A tortoise-like trolley for transferring stainless steel segments of inner bottom in a liquid cargo tank

Abstract

This invention discloses a tortoise-shaped trolley for transporting stainless steel inner bottom segments within a liquid cargo tank. The method involves prefabricating a stainless steel inner bottom segment in an indoor area using a low-temperature stainless steel plate and a carbon steel structural component to be installed on its reverse side. The complete stainless steel inner bottom segment is then hoisted into the tank and finally transported to the pump well area using a dedicated tortoise-shaped trolley, thus completing the assembly and welding. This effectively avoids the problems of dissimilar metal welding difficulties, low welding efficiency, and poor construction quality caused by a large number of loose structural parts in a confined space within the tank, significantly improving the working environment and increasing installation efficiency.

Description

Technical Field

[0001] This invention relates to the field of shipbuilding and repair technology, and in particular to a tortoise-shaped trolley for transporting stainless steel segments of the inner bottom in a liquid cargo tank. Background Technology

[0002] The steel plate in the pump well area at the bottom of the LNG carrier's cargo tank is made of cryogenic stainless steel. During the ship's construction or operation, due to special requirements from GTT or the shipowner, it is necessary to replace it with a higher grade of cryogenic stainless steel plate. Since the installation area involves dissimilar metal welding of cryogenic stainless steel plate and carbon steel, and there is overhead welding, direct installation or replacement on the ship will result in a large amount of assembly work, poor welding quality, low non-destructive testing pass rate, and limited construction space.

[0003] The conventional practice in the existing technology is to directly take the low-temperature stainless steel plate that needs to be installed or replaced onto the ship for installation, which has the following drawbacks:

[0004] First, the reverse side of the low-temperature stainless steel plate contains a large number of structural parts such as longitudinal girder components, T-shaped components, and reinforcing elbow plates, resulting in a large amount of assembly work.

[0005] Secondly, bulk operations leave a large number of low-temperature stainless steel and carbon steel welds to be done on the ship, including butt welding and overhead welding, resulting in low welding quality and efficiency.

[0006] Third, when replacing the stainless steel inner bottom, the assembly, welding, and grinding of the reverse structure must be carried out in the tunnel and ballast tank. The height inside the tank is less than 2m, the ventilation is poor, the working environment is bad, and it is also detrimental to the health of the personnel. Summary of the Invention

[0007] In view of this, the present invention provides a tortoise-shaped trolley for transporting stainless steel segments of the inner bottom in a liquid cargo tank. This method uses a dedicated tortoise-shaped trolley to transport the stainless steel segments of the inner bottom, which are hoisted into the tank, to the pump well area, thereby completing the assembly and welding. This effectively avoids the problems of difficulty in welding dissimilar metals and large quantities of structural parts in a small, confined space inside the tank, resulting in low welding efficiency and poor construction quality. It significantly improves the working environment, transportation efficiency, and the installation efficiency and quality of stainless steel plates.

[0008] A tortoise-shaped trolley for transporting stainless steel inner bottom segments in a liquid cargo tank. The tortoise-shaped trolley is used to transport stainless steel inner bottom segments that are lifted from the gas dome of the liquid cargo tank to the bottom plate of the liquid cargo tank to a pit position above the pump well area, and to lower and close the stainless steel inner bottom segments into the pit.

[0009] The tortoise-shaped trolley includes a frame body and multiple sets of pulley hoisting assemblies symmetrically arranged on the frame body. The pulley hoisting assembly includes a top lifting bracket fixed to the edge of the frame body, a second pulley fixed to the frame body by a column, a first pulley fixed to the frame body by a diagonal brace, and a steel wire rope. The second pulley is horizontally arranged, and the first pulley is vertically arranged. The exit height of the second pulley is equal to the entry height of the first pulley. One end of the steel wire rope is fixed to the top lifting bracket, and the other end passes through the second pulley and the first pulley in sequence and is connected to the hoisting eye plate of the inner bottom stainless steel segment. A second hand-operated hoist is provided on the steel wire rope.

[0010] Preferably, the center of the first pulley is aligned with the side edge of the frame body.

[0011] Preferably, the frame body includes multiple intersecting short and long side beams to form a rectangular frame, legs vertically fixed at the four corners of the rectangular frame, and casters fixed at the bottom of the legs. A second pulley is fixed on the short side beam located on the inner side, a first pulley is fixed on the long side beam located on the side, and a second hand chain hoist is mounted on the wire rope between the second pulley and the top hanging bracket.

[0012] Preferably, the overall height of the tortoise-shaped trolley does not exceed 1300mm.

[0013] Preferably, after the turtle-shaped trolley lowers and assembles the inner bottom stainless steel segment into the recess, the single-sided gap between the inner bottom stainless steel segment and the mother ship hull structure is 5mm-9mm.

[0014] Preferably, when the tortoise-shaped trolley transports the stainless steel section of the inner bottom, the bottom of the stainless steel section is at least 50mm away from the inner bottom plate of the liquid cargo tank.

[0015] Preferably, the inner bottom stainless steel segment includes a low-temperature stainless steel plate, T-row components, longitudinal girder components, reinforcing elbows, reinforcing ribs and bulb flats fixed on one surface of the low-temperature stainless steel plate, and a first lifting eye plate and a second lifting eye plate fixed on the other surface of the low-temperature stainless steel plate.

[0016] The T-row components are fixed to the low-temperature stainless steel plate in a horizontal and vertical distribution. The longitudinal girder components are vertically fixed to the ends of the horizontally arranged T-row components. Multiple equidistant reinforcing elbow plates are provided at the connection between the horizontally arranged T-row components and the low-temperature stainless steel plate, and at the connection between the longitudinal girder components and the low-temperature stainless steel plate. The reinforcing ribs are set between adjacent two rows of longitudinally arranged T-row components and between the longitudinally arranged T-row components and the longitudinal girder components. The ends of the reinforcing ribs are connected to the connecting elbow plates, and the bulb flat steel passes through the connecting elbow plates.

[0017] There are two sets of the first and second lifting eye plates, and the two sets of the first and second lifting eye plates are respectively set at the bow and stern ends of the low-temperature stainless steel plate.

[0018] Preferably, the line connecting the second pulley and the first pulley is perpendicular to the line connecting the second pulley and the top hanging bracket.

[0019] The beneficial effects of this invention are:

[0020] 1. In this invention, the inner bottom stainless steel segment is a pre-formed integral segment consisting of a low-temperature stainless steel plate and a carbon steel structural component to be installed on its reverse side in the inner field. The inner bottom stainless steel segment is hoisted into the cabin and transported to the pump well area using the tortoise-shaped trolley of this invention, thereby completing the assembly and welding. This effectively avoids the problems of dissimilar metal welding difficulties, low welding efficiency, and poor construction quality caused by a large number of structural parts scattered in the small and confined space of the cabin, greatly improving the working environment and increasing installation efficiency.

[0021] 2. By using a segmented construction method, a complete inner bottom stainless steel segment is constructed in the inner section workshop, which greatly improves the working environment and workload for the installation or maintenance of low-temperature stainless steel plates and increases the installation and construction accuracy. Furthermore, by completing 90% of the welding work between the low-temperature stainless steel plate and the carbon steel dissimilar metal in advance during the inner section fabrication, only the flat butt joint welding work needs to be carried out when the ship is assembled with the mother ship hull structure, which significantly improves welding efficiency and quality.

[0022] 3. The tortoise-shaped trolley of the present invention moves and installs stainless steel segments that have been hoisted into the liquid cargo tank to the recessed position in the pump well area, which not only improves transportation efficiency, but also improves the installation efficiency and installation quality of stainless steel segments; in addition to being used for the installation of stainless steel segments on the inner bottom, the tortoise-shaped trolley can also be used for the installation of other hull structures, ship outfitting, etc., with high versatility and very low cost for local modification. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram showing the installation steps of the stainless steel inner bottom segment.

[0025] Figure 2 This is a diagram illustrating how the tortoise-shaped vehicle lifts a section of stainless steel from its inner bottom off the ground.

[0026] Figure 3 This is a schematic diagram of the structure after the stainless steel segment of the inner bottom has been constructed in reverse.

[0027] Figure 4 This is a normal distribution diagram of the stainless steel segment of the inner bottom.

[0028] Figure 5 This is a schematic diagram of the stainless steel section of the inner bottom being hoisted into the cabin at an angle.

[0029] Figure 6 This is a front view of the tortoise-shaped car.

[0030] Figure 7 This is a top view of the tortoise-shaped car.

[0031] Figure 8 This is a side view of the tortoise-shaped car.

[0032] The labels in the diagram mean:

[0033] 1 is the inner bottom stainless steel segment; 11 is the low-temperature stainless steel plate; 12 is the longitudinal girder component; 13 is the T-row component; 14 is the reinforcing elbow plate; 15 is the first lifting eye plate; 16 is the second lifting eye plate; 17 is the reinforcing rib; 18 is the bulb flat steel; 19 is the connecting elbow plate;

[0034] 2 is the tortoise-shaped trolley; 21 is the main frame; 211 is the short side crossbeam; 212 is the long side crossbeam; 22 is the top hanging bracket; 231 is the first pulley; 232 is the second pulley; 24 is the second hand chain hoist; 25 is the column; 26 is the diagonal brace; 27 is the wire rope; 28 is the swivel caster.

[0035] 3 is the first manual chain hoist;

[0036] A is the liquid cargo tank; A1 is the gas dome of the liquid cargo tank; A2 is the inner bottom plate of the liquid cargo tank; A3 is the location of the pit in the pump well area;

[0037] B is the enclosure system installation platform; B1 is a temporary opening on the first storage layer of the enclosure system installation platform; B2 is a temporary opening on the second storage layer of the enclosure system installation platform; B3 is the support leg of the enclosure system installation platform.

[0038] C stands for crane. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0040] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0041] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms and should not be construed as indicating or implying relative importance. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0042] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "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.

[0043] To better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings.

[0044] This invention provides a tortoise-shaped trolley for transporting stainless steel segments of the inner bottom in a liquid cargo tank. The tortoise-shaped trolley lifts the stainless steel segments, which are then flipped into a normal shape and loaded into the tank through the air dome, and then transports them to the pump well area. Finally, it lowers the segments to complete the installation, thereby completing the assembly and welding. This effectively avoids the problems of difficult welding of dissimilar metals and low welding efficiency in the small, confined space of the tank, which result in a large number of structural parts being scattered, and poor construction quality. It significantly improves the working environment, transportation efficiency, and the installation efficiency and quality of stainless steel plates.

[0045] The present invention provides a tortoise-shaped trolley for transporting stainless steel segments of the inner bottom within a liquid cargo tank, comprising a frame body 21 and multiple sets of pulley lifting assemblies symmetrically arranged on the frame body 21. For example... Figure 7 As shown in this embodiment, the frame body 21 is provided with 4 sets of pulley hoisting assemblies, which are respectively located at the four corners of the frame body 21.

[0046] like Figure 7As shown, the frame body 21 includes multiple horizontal and vertical crossbeams 211 and long crossbeams 212 that are intersected to form a rectangular frame, support legs 213 that are vertically fixed at the four corners of the rectangular frame, and casters 28 that are fixed at the bottom of the support legs 213.

[0047] like Figure 6 , 7 As shown in Figure 8, the pulley hoisting assembly includes a top lifting bracket 22 fixed to the edge of the frame body 21, a second pulley 232 fixed to the frame body 21 by a column 25, a first pulley 231 fixed to the frame body 21 by a diagonal brace 26, and a wire rope 27.

[0048] Specifically, the top hanging bracket 22 is fixed to the short side beam 211 located on the side of the frame body, the second pulley 232 is fixed to the short side beam 211 located on the inner side, and the first pulley 231 is fixed to the long side beam 212 located on the side.

[0049] The second pulley 232 is horizontally positioned, and the first pulley 231 is vertically positioned. The line connecting the second pulley 232 and the first pulley 231 is perpendicular to the line connecting the second pulley 232 and the top hanging bracket 22. The exit height of the second pulley 232 is equal to the entry height of the first pulley 231, and the center of the first pulley 231 is flush with the upper surface of the frame body 21.

[0050] One end of the wire rope 27 is fixed to the top lifting bracket 22, and the other end passes through the second pulley 232 and the first pulley 231 in sequence before being connected to the lifting eye plate of the inner bottom stainless steel segment 1. A second hand chain hoist 24 is provided on the wire rope 27. Specifically, the second hand chain hoist 24 is set on the wire rope between the second pulley 232 and the top lifting bracket 22.

[0051] The installation method of the aforementioned inner bottom stainless steel segment 1 specifically includes the following steps:

[0052] S1, in the inner section workshop, the inner bottom stainless steel segment 1 is constructed in a reverse state.

[0053] like Figure 3 As shown, the inner bottom stainless steel segment 1 includes a low-temperature stainless steel plate 11, a longitudinal girder component 12, a T-shaped component 13, a reinforcing elbow plate 14, a first lifting eye plate 15, a second lifting eye plate 16, a reinforcing rib 17, and a bulb flat steel 18. The T-shaped component 13, the longitudinal girder component 12, the reinforcing elbow plate 14, the reinforcing rib 17, and the bulb flat steel 18 are disposed on the reverse side of the low-temperature stainless steel plate 11, and the first lifting eye plate 15 and the second lifting eye plate 16 are disposed on the front side of the low-temperature stainless steel plate 11.

[0054] Multiple T-shaped components 13 are provided, and the multiple T-shaped components 13 are arranged in a crisscross pattern and fixed on the low-temperature stainless steel plate 11. In this embodiment, as shown... Figure 3 As shown, two horizontally arranged T-shaped components 13 and two vertically arranged T-shaped components 13 are welded and fixed on the reverse side of the low-temperature stainless steel plate 11.

[0055] The longitudinal girder component 12 is vertically fixed to the end of the transversely arranged T-row component 13. Multiple equidistant reinforcing elbow plates 14 are provided at the connection between the transversely arranged T-row component 13 and the low-temperature stainless steel plate 11, and at the connection between the longitudinal girder component 12 and the low-temperature stainless steel plate 11.

[0056] Multiple reinforcing ribs 17 are provided between adjacent rows of longitudinally arranged T-shaped components 13 and between the longitudinally arranged T-shaped components 13 and the longitudinal girder components 12. The ends of the reinforcing ribs 17 are connected to connecting elbow plates 19, and bulb flat steel 18 passes through the connecting elbow plates 19, with the bulb flat steel 18 parallel to the longitudinally arranged T-shaped components 13. In this embodiment, as... Figure 3 As shown, two reinforcing ribs 17 are provided between two adjacent longitudinally arranged T-row components 13 and between the longitudinally arranged T-row components 13 and the longitudinal girder components 12.

[0057] The aforementioned T-row component 13, longitudinal girder component 12, reinforcing elbow plate 14, reinforcing rib 17, and bulb flat steel 18 are all carbon steel structural components.

[0058] Two sets of first lifting eye plates 15 and second lifting eye plates 16 are provided, with the two sets of first lifting eye plates 15 and second lifting eye plates 16 located at the bow and stern ends of the low-temperature stainless steel plate 11, that is, a total of four are installed on the front panel of the low-temperature stainless steel plate 11. The two sets of first lifting eye plates 15 and second lifting eye plates 16 are used to lift the inner bottom stainless steel segment 1 during the leveling and turning stages.

[0059] The construction accuracy of the inner bottom stainless steel segment 1, which is constructed in the inner section workshop, should meet the following requirements: the deviation range of length and width dimensions should be within ±4mm, the deviation of diagonal dimensions should be ≤5mm, and the finished size of the inner bottom stainless steel segment 1 should be 10 to 18mm smaller than the size of the recess at the installation position of the mother ship hull structure.

[0060] S2, the inner bottom stainless steel segment 1 is hoisted into the liquid cargo tank A from the gas dome A1 in an inclined position, and after passing through the temporary openings on each layer of the containment system installation platform B, it is placed normally on the center line of the inner bottom plate A2 of the liquid cargo tank A.

[0061] Specifically, the steps for hoisting the inner bottom stainless steel segment 1 into the liquid cargo tank A are as follows:

[0062] First, connect the crane hook to the first lifting eye plate 15 of the reversed inner bottom stainless steel segment 1, and use the crane to flip the inner bottom stainless steel segment 1 to an inclined position. Preferably, flip the inner bottom stainless steel segment 1 to an inclined position of 77°.

[0063] Then, the first hand chain hoist 3 is used to connect the crane hook to the second lifting eye plate 16 of the inner bottom stainless steel segment 1. One end of the first hand chain hoist 3 is suspended on the crane hook and the other end is fixed on the second lifting eye plate 16.

[0064] Then, the crane is started, and the inner bottom stainless steel segment 1 is lifted into the liquid cargo tank A from the gas dome A1 at an inclined position. It then passes downward through the temporary openings on the first storage layer B1 and the second storage layer B2 of the containment system installation platform B. The lifting is stopped when the inner bottom stainless steel segment 1 is 100-300mm away from the inner bottom plate A2 of the liquid cargo tank A. Wooden blocks are placed at the bottom of the inner bottom stainless steel segment 1 for temporary support. Preferably, the lifting is stopped when the inner bottom stainless steel segment 1 is 100-300mm away from the inner bottom plate A2 of the liquid cargo tank A, and wooden blocks are placed at the bottom of the inner bottom stainless steel segment 1 for temporary support to prevent it from shaking.

[0065] Then, tighten the first hand chain hoist 3 and simultaneously lower the hook to adjust the posture of the inner bottom stainless steel segment 1 to a normal state so that it sits on the wooden block;

[0066] Finally, remove the wooden pad and continue lowering the hook to place the inner bottom stainless steel segment 1 onto the inner bottom plate A2 of the liquid cargo tank A.

[0067] After the inner bottom stainless steel segment 1 is placed on the inner bottom plate A2 of the liquid cargo tank A, its position is slightly adjusted so that it is located on the center line of the inner bottom plate A2, that is, the center line of the inner bottom stainless steel segment 1 coincides with the center line of the inner bottom plate A2, and the bow, stern, port, and starboard directions of the inner bottom stainless steel segment 1 are consistent with the ship.

[0068] S3, the tortoise-shaped trolley 2 is hoisted into the liquid cargo tank A from the gas dome A1 of the liquid cargo tank, and after passing through the temporary openings on each layer of the containment system installation platform B (the temporary openings on the first storage layer B1 and the second storage layer B2), it is placed normally on the inner bottom plate A2 of the liquid cargo tank A.

[0069] S4, move the tortoise-shaped trolley 2 above the inner bottom stainless steel segment 1, then connect the wire ropes 27 in the four sets of pulley hoisting assemblies to the first hoisting eye plate 15 and the second hoisting eye plate 16 at their corresponding positions, then simultaneously tighten all the second hand chain hoists 24, and use the tortoise-shaped trolley 2 to lift the inner bottom stainless steel segment 1 off the ground.

[0070] In this embodiment, the inner bottom stainless steel segment 1 needs to be raised to more than 50mm off the ground.

[0071] S5, the tortoise-shaped trolley 2 transports the inner bottom stainless steel segment 1 to the pit position A3 above the pump well area. After adjusting the position of the inner bottom stainless steel segment 1 to be aligned with the pit position A3, all the second hand chain hoists 24 are released simultaneously to lower the inner bottom stainless steel segment 1 into the pit.

[0072] After the inner bottom stainless steel segment 1 is lowered and closed into the recess, the single-sided gap between the inner bottom stainless steel segment 1 and the mother ship hull structure is 5mm to 9mm.

[0073] When the tortoise-shaped trolley 2, carrying the inner bottom stainless steel segment 1, moves to the outside of the enclosure system installation platform B in the pump well area, the support leg B3 of the enclosure system installation platform B needs to be temporarily removed, and the height of the tortoise-shaped trolley 2 should not exceed 1300mm to ensure its smooth passage. After the inner bottom stainless steel segment 1 is installed, the support leg B3 of the enclosure system installation platform B is reinstalled in place.

[0074] S6. The assembly and welding of the joint between the inner bottom stainless steel segment 1 and the mother ship hull structure is carried out and inspected to complete the installation.

[0075] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A tortoise-shaped trolley for transporting stainless steel segments of the inner bottom within a liquid cargo tank, characterized in that, The tortoise-shaped trolley is used to lift the inner bottom stainless steel segment (1) from the gas dome (A1) of the liquid cargo tank onto the inner bottom plate (A2) of the liquid cargo tank and transport it to the pit position (A3) above the pump well area, and lower the inner bottom stainless steel segment (1) into the pit. The tortoise-shaped trolley includes a frame body (21) and multiple sets of pulley hoisting assemblies symmetrically arranged on the frame body. The pulley hoisting assemblies include a top lifting bracket (22) fixed to the edge of the frame body (21), a second pulley (232) fixed to the frame body (21) by a column (25), a first pulley (231) fixed to the frame body (21) by a diagonal brace (26), and a wire rope (27). The second pulley (232) is horizontally arranged, and the first pulley (231) is vertically arranged. The exit height of the second pulley (232) is equal to the entry height of the first pulley (231). One end of the wire rope (27) is fixed to the top lifting bracket (22), and the other end passes through the second pulley (232) and the first pulley (231) in sequence and is connected to the hoisting eye plate of the inner bottom stainless steel segment (1). A second hand-operated hoist (24) is provided on the wire rope (27). The inner bottom stainless steel segment (1) includes a low-temperature stainless steel plate (11), a T-row component (13), a longitudinal girder component (12), a reinforcing elbow plate (14), a reinforcing rib (17) and a bulb flat steel (18) fixed on one side of the low-temperature stainless steel plate (11), and a first lifting eye plate (15) and a second lifting eye plate (16) fixed on the other side of the low-temperature stainless steel plate (11). Among them, the T-row components (13) are fixed on the low-temperature stainless steel plate (11) in a horizontal and vertical distribution. The longitudinal girder components (12) are vertically fixed at the end of the horizontally arranged T-row components (13). Multiple equidistant reinforcing elbow plates (14) are provided at the connection between the horizontally arranged T-row components (13) and the low-temperature stainless steel plate (11) and the connection between the longitudinal girder components (12) and the low-temperature stainless steel plate (11). The reinforcing ribs (17) are provided between two adjacent longitudinally arranged T-row components (13) and between the longitudinally arranged T-row components (13) and the longitudinal girder components (12). The end of the reinforcing ribs (17) is connected to the connecting elbow plate (19). The bulb flat steel (18) passes through the connecting elbow plate (19).

2. The tortoise-shaped trolley for transporting stainless steel segments of the inner bottom within a liquid cargo tank according to claim 1, characterized in that, The center of the first pulley (231) is aligned with the side edge of the frame body (21).

3. The tortoise-shaped trolley for transporting stainless steel segments of the inner bottom within a liquid cargo tank according to claim 1 or 2, characterized in that, The main frame (21) includes multiple intersecting short side beams (211) and long side beams (212) forming a rectangular frame, support legs (213) vertically fixed at the four corners of the rectangular frame, and casters (28) fixed at the bottom of the support legs (213). The second pulley (232) is fixed on the short side beam (211) located on the inner side, the first pulley (231) is fixed on the long side beam (212) located on the side, and the second hand chain hoist (24) is set on the wire rope between the second pulley (232) and the top hanging bracket (22).

4. The tortoise-shaped trolley for transporting stainless steel segments of the inner bottom within a liquid cargo tank according to claim 1, characterized in that, The overall height of the tortoise-shaped trolley does not exceed 1300mm.

5. The tortoise-shaped trolley for transporting stainless steel segments of the inner bottom within a liquid cargo tank according to claim 1, characterized in that, After the turtle-shaped trolley lowers and closes the inner bottom stainless steel segment (1) into the recess, the single-sided gap between the inner bottom stainless steel segment (1) and the mother ship structure is 5mm-9mm.

6. The tortoise-shaped trolley for transporting stainless steel segments of the inner bottom within a liquid cargo tank according to claim 1, characterized in that, When the tortoise-shaped trolley transports the inner bottom stainless steel segment (1), the bottom of the stainless steel segment (1) is at least 50 mm away from the inner bottom plate (A2) of the liquid cargo tank.

7. The tortoise-shaped trolley for transporting stainless steel segments of the inner bottom within a liquid cargo tank according to claim 1, characterized in that, There are two sets of the first lifting eye plate (15) and the second lifting eye plate (16), and the two sets of the first lifting eye plate (15) and the second lifting eye plate (16) are respectively set at the bow and stern ends of the low-temperature stainless steel plate (11).

8. The tortoise-shaped trolley for transporting stainless steel segments of the inner bottom within a liquid cargo tank according to claim 1, characterized in that, The line connecting the second pulley (232) and the first pulley (231) is perpendicular to the line connecting the second pulley (232) and the top bracket (22).

Images