Hull with capacity space having backbone structural arrangement

Abstract

A hull of a floating unit configured to store a payload may define a capacity space delimited by top, floor, opposite side and opposite end faces such that the capacity space extends in a depth direction, in a longitudinal direction, and in a transverse direction. The top face and floor face may be spaced apart in the depth direction. The hull may comprise a backbone feature formed in one of the top or floor faces and extending inwardly into the capacity space in the depth direction toward the other of the top or floor faces by a distance less than the greatest height of the capacity space in the depth direction. The backbone feature may be spaced apart from said other of the top or floor faces by a gap that separates the backbone feature from said other of the top or floor faces.

Description

P609748PC00HULL WITH CAPACITY SPACE HAVING BACKBONE STRUCTURAL ARRANGEMENTTechnical Field

[0001] The present disclosure relates generally to hulls of floating units for storing payloads such as liquified natural gas and, more particularly (although not necessarily exclusively), to backbone features that may be utilized to strengthen hulls or capacity spaces defined by hulls or tanks for use in hulls of floating units.Background

[0002] The energy industry often utilizes large, complex industrial structures, referred to generally as “units,” that are purpose-built for performing specific functions, such as storage, processing, and / or transportation of oil, gas, wind, and other energy carriers. A so-called “floating unit” is specifically made to be deployed at sea: at shore, near shore, or offshore. It can be either in a floating, moored, or fixed configuration. It can also be laid on the sea ground after some ballasting operations. Floating units may be utilized in energy production operations in offshore, nearshore, or other marine settings. Some floating units are specifically used for extracting, purifying, liquefying, and storing gas from liquefied gas operations, such as liquified natural gas or liquified petroleum gas, for example. Floating units may include a processing plant (e.g., which may be moored offshore or nearshore for conducting operations) and / or transportation vessels in operation.Summary

[0003] One or more embodiments include a hull of a floating unit configured to store a payload, the hull defining a capacity space delimited by top, floor, opposite side and opposite end faces such that the capacity space extends in a depth direction, in a longitudinal direction, and in a transverse direction, the top face and floor face being spaced apart in the depth direction, the hull comprising a backbone feature formed in one of the top or floor faces and extending inwardly into the capacity space in the depthdirection toward the other of the top or floor faces by a distance less than the greatest height of the capacity space in the depth direction, the backbone feature being spaced apart from said other of the top or floor faces by a gap that separates the backbone feature from said other of the top or floor faces.

[0004] One or more embodiments include the hull of the previous paragraph, wherein the backbone feature comprises an inwardly extending projection ending in an end face bounded laterally by sloped sides.

[0005] One or more embodiments include the hull of any previous paragraph, wherein the backbone feature is formed in the top face and extends inwardly into the capacity space in the depth direction toward the floor face by a distance less than the greatest height of the capacity space in the depth direction, the backbone feature being spaced apart from said floor face by a gap that separates the backbone feature from said floor face.

[0006] One or more embodiments include the hull of any previous paragraph, wherein the backbone feature is formed in the floor face and extends inwardly into the capacity space in the depth direction toward the top face by a distance less than the greatest height of the capacity space in the depth direction, the backbone feature being spaced apart from said top face by a gap that separates the backbone feature from said top face.

[0007] One or more embodiments include the hull of any previous paragraph, wherein a backbone feature is formed in each of the top face and floor face, each backbone feature extending inwardly into the capacity space in the depth direction toward the other of the top or floor face by a distance less than the greatest height of the capacity space in the depth direction, the backbone feature being spaced apart from said other of the top or floor face by a gap that separates the respective backbone feature from said face.

[0008] One or more embodiments include the hull of any previous paragraph, wherein a plurality of backbone features are formed in one of the top or floor faces and extending inwardly into the capacity space in the depth direction toward the other of the top or floor faces by a distance less than the greatest height of the capacity space in the depth direction, the backbone features being spaced apart from said other of the top or floor faces by a gap that separates the backbone feature from said other of the top or floor faces.

[0009] One or more embodiments include the hull of any previous paragraph, wherein:(i) two backbone features as set out above are formed in the top face and zero, one or two backbone features as set out above are formed in the floor face; or(ii) two backbone features as set out above are formed in the floor face and zero or one backbone features as set out above are formed in the top face.

[0010] One or more embodiments include the hull of any previous paragraph, further comprising a deck positioned outwardly from the top face in the depth direction.

[0011] One or more embodiments include the hull of the preceding paragraph, and where a backbone feature is formed in the top face, wherein the backbone feature is sized and arranged for withstanding load from one or more structures supported on the deck.

[0012] One or more embodiments include the hull of any previous paragraph, further comprising a bottom positioned outwardly from the floor of the tank in the depth direction.

[0013] One or more embodiments include the hull of the preceding paragraph, and where a backbone feature is formed in the floor face, wherein the backbone feature is sized and arranged for withstanding load applied on the bottom, and / or further comprising a communication passage extending laterally through the backbone featureformed in the floor face and positioned to enable liquid passage between portions of the capacity space on either lateral side of the backbone feature.

[0014] One or more embodiments include the hull of any previous paragraph wherein the or each backbone feature is positioned without any structure in an intervening space directly between the backbone feature and the face opposite the face in which the backbone feature is formed, and / or wherein the or each backbone feature comprises a beam extending in the longitudinal direction.

[0015] One or more embodiments include the hull of any previous paragraph, wherein the backbone feature is at least partially formed in a set of web-frames that are spaced from one another in the longitudinal direction and that define a cross-sectional shape of the capacity space extending in the depth direction and in the transverse direction.

[0016] One or more embodiments include the hull of the previous paragraph, wherein the web-frames are connected to one another by girders extending along the longitudinal direction.

[0017] One or more embodiments include the hull of any previous paragraph, wherein the capacity space is bounded along the longitudinal direction by cofferdams or transverse bulkheads.

[0018] One or more embodiments include the hull of the previous paragraph, wherein the backbone assembly is arranged to transfer load received along a deck over the top face of the capacity space into the cofferdams or transverse bulkheads; and / or wherein the backbone feature is arranged to transfer load received along a bottom below the floor face of the capacity space into the cofferdams or transverse bulkheads.

[0019] One or more embodiments include the hull of any previous paragraph, wherein at least one of: lateral corners of an interior surface of the capacity spaceinclude slanted surfaces; and / or the hull further comprises ballast tanks formed in the hull at positions around the capacity space; and / or the capacity space comprises a membrane system comprising a liner and insulation and / or the capacity space comprises or contains a tank, for example a self-supporting prismatic tank, where the tank may be configured for receiving liquified natural gas or other liquefied gas. In other embodiments the capacity space may be adapted to contain other payload types, whether liquid or solid.

[0020] One or more embodiments include the hull of any previous paragraph, wherein the capacity space is included in a plurality of payload tanks arranged longitudinally along the hull in a single row arrangement.

[0021] One or more embodiments include the hull of any previous paragraph, wherein the hull is incorporated into a floating processing plant.

[0022] One or more embodiments include the hull of any previous paragraph, wherein the hull is incorporated into a transportation vessel.Brief Description of the Drawings

[0023] FIG. 1 illustrates a floating unit, according to at least some examples of the present disclosure.

[0024] FIG. 2 illustrates a cross-sectional view of a tank that may be utilized in the floating unit of FIG. 1 , according to at least some examples of the present disclosure.

[0025] FIG. 3 illustrates some examples of structural members that may be utilized to form the tank of FIG. 2, according to at least some embodiments of the present disclosure.

[0026] FIG.4 illustrates a cross-sectional view of another tank that may be utilized in the floating unit of FIG. 1, according to at least some examples of the present disclosure.

[0027] FIG.5 illustrates a cross-sectional view of further tanks, shown to a smaller scale than FIGS. 2 and 4, that may be utilized in the floating unit of FIG. 1 , according to at least some examples of the present disclosure.Detailed DescriptionCertain aspects and features of the present disclosure relate to a backbone feature that may be included in tanks for, or capacity spaces defined by the hull of, a floating unit. The backbone feature may correspond to portions of a tank / capacity space along a top or floor or both that are larger in depth in a middle area between two lateral areas of the tank / capacity space. The backbone features may improve local stiffness and resist bending moments across substantial spans that may be relevant in large structures that may be utilized, such as in floating liquid natural gas processing operations, for example. The backbone features may be relevant for considerations relating to selection among different options of tank configurations, such as a single row configuration, a double row configuration, a triple row configuration, etc. For example, a single row configuration may refer to an arrangement in which a longitudinally-extending line following the longitudinal axis of the unit passes through all of the tanks (e.g., such that there is only one central tank in a cross-section along a transverse direction) regardless of whether the tanks are arranged with or without some degree of staggering along the line. In comparison, for double and triple row configurations, there may be respectively two and three tanks for a cross-section of the hull separated by longitudinal bulkheads (e.g., such that there are two or three lines of tanks following the longitudinal axis of the unit). Including the backbone features may allow tanks to be utilized in a single row configuration and improve efficiency of space usage in comparison to double row arrangements or arrangements with more rows that in use may involve support bulkheads or other structures in between rows that may occupy space and thereby reduce available space for storing payload. Single row arrangement may also provide a simplified construction process, as well as savings in membrane system surface and other equipment for each tank.

[0028] FIG. 1 illustrates a floating unit 101 , according to at least some examples of the present disclosure. In the particular example of FIG. 1 , the floating unit 101 is a floating processing plant. In other implementations, the floating unit 101 may be other types of floating units such as transportation vessels. Floating units 101 may be implemented in nearshore, offshore, or other marine environments, for example.

[0029] The floating unit 101 depicted in FIG. 1 includes a hull 103. The hull 103 may be sized to be able to float and support other structures in use. For example, the hull 103 may support utilities 105, e.g., which may include utility buildings or structures. Examples of the utilities 105 may include a turret (e.g., for extracting natural gas or other fuel from undersea fields and anchoring the unit to the sea ground), gas reception, CO2 absorber, acid gas removal, dehydration, mercury removal, natural gas liquids extraction, cryogenic exchangers, refrigeration, and / or other units. The utilities 105 may be utilized for extracting, purifying, liquefying, and storing gas from liquefied natural gas operations, for example. Living quarters, helipads, and / or other structures may also be supported by the hull 103.

[0030] The floating unit 101 may be suitably sized for offloading and / or onloading a payload (e.g., a fluid payload such as liquified natural gas or other substance, or payloads with at least some solid material). Transfers may be performed relative to a vessel 107 and may include loading arms and / or other suitable structure for such transfers. Generally, the payload may be any fluid etc. that is loaded onto, unloaded from, and / or held by the floating unit 101, including, such as, liquified natural gas. For example, operations may include transferring liquified natural gas, condensate, and / or other substances that may be obtained by operation of the utilities 105 and / or processed by the utilities 105. Payload may be offloaded from storage space within the hull 103, for example. Moreover, although the hull 103 is largely described herein byway of example as included in the floating unit 101, the hull 103 and / or other features described herein may alternatively correspond to a suitable structure that may be included in the vessel 107 (e.g., which may be a transporting vessel) in some embodiments.

[0031] As may be best appreciated by the cutaway call-out portion of FIG. 1, the floating unit 101 is depicted including a series of tanks or capacity spaces 109 within the hull 103. The tanks or capacity spaces 109 may be contained in or defined by the hull 103. The hull 103 may define a single tank or capacity space 109 along the length thereof. The terms “tank 109” and “tanks 109” are used hereafter to include tanks or capacity spaces contained in or defined by the hull 103. The tanks 109 may correspond to payload tanks, e.g., which may be present among machinery space (e.g., aft machinery space, forward machinery space, etc.). The tanks 109 may additionally or alternativelycorrespond to other structures (e.g., propane tanks, butane tanks, condensate tanks, etc.). In use, the tanks 109 may be configured to receive, include, or hold natural gas products (such as liquified natural gas and / or gaseous natural gas), petroleum products (such as liquified petroleum gas and / or gaseous petroleum gas), or other fluid payload (e.g., which may be present in gaseous and / or liquid form), such as may be obtained by processing from the utilities 105, for example.

[0032] The tanks 109 in FIG. 1 are each divided by cofferdams or transverse bulkheads 111. In this particular example, a cofferdam or transverse bulkhead 111 is a barrier structure having structural components (e.g., for withstanding forces of fluid in the tank 109) and thermal components (e.g., such as suitable insulation and / or temperaturemodulating components for maintaining suitable temperatures in the tank 109 and / or preventing excessive thermal migration into and / or from the tank 109), although more, fewer, and / or different sub-elements may be suitable in use. The tanks 109 and / or the cofferdam or transverse bulkheads 111 may be distributed along a longitudinal direction 113. The longitudinal direction 113 may correspond to a length of the hull 103 in use, such as a direction extending between aft and fore and / or between bow and stern. Other features that may be relevant to the hull 103 and / or the tanks 109 may be appreciated with respect to FIG. 2. For example, other directions that may be perpendicular to the longitudinal direction 113 may be represented in FIG. 2, which may correspond to a view taken along the section line 2-2 in FIG. 1.

[0033] FIG. 2 illustrates a cross-sectional view of one of the tanks 109 from FIG. 1 taken along line 2-2 in FIG. 1. The tank 109 (e.g., in addition to the longitudinal direction 113 represented in FIG. 1) as shown in FIG. 2 extends in a transverse direction 115 and a depth direction 117 (e.g., where the longitudinal direction 113, the transverse direction 115, and the depth direction 117 may be perpendicular to each other). The transverse direction 115 may correspond to a lateral or width direction, such as extending between starboard and port. The depth direction 117 may correspond to a vertical direction, such as extending along a direction of force exerted by gravity.

[0034] As shown in FIG. 2, the tank 109 includes a top 119. The tank 109 is further depicted with a floor 121, e.g., with the floor 121 and the top 119 spaced apart in the depth direction 117. In some implementations, the top 119 may be an upper boundary ofa volume of the tank 109, and the floor 121 may be a lower boundary of the volume of the tank 109.

[0035] The tank 109 is depicted in FIG. 2 with a first lateral portion 123 and a second lateral portion 125. A middle portion 127 is further shown between the first lateral portion 123 and the second lateral portion 125. The first lateral portion 123, the middle portion 127, and the second lateral portion 125 may be distributed along the transverse direction 115, for example.

[0036] The hull 103 depicted in FIG. 2 includes a deck 129. The deck 129 may be positioned outwardly from the top 119 of the tank 109 in the depth direction 117. The deck 129 is further shown including and / or accompanied by suitable supports 131, such as for supporting utilities 105 or other structures on the deck 129. The deck 129 accordingly may be subject to and / or convey significant quantities and / or magnitude of loads, which may include significant moment or bending loads, e.g., especially in an area over and / or along the middle portion 127 of the tank 109. The combination of the deck 129 and the top 119 as well as the space between them may be called a trunk deck or double deck. A trunk deck provides internal volume between the outer deck of the hull and the inner deck along the tank 109, e.g., such that the internal volume in the trunk deck may provide suitable locations for anchoring supports 131 and / or other structures of the floating unit 101 in use.

[0037] The hull 103 may include a bottom 133 (which may alternatively be referred to as a keel bottom). The bottom 133 may be positioned outwardly from the floor 121 of the tank 109 in the depth direction 117. The bottom 133 may be suitably constructed to withstand forces from water pressure that may be asserted against the floating unit 101 in use, such as which may impart pressure along an underside of the bottom 133. The combination of the floor 121 of the tank 109 and the bottom 133 as well as the space between them may be called a double bottom. For example, a double bottom may be included to potentially satisfy regulations from the “International Maritime Organization and “International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk” and / or other standards relating to providing suitable separation between outer surfaces of the bottom 133 and the tank 109, e.g., to mitigate against spillage and / orotherwise to provide multiple layers in case of collision of the hull 103 with objects that may be sufficient to puncture or cause a breach through an outermost layer.

[0038] The hull 103 can include a backbone feature 135 (which may alternatively be referred to as a backbone assembly 135). The backbone feature 135 may be useful for withstanding and / or transferring forces from loads that may be present at and / or conveyed through the deck 129 and / or the bottom 133 and / or otherwise present or asserted against the hull 103. The backbone assembly 135 may be positioned in the middle portion 127 of the tank 109.

[0039] The backbone assembly 135 can include an upper backbone portion 137. The upper backbone portion 137 may be sized and arranged for withstanding load from one or more structures supported on the deck 129. The upper backbone portion 137 may be formed in the top 119. The upper backbone portion 137 may be positioned in the middle portion 127 of the tank 109. The upper backbone portion 137 may extend inwardly away from the deck 129. The upper backbone portion 137 may extend into the tank 109 in the depth direction 117 by a downward distance 139 that may be less than the greatest height 141 of the tank 109 in the depth direction 117.

[0040] The upper backbone portion 137 can be spaced apart from the floor 121 by a gap 143 (e.g., an intervening space) that separates the upper backbone portion 137 from the floor 121. This may include arrangements in which the upper backbone portion 137 may be suspended from above (e.g., from the top 119) without any structure directly underneath in an intervening space 143 between the upper backbone portion 137 and the floor 121. For example, the upper backbone portion 137 may be free of spanning structure underneath and / or may be not connected by any crossing structure with the portion of the floor 121 directly underneath the upper backbone portion 137. Connection between the upper backbone portion 137 and the floor 121 may be provided entirely without structure crossing an inside of the tank and may be provided instead by structure along peripheries of the tank 109, such as by walls extending toward and / or along lateral sides of the tank 109, for example. However, the gap 143 separating the upper backbone portion 137 from the floor 121 can also include other arrangements, such as, but not limited to, arrangements with support columns spaced apart from one another (e.g., alongthe longitudinal direction 113) and intermittently extending between the upper backbone portion 137 and the floor 121.

[0041] Including the gap 143 may allow for easier and / or simplified construction in comparison to a structure in which a double row of tanks 109 is formed with intervening structure instead (e.g., between what is represented by the first lateral portion 123 and the second lateral portion 125 in FIG. 2). For example, the tank 109 may be included in a plurality of payload tanks that may be arranged longitudinally along the hull 103 in a single row arrangement (e.g., in contrast to a double row arrangement that may have intervening structures such as a central bulkhead or cofferdams extending longitudinally among different rows of tanks 109). In general, including the backbone feature 135 may allow for withstanding of loads from supports 131 or other structures on the deck 129 or other forces that may be present in operation without resorting to a double row, a triple row, or other multiple row arrangement and consequential additional material and / or difficulty of construction in use. Additionally or alternatively, including the intervening space 143 that does not include structure directly between the upper backbone portion 137 and the floor 121 of the tank 109 can allow payload such as liquefied natural gas or other liquid to move between the first lateral portion 123 and the second lateral portion 125 of the tank 109. Including the intervening space 143 can allow for additional area or volume in which payload can be positioned compared to multiple row arrangements, for example.

[0042] The upper backbone portion 137 may correspond to and / or include a downwardly extending projection ending in an end face 145. The end face 145 may be substantially flat and / or horizontally oriented. The end face 145 may be bounded laterally by sloped sides 147. For example, the sloped sides 147 are shown in FIG. 2 at an angle of approximately 45° extending away or upward from the end face 145, although other suitable angles for the sloped sides 147 may be implemented in use. The upper backbone portion 137 may be trapezoidal shaped. The trapezoidal shape may provide a suitable transition between the upper backbone portion 137 and surrounding areas of the top 119 and / or facilitate load transfer in use. More generally, including additional material in the backbone assembly 135 than at surrounding areas can increase an amount of material available for withstanding bending moments and / or other forces that may be exerted against the tank 109 and / or other associated structure in use.

[0043] In various embodiments, the backbone assembly 135 additionally or alternatively includes a lower backbone portion 151. The lower backbone portion 151 may be formed in the floor 121. The lower backbone portion 151 may be positioned in the middle portion 127 of the tank 109. The lower backbone portion 151 may extend inwardly away from the bottom 133 into the tank 109 in the depth direction 117 by an upward distance 153 that may be less than the greatest height 141 of the tank 109 in the depth direction 117.

[0044] The lower backbone portion 151 can be spaced apart from the top 119 by the gap 143 (e.g., intervening space), which may be arranged to separate the lower backbone portion 151 from the top 119. This may include arrangements in which the lower backbone portion 151 may be positioned without any structure directly overhead in the intervening space 143 between the lower backbone portion 151 and the top 119. For example, the lower backbone portion 151 may be free of spanning structure overhead and / or may be not connected by any crossing structure with the portion of the top 119 directly overhead the lower backbone portion 151. Connection between the lower backbone portion 151 and the top 119 may be provided entirely without structure crossing an inside of the tank and may be provided instead by structure along peripheries of the tank 109, such as by walls extending toward and / or along lateral sides of the tank 109, for example. However, the gap 143 separating the lower backbone portion 151 from the top 119 can also include other arrangements, such as, but not limited to, arrangements with support columns spaced apart from one another (e.g., along the longitudinal direction 113) and intermittently extending between the lower backbone portion 151 and the top 119.

[0045] The lower backbone portion 151 may be sized and arranged for withstanding load from and / or through the bottom 133 (such as from water pressure acting on the bottom 133). For example, the lower backbone portion 151 may be suitable to withstand bending moments that may be subjected by water pressure along an underside of the hull 103 in use.

[0046] The lower backbone portion 151 may correspond to and / or include an upwardly extending protrusion that may terminate in a terminal face 155. The terminal face 155 may be flat and / or horizontally oriented. The terminal face 155 may be boundedlaterally by sloping sides 157. For example, the sloping sides 157 are shown in FIG. 2 at an angle of approximately 45° extending away or downward from the terminal face 155, although other suitable angles for the sloping sides 157 may be implemented in use. The sloping sides 157 may be chamfers in various examples. The sloping sides 157 of the lower backbone portion 151 may be symmetric to or differ from the sloped sides 147 of the upper backbone portion 137. More generally, the lower backbone portion 151 may be a mirror reflection across a horizontal axis (e.g., which may be a horizontal bisecting axis for the tank 109) or may be otherwise symmetric with the upper backbone portion 137. The lower backbone portion 151 may be trapezoidal shaped. The trapezoidal shape may provide a suitable transition between the lower backbone portion 151 and surrounding areas of the floor 121 and / or facilitate load transfer in use. More generally, including additional material in the backbone assembly 135 than at surrounding areas can increase an amount of material available for withstanding bending moments and / or other forces that may be exerted against the tank 109 and / or other associated structure in use.

[0047] The lower backbone portion 151 may include a communication passage 159. The communication passage 159 may extend through the lower backbone portion 151 laterally, e.g., along the transverse direction 115. The communication passage 159 may be positioned to enable liquid passage between portions of the tank 109 on either lateral side of the lower backbone portion 151. For example, the communication passage 159 may permit liquid that may be received near and / or along the floor 121 in recessed areas on either side of the lower backbone portion 151 to pass between the first lateral portion 123 and the second lateral portion 125. Including the communication passage 159 can allow liquid in one portion of the tank 109 below the terminal face 155 of the lower backbone portion 151 to reach another portion of the tank 109 also below the terminal face 155 and on an opposite side of the lower backbone portion 151, e.g., which may enable or facilitate use of a single pump to extract liquid from recessed portions of the tank 109 in use (e.g., rather than lending to a duplicative arrangement that involves multiple pumps to extract liquid from different portions of the tank 109 that are disconnected or separated from each other). In another embodiment, a siphon arrangement may be provided to permit passage of liquid from one lateral portion to another.

[0048] The backbone assembly 135 may be included in a tank 109 that may be implemented with other features in the hull 103. For example, the hull 103 may be equipped with ballast tanks 161. The ballast tanks 161 may be differentiated from the tank 109 (which may be a payload tank). The ballast tanks 161 can be formed in the hull 103 in positions around the tank 109 and / or may otherwise be included in suitable number and position to provide a suitable location for pumping / discharging in sea water to adjust a buoyancy of the hull 103 in use. For example, the ballast tanks 161 may be emptied or filled by suitable amounts to facilitate a consistent or target range of draft along the hull 103 among different configurations that may include when the tank 109 is empty, partially full, or fully filled, for example.

[0049] In FIG. 2, the tank 109 is depicted with slanted surfaces 149 at lateral corners of an interior surface of the tank 109. The slanted surfaces 149 may be chamfers in various examples. The slanted surfaces 149 may be useful for purposes of transferring loads. The slanted surfaces 149, the upper backbone portion 137, and / or the lower backbone portion 151 additionally or alternatively may function to facilitate reduction of sloshing of payload in the tank 109 in use, such as by providing an angled surface that may dissipate force from payload movement in use. Moreover, sloshing may be a less prominent issue in near shore conditions, which may be particularly suited for implementation of the backbone assembly 135 and avoiding internal walls in the middle portion 127 of the hull 103.

[0050] The tank 109 and / or other features described herein may be at least partially formed or constructed by suitable structural members. Some suitable examples are described with respect to FIG. 3

[0051] FIG. 3 illustrates some examples of structures that may be utilized to form the tank 109 in use. In various examples, the tank 109 may be formed at least in part by web-frames 163. The web-frames 163 may be spaced from one another in the longitudinal direction 113. The web-frames 163 may be arranged to define a cross-sectional shape of the tank 109, e.g., which may extend in the transverse direction 115 and / or in the depth direction 117. The backbone assembly 135 (e.g., the downward projection of the upper backbone portion 137 and / or the upward protrusion of the lower backbone portion 151) maybe at least partially formed within the web-frames 163 in use.For example, the web-frames 163 may at least partially define structure of upper backbone portion 137 and / or the lower backbone portion 151 of the backbone assembly 135. The upper backbone portion 137 and / or the lower backbone portion 151 may be aligned along the longitudinal direction 113.

[0052] The web-frames 163 may be connected to one another by girders 165. The girders 165 may extend in the longitudinal direction 113, for example. The web-frames 163, girders 165, and / or other components forming the tank 109 and / or the hull 103 may be formed of steel or other material suitable for withstanding impact loads and / or load resistance, for example.

[0053] The tank 109 may be bounded along the longitudinal direction 113 by cofferdams or transverse bulkheads 111. The cofferdams or transverse bulkheads 111 may include suitable structure to separate one tank 109 from another.

[0054] The cofferdams or transverse bulkheads 111 may further include structural members 171 that may be suitable for transferring load among connected components. Structural members 171 in the cofferdams or transverse bulkheads 111 may be arranged to receive and transfer load from the backbone feature 135 in use. For example, there may be a structural continuity between backbone features 135 from different tanks 109, e.g., such that structural members 171 may be arranged in order to extend the backbone feature 135 inside the cofferdam or transverse bulkheads 111. In use, the upper backbone portion 137 and / or the lower backbone portion 151 may be arranged to transfer load received along the deck 129 and / or the bottom 133 into the cofferdams or transverse bulkheads 111. This may correspond to transferring of load received in the depth direction 117 and transferring along the longitudinal direction 113, for example. Load received in the depth direction 117 additionally or alternatively may be transferred along the transverse direction 115, such as along the web-frames 163.

[0055] In various embodiments, the tank 109 can include an interior surface that is formed at least in part by a membrane system 173. The membrane system 173 can include at least a liner 175 and an insulating material 177. The membrane system 173 may be implemented relative to a material 179 of the hull 103. The liner 175 may be positioned inward of the insulating material 177 in a direction toward an interior volume of the tank 109, and the insulating material 177 may be positioned inward of the material179 of the hull 103. In use, the liner 175 may include a stainless steel material or other material that may be sufficiently robust to withstand low temperatures at which liquefied natural gas may be present within the tank 109. The liner 175, for example, acting as a primary barrier, may protect the insulating material 177 from direct contact with the liquefied natural gas or other payload within the tank 109. The insulating material 177 may include suitable insulation to prevent thermal transfer between payload in the tank 109 and the material 179 of the hull 103. For example, the insulating material 177 can include a secondary barrier and help prevent steel or other material 179 of the hull 103 from being subjected to extreme cold temperature that may cause damage or other negative effects on the hull 103 in use.

[0056] In fig.4, another embodiment of hull 103 is shown. Parts corresponding to parts in Fig. 2 carry the same reference numerals. The hull 103 of fig.4 is similar to the hull 103 of Fig.2 save for the presence of two backbone features (137, 151) formed on each of the top 119 and floor 121 of the tank 109. In that arrangement, the upper and lower backbone portions 137, 151 are positioned symmetrically about the lateral centreline of the hull, spaced inwardly from the ballast tanks 161. In other arrangements the upper and lower backbone portions 137, 151 could be positioned without symmetry.

[0057] In fig.5, a series of schematic representations of the hull 103, shown to a smaller scale than figures 2 and 4, show alternative permutations of numbers and locations of backbone features. Those alternative permutations include, non-exhaustively, two upper and i) zero or ii) one lower backbone portions 137,151 or two lower and i) zero or ii) one upper backbone portions 137,151. Where one backbone portion is provided on either the top 119, or floor 121, the backbone portion may be positioned generally centrally of the tank 109, as shown in fig.2. Where two backbone portions are provided on either of the top 119 or floor 121, the backbone portions may be positioned as shown in fig. 4. In another embodiment, where a single backbone portion is provided on either of the top 119 or floor 121, the backbone portion may be arranged off-centre relative to the hull 103 or tank 109.

[0058] The foregoing description of certain examples, including illustrated examples, has been presented only for the purpose of illustration and description and is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Numerous modifications, adaptations, and uses thereof will be apparent to those skilled in the art without departing from the scope of the disclosure. For instance, any examples described herein may be combined with any other examples to yield further examples.

Claims

Claims1. A hull of a floating unit configured to store a payload, the hull defining a capacity space delimited by top, floor, opposite side and opposite end faces such that the capacity space extends in a depth direction, in a longitudinal direction, and in a transverse direction, the top face and floor face being spaced apart in the depth direction,the hull comprising a backbone feature formed in one of the top or floor faces and extending inwardly into the capacity space in the depth direction toward the other of the top or floor faces by a distance less than the greatest height of the capacity space in the depth direction, the backbone feature being spaced apart from said other of the top or floor faces by a gap that separates the backbone feature from said other of the top or floor faces.

2. The hull of claim 1 , wherein the backbone feature comprises an inwardly extending projection ending in an end face bounded laterally by sloped sides.

3. The hull of claim 1 or 2, wherein the backbone feature is formed in the top face and extends inwardly into the capacity space in the depth direction toward the floor face by a distance less than the greatest height of the capacity space in the depth direction, the backbone feature being spaced apart from said floor face by a gap that separates the backbone feature from said floor face.

4. The hull of claim 1 or 2, wherein the backbone feature is formed in the floor face and extends inwardly into the capacity space in the depth direction toward the top face by a distance less than the greatest height of the capacity space in the depth direction, the backbone feature being spaced apart from said top face faces by a gap that separates the backbone feature from said top face.

5. The hull of any preceding claim, wherein a backbone feature is formed in each of the top face and floor face, each backbone feature extending inwardly into the capacity space in the depth direction toward the other of the top or floor face by a distance lessthan the greatest height of the capacity space in the depth direction, the backbone feature being spaced apart from said other of the top or floor face by a gap that separates the respective backbone feature from said face.

6. The hull of any preceding claim, wherein a plurality of backbone features are formed in either or both of the top or floor faces and extending inwardly into the capacity space in the depth direction toward the other of the top or floor faces by a distance less than the greatest height of the capacity space in the depth direction, the backbone features being spaced apart from said other of the top or floor faces by a gap that separates the backbone feature from said other of the top or floor faces.

7. The hull of any preceding claim, wherein:(i) two backbone features as set out in claim 1 are formed in the top face and zero, one or two backbone features as set out in claim 1 are formed in the floor face; or(ii) two backbone features as set out in claim 1 are formed in the floor face and zero or one backbone features as set out in claim 1 are formed in the top face.

8. The hull of any preceding claim, further comprising a deck positioned outwardly from the top face in the depth direction.

9. The hull of claim 8, and where a backbone feature is formed in the top face, wherein the backbone feature is sized and arranged for withstanding load from one or more structures supported on the deck.

10. The hull of any of preceding claim, further comprising a bottom positioned outwardly from the floor face of the tank in the depth direction.

11. The hull of claim 10, and where a backbone feature is formed in the floor face, wherein the backbone feature is sized and arranged for withstanding load applied on the bottom.

12. The hull of claim 4, further comprising a communication passage extending laterally through the backbone feature formed in the floor face and positioned to enable liquid passage between portions of the capacity space on either lateral side of the backbone feature.

13. The hull of any of claims 1 to 4, wherein the or each backbone feature is positioned without any structure in an intervening space directly between the backbone feature and the face opposite the face in which the backbone feature is formed, and / or wherein the or each backbone feature comprises a beam extending in the longitudinal direction.

14. The hull of any preceding claim, wherein the or each backbone feature is at least partially formed in a set of web-frames, which are spaced from one another in the longitudinal direction of the capacity space and which define a cross-sectional shape of the capacity space extending in the depth direction and in the transverse direction.

15. The hull of claim 14, wherein the web-frames are connected to one another by girders extending along the longitudinal direction.

16. The hull of any preceding claim, wherein the capacity space is bounded along the longitudinal direction by cofferdams or transverse bulkheads.

17. The hull of claim 16, wherein the or each backbone feature is arranged to transfer load received along a deck over the top face of the capacity space into the cofferdams or transverse bulkheads or to transfer load received along a bottom below the floor face of the capacity space into the cofferdams or transverse bulkheads.

18. The hull of any preceding claim, wherein at least one of:lateral corners of an interior surface of the capacity space include slanted surfaces; and / orthe hull further comprises ballast tanks formed in the hull at positions around the capacity space; and / or the capacity space comprises a membrane system comprising a liner andinsulation; and / or the capacity space comprises or contains a tank, the tank preferably configured for receiving liquified gas, e.g. a self-supporting, prismatic tank.

19. The hull of any preceding claim, wherein the capacity space is included in a plurality of payload tanks arranged longitudinally along the hull in a single row arrangement.

20. The hull of any preceding claim, wherein the hull is incorporated into a floating processing plant or a transportation vessel.

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