Rope maintenance system

Abstract

A method of spooling a crane rope (2) onto a crane drum through a crane rope spooling system (1) from a reel (31) under a predetermined back tension is described and includes the steps of: unspooling the crane rope (2) from a reel (31) and passing the crane rope through a tensioning system (10) comprising a primary back tensioner (12) and a secondary back tensioner (16); gripping the crane rope (2) within the secondary back tensioner (16) and thereby preloading the crane rope (2) with tension prior to the crane rope (2) passing through the primary back tensioner (12); and applying a predetermined back tension to the crane rope (2) with the primary back tensioner (12) as the crane rope (2) is being spooled onto the crane drum under the predetermined back tension. A crane rope spooling system (1) for spooling crane rope (2) onto a crane drum under a predetermined back tension is also described, said system (10) comprising a tensioning system (10) comprising at least a primary back tensioner (12) and a secondary back tensioner (16) and a reel (31).

Claims

1. A method of spooling a crane rope onto a crane drum through a crane rope spooling system from a reel under a predetermined back tension, wherein the method includes the steps of: unspooling the crane rope from a reel and passing the crane rope through a tensioning system comprising a primary back tensioner and a secondary back tensioner; gripping the crane rope within the secondary back tensioner and thereby preloading the crane rope with tension prior to the crane rope passing through the primary back tensioner; and applying a predetermined back tension to the crane rope with the primary back tensioner as the crane rope is being spooled onto the crane drum under the predetermined back tension.

2. The method of claim 1, including monitoring and logging the tension on the crane rope at all times as it is being spooled onto the crane drum to assess the laying-on of the crane rope onto the crane drum.

3. The method of claim 1, including passing the crane rope through a greasing unit and thereby applying grease to the crane rope as it is being spooled onto the crane drum.

4. The method of claim 1, including connecting calibrated weights to a free end of the crane rope for load testing of the crane rope.

5. The method as claimed in claim 1, including configuring the primary back tensioner and the secondary back tensioner to provide resistance against the pulling force of the crane drum, and thereby maintain a defined load on the crane rope as it is spooled onto the crane drum.

6. The method as claimed in claim 1, including positioning the crane rope spooling system on a deck of a vessel and including compensating for heave of the vessel by using a heave compensation mechanism that is configured to move in response to movements of the vessel.

7. The method as claimed in claim 6, wherein the heave compensation mechanism is a movable wheel forming part of the sheave assembly and the method includes weighting down the sheave assembly to prevent lifting of the sheave assembly as the crane rope is spooled on to the crane drum under the predetermined back tension.

8. The method as claimed in claim 1, including the prior steps of unspooling the crane rope from the crane drum, passing the crane rope through the crane rope spooling system, and spooling the crane rope onto a reel drum within a reel drive system.

9. The method as claimed in claim 8, wherein the method includes the prior step of connecting a free end of the crane rope to a cable that is reeled out from an initiation winch, including the further step of pulling the crane rope into the crane rope spooling system by reeling the cable back around the initiation winch and thereby guiding the crane rope into the crane rope spooling system and further including applying a constant tension to the crane rope after it has been pulled into the crane rope spooling system by the initiation winch.

10. The method as claimed in claim 8, including passing the crane rope through a spooling unit before the crane rope is spooled onto the reel within the reel drive system, wherein the spooling unit moves laterally in a repeated motion to evenly lay the crane rope onto the reel drum.

11. The method of claim 8 further including mounting the reel drive system on tracks along which the reel drive system is configured to skid; disconnecting the reel drive system from the reel when the reel is no longer required; skidding the reel drive system between reels; and reconnecting the reel drive system to a new reel to be utilized.

12. The method as claimed in claim 9, including configuring the primary back tensioner and the secondary back tensioner to provide resistance against the pulling force of the initiation winch and thereby maintain the tautness of the crane rope.

13. The method as claimed in claim 12, wherein the method includes tensioning the crane rope as it is removed from the crane drum and applying back tension to the crane rope as it is laid onto the reel within the reel drive system and including preloading the crane rope with tension applied by the secondary back tensioner as the crane rope is spooled onto the reel within the reel drive system.

14. The method as claimed in claim 1, including testing the crane rope using non-destructive testing methods after the crane rope passes through at least part of the tensioning system.

15. The method of claim 14, including changing out the crane rope in response to detection of a defect during testing of the crane rope.

16. A crane rope spooling system for spooling crane rope onto a crane drum under a predetermined back tension, said system comprising a tensioning system comprising at least a primary back tensioner and a secondary back tensioner and a reel.

17. A crane rope spooling system as claimed in claim 16, wherein as crane rope is being spooled on to the crane drum, the secondary back tensioner preloads the crane rope and allows the primary back tensioner to generate a predetermined back tension on the crane rope.

18. A crane rope spooling system as claimed in claim 16, wherein the tensioning system applies back tension to the rope of 20 t-100 t.

19. A crane rope spooling system as claimed in claim 16, wherein the crane rope spooling system comprises monitoring and logging means configured to monitor and log the tension on the crane rope at all times as the crane rope is being spooled onto the crane drum.

20. A crane rope spooling system as claimed in claim 16, wherein the primary back tensioner is a traction winch and wherein the traction winch comprises two drums around which the crane rope is spooled, wherein the drums are adapted to be turned by a motor.

21. A crane rope spooling system as claimed in claim 16, wherein a surface of the primary back tensioner comprises grooves, wherein the grooves are offset or angled such that the crane rope is wound around the primary back tensioner at an angle relative to the axis of the primary back tensioner.

22. A crane rope spooling system as claimed in claim 16, wherein the secondary back tensioner is a 2-track tensioner.

23. A crane rope spooling system as claimed in claim 16, wherein the crane rope spooling system further comprises a grease injector, wherein the grease injector is configured to apply grease to the crane rope.

24. A crane rope spooling system as claimed in claim 16, wherein the crane rope spooling system further comprises a wire guide, wherein the wire guide is adapted to maintain the crane rope at the correct level and angle prior to feeding the crane rope into the secondary back tensioner when the crane rope is being spooled on to the crane drum.

25. A crane rope spooling system as claimed in claim 16, wherein the crane rope spooling system includes an initiation winch located adjacent to the reel, wherein the reel is within a reel drive system; wherein the initiation winch comprises a cable, wherein the cable is connected to a free end of the crane rope on a crane drum.

26. A crane rope spooling system as claimed in claim 16, wherein the crane rope spooling system is further suitable for removing a crane rope from a crane drum and passing the crane rope through the crane rope spooling system.

27. A crane rope spooling system as claimed in claim 26, wherein as the crane rope is being reeled off the crane drum, the crane rope passes through the primary back tensioner prior to passing through the secondary back tensioner; and wherein the crane rope is preloaded with tension by the primary back tensioner before it enters the secondary back tensioner, thereby enhancing the grip of the secondary back tensioner on the crane rope as it feeds through the secondary back tensioner.

28. A crane rope spooling system as claimed in claim 26, further comprising a non-destructive testing unit for testing the crane rope as it is being removed from the crane drum by passing the crane rope through the non-destructive testing unit.

29. A crane rope spooling system as claimed in claim 26, wherein a spooling unit moves laterally as the crane rope is spooled onto the reel within a reel drive system, thereby laying the crane rope evenly across the reel.

30. A crane rope spooling system as claimed in claim 26, further comprising a reel drive system, wherein the reel drive system comprises an empty reel within the reel drive system, onto which the crane rope undergoing testing is spooled.

31. A crane rope spooling system as claimed in claim 27, wherein the secondary back tensioner preloads the crane rope with tension as it is spooled onto the reel within a reel drive system.

32. A crane rope spooling system as claimed in 10, wherein the reel drive system comprises a reel with a new crane rope spooled onto it.

33. A crane rope spooling system as claimed in claim 30, wherein the reel drive system comprises parallel tracks, wherein the reel drive system is configured to skid along said tracks between the crane rope spooling system reel and the reel within the reel drive system and wherein the reel drive system is connected to an active reel, wherein the active reel is the reel on which rope currently in use is spooled.

34. A crane rope spooling system as claimed in claim 16, wherein the crane rope spooling system further comprises a sheave assembly, wherein the sheave assembly comprises a wheel, and wherein the wheel of the sheave assembly is adapted to turn the crane rope and thereby ensure that the crane rope is entering the tensioning system at the correct angle.

35. A crane rope spooling system as claimed in claim 16, wherein the crane rope spooling system further comprises an initiation winch, the initiation winch comprising a winch cable, and wherein when the crane rope is to be removed from the crane drum and passed through the crane rope spooling system, the winch cable is connected to a free end of the crane rope, the initiation winch is turned, and the initiation winch cable is reeled back onto the initiation winch drum; and wherein as the initiation winch cable is reeled in, the crane rope is extracted from the crane drum and pulled into the crane rope spooling system.

36. A crane rope spooling system as claimed in claim 16, wherein the crane rope passes through a sheave assembly and wherein the sheave assembly comprises a wheel, wherein the wheel is configured to turn the crane rope and thereby ensure that the crane rope is exiting the tensioning system at the correct angle.

37. A crane rope spooling system as claimed in claim 36, wherein the sheave assembly comprises a heave compensation mechanism, wherein the wheel of the sheave assembly is configured to move in response to heave experienced by a vessel on which the crane rope spooling system is located.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) In the accompanying drawings:

(2) FIG. 1 shows a first example of a conventional (prior art) wire rope testing system with a capstan winch and reel drive system; and

(3) FIG. 2 shows a second example of a conventional (prior art) wire rope testing system with a sheave, 4-track tensioner and reel drive system. Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

(4) FIG. 3 shows a side view of an embodiment of a crane rope spooling system in accordance with the present invention, where the crane rope is to be removed from the crane, prior to any rope entering the system, as comprising (from left to right) a heave compensation sheave assembly, a grease injector, a traction winch, an NDT unit, a tensioning system, a wire guide, a spooling unit, a reel drive system and an initiation winch;

(5) FIG. 4 shows the crane rope spooling system of FIG. 3 at the start of the method in accordance with the present invention, with the cable of the initiation winch being pulled out for connection to the free end of the crane rope (not shown in FIG. 4);

(6) FIG. 5 shows the crane rope spooling system of FIG. 3 showing the next stage of the method on from the stage shown in FIG. 4, with the cable of the initiation winch having been fully extended through the system towards the free end (not shown in FIG. 5) of the crane rope;

(7) FIG. 6 shows the crane rope spooling system of FIG. 3 showing the next stage of the method on from the stage shown in FIG. 5, with the free end of the crane rope being guided into the sheave assembly;

(8) FIG. 7 shows the crane rope spooling system of FIG. 3 showing the next stage of the method on from the stage shown in FIG. 6, with the crane rope extending further into the crane rope maintenance system;

(9) FIG. 8 shows the crane rope spooling system of FIG. 3 showing the next stage of the method on from the stage shown in FIG. 7, with the crane rope beginning to be laid onto the drum of the reel drive system;

(10) FIG. 9 shows the crane rope spooling system of FIG. 3 showing the next stage of the method on from the stage shown in FIG. 8, with the crane rope reaching it full extent spooled onto the reel drive system;

(11) FIG. 10 shows the crane rope spooling system of FIG. 3 showing the next stage of the method on from the stage shown in FIG. 9, with the crane rope beginning to be returned to the crane (not shown);

(12) FIG. 11 shows the crane rope spooling system of FIG. 3 showing the next stage of the method on from the stage shown in FIG. 10, with the crane rope having been unspooled from the reel drive system and returning to the crane (not shown);

(13) FIG. 12 shows the crane rope spooling system of FIG. 3 showing the next stage of the method on from the stage shown in FIG. 11, with the rope having been further reeled back towards the crane (not shown) and exiting the tensioning system; and

(14) FIG. 13 shows the crane rope spooling system of FIG. 3 showing the next stage of the method on from the stage shown in FIG. 12, with the rope having been reeled back further towards the crane (not shown) and exiting the rope maintenance system.

DETAILED DESCRIPTION OF EXAMPLES OF THE INVENTION

(15) Referring now to the drawings, FIG. 3 shows an example of a crane rope spooling system 1 for spooling crane ropes on to a crane drum (not shown). The system 1 as shown in FIG. 3 comprises, from left to right: a sheave assembly 5 including a heave compensation system 6hc; a grease injector 11; a tensioning system 10 comprising at least a primary back tensioner, in this example a twin-drum traction winch 12 and a secondary back tensioner, in this example a 2-track tensioner 16 and a Non-Destructive Testing (NDT) inspection unit 15 located between the traction winch 12 and the tensioner 16; a wire guide 18; a spooling unit 20 and a reel drive system 30 which comprises at least one reel 31 and more preferably at least one spare reel 39 such that the reel drive system 30 preferably comprises at least two reels 31, 39 and an initiation winch 8.

(16) Optionally the ropes to be maintained are wire ropes, optionally steel wire ropes typically used on cranes (not shown), for example shipboard cranes or offshore cranes (such as platform, rig, and vessel cranes).

(17) The crane rope spooling system 1 is suitable for positioning on the back deck of a sea- or ocean-going vessel (not shown) such as an Offshore Supply Vessel (OSV) (not shown) or Platform Supply Vessel (PSV) (not shown), which can then travel around visiting e.g. oil and gas platforms, rigs, FPSOs and the like (not shown) which have a crane (not shown) whose rope 2 requires to be serviced, inspected, maintained or replaced. The system 1 is sufficiently compact that there is room on the deck of the vessel for several spare reels of new rope, offering the option of changing out multiple defective or damaged ropes during a single trip. Using the back deck of such a vessel as the work space for the system 1 also saves space on the rigs, platforms, FPSOs etc. where space can be extremely limited.

(18) Alternatively, the crane rope spooling system 1 is positioned on a quayside (not shown) or similar onshore location (not shown) and can be used to maintain crane ropes on a vessel (not shown) such as a platform or rig that has a crane (not shown) whose rope requires to be serviced, inspected, maintained or changed out in port (not shown), or can even be used in relation to wholly onshore or land-based cranes (not shown).

(19) As can be seen in FIG. 3, the initiation winch 8 is located immediately adjacent to the reel drive system 30 and is integral with it. To save weight, the initiation winch 8 can comprise a cable 7 made from lightweight materials such as polyester or similar. The cable 7 is sufficiently strong to pull the crane rope 2 into the crane rope spooling system 1 without fraying or breaking.

(20) FIGS. 4-5 show the cable 7 of the initiation winch 8 being reeled out to connect to the free end of the crane rope 2 which is to be removed from the crane drum for testing before the same or a new crane rope 2 is then spooled onto the crane drum.

(21) The crane hook (not shown) is firstly removed from the free end of the rope 2, if required. The initiation winch cable 7 is then connected to the free end of the crane rope 2, in this example terminated by a spelter socket 3. The initiation winch 8 pays in and the cable 7 is reeled back onto the drum of the initiation winch 8, reeling out the crane rope 2 from the crane drum (not shown) and into the crane rope spooling system 1, as seen in FIG. 6. As the initiation winch 8 is reeling the rope 2 into the crane rope spooling system 1, the motor applies a constant tension to the rope 2 through the cable 7.

(22) The rope 2 first passes through the sheave assembly 5, which in this example includes a passive heave compensation system 6hc comprising a movable wheel 6. The wheel 6 can move vertically to compensate for heave of the marine vessel (not shown) on which the crane rope spooling system 1 is located and secured to. In this way, the rope 2 is kept taut and in contact with the wheel 6 at all times, and the rope 2 is prevented from going slack or too tight. To achieve this, the wheel 6 is connected through its central axis to a bracket 6a on either side of the wheel 6. Each bracket 6a is retained within vertical guides 6t so that the wheel 6 may rotate around its axis and move vertically, but is restricted from lateral movement. The vertical movement of the wheel 6 is itself restrained by cylinders 6p which are connected to at least one of and more preferably both of the brackets 6a or a similar resilient device that acts to dampen the vertical motion of the wheel 6. The cylinders 6p provide the main element of the heave compensation system 6hc and thereby prevent damage to the rope 2, the vessel or the system with increased loading, or the components of the sheave assembly 5, through sudden movement caused by e.g. waves hitting the vessel on which the system 1 is located. The heave compensation system 6hc further reduces the power requirements of the crane rope spooling system 1 as the heave compensation system 6hc maintains a constant tension between the traction winch 12 and the crane, by compensating for the heave of the vessel and thereby removing the necessity to alter the speed of either removal of the rope 2 from the crane or return of the rope 2 to the crane.

(23) If the crane rope spooling system 1 is positioned in an onshore location, the sheave assembly 5 may be locked in position so that the wheel 6 can rotate but not otherwise move and thus the heave compensation system 6hc is deactivated or disabled. The wheel 6 then ensures that the rope 2 is entering the tensioning system 10 at the correct angle. The sheave assembly 5 can thus either comprise a heave compensation system 6hc at all times and the operator can merely lock the brackets 6a in place on the tracks 6t if no heave compensation is required, or the sheave assembly 5 may be changed out for a standard sheave assembly (not shown) with no capacity for vertical movement of the wheel 6.

(24) After the rope 2 passes through the sheave assembly 5, as shown in FIG. 7, the rope 2 may then be passed through a grease injector 11. At this stage in the method, as the rope 2 is being reeled out from the crane drum, the grease injector 11 is not applying grease to the rope 2. However, the grease injector 11 can be activated at a later stage in the method to apply grease to the rope 2 after the testing process is complete, while the rope 2 is returning to the crane (e.g. during the later stage shown in FIGS. 10 to 12). When the grease injector 11 is activated, the grease lubricates the rope 2 and protects the rope 2 from both frictional damage and environmental damage.

(25) Returning to FIGS. 6 and 7, after the rope 2 has passed through the grease injector 11 as it is being taken off the crane drum, it is then spooled around the twin drums 13, 14 of the traction winch 12. Each drum 13, 14 comprises two half circular shells that are put together to create the outer surfaces of the drums 13, 14. The shells have grooved surfaces formed on their outer surface (i.e. on their outer circumference) that can accommodate different diameters of rope 2. In order to accommodate different rope diameters, the shells can be taken off and replaced with shells having the appropriate size of grooves; for example one surface may comprise grooves that can accommodate rope with diameter 100-104 mm and another may accommodate a rope with diameter 120-125 mm. The ability to test and change out a variety of ropes with different diameters allows the same system 1 to be used for many different cranes and/or hoists which may have very different tonnage ratings, lifting capacities, and rope diameters. Additionally, the grooves in the surfaces of each drum 13, 14 of the traction winch 12 protect the rope 2 from being crushed against the surface of the drum 13, 14 in contrast to a capstan winch.

(26) The drums 13, 14 of the traction winch 12 are offset from one another vertically so that the rope 2 is spooled onto the drums 13, 14 at an angle in a first direction. The grooves in the surfaces of the first drum 13 are offset from the grooves in the second drum 14, so that the rope 2 is wound around the surfaces of the drums 13, 14 at a second angle, relative to the mutual axis of the drums 13, 14. This negates a fleeting angle between the drums and reduces torque generation within the rope 2 as tension is applied to it throughout the maintenance process. The drums 13, 14 of the traction winch 12 are driven by a motor (not shown) to apply a pulling tension to the rope 2 and to hold it taut as it is fed into the tensioner 16. The traction winch 12 having two drums 13, 14 offers the advantage that the drums act to multiply the tension and force on the rope 2 in a similar fashion to a pulley sheave system.

(27) As shown in FIGS. 3-13, a Non-Destructive Testing (NDT) inspection unit 15 is located between the traction winch 12 and the tensioner 16. The crane rope 2 passes through the NDT unit 15 as it is being transpooled on the reel drum 32 of the first reel 31 of the reel drive system 30 and is subject to non-destructive testing, for example using electromagnetic testing. However, any suitable non-destructing testing method may be used. The testing provides data regarding the integrity of the rope 2, which can then be rendered if desired, providing an operator with a visual output e.g. graphs illustrating any defects such as cracks, corrosion, etc. in the rope 2.

(28) After the rope 2 passes through the traction winch 12 and the NDT inspection unit 15, the rope 2 then passes through the secondary back tensioner 16. In this example, the secondary back tensioner is a 2-track tensioner 16. The 2-track tensioner 16 grips the rope 2 between respective sets of pads such as polyurethane (PU) pads provided on each of its tracks 17, which cooperate to compress the rope 2 without deforming it. The frictional grip provided by the pads of the tracks 17 of the tensioner 16 acts to keep the rope 2 taut as it is being removed from the traction winch 12 (and before that the crane drum) so that the rope 2 is tightly laid onto the drum 32 of the reel 31. Preloading the rope 2 with tension using the traction winch 12 enhances the grip that the 2-track tensioner 16 can get on the rope 2 as it feeds through the tensioner 16 and moreover means that the rope 2 can be wound around the drum 32 with significantly higher tension loads than hitherto possible.

(29) Preferably, one motor drives the twin drums of the traction winch 12 so that both drums of the traction winch 12 work together. Optionally the traction winch 12 is the master motor and the 2-track tensioner 16 is a slave; optionally an operator can set the amount of tension applied to the rope 2 by either or preferably both of the respective traction winch 12 and the 2-track tensioner 16. Optionally the 2-track tensioner 16 comprises at least one further motor. Optionally the 2-track tensioner 16 and the traction winch 12 work synchronously to prevent the rope 2 from sagging between the traction winch 12 and the 2-track tensioner 16. Loss of tension in the rope 2 can potentially lead to unwanted movement of the rope 2 within the NDT inspection unit 15, or problems with the data collected due to the rope 2 not being taut. For example, if the rope 2 was being transpooled onto the reel 31 and the 2-track tensioner 16 was moving the rope 2 more slowly than the traction winch 12, the delay between the rope exiting the traction winch 12 and entering the 2-track tensioner 16 could lead to the rope 2 becoming slack and inspection becoming less accurate and/or tension in the rope 2 is reduced. The motor(s) of the 2-track tensioner 16 and optionally the traction winch 12 offers resistance against the pulling force of the initiation winch 8 and, once the rope 2 has started to be spooled onto the reel 31, against the motor of the reel drive system 30. This resistance prevents the rope 2 moving freely within the system 1, for example sliding backwards or out of components of the maintenance system 1 and also imparts increased tension to the rope 2.

(30) Optionally the reel drive system 30 determines the speed at which the rope 2 is spooled onto the reel 31. Optionally an operator can set the speed of the reel drive system 30. Optionally the reel drive system 30 drives the extraction of the rope 2 from the crane drum. Optionally the crane drum, together with the load applied on the rope by the traction winch 12, determines the speed at which the rope 2 is returned or transpooled onto the crane drum when the crane drum is rotated by its motor (not shown).

(31) Preloading the rope 2 with tension from the traction winch 12 as it is being reeled off the crane drum is particularly useful when the rope 2 is coated in residual grease, as there is a potential risk of slippage of the rope 2 as it passes through the tensioning system 10 (and in particular through the tensioner 16), which may result in damage to the rope 2 and/or the rope 2 not spooling evenly onto the reel drum 32. The preloading of tension on the rope 2 by the traction winch 12 enhances the grip that the 2-track tensioner 16 gets on the rope 2, improving the laying-on of the rope 2 onto the reel drum 32, providing a compact layering of the rope 2 across and on the reel drum 32. Optionally the traction winch 12 and optionally the 2-track tensioner 16 each have a pre-set loading value, and/or optionally have a pre-set combined loading value.

(32) Adjacent to the 2-track tensioner 16, there is a wire guide 18 for keeping the rope 2 at the correct level and angle prior to feeding into the spooling unit 20, when the rope 2 is being removed from the crane and spooled onto the drum 32 of the reel drive system 30 as shown in FIG. 8.

(33) The 2-track tensioner 16 preloads the rope 2 with tension as it is spooled onto the drum 32 of the reel 31. The tensioner 16 typically preloads the rope with 1 t-12 t (1,000 kg-12,000 kg), optionally 1 t-6 t (1,000 kg-6,000 kg) and preferably around 2 t-5 t (2,000 kg-5,000 kg) of tension as it is spooled onto the drum 32.

(34) After the rope has passed through the tensioning system 10, it then passes through a spooling unit 20. The spooling unit 20 is positioned so that it is immediately adjacent to the reel drive system 30, in particular the first reel 31 of the reel drive system 30 as described in more detail below. The spooling unit 20 moves the rope 2 laterally, from side to side relative to the reel 31, as the rope 2 is spooled onto the drum 32 of the reel 31, thereby laying the rope 2 evenly across the drum 32.

(35) The reel drive system 30 comprises a first empty reel 31, which receives the rope 2 that is undergoing testing as it is reeled out from the crane. The reel drive system 30 further comprises at least a second reel 39 with a new rope spooled onto it (not illustrated). Where the rope 2 undergoing testing is identified as requiring changing out, the new rope from the second reel 39 may be used to replace the old rope 2 that has undergone testing and requires changing out.

(36) The reel drive system 30 comprises a skid system 34 that allows sliding movement of at least one tower 36 for connection to the reels 31, 39. The skid system comprises parallel rails 37 extending on either side of the reel drive system 30 and tower 36 which is configured to slide along the rails 37. The reel drive system 36 is connected to the “active” reel that is in current use, which in FIGS. 3-13 is the first reel 31. The reel drive system 34 is connected through the central axis of the reel 31 so that the reel 31 can rotate around the tower 36.

(37) The tower 36 may comprise lifting apparatus (not illustrated). When the tower 36 is connected to a reel 31, 39, the lifting apparatus lifts the reel 31, 39 from the surface on which it is resting and thereby permits rotation of the reel 31, 39 around the tower 36.

(38) The reels 31, 39 of the reel drive system 30 are each on pallets 35, 38 and thus can be easily lifted and repositioned, for example by a crane on vessel itself, or at the quayside or other onshore location when the reels 31, 39 are to be disposed of. Where, for example the crane rope 2 has been identified as defective and must be changed out, the rope 2 is completely removed from the crane so that the crane drum is empty and can receive a new replacement rope. The tower 36 is disconnected from the reel 31 and slid along the rails 37 to the second reel 39, which is holding new crane rope. The tower 36 is connected through the axis of the second reel 39 and the second reel 39 is then lifted from the pallet 38. Preferably, the pallets 35, 38 are seated on platforms (not shown), with the first platform holding the first pallet 35 at a higher level than the second platform holding the second pallet 38. This permits the new replacement rope to pass underneath the first reel 31 as it is payed out from the second reel 39.

(39) The return of the rope 2 to the crane drum following testing by the NDT unit 15 is shown in FIGS. 10-13 and is substantially the same whether it is the old rope 2 being returned or a new rope being transpooled onto the crane drum. In this example, it is the same rope 2 being returned. As the rope 2 is being returned to the crane, it is payed out from the reel 31 and reeled in by the crane. The rope 2 passes through the spooling unit 20 and the wire guide 18, both of which guide the rope 2 from the reel 31 into the 2-track tensioner 16.

(40) The 2-track tensioner 16 preloads the rope 2 and allows the traction winch 12 to generate much greater tension on the rope 2 as it is transpooled onto the crane drum. The 2-track tensioner 16 preferably preloads the rope 2 with a force within the range of 1 t-12 t (1,000 kg-12,000 kg), optionally 1 t-6 t (1,000 kg-6,000 kg), more preferably around 2-5 t (2,000 kg-5,000 kg) prior to the rope 2 being spooled onto the traction winch 12.

(41) The traction winch 12 applies a predetermined back tension within the range of around 40 t-80 t (40,000 kg-80,000 kg), with the predetermined value being dependent/predetermined on the rope manufacturer's specifications. This leads to a total back tension on the rope 2 as it returns to the crane of about 20 t-100 t (20,000 kg-100,000 kg), preferably 40 t-80 t (40,000 kg-80,000 kg) in total, with the final value again being dependent on the manufacturer's specifications. In other words, the crane rope manufacturer specifies what total back tension the crane rope 2 should/must experience when wound onto the crane drum and the operator responsible for spooling the crane rope onto the crane drum will therefore take that manufacturer specified tension into account when setting the said predetermined tension figure. The tension that is applied to the rope 2 can be monitored and logged in real-time via a load cell (not shown) within the traction winch 12 as the rope 2 returns to the crane, which provides confirmation to users of the crane rope spooling system 1 that the rope 2 is being laid onto the crane drum tightly and in accordance with the manufacturer's specifications.

(42) After the rope 2 passes through the traction winch 12 on its way back to the crane drum, it feeds through the grease injector 11, which applies a coating of lubricative and protective grease to the outside of the rope 2. This reduces frictional damage to the rope 2 as it is used and protects the wires and core of the rope 2 from the environment.

(43) Finally the rope 2 passes through the sheave assembly 5 to turn approximately 90° and return to the crane in a substantially vertical orientation. The predetermined back tension that is applied to the rope 2 is experienced by the sheave assembly 5 as the rope turns around the wheel 6. The sheave assembly 5 is therefore weighted down by calibrated weights 4, which weigh around 60 t-80 t (60,000 kg-80,000 kg). The calibrated weights 4 are typically greater in weight than the maximum back tension applied to the rope 2 and which hold the sheave assembly 5 in place and resist the pulling and lifting effect of the back tension on the rope 2. The new rope can be loaded with the calibrated weights for additional back tension.

(44) Modifications and improvements may be made to the examples hereinbefore described without departing from the scope of the invention.