Method for manufacturing a floating structure equipped with a liquefied gas storage tank
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- GAZTRANSPORT & TECHNIGAZ SA
- Filing Date
- 2023-07-25
- Publication Date
- 2026-05-11
AI Technical Summary
Existing methods for manufacturing floating structures with sealed insulated tanks for liquefied gases require extensive use of dry docks, leading to prolonged occupancy and limited production capacity in shipyards.
A method involving prefabrication of floating structure sections with integrated insulating barriers and sealing membranes, allowing assembly in any available shipyard space and reducing dry dock time by installing tanks before final assembly.
Significantly reduces dry dock occupancy time and enhances manufacturing efficiency by enabling parallel construction and assembly of tanks in non-dock areas, thus increasing production capacity.
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Abstract
Description
[Technical Field]
[0001] The present invention relates to the field of floating structures, in particular ships and barges, for storing and / or transporting liquefied gases, and in particular to the field of floating structures with sealed, insulated membrane tanks for storing and / or transporting liquefied gases, such as liquefied natural gas, liquefied petroleum gas, ammonia, hydrogen, etc.
[0002] The present invention more particularly relates to a method for manufacturing such a floating structure. [Background technology]
[0003] Ships with double hulls, i.e., inner and outer hulls, are known in the prior art. The inner hull defines a number of compartments, each section forming a load-bearing structure, inside which is fitted a sealed, insulated tank for storing liquefied gas. The compartments are arranged one after the other along the length of the ship, and each compartment is separated from the interior space of the adjacent compartment by a transverse cofferdam space.
[0004] To build such a ship, it is known to prefabricate ship sections, each consisting of an outer hull and an inner hull, and then assemble the sections together in a dry dock. Then, once the sections are assembled together, the walls of the sealed, insulated tank are installed and secured within the compartments of the inner hull. These operations to manufacture the tank can be carried out in a dry dock or at the dock after the ship has been launched, so that the ship can leave the dry dock as quickly as possible. Alternatively, the operations can be carried out partly in a dry dock and partly at the dock.
[0005] This manufacturing method is not entirely satisfactory, especially since all the work of installing and fastening the walls of the closed tank is carried out in a dry dock or dock, and this manufacturing method results in the dry dock or dock being monopolized for a long period of time. Currently, shipyards have a limited number of docks and dry docks, which limits the production capacity of the shipyards. Summary of the Invention
[0006] One idea behind the present invention is to propose a method for manufacturing floating structures with sealed insulated tanks, which allows to significantly reduce dry dock and / or dock occupancy times.
[0007] Another idea behind the present invention is to propose a faster and easier method for manufacturing floating structures.
[0008] According to a first aspect, the present invention provides a method for manufacturing a floating structure, comprising: - manufacturing a first section and a second section of the floating structure, wherein the first section and the second section are each an outer hull portion; an inner hull portion comprising a plurality of load-bearing walls defining a compartment, the plurality of load-bearing walls including a first cofferdam wall and a second cofferdam wall extending transversely to a longitudinal direction of the floating structure, an upper wall, a lower wall, and a side wall, the upper wall, the lower wall, and the side wall extending longitudinally between the first cofferdam wall and the second cofferdam wall; at least one insulating barrier of a sealed insulated tank fixed within the compartment to each of the plurality of load-bearing walls defining the compartment; and - assembling the first section and the second section, wherein the outer hull portion of the first section and the outer hull portion of the second section are welded together in a liquid-tight manner, and the first cofferdam wall of the first section, together with the second cofferdam wall of the second section, forms a cofferdam space between the compartment of the first section and the compartment of the second section; The present invention relates to a method for providing a plurality of sensors in a single device.
[0009] Thus, the insulating barriers of at least the first and second sections of the tank can be installed inside the inner hull in any zone of the shipyard where there is sufficient space, limiting the time spent in drydock.
[0010] Furthermore, each section is made up of all the load-bearing walls that define the compartment, which limits deformation of the insulating barrier when the sections are moved and assembled together.
[0011] According to some embodiments, such a manufacturing method may include one or more of the following features.
[0012] According to one embodiment, the method contemplates manufacturing n sections (n greater than 2), at least some of which are manufactured similarly to the first and second sections described above, and then assembling each of the n sections with an adjacent section using assembly steps similar to those used to assemble the first and second sections.
[0013] According to one embodiment, the step of manufacturing the first section includes a step of fastening structural reinforcement to the first cofferdam wall of the first section; the structural reinforcement projects away from the compartment of the first section; the step of fabricating the second section includes the step of fastening structural reinforcement to the second cofferdam wall of the second section; the structural reinforcement projects away from the compartment of the second section; When the first section is assembled with the second section, the structural reinforcement protruding from the first cofferdam wall of the first section is welded to the structural reinforcement protruding from the second cofferdam wall of the second section at a weld region; Or, The structural reinforcement protruding from the first cofferdam wall of the first section and the structural reinforcement protruding from the second cofferdam wall of the second section are welded to an intermediate reinforcement connecting the structural reinforcement of the first and second cofferdam walls at a welding region, thereby facilitating assembly of the sections.
[0014] According to one embodiment, the welding area is located at a distance of more than 100 mm from the first cofferdam wall of the first section and from the second cofferdam wall of the second section, thereby avoiding deterioration of the part of the thermal insulation barrier attached to the first cofferdam wall of the first section and / or the part of the thermal insulation barrier attached to the second cofferdam wall of the second section due to the welding operation.
[0015] According to one embodiment, the steps of manufacturing the first section and manufacturing the second section each include fixing a sealing membrane in the compartment of the first or second section to the insulating barrier before assembling the first section to the second section, thereby further reducing the time required in dry docking.
[0016] According to one embodiment, the insulating barrier is a secondary insulating barrier and the sealing membrane is a secondary sealing membrane.
[0017] According to one embodiment, the steps of manufacturing the first section and manufacturing the second section each include a step of fixing a primary insulating barrier in the compartment of the first or second section to the secondary sealing membrane before assembling the first section to the second section.
[0018] According to one embodiment, the steps of manufacturing the first section and manufacturing the second section each include a step of fixing a primary sealing membrane in the compartment of the first or second section to the primary insulating barrier before assembling the first section to the second section.
[0019] According to one embodiment, before assembling the first section to the second section, the first section and the second section each comprise a sealed, insulated tank fixed within the compartment of the first section or the second section, the sealed, insulated tank comprising a tank wall for each of the load-bearing walls defining the compartment, each tank wall having a multi-layer structure including at least the insulating barrier and sealing membrane, preferably a secondary insulating barrier, a secondary sealing membrane, a primary insulating barrier, and a primary sealing membrane.
[0020] According to one embodiment, in the step of manufacturing the first and second sections, a leak test is performed on the sealing membranes of the first and second sections, preferably a leak test on the primary and secondary sealing membranes if each section includes two sealing membranes.
[0021] According to one embodiment, the sealing membrane is leak tested before the initial cool down.
[0022] According to one embodiment, in the step of manufacturing the first and second sections, the sealing membrane is cooled down before assembling the first section to the second section. According to a variant of the embodiment, the cooling down is obtained by cooling the tank, for example, using liquid nitrogen.
[0023] According to one embodiment, in the step of manufacturing the first and second sections, before assembling the first section to the second section, the sealing membranes of the first section and the second section are leak tested after an initial cool down.
[0024] According to one embodiment, the first section and the second section are manufactured in a first zone, the first section and the second section are moved to a dry dock using a lifting device, and the first section and the second section are assembled to each other in the dry dock. The lifting device may consist of a plurality of cranes.
[0025] According to one embodiment, the steps of manufacturing the first section and the second section include assembling and fixing the sealed, insulated tank in the compartment of the first section or the second section before assembling the first section to the second section, the sealed, insulated tank having an interior space for accommodating liquefied gas and including a tank wall for each of the load-bearing walls defining the compartment, each tank wall having a multi-layer structure including at least the insulating barrier and the sealing membrane. During the transportation of the first section of the first zone to the dry dock and / or during the assembly of the first section and the second section, a pressure difference occurs between a first pressure present in the interior space of the sealed, insulated tank of the first section and a second pressure present in the insulating barrier of the sealed, insulated tank of the first section, the first pressure being greater than the second pressure. This allows the sealing membrane to be tightly pressed against the insulating barrier, making it possible to avoid or at least limit deformation of the sealing membrane when the first section is transported or assembled with the second section.
[0026] According to one embodiment, such a pressure difference also occurs between the interior space of the sealed insulated tank of the second section and the insulating barrier while the second section is being moved from the first zone to the dry dock and / or while the first and second sections are being assembled together.
[0027] According to one embodiment, the pressure difference between the first pressure and the second pressure is greater than 2 kPa, preferably greater than or equal to 5 kPa.
[0028] According to one embodiment, the pressure difference between the first pressure and the second pressure is between 5 kPa and 25 kPa.
[0029] According to one embodiment, the pressure difference is created by placing the insulating barrier at a pressure below atmospheric pressure.
[0030] According to one embodiment, each tank wall includes a secondary insulating barrier, a secondary sealing membrane, a primary insulating barrier, and a primary sealing membrane; While the first section of the first zone is being moved to the dry dock and / or while the first section and the second section are being assembled together, a pressure difference occurs between the pressure of the secondary insulating barrier and the primary insulating barrier of the sealed insulated tank of the first section, and the pressure of the secondary insulating barrier is lower than the pressure of the primary insulating barrier.
[0031] According to one embodiment, the pressure difference is created by placing the interior space of the sealed, insulated tank at a pressure higher than atmospheric pressure.
[0032] According to one embodiment, the steps of manufacturing the first section and manufacturing the second section each include: - welding the bottom wall and the side walls to the first and second cofferdam walls; - introducing a scaffold into said compartment through an opening intended to be closed by said top wall; - assembling the scaffold within the compartment; - welding the top wall to the side walls and the first and second cofferdam walls to close the compartment; - fixing the insulating barrier to each of the load-bearing walls defining the compartment; Equipped with.
[0033] This simplifies the scaffolding installation work and further reduces the time required to manufacture the floating structure.
[0034] According to one embodiment, the steps of manufacturing the first section and manufacturing the second section each further comprise the step of fixing the sealing membrane to the insulating barrier.
[0035] According to one embodiment, the floating structure is a ship.
[0036] According to another embodiment, the floating structure is a reliquefaction and gasification barge or a methane carrier type vessel.
[0037] The present invention will be better understood and other objects, details, features and advantages of the present invention will become more clearly apparent through the following description of some particular embodiments thereof, which are given by way of non-limiting example only with reference to the accompanying drawings, in which: [Brief explanation of the drawings]
[0038] [Figure 1] FIG. 1 is a schematic side view of a double-hull vessel. [Figure 2] FIG. 2 is a schematic side view of the double-hull vessel of FIG. 1 during manufacture, before successive pre-assembled sections are fastened together. [Figure 3] FIG. 3 is a partial schematic view of the interior space of a pre-assembled section intended to house a sealed, insulated tank. [Figure 4] FIG. 4 is a schematic perspective view of one section. [Figure 5] FIG. 5 is a partial cross-sectional view along the transverse axis of the cofferdam space. [Figure 6] FIG. 6 is a schematic diagram showing the multi-layer structure of the tank wall. [Figure 7] FIG. 7 is a partial schematic view of a section with scaffolding used to attach the tank walls within the compartments of the section. DETAILED DESCRIPTION OF THE INVENTION
[0039] Figure 1 shows a ship 1 having a double hull, with a number of sealed insulated tanks 2 for storing liquefied gas mounted within the double hull. The double hull comprises an outer hull 3 and an inner hull 4. To ensure the stability of the ship 1, the outer hull 3 and the inner hull 4 are separated by a ballast space 5, which is filled with seawater and whose volume increases or decreases depending on the load of the ship 1.
[0040] The liquefied gas intended to be stored in tank 2 may in particular be liquefied natural gas (LNG) (i.e. a gas mixture comprising mainly methane and one or more other hydrocarbons, ethane), liquefied petroleum gas (LPG) (i.e. a mixture of hydrocarbons obtained from the refining of petroleum and comprising essentially propane and butane), liquefied hydrogen, or liquefied ammonia.
[0041] The inner hull 4 includes a plurality of polyhedron-shaped compartments 6, each defined by a plurality of load-bearing walls, intended to form a load-bearing structure for receiving one of the tanks of the vessel 1. The inner hull 4 includes cofferdam walls 7, 8 extending transversely to the longitudinal direction of the vessel 1, which define cofferdam spaces 9 that divide the inner hull 4 into a plurality of compartments 6. Each cofferdam space 9 is defined by two cofferdam walls 7, 8, one on each side of the cofferdam space 9, which form the respective load-bearing walls of two adjacent compartments 6. The width of the cofferdam spaces is approximately 1.5 to 3 meters.
[0042] A method for manufacturing such a vessel 1 will now be described with reference to FIG.
[0043] First, a number of sections 10, 11, 12, 13, 14, 15 are manufactured, of which sections referenced 11, 12, 13, 14 incorporate all the load-bearing walls that define the compartments 6, respectively.
[0044] Therefore, as shown in Figure 2, these sections 11, 12, 13, 14 form part of the inner hull 4 which includes two cofferdam walls 7, 8 which respectively define the front and rear walls of the compartment 6, and each cofferdam wall defines a cofferdam space 9 together with the cofferdam walls 7, 8 of the adjacent sections 11, 12, 13, 14. The part of the inner hull 4 of each of the sections 11, 12, 13, 14 includes an upper wall 16, a lower wall 17, and a side wall which extends in the longitudinal direction of the ship 1 and connects the two cofferdam walls 7, 8 of the sections 11, 12, 13, 14.
[0045] In other words, the joint surfaces at the joints between successive sections 11, 12, 13, 14 pass through a cofferdam space 9 extending transversely to the longitudinal direction of the vessel 1, the cofferdam space 9 being between two cofferdam walls 7, 8 that delimit the cofferdam space 9.
[0046] Preferably, the cofferdam walls 7, 8 are octagonal in shape, as shown in Figures 3 and 4. The side walls therefore include two vertical walls 19, 22, two upper sloping walls 18, 21, and two lower sloping walls 20, 23. The two vertical walls 19, 22 are each connected to the upper wall 16 by one of the upper sloping walls 18, 21 and to the lower wall 17 by one of the two lower sloping walls 20, 23.
[0047] 4 and 5, the sections 11, 12, 13, 14, 15 further comprise structural reinforcements 31. The structural reinforcements 31 are fixed to the cofferdam walls 7, 8 on the side facing away from the compartment 6. The structural reinforcements 31 are therefore intended to be located in the cofferdam space 9 formed between two adjacent cofferdam walls 7, 8. The structural reinforcements 31 therefore protrude from the cofferdam walls 7, 8 and extend in a direction away from the compartment 6 receiving the tank 2. In the figures, the structural reinforcements 31 are oriented either vertically or horizontally, thus forming a network of structural reinforcements 31 arranged perpendicular to one another. The structural reinforcements 31 are, for example, formed of metal plates welded to the cofferdam walls 7, 8.
[0048] According to one advantageous embodiment, to manufacture sections 11, 12, 13, and 14, the cofferdam walls 7 and 8, their structural reinforcement 31, the bottom wall 17, and the side walls 18, 19, 20, 21, 22, and 23 are first welded together. The top wall 16 itself is not yet welded to the other load-bearing walls, so the inner hull 4 has an opening above the compartment 6. Therefore, as shown in Figure 7, the scaffolding 32 is introduced into the compartment 6 through this opening and assembled inside the compartment 6. This facilitates the installation of the scaffolding. In a second step, the top wall 16 is welded to the other load-bearing walls, and the compartment 6 is closed.
[0049] The tank 2 is then installed and fixed in the compartment 6 using scaffolding 39. The tank 2 is preferably a membrane tank. The walls of such a tank 2 have a multi-layer structure, as shown in Figure 6. Each wall comprises, from the outside to the inside, in the direction of the thickness of the wall, a secondary insulating barrier 24 comprising an insulating element 26 fixed to the load-bearing wall 25, a secondary sealing membrane 27 fixed to the insulating element 26 of the secondary insulating barrier 24, a primary insulating barrier 28 comprising an insulating element 29 fixed to the insulating element 26 of the secondary insulating barrier 24 or to the load-bearing wall 25 and in contact with the secondary sealing membrane 27, and a primary sealing membrane 30 fixed to the insulating element of the primary insulating barrier 28 and intended to be in contact with the liquefied gas contained in the tank 2. The tank walls may be manufactured using any technique known in the field of membrane tanks. The tank wall is, for example, of the Mark III® type described in patent application FR 2 691 520, of the NO 96® type described in patent application FR 2 877 638 or of the Mark V® type described in WO 2014 / 057221.
[0050] According to another embodiment, the multi-layer structure has only one insulating barrier fixed to the load-bearing wall and only one sealing membrane designed to be in contact with the liquefied gas in the tank 2 and adjoin the insulating barrier. According to another variant, the multi-layer structure may have more than two sealing membranes.
[0051] All the load-bearing walls of each compartment 6 are covered with the tank walls having the aforementioned multi-layer structure. In other words, each section 11, 12, 13, 14 includes all the load-bearing walls that define a compartment 6, so that all the walls of the tank 2 are attached to the compartment 6 of said section 11, 12, 13, 14 before this section is assembled with the other sections 11, 12, 13, 14 in the drydock.
[0052] Thus, the tanks 2 of the vessel 1 can be installed within the inner hull 4 in any zone of the shipyard where there is sufficient space. The sections 11, 12, 13, 14 are then placed in a dry dock using a lifting device 32, such as a crane shown in Figure 2, and assembled together there, thereby reducing the time required in the dry dock.
[0053] Furthermore, such a method may allow for parallel construction operations of some or all of the tanks 2, thereby reducing the total time taken to build the vessel 1.
[0054] According to one advantageous embodiment, a leak check operation of the sealing membranes 27, 30 of the tank 2 is also carried out before the sections 11, 12, 13, 14 are assembled together, which allows the time required in the drydock to be further reduced.
[0055] According to the international standard "International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk", the sealing membranes 27, 30 are leak tested at least once before the first cool-down of the tank 2 and a second time after the first cool-down of the tank 2. Thus, according to one advantageous embodiment, at least the first leak test (which is carried out before the first cool-down of the tank 2) is carried out before the sections 11, 12, 13, 14 are transferred to the dry dock and assembled there. According to a variant of one advantageous embodiment, the first cool-down of the tank 2 and the aforementioned second leak test are also carried out on the sections 11, 12, 13, 14 before they are assembled there. To do this, according to one embodiment, the tank 2 may be cooled and cooled down using liquefied nitrogen before the sections 11, 12, 13, 14 are transferred to the dry dock and assembled there.
[0056] Preferably, in order to avoid or limit deformation of the walls of the tank 2, in particular the sealing membranes 27, 30, when the sections 11, 12, 13, 14 are moved to the dry dock by the lifting equipment 32 and then assembled with the adjacent sections 11, 12, 13, 14, a pressure difference is created between the pressure P1 existing in the internal space of the tank 2 and the pressures P2, P3 existing respectively in the primary insulating barrier 28 and the secondary insulating barrier 24, such that the pressure P1 in the internal space of the tank 2 is higher than the pressures existing in the secondary insulating barrier 24 and the primary insulating barrier 28. This has the effect that the primary sealing membrane 30 and the secondary sealing membrane 27 are pressed tightly against the primary insulating barrier 28 and the secondary insulating barrier 24, respectively, thereby avoiding or at least limiting deformation thereof when the sections 11, 12, 13, 14 are moved and assembled with each other.
[0057] According to a variant embodiment, the pressure difference is obtained by injecting air or an inert gas into the internal space of the tank 2, thereby maintaining the internal space at a pressure higher than atmospheric pressure. By way of example, the gauge pressure present in the internal space of the sealed, insulated tank 2 is greater than 2 kPa, advantageously between 5 kPa and 25 kPa, preferably between 5 kPa and 20 kPa, for example in the order of 5, 15 or 20 kPa.
[0058] According to an alternative or additional embodiment variant, the pressure difference is obtained by applying reduced pressure to the primary insulating barrier 28 and the secondary insulating barrier 24. To do this, a vacuum pump is connected to each of the secondary insulating barrier 24 and the primary insulating barrier 28. By way of example, the gauge pressure applied to the primary insulating barrier 28 and the secondary insulating barrier 24 is less than −2 kPa, advantageously between −5 kPa and −25 kPa, and preferably between −5 kPa and −20 kPa. According to an advantageous variant, the pressure P3 in the secondary insulating barrier 24 is lower than the pressure P2 in the primary insulating barrier 28, thereby making it possible to press the secondary sealing membrane 27 towards the secondary insulating barrier 24.
[0059] It should be noted that in the advantageous embodiment described below, all layers of the multi-layer structure of each wall of the sealed, insulated tank 2 are installed in the compartments 6 of the sections 11, 12, 13, 14 before the sections 11, 12, 13, 14 are assembled with the other sections 11, 12, 13, 14. However, according to other possible embodiment variants, it is also conceivable that only some of the components of the multi-layer structure are installed in the compartments 6 before the sections 11, 12, 13, 14 are moved to the dry dock and assembled with each other.
[0060] For example, before assembling sections 11, 12, 13, and 14 with other sections 11, 12, 13, and 14, -Secondary Insulation Barrier 24 only, - only the secondary insulating barrier 24 and the secondary sealing membrane 27, or - only the secondary insulating barrier 24, the secondary sealing membrane 27, and the primary insulating barrier 28; can be attached.
[0061] To assemble the sections 11, 12, 13, 14 together, the outer hull parts 3 are hermetically welded to one another. Furthermore, the structural reinforcements 31 protruding from each cofferdam wall 7, 8 are welded to the structural reinforcements 31 of the opposing cofferdam wall 7, 8 belonging to the adjacent section 11, 12, 13, 14. Preferably, the structural reinforcements 31 of adjacent sections 11, 12, 13, 14 are welded to one another in welding zones located at a distance of more than 100 mm from each of the two adjacent cofferdam walls 7, 8. Such a distance is intended to avoid deterioration of the walls of the tank 2 attached to the two adjacent cofferdam walls 7, 8 due to temperatures likely to be reached during the welding operation, especially if the multi-layer construction of the walls includes mastic beads between the load-bearing walls and the insulating blocks of the secondary insulating barrier 24.
[0062] According to one alternative embodiment, the structural reinforcement 31 protruding from each cofferdam wall 7, 8 is indirectly fastened via an intermediate reinforcement to the structural reinforcement 31 of the opposing cofferdam wall 7, 8 of sections 11, 12, 13. Each intermediate reinforcement therefore has a portion welded to the structural reinforcement 31 of one of the cofferdam walls 7, 8 and another portion welded to the structural reinforcement 31 of the other of the cofferdam walls 7, 8. As in the previous embodiment, the welding area where the intermediate reinforcement is welded to the structural reinforcement 31 is located at a distance of more than 100 mm from each of the two adjacent cofferdam walls 7, 8.
[0063] Although the present invention has been described with reference to some particular embodiments, it is clear that the invention is not limited thereto but encompasses all technical equivalents of the described means and combinations thereof, provided they fall within the scope of the invention as defined by the claims.
[0064] Use of the verbs "comprise", "have" or "include" and their conjugations does not exclude the presence of elements or steps other than those stated in a claim.
[0065] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.
Claims
1. A method for manufacturing a floating structure (1), - A step of manufacturing the first section (11) and the second section (12) of the floating structure (1), wherein the first section (11) and the second section (12) are each, - Outer hull section (3), - An inner hull portion (4) comprising a plurality of load-bearing walls defining a compartment (6), wherein the plurality of load-bearing walls include a first cofferdam wall (7) and a second cofferdam wall (8) extending laterally with respect to the longitudinal direction of the floating structure (1), an upper wall (16), a lower wall (17), and side walls (18, 19, 20, 21, 22, 23), wherein the upper wall (16), the lower wall (17), and the side walls (18, 19, 20, 21, 22, 23) extend longitudinally between the first cofferdam wall (7) and the second cofferdam wall (8), and the inner hull portion (4), - At least one thermal barrier (24, 28) of a sealed thermal tank (2) fixed within the compartment (6) to each of the plurality of load-bearing walls defining the compartment (6), Steps including, - A step of assembling the first section (11) and the second section (12), wherein the outer hull portion (3) of the first section (11) and the outer hull portion (3) of the second section (12) are liquid-tightly welded to each other, and the first cofferdam wall (7) of the first section (11), together with the second cofferdam wall (8) of the second section (12), forms a cofferdam space (9) between the compartment (6) of the first section (11) and the compartment (6) of the second section (12), A method for continuously acquiring these.
2. The step of manufacturing the first section (11) includes the step of fixing the structural reinforcement (31) to the first Koffadam wall (7) of the first section (11), The structural reinforcing member (31) protrudes in a direction away from the compartment (6) of the first section (11), The step of manufacturing the second section (12) includes the step of fixing the structural reinforcement (31) to the second Koffadam wall (8) of the second section (12), The structural reinforcing member (31) protrudes in a direction away from the compartment (6) of the second section (12), When the first section (11) is assembled with the second section (12), The structural reinforcement member (31) protruding from the first Koffadam wall (7) of the first section (11) is welded in the welding area to the structural reinforcement member (31) protruding from the second Koffadam wall (8) of the second section (12). Or, The structural reinforcing members (31) protruding from the first Koffadam wall (7) of the first section (11) and the structural reinforcing members (31) protruding from the second Koffadam wall (8) of the second section (12) are welded in the welding area to an intermediate reinforcing member that connects the structural reinforcing members of the first and second Koffadam walls (7, 8). A method for manufacturing the floating structure (1) described in claim 1.
3. The welding area is located at a distance of more than 100 mm from the first Koffadam wall (7) of the first section (11) and from the second Koffadam wall (8) of the second section (12). A method for manufacturing the floating structure (1) described in claim 2.
4. The steps of manufacturing the first section (11) and the second section (12) each include fixing the sealing membranes (27, 30) within the compartments (6) of the first or second section (12) to the thermal insulation barriers (24, 28), A method for manufacturing a floating structure (1) according to any one of claims 1 to 3.
5. The aforementioned thermal insulation barrier is a secondary thermal insulation barrier (24), The aforementioned sealing membrane is a secondary sealing membrane (27), The steps of manufacturing the first section (11) and the second section (12) each include fixing the primary insulating barrier (28) in the compartment (6) of the first or second section (12) to the secondary sealing membrane (27), A method for manufacturing the floating structure (1) described in claim 4.
6. The steps of manufacturing the first section (11) and the second section (12) each include fixing the primary sealing membrane (30) in the compartment (6) of the first or second section (12) to the primary insulating barrier (28), A method for manufacturing the floating structure (1) described in claim 5.
7. In the step of manufacturing the first section (11) and the second section (12), a leak test is performed on the sealing membranes (27, 30) of the first section (11) and the second section (12). A method for manufacturing the floating structure (1) described in claim 4.
8. The first section (11) and the second section (12) are manufactured in the first zone. The first section (11) and the second section (12) are moved to the dry dock using a lifting device (32). The first section (11) and the second section (12) are assembled together in the dry dock. A method for manufacturing a floating structure (1) according to any one of claims 1 to 3.
9. The steps of manufacturing the first section (11) and the second section (12) include the steps of assembling and securing the sealed insulated tank (2) within the compartment (6) of the first section (11) or the second section (12), The sealed insulated tank (2) has an internal space for containing liquefied gas and is provided with tank walls for each of the load-bearing walls that define the compartment (6). Each tank wall has a multilayer structure including at least the thermal insulation barriers (24, 28) and sealing membranes (27, 30), While the first section (11) of the first zone is being moved to the dry dock and / or while the first section (11) and the second section (12) are being assembled together, a pressure difference is generated between a first pressure (P1) present in the internal space of the sealed insulated tank (2) of the first section (11) and a second pressure (P2, P3) present in the insulated barriers (24, 28) of the sealed insulated tank (2) of the first section (11). The first pressure (P1) is greater than the second pressures (P2, P3). A method for manufacturing the floating structure (1) described in claim 8.
10. A method for manufacturing a floating structure (1) according to claim 9, wherein the pressure difference between the first pressure (P1) and the second pressures (P2, P3) is greater than 2 kPa.
11. A method for manufacturing a floating structure (1) according to claim 9, wherein the pressure difference between the first pressure (P1) and the second pressures (P2, P3) is between 5 kPa and 25 kPa.
12. A method for manufacturing the floating structure (1) according to claim 9, wherein the pressure difference is generated by placing the adiabatic barriers (24, 28) at a pressure lower than atmospheric pressure.
13. The method for manufacturing the floating structure (1) according to claim 9, wherein the pressure difference is generated by placing the internal space of the sealed insulated tank (2) at a pressure higher than atmospheric pressure.
14. The steps of manufacturing the first section (11) and manufacturing the second section (12) are, respectively, - A step of welding the lower wall (17) and the side walls (18, 19, 20, 21, 22, 23) to the first and second Koffadam walls (7, 8), - The step of introducing scaffolding (39) into the compartment (6) through an opening intended to be closed by the upper wall (16), - The step of assembling the scaffolding (39) inside the compartment (6), - The steps of welding the upper wall (16) to the side walls (18, 19, 20, 21, 22, 23) and the first and second Koffadam walls (7, 8) to close the compartment (6), - A step of fixing the heat insulating barriers (24, 28) to each of the load-bearing walls that define the compartment (6), A method for manufacturing a floating structure (1) according to any one of claims 1 to 3, comprising the above.
15. A method for manufacturing a floating structure (1) according to claim 14, wherein the steps of manufacturing the first section (11) and manufacturing the second section (12) each further include the step of fixing a sealing membrane (27, 30) to the heat insulating barrier (24, 28).