A hoisting method for an ultra-wide single-shell segment

Abstract

The application discloses a hoisting method for an ultra-wide single-shell total section, which comprises the following steps: firstly, the weight gravity of the single-shell total section is counted, the lifting point position is designed according to the weight gravity, the lifting point position is divided into four groups, the four groups of lifting points are symmetrically arranged according to the weight gravity, the position of the lifting point is determined according to the lifting point arranged according to the number of strong structures; the connecting support rod is arranged according to the distance between the floating crane hook and the lifting point position; the construction and the outfitting of the ultra-wide single-shell total section are completed; the lifting rig and the support rod structure are connected to the floating crane hook; the floating crane is moved to the position near the total section total group, the support rod structure is connected to the lifting point of the total section; the total section is slowly lifted until the hoisting positioning is completed. According to the hoisting method, the lifting points of the total section are designed into multiple numbers and are formed into structural lifting rings, the support rod is connected to the floating crane hook, the vertical hoisting of the lifting points is ensured, the deformation in the hoisting process of the ultra-wide total section is beneficial to be controlled, the integrity of the outfitting parts in the total section is beneficial to be ensured, and the positioning time in the subsequent loading is reduced.

Description

Technical Field

[0001] This invention relates to the field of shipbuilding, and in particular to a method for hoisting an ultra-wide single-hull section. Background Technology

[0002] In 2017, the German shipyard GDD initiated the world's first dual-fuel conversion project for container ships, transforming a 1036 TEU feeder container ship into a dual-fuel propulsion vessel. During the conversion, a 490-cubic-meter LNG fuel tank was installed in the 1036 TEU feeder container ship as a storage device for LNG fuel. Subsequently, dual-fuel conversions of other ship types were carried out, primarily through the installation of LNG storage tanks, with the aim of achieving LNG propulsion for the vessels.

[0003] The LNG-powered conversion of the 15,000 TEU container ship is the world's first LNG dual-fuel conversion project for a large operational container ship. This LNG dual-fuel conversion project requires the installation of a membrane-type containment fuel tank in the 9F cargo hold of the 15,000 TEU container ship. The fuel tank is constructed as a single-hull thin-walled structure and is then hoisted as a whole after the fuel tank construction is completed.

[0004] Since the specially constructed fuel tank is an ultra-wide single-hull type, there is currently no precedent in the world for hoisting an ultra-wide single-hull section as a whole. It is necessary to develop and design it specifically so that the ultra-wide single-hull section can be safely and stably hoisted as a whole onto the ship that needs to be modified. Summary of the Invention

[0005] To address the lack of existing technology for the overall hoisting of single-hull fuel tank sections, this invention provides a hoisting method for ultra-wide single-hull sections. The aim is to address the issue of deformation during the hoisting of single-hull fuel tank sections by employing a dedicated hoisting method to reduce hoisting risks, shorten subsequent section positioning time, and improve hoisting efficiency.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] A method for hoisting an ultra-wide single-hull section, the section being over 50 meters wide and weighing over 1400 tons, comprising transverse bulkheads, a deck, an inner bottom, and sides. Two transverse bulkheads are located forward and aft, the sides are on the port and starboard sides, the upper part is the deck, and the bottom is the inner bottom of the section. This hoisting method is divided into a design phase, a construction phase, and a hoisting phase, specifically including the following steps:

[0008] In the design phase:

[0009] S1. Design the ultra-wide single-shell section using design software, and calculate the weight and center of gravity of the ultra-wide single-shell section.

[0010] S2. Based on the weight and center of gravity of the ultra-wide single-shell section, the lifting points are divided into 4 groups. The 4 groups of lifting points are arranged symmetrically according to the center of gravity. Multiple lifting points are set according to the number of strong structures on the ultra-wide single-shell section, and the specific position of each lifting point is determined.

[0011] S3. Determine the structural type of each lifting point according to the lifting scheme. The lifting scheme is that the hull structure floats on the shore and the ultra-wide single hull section is lifted onto the hull structure by a floating crane.

[0012] S4. The support rods are designed according to the spacing of the floating crane hooks and lifting points. The support rods include longitudinal support rods and transverse support rods, and a rectangular frame-like support rod structure is formed by two longitudinal support rods and two transverse support rods.

[0013] During the construction phase:

[0014] S5. Complete the ultra-wide single-hull section according to the design plan, carry out the construction and outfitting of the section, and install lifting rings at the lifting points, which protrude from the deck of the ultra-wide single-hull section;

[0015] S6. Install lifting slings and a support structure on the hook of the floating crane. The bottom of the support structure is connected to four lifting blocks by lifting ropes, and the bottom of the lifting blocks is equipped with multiple pulleys.

[0016] During the hoisting process:

[0017] S7. Move the floating crane to the assembly position of the ultra-wide single-shell section and connect the pulleys under each lifting block to the corresponding lifting rings;

[0018] S8. Slowly start the floating crane to steadily lift and move the ultra-wide single-hull section to the hull structure. Control the floating crane hook to steadily lower the ultra-wide single-hull section to the installation position of the hull structure until the lifting and positioning of the ultra-wide single-hull section is completed.

[0019] S9. Loosen the shackle of the wire rope between the lifting platform and the hook. The floating crane moves the lifting platform and the strut structure away. Cut the lifting ring on the main deck of the ultra-wide single hull section, so that the ultra-wide single hull section becomes part of the hull structure.

[0020] In step S2, the floating crane has 4 hooks, so the lifting points are divided into 4 groups. The 4 groups of lifting points should be designed to be symmetrical front to back and left to right to prevent the load on any one group from being too large and causing deformation. The number of lifting points in each group should be designed to be even to facilitate the configuration of lifting slings. In addition, considering the number of strong structures, in this ultra-wide single hull section, the strong structures refer to the ribs and transverse bulkheads. To ensure that the load on a single lifting point is controlled within 50t, each group is set with 8 lifting points, for a total of 32 lifting points.

[0021] Furthermore, in step S2, the lifting point should be located above the transverse bulkhead of the main section in the longitudinal direction, which is beneficial for the transmission of force at the lifting point.

[0022] Furthermore, in step S3, conventional lifting ring removal causes significant damage to the deck paint, and the isolation compartment on the reverse side of the main section has a small space, making it difficult for personnel to enter for construction. Therefore, the structure of the lifting ring should minimize damage to the deck paint. Thus, a structural lifting ring is required, consisting only of the main lifting ring plate and without elbow plates. When the lifting ring is cut off, the root is left to be removed, which can avoid damage to the paint on the reverse side of the deck.

[0023] Furthermore, in step S4, since the spacing of the four sets of lifting points in the front-to-back and left-to-right directions is different, and the spacing of the floating crane hooks in the length and width directions is also inconsistent, at least two sizes of support rods should be designed. In order to ensure the vertical force of the lifting points, the connection with the lifting ring should adopt the connection type of movable pulley. Therefore, the support rod and the lifting point cannot be directly connected, and a lifting plate needs to be designed in between.

[0024] Furthermore, in step S5, the connection between the lifting ring and the hull structure needs to be inspected for flaws after welding is completed.

[0025] Furthermore, in step S6, the bottom of the lifting block is provided with fixed pulleys, the number of which corresponds to the number of lifting rings.

[0026] Furthermore, in step S7, the movable pulley is connected to the corresponding lifting ring using a shackle.

[0027] Furthermore, in step S9, to avoid damaging the deck paint when cutting the lifting ring, it is necessary to cut at least 15mm upwards along the deck line, then use a carbon plane to remove the part above 5mm, and then grind the root smooth.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] 1. In the hoisting method of the ultra-wide single-hull section of the present invention, the section is hoisted into the floating hull structure by means of a floating crane, instead of construction in the dock. The floating crane hook and the hoisting bar are connected by a strut, which ensures the vertical force of the lifting ring and makes the hoisting more stable.

[0030] 2. In the hoisting method of the ultra-wide single-shell section of the present invention, a hoisting bar and a hoisting ring are used for connection. The four hoisting bars make the connection points between the hoisting ring and the hoisting bar numerous and the force is stable and balanced, thereby ensuring that the hoisting points are evenly stressed during the hoisting process, increasing safety and hoisting stability.

[0031] 3. To meet the requirements of large size and heavy weight of the ultra-wide single-shell section, a special strut structure and four lifting rods were designed to create a dedicated transition device for the ultra-wide single-shell section. This ensures that the tension at the lifting points is basically applied vertically downwards, and the force on each lifting ring is basically the same, thus maintaining stability and smooth operation. Except for the crossbars and lifting rods of the corresponding specifications, the rest are existing tooling, which helps to reduce costs.

[0032] 4. In the ultra-wide single-shell section hoisting method of the present invention, since a floating crane is used to hoist the section, the floating crane cannot adjust its posture in the middle. Therefore, the center of gravity needs to be calculated in advance during the design stage, the hoisting point position is determined based on the calculated center of gravity, and a lifting ring is designed at the hoisting point position. The lifting ring installation must be connected to the strong structure so that the ultra-wide single-shell section will not be deformed or damaged during the hoisting process.

[0033] 5. In the method for hoisting the ultra-wide single hull section of the present invention, it can be ensured that the ultra-wide single hull section is subjected to balanced force during hoisting, and the center of gravity of the hoisting point is consistent with the center of gravity of the section, ensuring the levelness of construction, preventing interference between the fuel tank section and the hull structure during hoisting, and avoiding collisions that could cause damage. Attached Figure Description

[0034] Figure 1 This is a three-dimensional schematic diagram of the ultra-wide single-shell assembly.

[0035] Figure 2 This is a front view of the hoisting process for the ultra-wide single-shell section in this invention.

[0036] Figure 3 This is a left view of the hoisting of the ultra-wide single-shell section in this invention.

[0037] Figure 4 This is a schematic diagram of the installation of lifting rings in a hoisting method for an ultra-wide single-shell section according to the present invention.

[0038] The labels in the diagram mean:

[0039] 1 is the ultra-wide single-hull section; 2 is the lifting ring; 3 is the lifting platform; 4 is the first seamless rope loop; 5 is the supporting pulley block; 6 is the transverse strut; 7 is the longitudinal strut; 8 is the second seamless rope loop; 9 is the articulated pulley block; 10 is the upper connecting pulley block; 11 is the third seamless rope loop; 12 is the fourth seamless rope loop; 13 is the fifth seamless rope loop; 14 is the floating crane hook; 15 is the section deck; 16 is the movable pulley; 17 is the transverse bulkhead. Detailed Implementation

[0040] The following detailed description of a hoisting method for an ultra-wide single-shell section of the present invention, in conjunction with the accompanying drawings and specific embodiments, should not be construed as limiting the scope of protection of the present invention.

[0041] This embodiment describes a method for hoisting an ultra-wide single-hull section for the LNG-powered conversion of a 15,000 TEU container ship, as part of a large container ship LNG dual-fuel conversion project. This LNG dual-fuel conversion project requires the installation of a membrane-type containment fuel tank in the 9F cargo hold of the 15,000 TEU container ship. This fuel tank is constructed as a single-hull, thin-walled structure and is hoisted as a whole after its construction is completed. The membrane-type containment fuel tank needs to be designed as an ultra-wide single-hull section, which is then hoisted onto the hull structure of the container ship after completion.

[0042] like Figure 1 As shown, the aforementioned ultra-wide single-hull section 1 has a width exceeding 50 meters and a weight exceeding 1400 tons. Its structural components include transverse bulkheads, decks, an inner bottom, and sides. Two transverse bulkheads are located forward and aft, while the sides are located on the port and starboard sides. The upper part is the deck, and the bottom is the inner bottom of the section. During the hoisting of this ultra-wide single-hull section, the lifting hooks need to act on the outer wall of the section. The existing hoisting equipment is a floating crane, which contains four hooks with a small spacing between them. The hooks are directly connected to the wire ropes, and the angle of the wire ropes is relatively large, which can easily lead to deformation of the section during hoisting.

[0043] like Figure 2 and Figure 3 As shown, we divide the entire hoisting process into three stages: design, construction, and hoisting. Specifically, this method includes the following steps:

[0044] During the design phase, existing computer-aided design software was used to design the ultra-wide single-shell section 1, determine the specific location of the lifting points, and then design the shape of the lifting ring 2 at the lifting point location.

[0045] S1. In the computer design software, based on the segmentation diagram completed in the design, the weight and center of gravity of all segments in the ultra-wide single shell section 1 are calculated. The total weight of the section is close to 1400t, and the center of gravity of the section is consistent with the center of the shape in the front-back and left-right directions.

[0046] S2. Since the planned lifting crane has four hooks, the lifting points are divided into four groups based on the center of gravity of the ultra-wide single-hull section. These four groups are symmetrically arranged front-to-back and left-to-right according to the center of gravity of the ultra-wide single-hull section, ensuring that each group bears an average force of approximately 350t. The number and location of the lifting points are maximized to ensure that the load on each individual lifting point is controlled within 50t. Therefore, eight lifting points are set in each group, for a total of 32 lifting points. To facilitate force transmission, the lifting points are positioned directly above the transverse bulkhead 17. Positioning the lifting points above the transverse bulkhead along the length of the section facilitates force transmission at the lifting points.

[0047] S3. To avoid damaging the paint on the reverse side of the deck during the removal of the lifting rings, the size of the lifting rings should be minimized, and a specially designed lifting ring 2 should be used. Considering all factors, lifting ring 2 should be designed only in a main plate type and integrated with the deck structure as a structural lifting ring, such as... Figure 3 As shown. Because conventional lifting ring removal causes significant damage to the deck paint, and the space in the isolation compartment on the reverse side of the ultra-wide single-hull section 1 is small, making it difficult for personnel to enter for work, the lifting ring structure should minimize damage to the deck paint. Therefore, a structural lifting ring is required. That is, only a main lifting ring plate is installed, without an elbow plate. This allows the lifting ring 2 to be removed while leaving a stub, avoiding damage to the reverse side of the deck paint.

[0048] S4. Based on the spacing of the floating crane hooks and the center distance of the four sets of lifting points, the center distance of the lifting points must be greater than the hook spacing. To maintain stability during vertical lifting, specialized support rods need to be designed to ensure the vertical force on the slings above the lifting points. These support rods include longitudinal support rods 7 and transverse support rods 6, forming a rectangular frame-like support rod structure composed of two longitudinal support rods 7 and two transverse support rods 6. Furthermore, the spacing of the floating crane hooks is inconsistent in both length and width directions, therefore at least two sizes of support rods must be designed. To ensure the vertical force on the lifting points, a movable pulley connection should be used at the connection points with each lifting ring 2. Therefore, the support rods cannot be directly connected to the lifting points; a lifting platform 3 must be designed between them. The bottom of the lifting platform 3 has multiple fixed pulleys, which are connected to the movable pulleys at the bottom via wire ropes.

[0049] During the construction phase, an ultra-wide single-shell section was built according to the design, and lifting equipment for hoisting was prepared in accordance with the design.

[0050] S5. In accordance with the above structural design, the ultra-wide single-shell section 1 was constructed and the constructed section was outfitted. The completed ultra-wide single-shell section 1 was designed with lifting rings 2 according to the designed lifting point positions, and the lifting points were set directly above the transverse bulkhead 17.

[0051] S6. The lifting slings and struts are manufactured, and the lifting slings are connected to the floating crane hooks. The completed lifting auxiliary device comprises the following structure: each hook 14 is connected to an upper connecting pulley block 10 via a fifth seamless coil 13, and adjacent upper connecting pulley blocks 10 are connected via a third seamless coil 12, so that four upper connecting pulley blocks 10 are distributed at the four corners of the bottom of the four hooks 14, and are connected by a flexible frame using four third seamless coils 12. The bottom of the upper connecting pulley block 10 is a hinged pulley block 9. The hinged pulley block 9 is connected to the support pulley block 5 through the second seamless coil 8. The support pulley block 5 is set on the strut structure, that is, one support pulley block 5 is set at each of the four corners of the strut structure. The bottom of each support pulley block 5 is connected to a lifting rack 3 through two first seamless coils 4, so a total of four lifting racks 3 are set. The four lifting racks are divided into two parallel rows. The lifting racks 3 in the same row are distributed across the upper end of the ultra-wide single hull section 1 and are parallel to the deck surface. Multiple lifting points are set at the bottom of the lifting rack 3. Each lifting point is equipped with a fixed pulley. Each fixed pulley is suspended by a steel wire rope from a movable pulley 16. The movable pulley 16 extends to each lifting ring 2 on the deck section 15.

[0052] During the hoisting phase, the ultra-wide single-hull section 1 is hoisted onto the hull structure using the floating crane hook 14.

[0053] S7. Move the floating crane to the vicinity of the main section assembly position and bring the pulleys under the lifting platform close to each lifting ring 2 in preparation for connection.

[0054] S8. Connect each lifting ring 2 to the movable pulley 16 using a lifting rope and shackle. After verifying that the connection is stable and correct, start the floating crane hook 14 to slowly lift the ultra-wide single hull section 1, move it to the hull structure, and slowly lower it to the installation position until the lifting and positioning of the ultra-wide single hull section 1 is completed.

[0055] S9. Remove the shackle connecting the lifting ring 2 and the lifting rope, remove the floating crane, cut off the lifting ring 2 at least 15mm above the deck section 15, then remove the part above 5mm with a carbon planer, and finally grind the remaining root flat to complete the hoisting work of the ultra-wide single hull section 1, so that the ultra-wide single hull section is integrated into the hull structure.

[0056] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and various changes or modifications can be made to these embodiments without departing from the principles and essence of the present invention. Therefore, the scope of protection of the present invention is defined by the appended claims.

Claims

1. A method for hoisting an ultra-wide single-hull section, the ultra-wide single-hull section being wider than 50 meters and weighing over 1400 tons, its structure including transverse bulkheads, decks, inner bottom, and sides, characterized in that... The hoisting method is divided into three stages: design, construction, and hoisting, and specifically includes the following steps: In the design phase: S1. Design the ultra-wide single-shell section using design software, and calculate the weight and center of gravity of the ultra-wide single-shell section. S2. Based on the weight and center of gravity of the ultra-wide single-shell section, the lifting points are divided into 4 groups. The 4 groups of lifting points are arranged symmetrically according to the center of gravity. Multiple lifting points are set according to the number of strong structures on the ultra-wide single-shell section, and the specific position of each lifting point is determined. The floating crane has 4 hooks. The lifting points are divided into 4 groups according to the hook settings. The 4 groups of lifting points are designed to be symmetrical front and back and left and right. The number of lifting points in each group is designed to be even to configure lifting slings. Based on the number of strong structures on the ultra-wide single-shell section and the load-bearing capacity of a single lifting point not exceeding 50t, 8 lifting points are set in each group, for a total of 32 lifting points. S3. Determine the structural type of each lifting point according to the lifting scheme. The lifting scheme is that the hull structure floats on the shore and the ultra-wide single hull section is lifted onto the hull structure by a floating crane. S4. The support rods are designed according to the spacing of the floating crane hooks and lifting points. The support rods include longitudinal support rods and transverse support rods, and a rectangular frame-like support rod structure is formed by two longitudinal support rods and two transverse support rods. During the construction phase: S5. Complete the ultra-wide single-hull section according to the design plan, carry out the construction and outfitting of the section, and install lifting rings at the lifting points, which protrude from the deck of the ultra-wide single-hull section; S6. Install lifting slings and a support structure on the hook of the floating crane. The bottom of the support structure is connected to four lifting blocks by lifting ropes, and the bottom of the lifting blocks is equipped with multiple pulleys. During the hoisting process: S7. Move the floating crane to the assembly position of the ultra-wide single-shell section and connect the pulleys under each lifting block to the corresponding lifting rings; S8. Slowly start the floating crane to steadily lift and move the ultra-wide single-hull section to the hull structure. Control the floating crane hook to steadily lower the ultra-wide single-hull section to the installation position of the hull structure until the lifting and positioning of the ultra-wide single-hull section is completed. S9. Loosen the shackle of the wire rope between the lifting platform and the hook. The floating crane moves the lifting platform and the strut structure away. Cut the lifting ring on the main deck of the ultra-wide single hull section, so that the ultra-wide single hull section becomes part of the hull structure.

2. The hoisting method for an ultra-wide single-shell section according to claim 1, characterized in that, In step S2, the lifting point is located above the transverse bulkhead on the ultra-wide single-hull section in the longitudinal direction.

3. The hoisting method for an ultra-wide single-shell section according to claim 1, characterized in that, In step S3, the lifting ring is a structural lifting ring, the structure of which includes a lifting ring main plate, which is triangular and has a lifting hole in the middle of the triangle.

4. The hoisting method for an ultra-wide single-shell section according to claim 1, characterized in that, In step S4, the connection with the lifting ring adopts a movable pulley connection type, and the lifting plate is provided between the support structure and the lifting point.

5. The hoisting method for an ultra-wide single-shell section according to claim 1, characterized in that, In step S5, the connection between the lifting ring and the hull structure needs to be inspected for flaws after welding is completed.

6. The method for hoisting an ultra-wide single-shell section according to claim 1, characterized in that, In step S6, multiple fixed pulleys are provided at the bottom of the lifting block, and the number of fixed pulleys corresponds to the number of lifting rings.

7. The hoisting method for an ultra-wide single-shell section according to claim 4, characterized in that, In step S7, the movable pulley is connected to the corresponding lifting ring using a shackle.

8. The method for hoisting an ultra-wide single-shell section according to claim 1, characterized in that, In step S9, when the lifting ring is removed, it is first cut 15mm up along the deck line, and then the part above 5mm is removed using a carbon planer.

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