Floating-state tail full-rotation segmented installation method

Abstract

The invention discloses a method for mounting a tail full-rotation section in a floating state, which is characterized by comprising the following steps of: berthing a ship at a wharf, arranging a mounting part on a bottom plate at the tail part of a ship body, mounting the tail full-rotation section on the mounting part, and forming a process hole in a main deck above the mounting part; hoisting a tail full-rotation section on the square barge; and a gantry crane steel wire penetrates through an auxiliary hole of the main deck to be connected with the tail full-rotation section, the tail full-rotation section is hoisted to the installation part, and installation of the tail full-rotation section in the wharf floating state is completed. According to the floating-state lower tail full-rotation segmented installation method, segmented floating-state hoisting and positioning operation is carried out on a wharf, and an existing flat barge is transformed into a recovery workboat. And through accurate precision control, the construction requirement standard is met, the in-dock hoisting time is greatly shortened, and the economic benefits are effectively improved. And compared with a newly-manufactured ship, the construction period for refitting the ship is greatly shortened, and the market core competitiveness is remarkably enhanced.

Description

Technical Field

[0001] This invention belongs to the field of marine technology and relates to a method for installing a stern section in a floating, fully rotating manner. Background Technology

[0002] With the booming development of marine recycling, the demand for recycling vessels is increasing daily. Recycling flat barges, as cargo ships that lack self-propulsion and rely on tugboats or pushboats for towing, have the potential to be converted into recycling vessels. The current plan is to convert recycling flat barges into recycling vessels. The converted vessels must maintain positioning and stability at designated locations within the recycling area. To enable the converted flat barges to have DP2-level dynamic positioning capabilities, two azimuth propulsion units need to be installed at the stern.

[0003] Currently, installing a full-rotation propulsion system requires raising the hull or digging pits to increase the height of the hull support if a monolithic installation method is used. However, increasing the support height severely threatens the stability of the hull, posing significant safety hazards during the relocation process and increasing technical risks. If a modular installation method is used, multiple precision calibrations are required during the modification phase, which not only prolongs the modification time but also makes it difficult to guarantee stable installation accuracy. Summary of the Invention

[0004] To solve the above problems, the present invention adopts the following technical solution: A method for segmented installation with full tail rotation in a floating state, the steps of which are as follows: When the ship docks, an installation part is installed on the bottom plate at the stern of the ship. The installation part is installed on the stern full rotation section, and process holes are opened on the main deck above the installation part. The tail section is hoisted onto the square barge and then pulled to the bottom of the installation unit by tugboats. The stern azimuth section is connected by passing the steel wire of the gantry crane through the process hole of the main deck, and then hoisted to the installation unit to complete the installation of the stern azimuth section in a floating state at the dock.

[0005] As a further aspect of the present invention, it also includes prefabricating the hull before hoisting. Mark the baseline; The original ship structure was dismantled according to the stern dismantling structure diagram and the stern full rotation structure diagram, and an installation part was set on the bottom plate of the stern of the ship. Several lifting rings are installed on the longitudinal girder at both ends of the installation section. The lifting rings are connected to chain hoists. Reinforcing triangular plates are installed under the longitudinal girder. Temporary platforms are installed on the longitudinal walls at both ends of the installation section. After the tail full rotation section is hoisted into place, the tail full rotation section is precisely positioned by pulling the chain hoist on the temporary platform. Install safety plates on the longitudinal walls and rib frames at both ends of the mounting section; The watertight door at the stern of the ship is fixed by welding with a plate.

[0006] As a further aspect of the present invention: the reference line includes: the hull baseline elevation and the centerline, and the ocean strike point is marked in the hull compartment of the installation part, which serves as the reference line for the stern full rotation section installation in floating state.

[0007] As a further aspect of the present invention: the insurance card is welded from a panel and a triangular plate, and is subjected to flaw detection after welding.

[0008] As a further aspect of the present invention, it also includes prefabricating the tail section in a full-rotation manner before hoisting: Several lifting rings are installed on the T-shaped panel of the tail full-spinning section, and the lifting rings are connected to the chain hoist; reinforcing triangular plates are welded and installed below the T-shaped panel, and the reinforcing triangular plates are located on opposite sides of the lifting rings.

[0009] As a further aspect of the present invention, it also includes the prefabrication of the barge before hoisting. After the installation unit is set up, the barge is placed under the stern of the hull. Lifting rings are welded to the bottom plate on the outside of the barge, and the lifting rings are connected to the cables to secure the barge to the dock.

[0010] As a further aspect of the present invention, it also includes prefabricating the angle steel frame before hoisting. An angle steel frame is erected at the junction of the stern azimuth section and the hull. After the stern azimuth section is installed in place, the section junction is assembled and welding is completed while standing on the angle steel frame.

[0011] As a further aspect of the present invention: the gantry crane wire passes through the process hole on the main deck and connects to the stern azimuth section; the process of hoisting the stern azimuth section to the installation unit to complete the installation of the stern azimuth section in a floating state at the dock includes: On the stern-rotating, segmented, fixed barge, located below the installation section; The gantry crane located at the dock passes through the process hole on the deck, and the wire is hooked onto a part of the lifting ring of the stern swivel section. The hook is then lifted to lift the stern swivel section. When the stern azimuth section is 220-30mm away from the lower end of the hull installation section, a chain hoist is connected between the other part of the stern azimuth section's lifting ring and the lifting ring on the hull longitudinal girder. A limiting plate is welded onto the tail full-rotation section. When the chain hoist is under force, the welding with the limiting plate is completed, and the gantry crane is detached from the tail full-rotation section. Tighten the chain hoist, and then readjust the tail full rotation segment using the chain hoist to ensure the tail full rotation segment is in place with high precision.

[0012] As a further aspect of the present invention: the accuracy includes: According to the marked baseline, install angle steel for pulling steel wire on the two longitudinal walls at both ends of the installation part, and pull steel wire between the angle steel on the two longitudinal walls. Measure the distance from the steel wire to the flange face, and the horizontal deviation should be less than ±3mm; measure the distance from the stern sealing plate to the center of the flange, and the centerline deviation should be less than ±2mm; measure the gap between the limit plate and the stern full rotation section, and the gap deviation should be less than 20mm.

[0013] As a further aspect of the present invention, it also includes: after the tail full-rotation segment is assembled, welding is carried out according to the full-return welding process, the welding sequence is marked, and the welding deformation of the tail full-rotation segment is monitored during the welding process; after the tail full-rotation segment is welded, flaw detection is performed.

[0014] The beneficial effects of this invention are: A floating, fully azimuth-rotating stern section installation method involves segmented floating hoisting and positioning operations at the dock, transforming existing flatbed barges into recovery vessels. Through precision control, the process achieves integral installation of the stern fully azimuth-rotating sections from the hull bottom, significantly shortening dockside hoisting time and effectively improving economic efficiency. Compared to new shipbuilding, the construction period for converted vessels is significantly shortened, resulting in a marked increase in core market competitiveness. Furthermore, the installation process of the stern fully azimuth-rotating sections allows workers to accumulate extensive practical experience in precision control and construction techniques, comprehensively enhancing their individual capabilities and laying a solid foundation for improving the efficiency of converted vessel operations. Attached Figure Description

[0015] Figure 1 This is a flowchart illustrating a segmented installation method with full tail rotation under floating conditions. Figure 2 This is a supplementary flowchart illustrating a segmented installation method with full tail rotation under floating conditions. Figure 3 This is a structural schematic diagram of step S10 of a floating tail-rotation segmented installation method; Figure 4 This is a partial structural diagram of step S10 of a floating tail-rotation segmented installation method; Figure 5 This is a structural schematic diagram of step S20 of a floating tail-rotation segmented installation method; Figure 6 This is a structural schematic diagram of step S30 of a floating tail-rotation segmented installation method; Figure 7 A schematic diagram of step S013 of a floating tail-rotation segmented installation method Figure 1 ; Figure 8 A schematic diagram of step S013 of a floating tail-rotation segmented installation method Figure 2 ; Figure 9A schematic diagram of step S014 of a floating tail-rotation segmented installation method. Figure 1 ; Figure 10 A schematic diagram of step S014 of a floating tail-rotation segmented installation method. Figure 2 ; Figure 11 This is a structural schematic diagram of step S015 of a floating tail-rotation segmented installation method; Figure 12 A schematic diagram of step S02 of a floating tail-rotation segmented installation method Figure 1 ; Figure 13 A schematic diagram of step S02 of a floating tail-rotation segmented installation method Figure 2 ; Figure 14 A schematic diagram of step S02 of a floating tail-rotation segmented installation method Figure 3 ; Figure 15 A schematic diagram of step S03 of a floating tail-rotation segmented installation method Figure 1 ; Figure 16 A schematic diagram of step S03 of a floating tail-rotation segmented installation method Figure 2 ; Figure 17 A schematic diagram of step S33 of a floating tail-rotation segmented installation method. Figure 1 ; Figure 18 A schematic diagram of step S33 of a floating tail-rotation segmented installation method. Figure 2 ; Figure 19 A schematic diagram of step S34 of a floating tail-rotation segmented installation method. Figure 1 ; Figure 20 A schematic diagram of step S34 of a floating tail-rotation segmented installation method. Figure 2 ; Figure 21 A schematic diagram of step S34 of a floating tail-rotation segmented installation method. Figure 3 ; Figure 22 A schematic diagram of step S34 of a floating tail-rotation segmented installation method. Figure 4 ; Figure 23 A schematic diagram of step S35 of a floating tail-rotation segmented installation method. Figure 1 ; Figure 24A schematic diagram of step S35 of a floating tail-rotation segmented installation method. Figure 2 .

[0016] The diagram shows: 1-Stern full-rotation section, 2-Hull, 201-Installation section, 202-Process hole, 3-Square barge, 4-Gantry crane, 5-Reinforcing triangular plate, 6-Lifting ring, 7-Temporary platform, 8-Chain hoist, 9-Safety plate, 10-Limiting plate, 11-Welding position, 12-Angle steel, 13-Steel wire. Detailed Implementation

[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. It should be understood that this application is not limited to the exemplary embodiments disclosed herein. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0018] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0020] In the embodiments of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0021] Example 1 like Figure 1As shown, a segmented installation method for the tail section under floating conditions with full rotation is described below: S10: When the ship docks, an installation part 201 is installed on the bottom plate at the stern of the ship 2. The installation part 201 is installed on the stern full-rotation section 1. A process hole 202 is opened on the main deck above the installation part 201. S20: Hoist the tail-turning section 1 onto the barge 3, and use a tugboat to move the barge 3 to below the installation section 201; S30: The gantry crane 4 steel wire 13 passes through the process hole 202 on the main deck to connect the stern full rotation section 1, and the stern full rotation section 1 is hoisted onto the installation part 201 to complete the installation of the stern full rotation section 1 in the floating state of the dock.

[0022] Specifically, the transverse members arranged along the length of hull 2 ​​are called ribs FR, which support the outer plating of hull 2 ​​and maintain its shape. Their numbering is based on the rudder shaft centerline. The longitudinal members arranged along the length of hull 2 ​​are called longitudinal girder L, which, together with the ribs FR, form a plate frame system to distribute the load. The numbering method for the longitudinal girder structure of a ship is usually based on the midship section of hull 2, i.e., the midship section, as the reference point.

[0023] like Figure 3-6 As shown, converting a recovery flat barge into a recovery operation vessel requires the installation of two azimuth propulsion devices, namely two stern azimuth sections 1. First, an installation section 201 and a process hole 202 are made on each side of the bottom of the recovery flat barge. Next, the stern azimuth section 1 is fixed to the square barge 3 and moved below the installation section 201, i.e., below the stern. Finally, using the steel wire 13 of the gantry crane 4, which passes through the process hole 202, the stern azimuth section 1 is lifted and precisely installed onto the pre-made installation section 201. Through these steps, the process of installing the stern azimuth section 1 as a whole from the bottom of the vessel is achieved.

[0024] The stern azimuth section is a azimuth propulsion device installed at the stern of a ship. A floating installation method for the stern azimuth section involves the floating hoisting and positioning of the stern azimuth section 1 at the dock, converting an existing flatbed barge into a recovery vessel. Through precision control, the process of installing the stern azimuth section 1 as a whole from the hull bottom is achieved, significantly shortening the dockside hoisting time and effectively improving economic efficiency. Compared to new shipbuilding, the construction period for converted ships is significantly shortened, and their core market competitiveness is significantly enhanced. Furthermore, the installation process of the stern azimuth section 1 allows workers to accumulate extensive practical experience in precision control and construction techniques, comprehensively improving their individual capabilities and laying a solid foundation for improving the efficiency of converted ship operations.

[0025] Example 2 The main technical solution of this embodiment is basically the same as that of Embodiment 1. Features not explained in this embodiment are explained in the embodiments and will not be repeated here. The difference between this embodiment and Embodiment 1 is that: like Figure 2 As shown, it also includes, S01: Before hoisting, the hull 2 ​​is prefabricated: S011: Mark the baseline.

[0026] Specifically, such as Figure 3 As shown, after the ship enters the dry dock, the deflection of the ship bottom needs to be measured to determine the baseline of the hull 2. The elevation and centerline of the baseline of the hull 2 ​​are measured using a total station. The baseline of the stern azimuth section 1 is marked in the cabin. These marks also serve as the reference line for the installation of the stern azimuth section 1 in the floating state.

[0027] S012: Dismantle the original ship structure according to the stern dismantling structure diagram and the stern full rotation structure diagram, and install part 201 on the bottom plate of the stern of the hull.

[0028] Specifically, based on the stern modification drawings, the deck ribs FR1-FR11 section and the deck longitudinal girder L8-L15 section are modified, leaving an installation section 201 at the stern of the hull.

[0029] S013: Install several lifting rings 6 on the longitudinal girder at both ends of the installation section 201. The lifting rings 6 are connected to the chain hoist 8. Install the reinforcing triangular plate 5 under the longitudinal girder panel.

[0030] Specifically, such as Figure 7 and 8 As shown, in this embodiment, two lifting rings 6 are installed on each of the longitudinal girder L8 and L16 of the hull 2, for a total of four lifting rings 6. A reinforcing triangular plate 5 is installed under the panel of the longitudinal girder. The reinforcing triangular plate 5 can increase the local cross-sectional area and moment of inertia of the deck, effectively distributing and bearing these loads, and preventing the longitudinal girder panel from deforming or being damaged due to excessive force during the lifting process.

[0031] S014: Temporary platforms 7 are installed on the longitudinal girder at both ends of the installation section 201. After the tail full rotation section 1 is hoisted into place, the staff stands on the temporary platform 7 and pulls the chain hoist 8 to perform precision positioning of the tail full rotation section 1.

[0032] Specifically, such as Figure 9 and 10 As shown, temporary platforms 7 are installed on longitudinal girders L6 and L18. After the tail full-rotation section 1 is hoisted into place, personnel stand on the temporary platform 7 and pull the chain hoist 8 to perform precision positioning of the tail full-rotation section 1.

[0033] S015: Install safety plates 9 on the longitudinal girder and rib frame at both ends of the installation section 201 respectively.

[0034] Specifically, such as Figure 11As shown, the safety plate 9 is welded from a panel and a triangular plate, with a weld leg height of 9mm. After welding, a flaw detection inspection is performed. The safety plate 9 of the tail full-rotation segment 1 is installed on the bottom plate positions of the longitudinal girders L6 and L18 of frames FR2 and FR8. The safety plate 9 forms a stable triangular structure with the longitudinal girders and rib frames, which can significantly improve the overall rigidity of the longitudinal girders and rib frames.

[0035] S016: The watertight door at the stern of hull 2 ​​is fixed by welding with a plate.

[0036] Specifically, to ensure that the watertight door at the stern of the hull 2 ​​plays its role in watertight protection, after the installation part 201 is installed, it is further stabilized by welding the mounting plate.

[0037] like Figure 2 As shown, it also includes, S02: Before hoisting, the tail full rotation section 1 is prefabricated: several lifting rings 6 are installed on the T-shaped panel of the tail full rotation section 1, and the lifting rings 6 are connected to the chain hoist 8; a reinforcing triangular plate 5 is welded and installed below the T-shaped panel, and the reinforcing triangular plate 5 is located on the opposite sides of the lifting rings 6.

[0038] Specifically, such as Figure 12-14 As shown, in this embodiment, the top of the tail swivel segment 1 is a T-shaped panel. Four lifting rings 6 are installed in a ring at the center hole of the T-shaped panel. Additionally, lifting rings 6 are installed at the intersections of ribs L18 and L6 with longitudinal girder FR2 and FR8, totaling eight lifting rings 6. On both sides of the lifting rings 6, below the T-shaped panel, 100*100*16mm reinforcing triangular plates 5 are installed with 10mm weld legs.

[0039] like Figure 2 As shown, it also includes, S03: Before hoisting, the barge 3 is prefabricated: such as Figure 15 and 16 As shown, after the installation unit 201 is set up, the barge 3 is placed below the stern of the hull 2. A lifting ring is welded to the bottom plate on the outside of the barge 3, and the lifting ring is connected to a cable to secure the barge to the dock.

[0040] like Figure 2 As shown, it also includes S04: Before hoisting, 12 angle steel frames are prefabricated: 12 angle steel frames are erected in the area where the stern full-turn section 1 and the hull 2 ​​meet. After the stern full-turn section 1 is installed in place, the workers stand on the 12 angle steel frames to assemble the stern full-turn section 1 and complete the welding work.

[0041] Specifically, after the bottom plate of the stern azimuth section 1 is removed, a barge is placed under the stern, and the barge is moored to the dock. On the outside of the barge, lifting rings 6 are welded to the bottom plate and the barge moored. The barge is then fixed to the bottom of the stern to prevent collisions with the ship. 12 angle steel frames are erected in the area where the stern azimuth section 1 and the original ship meet. After the stern azimuth section 1 is installed in place, the construction workers assemble the meeting point of the stern azimuth section 1 and perform welding work on the 12 angle steel frames.

[0042] In Embodiments 1 and 2, S30: The gantry crane 4's steel wire 13 passes through the process hole 202 on the main deck and connects to the stern azimuth section 1, hoisting the stern azimuth section 1 onto the installation unit 201, completing the stern azimuth section 1 in a floating state at the dock, including: S31: Located on the fixed barge 3 of the stern full-turn section 1, below the installation section 201.

[0043] S32: The steel wire 13 of the gantry crane 4 located at the dock passes through the process hole 202 on the deck and is hooked onto a part of the lifting ring 6 of the stern swivel section 1. The hook is then used to lift the stern swivel section 1.

[0044] like Figure 6 and Figure 16 As shown, the ship is moored at the dock and reliably secured using cable-operated methods. Barge 3 is moored a distance from the stern of the ship. A gantry crane 4 is used to lift the stern azimuth section 1 onto the barge 3 and secure it. A tugboat then tows the barge 3 to a location below the installation area of ​​the stern azimuth section 1. The gantry crane 4's steel wire 13 passes through the process hole 202 on the deck and is hooked onto the lifting ring 6 installed at the center hole of the T-shaped panel on the stern azimuth section 1. The hook is then slowly lifted to raise the stern azimuth section 1.

[0045] S33: When the stern azimuth section 1 is 20-30mm away from the lower end of the hull 2 ​​installation part 201, the other part of the stern azimuth section 1 lifting ring 6 is connected to the lifting ring 6 on the longitudinal girder of the hull 2 ​​by a chain hoist 8.

[0046] Specifically, such as Figure 17 and 18 As shown, when the stern azimuth section 1 is 20-30mm away from the lower end of the mounting part 201 of the hull 2, the lifting ring 6 installed on the T-shaped panel of the stern azimuth section 1 at the non-center hole is connected to the lifting ring 6 on the longitudinal girder of the hull 2 ​​by a chain hoist 8.

[0047] S34: Weld a limiting plate 10 onto the tail full-rotation section 1. When the chain hoist 8 is under force and the welding with the limiting plate 10 is completed, the gantry crane 4 disengages from the tail full-rotation section 1.

[0048] Specifically, when the stern azimuth section 1 is approximately 20-30mm from the bottom plate, in order to disassemble the gantry crane 4, a chain hoist 8 is used between the lifting ring 6 installed at the non-center hole of the T-shaped panel of the stern azimuth section 1 and the lifting ring 6 of the longitudinal girder of the hull 2 ​​to precisely adjust the position and reliably fix the stern azimuth section 1. Therefore, a limiting plate 10 is welded onto the stern azimuth section 1 to ensure that when the chain hoist 8 becomes slack, the limiting plate 10 is engaged at the mounting part 201, preventing the stern azimuth section 1 from continuously falling, thus providing a safety guarantee. Specifically, as... Figure 19-22 As shown, the welding positions 11 and the limit plate 10 are: at the intersection of rib FR8, tail full-spinning section 1, and longitudinal girder L6 and L18; at the intersection of rib FR2, tail full-spinning section 1, and longitudinal girder L6 and L18; at the intersection of longitudinal girder L8, tail full-spinning section 1, and rib; and at the intersection of longitudinal girder L16, tail full-spinning section 1, and rib. The limit plate 10 has dimensions of 200*800*20mm, and the weld leg must be no less than 10mm. The spatial clearance deviation between the limit plate 10 and tail full-spinning section 1 must be less than 20mm. Only after ensuring that the chain hoist 8 of tail full-spinning section 1 fully bears the load, and that the limit plate 10 is fully installed and welded, can the crane be directed to release the hook.

[0049] S35: Tighten the chain hoist 8, and readjust the tail full rotation section 1 again through the chain hoist 8 to ensure the tail full rotation section 1 is in place with high precision.

[0050] Specifically, slowly tighten the 20T chain hoist 8, and use the chain hoist 8 to readjust the tail full rotation segment 1 again, so that the basic accuracy of the tail full rotation segment 1 is in place.

[0051] In step S35, the accuracy includes: according to the marked baseline, installing angle steel 12 for pulling steel wire 13 on the two longitudinal girder at both ends of the installation part 201, pulling steel wire 13 between the angle steel 12 of the two longitudinal girder, measuring the distance from steel wire 13 to flange surface, with a horizontal deviation of less than ±3mm; measuring the distance from the stern sealing plate to the center of the flange, with a centerline deviation of less than ±2mm; measuring the clearance between safety plate 9 and stern full rotation section 1, with a clearance deviation of less than 20mm.

[0052] Specifically, such as Figure 23 As shown and as Figure 24 As indicated by the upper markings, horizontal positioning lines for the flanges are drawn on the longitudinal girder L6 and L18 according to the marked baselines. Angle steel 12 is installed on these two longitudinal girder sections, and steel wire 13 is stretched between the two angle steel 12 sections. A steel wire 13 is stretched longitudinally at intervals. These steel wires 13 will serve as the baseline for the precise positioning of the tail slewing section 1. After the steel wires 13 are stretched, the distance from the steel wire 13 to the flange face is measured to perform horizontal positioning of the tail slewing section 1. Figure 24As shown by the marking on the right, steel wire 13 is pulled at the FR15 wall of the tail seal plate to mark the centerline position. This centerline position is used to locate the left and right centers of the flange.

[0053] The stern full-rotation section 1 is hoisted and positioned while floating at the dock. Using the aforementioned measurement and positioning method, its accuracy control meets shipbuilding requirements. This positioning method solves the problems of positioning difficulties in traditional installation methods, reducing construction difficulty and cost while ensuring positioning accuracy. Furthermore, it significantly reduces dockside hoisting time, effectively improving economic efficiency. This experience enhances the company's market competitiveness.

[0054] This also includes S36: After the tail full-turn section 1 is assembled, it is welded according to the full-turn welding process, the welding sequence is marked, and the welding deformation of the tail full-turn section 1 is monitored during the welding process; after the tail full-turn section 1 is welded, it is subjected to flaw detection.

[0055] Specifically, during the welding process, the amount of welding deformation of the tail full-rotation segment 1 is monitored and recorded in detail. After the welding of the tail full-rotation segment 1 is completed, it is promptly subjected to flaw detection to ensure that the welding quality meets the relevant standard requirements.

[0056] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0057] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for segmented installation of the tail section under floating conditions with full rotation, characterized in that, The steps are as follows: When the ship docks, an installation part is installed on the bottom plate at the stern of the ship. The installation part is installed in the stern full rotation section, and process holes are opened on the main deck above the installation part. The tail section is hoisted onto the square barge and then pulled to the bottom of the installation unit by tugboats. The stern azimuth section is connected by passing the steel wire of the gantry crane through the process hole of the main deck, and then hoisted to the installation unit to complete the installation of the stern azimuth section in a floating state at the dock.

2. The segmented installation method for the tail section in a floating state with full rotation as described in claim 1, characterized in that, This also includes the prefabrication of the hull before hoisting: Mark the baseline; The original ship structure was dismantled according to the stern dismantling structure diagram and the stern full rotation structure diagram, and an installation part was set on the bottom plate of the stern of the ship. Several lifting rings are installed on the longitudinal girder at both ends of the installation section. The lifting rings are connected to chain hoists. Reinforcing triangular plates are installed under the longitudinal girder. Temporary platforms are installed on the longitudinal walls at both ends of the installation section. After the tail full rotation section is hoisted into place, the tail full rotation section is precisely positioned by pulling the chain hoist on the temporary platform. Install safety plates on the longitudinal walls and rib frames at both ends of the mounting section; The watertight door at the stern of the ship is fixed by welding with a plate.

3. The segmented installation method for the tail section in a floating state under full rotation as described in claim 2, characterized in that, The baseline includes: the hull baseline elevation and the centerline. A rudder point is marked inside the hull compartment of the installation section. The rudder point serves as the baseline for the stern full-rotation section installation in a floating state.

4. The segmented installation method for the tail section in floating state under full rotation as described in claim 2, characterized in that, The safety card plate is welded from a panel and a triangular plate, and is inspected for defects after welding.

5. The segmented installation method for the tail section in a floating state with full rotation as described in claim 2, characterized in that, This also includes the prefabrication of the tail section before hoisting: Several lifting rings are installed on the T-shaped panel of the tail full-spinning section, and the lifting rings are connected to the chain hoist; reinforcing triangular plates are welded and installed below the T-shaped panel, and the reinforcing triangular plates are located on opposite sides of the lifting rings.

6. The segmented installation method for the tail section in a floating state with full rotation as described in claim 5, characterized in that, This also includes the prefabrication of the barge before hoisting: After the installation unit is set up, the barge is placed under the stern of the hull. Lifting rings are welded to the bottom plate on the outside of the barge, and the lifting rings are connected to the cables to secure the barge to the dock.

7. The segmented installation method for the tail section in a floating state with full rotation as described in claim 6, characterized in that, This also includes the prefabrication of the angle steel frame before hoisting: An angle steel frame is erected at the junction of the stern azimuth section and the hull. After the stern azimuth section is installed in place, the section junction is assembled and welding is completed while standing on the angle steel frame.

8. The segmented installation method for the tail section in a floating state with full rotation as described in claim 7, characterized in that, The gantry crane's steel wire passes through the process hole on the main deck and connects to the stern azimuth section. The process of hoisting the stern azimuth section to the installation unit, completing the installation of the stern azimuth section in a floating state at the dock, includes: On the stern-rotating, segmented, fixed barge, located below the installation section; The gantry crane located at the dock passes through the process hole on the deck, and the wire is hooked onto a part of the lifting ring of the stern swivel section. The hook is then lifted to lift the stern swivel section. When the stern azimuth section is 220-30mm away from the lower end of the hull installation section, a chain hoist is connected between the other part of the stern azimuth section's lifting ring and the lifting ring on the hull longitudinal girder. A limiting plate is welded onto the tail full-rotation section. When the chain hoist is under force, the welding with the limiting plate is completed, and the gantry crane is detached from the tail full-rotation section. Tighten the chain hoist, and then readjust the tail full rotation segment using the chain hoist to ensure the tail full rotation segment is in place with high precision.

9. The segmented installation method for the tail section in floating state under full rotation as described in claim 8, characterized in that, The accuracy includes: According to the marked baseline, install angle steel for pulling steel wire on the two longitudinal walls at both ends of the installation part, and pull steel wire between the angle steel on the two longitudinal walls. Measure the distance from the steel wire to the flange face, and the horizontal deviation should be less than ±3mm; measure the distance from the stern sealing plate to the center of the flange, and the centerline deviation should be less than ±2mm; measure the gap between the limit plate and the stern full rotation section, and the gap deviation should be less than 20mm.

10. The segmented installation method for the tail section in a floating state with full rotation according to claim 8, characterized in that, It also includes welding operations according to the full-return welding process after the tail full-return section is assembled, marking the welding sequence, and monitoring the welding deformation of the tail full-return section during the welding process; After the tail section is welded in a full rotation, it undergoes flaw detection.

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