Method for separating crane carriage from offshore crane

Abstract

A method for separating a portion of a crane block from a crane jib of a crane, the crane block comprising at least one pulley block, the crane being mounted on a vessel, the method comprising: positioning the crane jib in an inclined position; lowering the portion of the crane block towards the vessel; connecting an auxiliary cable to at least one of the at least one pulley block to be separated from the portion of the crane block; separating the pulley block connected to the auxiliary cable from the portion of the crane block; the pulley block connected to the auxiliary cable is pulled toward the crane jib.

Description

Technical Field

[0001] The present invention relates to a method for separating a crane tackle from an offshore crane, such as a method for separating a part of a crane from an offshore crane. Background Art

[0002] Offshore vessels (such as offshore lifting vessels) are generally equipped with cranes for performing lifting and handling operations at sea. The offshore lifting vessel can be any type of vessel commonly used for offshore operations (especially offshore wind operations). For example, it can be a jack-up rig, a dynamically positioned vessel, a barge, a ship, etc. Specifically, vessels designed to install wind turbine towers, wind turbine blades, monopiles, etc. are generally equipped with large cranes that can lift heavy loads and reach relatively high heights, especially when lifting nacelles or wind turbine blades for installation on wind turbine towers. Due to the increasing height of wind turbine towers and the increasing length of wind turbine blades, such cranes tend to become larger and larger. The crane can become so large that the length of the crane boom extends beyond the length of the vessel. When the crane boom is in a stationary position, meaning the crane boom is in a lying position or a substantially horizontal position where the crane boom is stored during the voyage or transportation from the port to the offshore location or from one offshore location to another, the crane boom extends outside the vessel.

[0003] The offshore crane is equipped with at least one crane tackle for lifting and / or hoisting a load. The crane tackle is provided at the end of the crane boom and can be lowered by a rope reeving system that includes slings passing through pulleys, the crane boom, etc. leading to a winch installed on or near the crane base. The crane tackle itself generally includes a plurality of pulley blocks, and the pulley blocks include pulleys around which the slings pass through. The crane tackle can include a lower tackle and one or more pulley blocks. The lower tackle and the pulley blocks can be detachably connected to each other. The pulley blocks can include one or more pulleys. The lower tackle can generally be arranged to be connected to a handling element such as a crane hook. The crane can be provided with a plurality of crane tackles, each crane tackle including a lower tackle and at least one upper pulley block.

[0004] Such crane trolleys are typically very heavy and can have a weight of, for example, approximately 100 metric tons for lifting a safe working load of up to 2500 metric tons. These figures are exemplary, but it should be understood that the envisaged crane trolleys can weigh thousands of metric tons. When the crane boom and thus the crane trolley at the end of the crane boom are in a stationary position, a part of the crane boom extends outside the ship, and the heavy weight of the crane trolley is suspended at the outer end of the boom outside the ship's side. During navigation, such a heavy weight can introduce large loads (especially fatigue loads) into the crane boom, thereby compromising the strength and lifespan of the crane boom. Therefore, it is necessary to reduce the load on the crane boom, especially during navigation when in a stationary position.

[0005] A solution that has been considered is to provide an extendable boom having at least one boom section that can be extended for operation and can be slid in for storage in a stationary position. In the slid-in position, the crane boom can then be stored within the ship's profile such that the crane trolley can be stored on the ship's deck. Subsequently, the crane trolley does not introduce a load into the crane boom during navigation. However, such an extendable boom is more complex and more expensive. There is still a need for a more cost-effective solution to minimize the load on the crane boom from the crane trolley when in a stationary position.

[0006] An object of the present invention can be to provide an improved state of the crane boom when the crane boom is in a stationary position. Alternatively and / or additionally, an object of the present invention can be to provide an improved method for reducing the load on the crane boom, especially during navigation when in a stationary position on the crane boom bracket.

[0007] To this end, the present invention provides a method according to claim 1.

[0008] With this method, the crane boom in a stationary position extends partially outside the ship, while a separated part of the crane trolley rests on the ship's structure. A part of the crane trolley (especially the lower trolley or a part of the lower trolley) is separated from the crane boom, thereby reducing the weight suspended from the crane boom when the crane boom is in a stationary position, for example, during transportation. When the lower trolley is separated from the crane boom by separating at least one pulley block in the pulley system from the crane trolley, the weight at the crane boom is significantly reduced compared to the entire crane trolley, thereby reducing the load and / or fatigue on the crane boom. In this way, for a crane boom that is longer than the ship and extends outside the ship in a stationary position, the separation of the lower trolley can be accomplished in a safe and reliable manner. Summary of the Invention

[0009] The present invention provides a method for separating a part of a crane tackle from a crane boom of a crane, the crane tackle including at least one pulley block, and the crane being mounted on a ship. The method includes positioning the crane boom in an inclined position; lowering the part of the crane tackle towards the ship; connecting an auxiliary cable to at least one pulley block of at least one pulley block to be separated from the part of the crane tackle; separating the pulley block connected to the auxiliary cable from the part of the crane tackle; and pulling the pulley block connected to the auxiliary cable towards the crane boom.

[0010] A pulley may include a pulley block. A pulley block may include one or more pulleys. It is contemplated that the operation according to the method may be applied to a pulley block or directly to a pulley. The method for separating a part of a crane tackle is understood to be a method for separating a part of one or more crane tackles. A plurality of crane tackles may be provided for the crane, and all or some of them may be partially separated.

[0011] The crane tackle is understood to include a lower tackle, to which one or more pulley blocks may be connected. A pulley block may include one or more pulleys. The crane tackle may be a detachable tackle, wherein a part of the lower tackle having an associated pulley block may be disconnected from another part of the lower tackle having an associated pulley. The method is applicable to any type of crane tackle having at least one removable connectable pulley block such that the lower tackle may be completely or partially separated from the lifting system.

[0012] By positioning the crane boom in an inclined position, the crane tackle may be lowered substantially vertically onto the ship. By providing the inclined position, the crane tackle is within the profile or boundary of the ship when being lowered towards the ship. The profile or boundary of the ship refers to the extent or boundary of the ship, including any outwardly extending parts connected to the ship, such as a boom bracket, as would be seen from a top view of the ship.

[0013] The inclined position may be determined based on the position of the crane tackle relative to the desired position of the crane tackle, the ratio between the length of the crane boom and the length or width of the ship, the ratio between the weight of the crane boom and the weight of the ship, the weight distribution of the crane boom relative to the weight distribution of the ship, weather conditions, or based on a combination of these parameters, or based on any combination of these and / or other parameters.

[0014] The inclined position may be described by the elevation angle of the crane boom relative to the ship (e.g., relative to the deck of the ship) and the azimuth angle of the crane boom relative to the ship. In this specification, the elevation angle may be referred to as the inclination angle.

[0015] The inclined position may include an inclination angle of about 45 degrees between the crane boom and a plane that is substantially parallel to the deck of the ship or parallel to the water surface on which the ship sails (e.g., a substantially horizontal plane).

[0016] The inclination angle may be greater than or less than 45 degrees. The inclination angle may depend on the dimensions, weight, and / or weight distribution of the crane boom and the ship, the position of the crane boom relative to the ship, the free space on the deck of the ship for placing the crane tackle, the position of the support for receiving and / or holding the crane tackle, etc. Advantageously, the inclination angle is such that in the inclined position, the crane tackle can be lowered onto the ship, which may be a dedicated area on the deck of the ship or may be a dedicated structure extending from the ship, such as a boom bracket extension.

[0017] It is also conceivable that the crane tackle can be lowered along a direction that is not substantially vertical.

[0018] Auxiliary components can be used to guide the crane tackle onto the ship in a controlled manner along a predetermined path. The auxiliary components can assist in guiding the crane tackle towards the ship along a substantially vertical direction or along a direction that is not substantially vertical. Such auxiliary components can be, for example, a traction device. The auxiliary components can include an auxiliary cable. After positioning the crane boom in the inclined position, the crane tackle can be lowered towards the ship so as to be able to remove the part of the crane boom from the crane tackle to reduce the force acting on the crane boom.

[0019] The auxiliary cable can be provided by a traction device. Such a traction device can include a traction element, which can be a winch available on the crane or on its crane cabin, or can be a winch available on the deck of the ship or arranged on other structures of the ship (e.g., on a boom bracket or support or on a collapsible deck or a pulley block, etc.). The traction device can include an auxiliary cable, such as a tow cable or a tow rope. The auxiliary components can be a traction device that includes a traction element (such as a winch) and an auxiliary cable (such as a tow cable). One end of the auxiliary cable can be connected to at least one of the pulleys or pulley blocks to be separated from the part of the crane tackle, and the other end can be connected to the traction element of the traction device, such as a winch.

[0020] The opposite ends of the auxiliary cable can be fixed to the traction element, which can include a post or a winch, such as a winch of the crane boom or a separate traction winch arranged on the ship.

[0021] By providing an auxiliary cable, an auxiliary force, such as a traction force, can be applied to at least one of the pulley or pulley group to be separated. The traction force can be applied to effectively increase the weight of at least one of the pulley or pulley group to be separated. The self-weight of at least one of the pulley or pulley group to be separated may not be sufficient to act as a reaction force to the pulling force applied to pull the pulley or pulley group towards the crane boom. In other words, at least one of the pulley or pulley group to be separated may not be heavy enough to allow the pulley or pulley group to be effectively pulled towards the crane boom after separation. The applied traction force, together with the weight of at least one of the pulley or pulley group to be separated, cancels out the pulling force, and thus forms an additional reaction force against the pulling force.

[0022] It can also be envisaged that such an additional force can be applied to at least one of the pulley or pulley group to be separated by means other than using an auxiliary cable.

[0023] After connecting the auxiliary cable, the pulley or pulley group connected to or towed by the auxiliary cable is separated or removed from the part of the crane block. Separating the pulley group connected to the auxiliary cable from the part of at least one crane block can be performed manually or using an automated device. The separated part of the crane block (usually the lower block) is then retained on the ship, while the separated pulley group can be pulled upwards.

[0024] Finally, the towed pulley or pulley group is pulled towards the crane boom. Thus, after being separated, the separated pulley or pulley group can be pulled towards the crane boom in a controlled manner using the auxiliary cable. When the pulley or pulley group is at the crane boom, the auxiliary cable remains connected, but can be pulled tighter to reduce any slack in the cable. By connecting the auxiliary cable to at least one separated pulley group or pulley, the separated pulley group can be guided during upward movement. Preferably, the auxiliary cable can be in a constant tension mode to provide an even more controlled upward pull on the separated pulley group.

[0025] The crane boom can include a support structure (such as a support beam or support surface) disposed in, at, or near the end of the crane boom. The support structure allows the pulley cable to pass through or along the support structure and stops the pulley or pulley block being lifted by the support structure. The support beam is arranged to be adjacent to the detached pulley block when the detached pulley is lifted. Thus, the support structure inhibits further upward movement of the pulley or pulley block, thereby preventing the pulley or pulley block from tangling with other pulley blocks present near the end of the crane boom or on the crane boom or otherwise damaging the components of the crane. The pulley of the crane tackle can be tilted against and / or pulled against the lower surface of the support structure. The support beam can be provided with seats to receive the detached pulley block and thus effectively store the detached pulley block or pulley. Even a part of the pulley or pulley block can be received in the receiving opening of the support structure.

[0026] When the detached pulley block is pulled upward, preferably against the support beam, a part of the crane tackle is advantageously separated from the crane boom and the lifting system. Subsequently, the heavier weight of the part of the crane tackle is at the ship and supported by the ship, while the pulley or pulley block (whose weight is much smaller than that of the entire crane tackle) remains at the crane boom, thereby reducing the load and / or movement on the crane boom. This is advantageous for navigation as concerns about the heavy crane tackle hanging overboard at the end of the crane boom can be reduced. This can be advantageous for the crane boom (especially for the lifespan of the crane boom) while reducing fatigue loads.

[0027] The method can further include lowering the crane boom towards the ship to a stationary position.

[0028] The stationary position can include a substantially horizontal position, thus allowing the ship to navigate more effectively. In the stationary position, the crane boom can extend outside the ship. The crane boom in the stationary position can be positioned on a boom bracket which is arranged to hold the crane boom fixed in the stationary position. With the crane boom in the stationary position, the crane boom can be safely positioned for navigation. The crane boom is generally longer than the ship and also longer than the ship with an outwardly extending boom bracket extension. Even so, a part of the crane boom still freely hangs overboard of the ship.

[0029] Advantageously, the crane tackle can be lowered into a bracket mounted on the ship. Advantageously, a bracket can be provided into which the crane tackle can be firmly received when the crane tackle is lowered onto the ship. After at least one pulley block is separated from the crane tackle, the detached lower pulley can be held in the bracket so that it can be safely and reliably stored during the navigation of the ship.

[0030] The support can include a frame structure to which the lower pulley can be securely fixed. The frame structure can include a receiving space for receiving the crane pulley. The support can be provided with additional fastening means to prevent or reduce the moment of the crane pulley (especially the lower pulley) relative to the support. By providing a support that can safely receive a part of the crane pulley, the support and the part of the crane pulley can be firmly fixed to the ship for navigation. Receiving a part of the crane pulley in the support also allows for safe access to the crane pulley, for example, to disassemble the pulley or pulley block.

[0031] The support can be mounted on the deck of the ship or on another structure of the ship, such as a boom bracket or elsewhere. The position of the support can be selected based on the length of the crane boom.

[0032] During the pulling of the pulley block or pulley connected to the auxiliary cable towards the crane boom, the auxiliary cable can be advantageously tensioned, for example, in a constant tension mode.

[0033] By tensioning the auxiliary cable, an auxiliary force can be applied in a controlled manner to at least one of the pulley or pulley block to be separated as described above. The tensioned auxiliary cable provides a force to at least one of the pulley or pulley block to be separated, thereby increasing the effective weight of the pulley or pulley block.

[0034] The tensioning can be performed in a controlled manner by using a winch, such as a winch of the crane boom or a separate auxiliary winch arranged on the ship.

[0035] During the lowering of the crane boom to the stationary position, the auxiliary cable can be advantageously tensioned, for example, in a constant tension mode. This is done to prevent the auxiliary cable from hanging loosely around the crane boom. Allowing the auxiliary cable to slack during the tilting of the boom to the stationary position will reduce the safety and controllability of the movement of the auxiliary cable.

[0036] When two or more pulley blocks are separated from the lower pulley block and simultaneously pulled upwards, it can be advantageous to connect the associated slings of the respective pulley blocks to a connecting element. Such a connecting element can avoid or prevent twisting or entanglement with the slings during the pulling. In addition, such a connecting element can facilitate the pulley block falling onto the support beam in the upper position.

[0037] The method of lowering the crane pulley onto the ship when the crane boom is in the tilted position can also be used to replace handling tools (such as crane hooks) connected to the crane pulley. Subsequently, the crane pulley can be safely lowered onto the ship, for example, into the support, or on the deck, or on the boom bracket extension, etc. Here, the handling tool can be safely removed from the crane pulley and exchanged with a different handling tool. Such an exchange of the handling tool can then be completed without lowering the entire crane boom to its stationary position.

[0038] To move the crane back into an operating state, the method can be performed in reverse. The crane boom can be moved to an inclined position at which the separated pulley block can be lowered towards the part of the crane carriage on the ship. Preferably, the auxiliary cable still connected to the separated pulley block can be used for guiding and / or for tensioning during the lowering of the pulley block. When the pulley blocks are lowered and received in their respective receiving openings in the separated part of the crane carriage, they can be reconnected to the part of the crane carriage to form the crane carriage. After connecting the pulley blocks to a part of the crane carriage, the auxiliary cable can be disconnected and stored, for example, at a traction element. Subsequently, the crane carriage is reconnected to the crane, and the crane can be in an operating state.

[0039] The invention further provides a ship comprising a crane, the crane comprising a crane boom having at least one crane carriage, the at least one crane carriage comprising at least one pulley block, the at least one pulley block comprising at least one pulley, wherein at least one pulley or pulley block can be separated from a part of the at least one crane carriage, wherein the crane boom is longer than the length of the ship, and the ship is provided, for example for navigation, with a boom bracket for receiving the crane boom in a stationary position, and wherein the ship is further provided with a support for receiving a part of the at least one crane carriage and for separating the part of the at least one crane carriage from the separable at least one pulley or pulley block when the part of the crane carriage is in the support and the crane boom is in an inclined position.

[0040] The crane carriage or crane carriages can comprise one or more split or non-split crane carriages, each crane carriage can comprise a multi-pulley or single-pulley crane carriage. A split crane carriage can comprise two or more parts separable from each other, each part comprising a separate set of pulleys, while a non-split crane carriage comprises a single part from which the pulleys can be removed.

[0041] In the case where the crane carriage comprises a non-split crane carriage, separating the pulley or pulley block from the part of the crane carriage can comprise removing all the pulleys or pulley blocks at once such that the entire single part of the crane carriage remains in the support.

[0042] In the case of a split crane carriage, a first set of pulleys can be removed from a first part of the crane carriage while a second set of pulleys remains coupled to a second part of the crane carriage. If the separated pulley or pulley block is being lifted by the crane boom, the first part of the crane carriage can remain in the support while the second part of the crane carriage can be lifted together with the pulley or pulley block.

[0043] The boom bracket can be arranged to hold the crane boom in a stationary position and can include a frame structure. The boom bracket provides a supporting function such that the boom stays in place solely due to the weight of the boom bracket. Any additional fastening components are optional.

[0044] The ship can be provided with a boom bracket extension extending to the outside of the ship, and the boom bracket extension is provided with a boom bracket for receiving the crane boom in a stationary position.

[0045] The boom bracket extension can be an arm, such as an arm of a truss structure, which also extends to the outside of the ship by itself. By arranging the boom bracket extension outside the ship's hull, the support position of the boom can be made as close as possible to the end of the crane boom (also referred to as the tip of the crane boom). By moving the support position to the outside of the hull, the boom can be supported as well as possible while reducing the moment and load caused by the unsupported outer end of the crane boom.

[0046] Advantageously, the bracket can be arranged on the boom bracket extension, preferably adjacent to the boom bracket. In this way, part of the crane pulley block can be separated close to the boom bracket, so that the length of the auxiliary cable freely hanging on the water surface can be reduced. In addition, the boom bracket and the bracket are as far outside the hull as possible, which is beneficial to the load on the crane boom. For operational efficiency, it is advantageous to position the bracket close to the boom bracket. Thus, the operations of moving the crane to a stationary position can be carried out in the vicinity of each other. Of course, the bracket can also be positioned, for example, on the deck, while the boom bracket can be at the boom bracket extension extending to the outside of the ship. Considering such a long crane boom, it is advantageous to move the boom bracket as far outside the hull as possible. Even when the boom bracket is positioned as far outside the hull as possible, the freely hanging part of the crane boom still extends further than the boom bracket. Such a freely hanging part is not supported and is preferably limited in length to reduce the load and / or the tipping moment.

[0047] The features of the dependent claims provide further advantageous embodiments. Description of the Drawings

[0048] The present invention will be further illustrated with reference to the accompanying drawings, which include diagrams of exemplary embodiments. The following figures are in the drawings.

[0049] Figure 1 A schematic side view of a crane including a crane pulley block is shown, in which the crane boom is arranged in an inclined position.

[0050] Figures 2a and 2b show schematic side views of a crane pulley block including at least one pulley set.

[0051] Figure 3Shows a schematic side view of a crane including a crane pulley block, where an auxiliary cable is connected to at least one of the pulley or pulley group to be separated.

[0052] Figures 4a and 4b show schematic side views of the crane pulley block after connecting the auxiliary cable to at least one of the pulley or pulley group to be separated.

[0053] Figure 5 Shows a schematic side view of a crane including a crane pulley block, where at least one of the pulley or pulley group to be separated is pulled out of the crane pulley block.

[0054] Figures 6a and 6b show schematic side views of the crane pulley block after pulling out at least one of the pulley or pulley group to be separated from the crane pulley block.

[0055] Figure 7 Shows a schematic side view of a crane including a crane pulley block, where at least one of the pulley or pulley group to be separated is lifted.

[0056] Figures 8a and 8b show schematic side views of the crane pulley block during the lifting of at least one of the pulley or pulley group to be separated.

[0057] Figure 9 Shows a schematic side view of a crane including a crane pulley block, where at least one of the pulley or pulley group to be separated has been pulled upward towards the crane boom.

[0058] Figures 10a and 10b show schematic side views after at least one of the pulley or pulley group to be separated has been pulled upward towards the crane boom.

[0059] Figure 11 Shows a schematic side view of a crane including a crane pulley block, where after at least one of the pulley or pulley group to be separated has been pulled upward towards the crane boom, the main lifting cable is tensioned.

[0060] Figures 12a and 12b show schematic side views of at least one of the pulley or pulley group to be separated after tensioning the main lifting cable.

[0061] Figure 13 Shows a schematic side view of a crane including a crane pulley block, where the crane boom is being lowered to the rest position.

[0062] Figure 14 Shows a schematic side view of a crane including a crane pulley block, where the crane boom is in the rest position.

[0063] Figure 15 Shows a more detailed side view of the boom bracket extension.

[0064] Figures 16a and 16b respectively show a crane pulley block in a connected state and a separated state.

[0065] Figure 17 A side view showing a part of a crane including a boom bracket extension is shown.

[0066] Figure 18 A ship including a crane is shown.

[0067] Figure 19A and Figure 19B A side view of the top of a crane boom is shown where not all pulleys or pulley blocks have been pulled up. Detailed Description

[0068] It should be noted that the drawings are given by way of exemplary examples and are not intended to limit the present disclosure. The drawings are not drawn to scale. Corresponding elements are denoted by corresponding reference numerals.

[0069] To achieve a reasonable fatigue life of the crane boom related to sea transportation conditions, it may be necessary to store a part of the crane pulley block (such as the lower main hoist pulley block) in a bracket. This means that for example, the cable including the wire rope may have to be withdrawn to store a part of the crane pulley block in the bracket and lower the crane boom to the boom bracket. After sea transportation, the crane pulley block may have to be reeved again.

[0070] The present disclosure includes technical solutions for a more simplified and user-friendly procedure for splitting out a larger part of the crane pulley block 3 without the pulley block 6, without having to perform (un)reeving actions.

[0071] In the exemplary drawings, the pulley block is connected to the bracket of the crane pulley block using pins that can be easily removed, so as to disconnect the pulley block from the bracket of the lower pulley block (see Figure 16A and Figure 16B ). Then the pulley block can be pulled up and stored against the support beam structure at the end of the boom. The weight of the boom reduced due to splitting out the lower pulley block part can reach for example about 75t. The total weight of the lower pulley block can be for example 100t. Advantageously, it may no longer be necessary to withdraw the pulley block.

[0072] Figure 1Shows the main elements of the crane 1, including the crane boom 2, the crane tackle 3 and the main hoisting rope 4. The crane 1 may further include additional components known in the art, such as a main winch (not shown), which may include one or more winches. The present invention provides a method for separating a part of at least one crane tackle (such as the crane tackle 3) including at least one pulley block 6 from the crane boom 2 of the crane 1 mounted on a ship (not shown in the figure), and the at least one pulley block 6 includes at least one pulley.

[0073] To achieve a reasonable boom fatigue life related to sea transportation conditions, it may be necessary to store the crane tackle 3 in a bracket. The wire rope can be withdrawn so that the tackle can be stored in the bracket and the boom can be lowered towards the boom bracket. This can be a complex and time-consuming operation, especially under sea conditions. After sea transportation, the tackle must be reeved again.

[0074] The present disclosure provides a more simplified and user-friendly procedure for splitting out a larger part of the crane tackle 3 without the pulley block 6 without having to perform the (un)reeving action.

[0075] The crane boom 2 can be mounted on the crane 1 through a rotatable connection 5, and the rotatable connection 5 connects the crane boom 2 to the static part of the crane 1 that can be fixed to the ship.

[0076] The crane 1 can be mounted on a ship, for example, on a ship with a length and / or width less than the length of the crane boom 2.

[0077] The crane tackle 3 can include any type of crane tackle, such as a lower tackle with a separable pulley block or a split tackle. The main hoisting rope 4 can include a single rope, a double rope or any other type of rope. In the drawings, a double rope is shown by way of illustration.

[0078] The method includes positioning the crane boom 2 in an inclined position and lowering a part of the crane tackle towards the ship.

[0079] In Figure 1 the crane boom 2 is shown in an exemplary inclined position. By positioning the crane boom 2 in an inclined position, the crane tackle 3 can be lowered substantially vertically onto the ship rather than to a position outside the ship, such as into the sea water.

[0080] The inclined position can be described by the elevation angle of the crane boom relative to the ship and the azimuth angle of the crane boom relative to the ship. In this specification, the elevation angle can be referred to as the inclination angle. The elevation angle or inclination angle is denoted as α in the figure.

[0081] The inclined position may include an inclination angle α of about 45 degrees between the crane boom 2 and a substantially horizontal plane that is substantially perpendicular to the main sling 4, as shown in the figure. The inclination angle α may be greater than or less than 45 degrees.

[0082] An effective boom length of A×B can be achieved, where A includes the length of the crane boom 2 and B includes the cosine of the inclination angle α. Since the inclination angle α is in the range from 0 degrees towards 90 degrees, a shorter boom length can be achieved. Thus, the inclination angle α can be adjusted according to the environment.

[0083] It is also conceivable that the crane 1 includes a plurality of crane trolleys 3, and the plurality of crane trolleys 3 can be arranged at a certain distance along the crane boom 2. In this case, the method can be applied to the plurality of crane trolleys 3 sequentially or in parallel.

[0084] Figure 1 It is also shown that the crane trolley is being lowered into a bracket behind the boom bracket support structure in order to be separated from the pulley or pulley block 6.

[0085] Figures 2a and 2b show a schematic side view of the crane trolley 3 including at least one pulley block 6. The crane trolley 3 further includes a hook 7, and the hook 7 can include any type of hook, such as a single hook or a double hook, a closed hook or a semi-closed hook, etc. In the drawings, a four-hook is shown as an illustration.

[0086] The method further includes connecting an auxiliary cable 8 to at least one pulley block in at least one pulley block 6 to be separated from a part of the crane trolley. The auxiliary cable 8 can originate from an auxiliary winch of the crane 1 or can originate from another winch existing on the ship. The auxiliary cable can be a rope, for example.

[0087] Figure 3 A schematic side view of the crane 1 including the crane trolley 3 is shown, where the auxiliary cable 8 is connected to at least one of the pulley block 6 or the pulleys to be separated. Figures 4a and 4b show a schematic side view of the crane trolley 3 after the auxiliary cable 8 is connected to the pulley or pulley block 6 to be separated.

[0088] The auxiliary cable 8 can include multiple cables, depending on the settings of the main sling 4 and the pulley block 6 of the crane 1.

[0089] In practice, the auxiliary cable 8 can include a length of up to 200 meters or longer. Advantageously, the length of the auxiliary cable 8 can be too long, so as to provide a length longer than strictly required to reach the pulley.

[0090] Reference Figure 3As well as FIGS. 6a and 6b, an auxiliary cable 8 (e.g., a towing rope) from the crane boom 2 can be guided towards the connection point of the pulley or pulley block 6. The pulley block can be connected to a single auxiliary cable or to multiple auxiliary cables. Subsequently, the pulley block 6 can be disconnected from the lower pulley 3. The device required to connect the pulley block 6 to the bracket of the lower pulley 3 can be part of the crane pulley structure itself, such that no additional device is required to disconnect the pulley block 6 from the lower pulley 3.

[0091] Advantageously, a connecting element (e.g., a rod 9) can be provided between the pulleys 6 located at the two ends of the crane pulley 3, see FIGS. 4a and 4b. This can help prevent the distortion of the pulley or pulley block 6.

[0092] The method further includes separating the pulley connected to the auxiliary cable from a part of the crane pulley. Figure 5 A schematic side view of a crane 1 including a crane pulley 3 is shown, in which at least one of the pulleys or pulley blocks 6 to be separated is pulled out of the crane pulley 3. FIGS. 6a and 6b show a schematic side view of the crane pulley 3 after at least one of the pulleys or pulley blocks 6 to be separated has been pulled out of a part of the crane pulley 3.

[0093] When the auxiliary cable is under tension, by retracting the connecting member of the pulley or pulley block 6, the pulley or pulley block 6 can be pulled out of the crane pulley 3.

[0094] The method further includes pulling the pulley block 6 connected to the auxiliary cable towards the crane boom 2.

[0095] This process uses an auxiliary cable 8, which can originate from an auxiliary winch attached to the crane 1 and is guided from the crane boom 2 to an intended stationary position in the boom bracket structure, see Figure 17 and Figure 18 . There may be objects on the deck (such as cabins, deck crane navigation lights, etc.) that obstruct the indicated path of the auxiliary cable, depending on the maximum height of these objects above the main deck. When the crane auxiliary cable cannot reach the pulley basket, a solution of using an auxiliary winch near the pulley basket is feasible.

[0096] The present disclosure can include a permanent bracket having an inlet to be implemented in the boom bracket support structure, see Figure 15 .

[0097] Figure 7Fig. 0 shows a schematic side view of a crane 1 including a crane block 3, in which at least one of the pulleys or pulley blocks 6 to be separated is being pulled upward. The upward pulling is performed, for example, by a main winch or by another winch on the crane cabin / crane pedestal of a ship, and is achieved by the reaction force provided by an auxiliary cable 8, which can advantageously be set to a constant tension until the pulley or pulley block 6 reaches the crane boom 2.

[0098] Figs. 8a and 8b show schematic side views of a part of the crane block during the upward pulling of at least one of the pulleys or pulley blocks 6 to be separated.

[0099] Reference Figure 7 Figs. 8 and Figure 18 , the pulley block 6 can be lifted out of the crane block until the auxiliary rope is taut. At this time, the auxiliary cable can be switched to the constant tension mode. Subsequently, the pulley block 6 can be lifted towards the support beam 12 with a constant downward pulling tension from the auxiliary cable. This is advantageous because the weight of the pulley block 6 is very light. When the pulley block 6 can be reconnected to the crane block 3 after sea transportation, the same auxiliary cable 8 can be used to pull the pulley block 6 downward to the crane block 3 again. Therefore, the auxiliary cable 8 can remain connected to the pulley block 6 during sea transportation.

[0100] Figure 9 Fig. 14 shows a schematic side view of a crane 1 including a crane block 3, in which at least one of the pulleys or pulley blocks 6 to be separated has been pulled towards the crane boom 2. Figs. 10a and 10b show corresponding schematic side views after at least one of the pulleys or pulley blocks to be separated has been pulled upward towards the crane boom.

[0101] According to Fig. 10b, when the pulley or pulley block can rotate, the pulley or pulley block 6 may become misaligned during the upward pulling. When this occurs, the pulley block 6 may no longer fit well into the receiving opening of the support beam 12. To overcome this problem, the pulling force on the main sling 4 can be increased. In the case where the pulley or pulley block 6 includes a connecting element 9, this will ensure that the pulley or pulley block 6 remains connected to the connecting element 9. The connecting element 9 can include a strut, thereby preventing the pulley from tangling with the pulley cable during the upward pulling.

[0102] Reference Figure 9 Fig. 22 and Fig. 10, the pulley block 6 can be pulled upward until there is (controlled) contact between the pulley block 6 and the support beam 12 at the end of the crane boom.

[0103] Figure 11Fig. 1 shows a schematic side view of a crane 1 including a crane tackle 3, in which after at least one of the pulleys or pulley blocks to be separated has been pulled upwards towards the crane boom, the main sling is tensioned. Thus, the tension on the hauling cable can be slightly released without allowing the hauling cable to go slack.

[0104] Figs. 12a and 12b show schematic side views of at least one of the pulleys or pulley blocks 6 to be separated after tensioning the main sling 4. The pulley or pulley block 6 is now aligned and pulled towards the crane boom 2 in order to prevent the pulley or pulley block 6 from releasing or disengaging.

[0105] The method may further include lowering the crane boom towards the ship to a rest position. This is shown in Figure 13 which shows Figure 13 a schematic side view of a crane 1 including a crane tackle 3, in which the crane boom 2 is being lowered to the rest position, and Figure 14 a schematic side view of a crane 1 including a crane tackle 3 is shown in which the crane boom 2 has been moved to the rest position. In Figure 14 it is shown that the rest position is a substantially horizontal position of the crane boom 2, however, it is also conceivable that the crane boom 2 can rest in a position where the tilt angle α is significantly greater than 0 degrees.

[0106] The crane tackle 3 can be lowered into a bracket mounted on the ship. In the case of a plurality of crane tackles 3, brackets can be provided for each part of each of the plurality of crane tackles, or one or more brackets can be provided, which brackets can include two or more parts of the crane tackle.

[0107] During the pulling of the pulley or pulley block 6 connected to the auxiliary cable towards the crane boom 2, the auxiliary cable 8 can advantageously be tensioned, for example in a constant tension mode. This pre-tension determines the tension of the trailing part on the pulley.

[0108] During the lowering of the crane boom to the rest position, the cable connected to the auxiliary cable can advantageously be tensioned, for example in a constant tension mode, in order to provide greater stability and controllability of the operation, resulting in increased safety.

[0109] The present invention further provides a ship including a crane 1, the crane 1 including a crane boom 2 having at least one crane block 3, the at least one crane block 3 including at least one pulley block 6, the at least one pulley block 6 including at least one pulley, wherein at least one pulley block 6 is separable from a part of the at least one crane block 3, wherein the crane boom 2 is longer than the length of the ship, and the ship is provided with a boom bracket for receiving the crane boom 2 in a stationary position for example for navigation, and wherein the ship is further provided with a bracket for receiving a part of the at least one crane block 3 and for separating the part of the at least one crane block 3 from the separable at least one pulley or pulley block 6 when the part of the crane block 3 is in the bracket and the crane boom 2 is in an inclined position α.

[0110] The boom bracket may be arranged at an angle similar to the inclination angle in the stationary position, for example about 0 degrees, or significantly greater than 0 degrees. The boom bracket may include a shape corresponding to the shape of the crane boom 2. The boom bracket may include additional fastening elements for securely fixing and / or fastening the crane boom 2 to the boom bracket.

[0111] The ship may be provided with a boom bracket extension extending to the outside of the ship, and the boom bracket extension is provided with a boom bracket for receiving the crane boom 2 in a stationary position. The boom bracket extension may provide protection for the crane boom 2 against external factors such as wind and water. The boom bracket extension may form an extension of the boom bracket and may include a shape and / or structure similar to the boom bracket, or may include other or additional materials and / or components at the outer edge to provide better protection for the crane boom 2.

[0112] The bracket may be provided on the boom bracket extension, preferably adjacent to the boom bracket. Alternatively, the bracket may be provided on the ship.

[0113] Reference Figure 14 , the crane boom 2 can be lowered to the boom bracket while the auxiliary cable remains connected to the pulley block 6 when stored against the support beam 12. The part of the crane block 3 can be stored on a bracket on the boom bracket structure. The auxiliary cable can remain connected because for reverse operation, when the pulley block 6 will be connected again to a part of the crane block 3, the pulley block 6 can be pulled down again from their position at the support beam 12 towards this part of the crane block 3. The self-weight of the pulley block 6 may not be sufficient to lower them by themselves.

[0114] Regarding Figure 15 , the possible position of the bracket is schematically shown, immediately behind the boom support interface structure.

[0115] Figure 16a shows the crane trolley 3 when the pulley or pulley block 6 is connected to a part of the crane trolley. Figure 16b shows the crane trolley 3 when the pulley or pulley block 6 is separated from a part of the crane trolley.

[0116] Figure 17 A side view of a part of a crane including a boom bracket extension is shown. The side view shows the auxiliary cable path from the boom 2 to the boom bracket. The elevation can be about 31 m above the deck of the ship.

[0117] Figure 18 A top view of a ship including the crane is shown, where the auxiliary cable is guided from the boom 2 to the boom bracket.

[0118] Figure 19A and Figure 19B A side view of the top of the crane boom is shown where not all of the pulleys or pulley blocks have been pulled up.

[0119] For the purposes of clear and concise description, features are described herein as part of the same or separate embodiments. However, it should be understood that the scope of the claims and the disclosure may include embodiments having combinations of all or some of the described features. It can be understood that the illustrated embodiments have the same or similar components, unless they are described as different.

[0120] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The term "comprising" does not exclude the presence of other features or steps than those listed in a claim. Further, the terms "a" and "an" shall not be construed as "only one", but rather are used to mean "at least one", and do not exclude a plurality. The fact that certain measures are recited in mutually different claims does not mean that a combination of these measures cannot have advantages. Many variations will be apparent to those skilled in the art, provided they are included within the scope of the invention as defined in the appended claims.

Claims

1. A method for separating a part of a crane block from a crane boom of a crane, the crane block including at least one pulley block, the crane being installed on a ship, the method comprising: - positioning the crane boom in an inclined position; - lowering the part of the crane block towards the ship; - connecting an auxiliary cable to at least one pulley block of the at least one pulley block to be separated from the part of the crane block; - separating the pulley block connected to the auxiliary cable from the part of the crane block; - pulling the pulley block connected to the auxiliary cable towards the crane boom.

2. The method according to claim 1, further comprising lowering the crane boom towards the ship to a stationary position.

3. The method according to claim 1 or 2, wherein, The part of the crane block is lowered into a bracket installed on the ship.

4. The method according to any one of the preceding claims, wherein, During pulling the pulley block connected to the auxiliary cable towards the crane boom, the auxiliary cable is tensioned.

5. The method according to any one of the preceding claims 2 to 4, wherein, During lowering the crane boom to the stationary position, the auxiliary cable is tensioned.

6. The method according to any one of the preceding claims, wherein, When separating two or more pulley blocks from the crane block, a connecting element is provided between the slings of the pulley blocks.

7. A ship including a crane, the crane including a crane boom having at least one crane block, the at least one crane block including at least one pulley set, the at least one pulley set including at least one pulley, wherein at least one pulley set is separable from a part of the at least one crane block, wherein, The crane boom is longer than the length of the ship, and the ship is provided with a boom bracket for receiving the crane boom in the stationary position for navigation. Wherein, the ship is further provided with a bracket for receiving the part of the at least one crane block, and when the part of the at least one crane block is in the bracket and the crane boom is in the inclined position, separating the part of the at least one crane block from the separable at least one pulley block.

8. The ship according to claim 7, the ship is provided with a boom bracket extension extending to the outside of the ship, and the boom bracket extension is provided with a boom bracket for receiving the crane boom in the stationary position.

9. The ship according to claim 8, wherein, The bracket is provided on the boom bracket extension, preferably adjacent to the boom bracket.

10. The ship according to any one of claims 7 to 9, wherein, The crane is provided with a support structure, wherein the support structure is arranged near the end of the crane boom for abutting against the separated pulley block when it is pulled up.

11. The ship according to claim 10, wherein, The support structure is provided with a seat for receiving the separated pulley block.

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