore according to claim 2, characterized in that the height adjustment device comprises a stop (72; 18; 24) for limiting the maximum compression of the superstructure (6; 14; 21) and the resilient construction (7; 15; 23) relative to the substructure (5; 13; 20). 4. A bilge shore according to claims 2-3, characterized in that the upper surface of the superstructure (6,14, 21) can be mounted at an angle relative to the horizontal in order to shore both flat ships and ships having a rise of floor.

Inventors: BROUWER, GERT SIEM
Applicants: VEROLME BOTLEK BV
Application year: 1984
Main classification: B63C5
IPC codes: B63C5