Spud carrier

Abstract

A spud system for a dredging vessel with a longitudinal direction includes a spud carrier for mounting a spud therein in a generally vertical stance and a spud carrier cable driving device coupled with the dredging vessel and the spud carrier for driving the spud carrier with respect to the dredging vessel. The spud carrier is moveable with respect to a longitudinal direction of the dredging vessel for advancing the dredging vessel. The spud carrier cable driving device comprises at least an aft cable drive system which extends at an aft side of the spud carrier, and a fore cable drive system separate from the aft cable drive system. The fore cable drive system extends at a fore side of the spud carrier, and each of the aft cable drive system and the fore cable drive system is coupled with the dredging vessel and the spud carrier

Claims

1. A spud system for a dredging vessel with a longitudinal direction, which spud system comprises; a spud carrier for mounting a spud therein in a generally vertical stance, the spud carrier being moveable with respect to the longitudinal direction of the dredging vessel for advancing the dredging vessel, and a spud carrier cable driving device coupled with the dredging vessel and the spud carrier for driving the spud carrier with respect to the dredging vessel, wherein the spud carrier cable driving device comprises at least an aft cable drive system which extends at an aft side of the spud carrier for driving the spud carrier in a longitudinal direction with respect to the vessel, and a fore cable drive system separate from the aft cable drive system, wherein the fore cable drive system extends at a fore side of the spud carrier for driving the spud carrier in a longitudinal direction with respect to the vessel, and wherein each of the aft cable drive system and the fore cable drive system is coupled with the dredging vessel and the spud carrier.

2. The spud system according to claim 1, wherein at least one of the aft cable drive system and the fore cable drive system of the spud carrier cable driving device system comprises at least an upper cable drive system and a lower cable drive system, wherein each of the upper cable drive system and lower cable drive system is coupled with the dredging vessel and the spud carrier such that a spud mounted in the spud carrier maintains a generally vertical stance.

3. The spud system according to claim 2, wherein each cable drive system comprises a cable and a winch, wherein the winch of the upper cable drive system and the winch of the lower cable drive system are operationally coupled for equally paying out or hauling in the cable of the upper cable drive system and the cable of the lower cable drive system such that a spud mounted in the spud carrier maintains a generally vertical stance.

4. The spud system according to claim 1, wherein at least one of the cable drive systems comprises a cable drawback pulley, wherein one end of the cable is coupled with the vessel and the other end of the cable is coupled with the winch for pulling the spud carrier towards the winch or allowing the spud carrier to move away from the winch.

5. The spud system according to claim 4, wherein the drawback pulley is coupled with the spudcarrier, the winch is mounted on the vessel, and the cable extends around the drawback pulley.

6. The spud system according to claim 2, wherein a winch of the upper cable drive system and a winch of the lower cable drive system have a winch driving axis in common such that the winch of the upper cable drive system and the winch of the lower cable drive system are equally driven such that a spud mounted in the spud carrier maintains a generally vertical stance.

7. The spud system according to claim 4, wherein at least one cable drive system comprises an auxiliary sheave between the winch and the drawback pulley for guiding the cable.

8. The spud system according to claim 2, wherein an upper cable drive system and lower cable drive system extend from the aft side of the spud carrier towards the dredging vessel and an upper cable drive system and a lower cable drive system extend from the fore side of the spud carrier towards the dredging vessel.

9. The spud system according to claim 8, wherein the upper and lower cable drive systems on the aft side and fore side of the spud carrier each comprise parallel upper and lower cable drive systems arranged at the starboard-side and port-side of the spud carrier.

10. The spud system according to claim 9, wherein the cable drive system arranged at the starboard-side and the cable drive system arranged at the port-side have a winch driving axis in common.

11. The spud system according to claim 1, wherein at least one of the aft cable drive system and fore cable drive system comprises a plurality of parallel cable drive systems.

12. The spud system according to claim 1, wherein at least one of the cable drive systems is coupled with the spud carrier through a load limiting device.

13. The spud system according to claim 12, wherein the load limiting device comprises a centring cylinder and the fore cable drive system and aft cable drive system are coupled with the spud carrier through the self centring cylinder.

14. The spud system according to claim 13, wherein the centring cylinder comprises a pair of opposite pressurized fluid chambers, and a central pressurized fluid chamber, wherein the pair of opposite pressurized fluid chambers and central pressurized fluid chamber are formed by a pair of pistons and rods, one piston and rod coupled to each of the fore and aft cable drive systems.

15. The spud system according to claim 14, wherein the pair of opposite pressurized fluid chambers and/or the central pressurized fluid chamber are in fluid connection with an accumulator system.

16. The spud system according to claim 15, wherein the accumulator system comprises a source of pressure and the central pressurized fluid chamber is in fluid connection with the source of pressure.

17. The spud system according to claim 15, wherein the accumulator system comprises a number of sources of pressure and the pressurized fluid chambers are each in fluid connection with a respective source of pressure.

18. The spud system according to claim 15, wherein the accumulator system comprises an accumulator with an adjustable gas pressure in order to be able to adjust the centring force.

19. A dredger comprising the spud system according to claim 1.

20. The spud system according to claim 1, wherein the aft cable drive system and fore cable drive system work in parallel.

Description

DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 in perspective view a spud system according to the invention.

(2) FIG. 2 shows a load limiting device for use in the spud system according to FIG. 1.

DETAILED DESCRIPTION OF EMBODIMENTS

(3) FIG. 1 shows in perspective view spud system 1. The spud system 1 is suitable for use in a dredging vessel (not shown).

(4) The spud system 1 comprises a spud carrier 2 and a spud 3 mounted therein in a generally vertical stance. The spud carrier 2 is moveable with respect to the longitudinal direction of the dredging vessel, and is used for advancing the dredging vessel in a manner which is known per se.

(5) The spud system 1 comprises a spud carrier cable driving device generally referred to with reference number 4. The spud carrier cable driving device is coupled with the dredging vessel and the spud carrier 2 for driving the spud carrier with respect to the dredging vessel. The spud carrier cable driving device 4 comprises at least an aft cable drive system 5 and a fore cable drive system 6. The aft cable drive system 5 extends only at the aft side of the spud carrier 2. The fore cable drive system 6 extends only at the fore side of the spud carrier 2. The fore cable drive system 6 is separate from the aft cable drive system 5. Each of the aft and fore cable drive systems is coupled with the dredging vessel and the spud carrier. The aft and fore cable drive systems work in parallel.

(6) In this case, each of the aft cable drive system 5 and the fore cable drive system 6 of the spud carrier cable driving device system 4 comprises an upper and a lower cable drive system, with two parallel drive systems working in parallel on each of the upper and lower cable drive systems. Aft cable drive system 5 includes upper cable drive systems 5a, 5b working in parallel and lower cable drive systems 5c, 5d working in parallel. Fore cable drive system 6 includes upper cable drive systems 6a, 6b working in parallel and lower cable drive systems 6c, 6d working in parallel. Each of the upper and lower cable drive systems is coupled with the dredging vessel and the spud carrier such that a spud mounted in the spud carrier maintains a generally vertical stance. In this case, respective upper and lower cable drive systems extend from both the aft and fore side of the spud carrier towards the dredging vessel. As an example, respective upper and lower cable drive systems are arranged both at the starboard- and port-side of the spud carrier 2, working in parallel. In other embodiments, only one cable drive system can be used in upper cable drive system and/or lower cable drive systems. In a further embodiment, more than two parallel cable drive systems can be used in upper and/or lower cable drive systems or only one cable drive system can be used.

(7) The cable drive systems each comprise a cable 7a-7h. A winch 8a-8h can also be provided for each cable drive system. Winches 8a, 8b, 8e, 8f of the upper cable drive systems 5a, 5b, 6a, 6b and the winches 8c, 8d, 8g, 8h of the lower cable drive systems 5c, 5d, 6c, 6d can be respectively operationally coupled for equally paying out or hauling in the cable of the upper cable drive system and the cable of the lower cable drive system, ensuring that a spud mounted in the spud carrier maintains a generally vertical stance.

(8) The upper cable drive systems 5a, 5b, 6a, 6b each comprise a cable drawback pulley 9a, 9b, 9e, 9f One end 10a of the cable 7a is coupled with the vessel and the other end of the cable 7a is coupled with the winch 8a for pulling the spud carrier 2 towards the winch or allowing the spud carrier to move away from the winch 8a. All respective cable drive systems 5a-5d and 6a-6d have a respective cable drawback pulley 9a-9h. The drawback pulley is coupled with the spud carrier 2. The winch is mounted on the vessel. The respective cable extends or is wound around the respective cable drawback pulley.

(9) Here, the lower cable drive systems 5c, 5d, 6c, 6d each comprise an auxiliary sheave 11c, 11d, 11g, 11h between the winch 8c, 8d, 8g, 8h and the drawback pulley 9c, 9d, 9g, 9h for guiding the cable 7c, 7d, 7g, 7h.

(10) Optionally, the winch of the upper cable drive system and the winch of the lower cable drive system have a winch driving axis 12 in common. In such a system, the winch of the upper cable drive system and the winch of the lower cable drive system are equally driven, helping to ensure that a spud mounted in the spud carrier maintains a generally vertical stance.

(11) One or more cable drive systems (5a, 5c, 6a, 6c) can be arranged at the starboard side and one or more cable drive systems (5b, 5d, 6b, 6d) can be arranged at the port-side of the vessel. These cable drive systems at port side and starboard side can have a winch driving axis 12 in common. Having two or more parallel cable drive systems, as shown in FIG. 1, can help in situations where there is a particularly heavy load. Other embodiments could have only one cable drive system, more than two parallel cable drive systems and/or only upper or lower cable drive systems. Additionally, when there are two or more cable drive systems on a side, the winch driving axis can be in common or can be separate.

(12) As an option, both aft cable drive system 5 and fore cable drive system 6 can be coupled with the spud carrier 2 through a load limiting device 14. An example of such a load limiting device is shown in more detail in FIG. 2.

(13) Load limiting device 14 includes centering cylinder 15, pressure chambers 16, 17, 18, pistons 19 and rods 20, and accumulator system 22. Accumulator system 22 can include a number of pressure sources 22a, 22b which can be connected to the pair of opposite pressure chambers 16, 18, formed by pistons 19 which respectively connect to fore and aft cable drive systems through rods 20; and to central pressurized fluid chamber 17. The different pressure sources 22a, 22b; which provide pressure chambers 16, 17, 18 with pressurized fluid can work to provide overload protection to cable drive systems by helping to keep cables taut during operations. The pressure sources 22a, 22b, can be, for example, an accumulator with an adjustable gas pressure and/or a number of respective sources of pressure. Such a system with a load limiting device 14 can help to keep cables taut, giving overload protection to cable drive system 1.

(14) It will also be obvious after the above description and drawings are included to illustrate some embodiments of the invention, and not to limit the scope of protection. Starting from this disclosure, many more embodiments will be evident to a skilled person which are within the scope of protection and the essence of this invention and which are obvious combinations of prior art techniques and the disclosure of this patent.