A system and method for manufacturing shells for a ship

Abstract

A system for manufacturing shells of a ship, the system comprising: an array of elongate supports; and a plurality of diaphragms each configured to extend across (a row or column of) the array of supports, and shaped to receive a shell of a ship to define a selected curvature of the shell, wherein each diaphragm is removably attachable to two or more of the elongate supports to support the corresponding diaphragm.

Description

A SYSTEM AND METHOD FOR MANUFACTURING SHELLS FOR A SHIPTECHNICAL FIELD

[0001] The present disclosure relates to shipbuilding, including to a system and method for manufacturing shells for a ship.BACKGROUND

[0002] The manufacture of marine vessels, often referred to as shipbuilding, requires an enormous amount of materials, time and labour. The main external structure of a marine vessel includes a bow and stern, between which is a hull. The hull of the vessel can be formed by applying multiple sections of flat metal plate, commonly made from steel, over a series of structural diaphragms to form the required curvature.

[0003] During the manufacture of ships, particularly thin-shelled skin construction ships such as military vessels, and due mainly to the size of such ships, each section of the hull is generally manufactured separately prior to assembly. Jig stations are used to position the diaphragms and shells relative one another such that assembly of the shells can occur while they are held in the correct shape or curvature. In the prior art, these jig stations generally comprise fixed frames for holding diaphragms, the frames constructed to match the required shape of the ship being built. The prior art jig stations are pre-planned and designed for each project, and workers are tasked with new design and construction challenges upon each build. The fixed frames are rigid and often must be very tall in order to accommodate the ship's size.Accordingly, traditional jig stations must be bespoke, requiring significant labour and incurring significant cost to construct. Upon completion of ship manufacturing, the frames are generally disassembled and the frame components, including the diaphragms, left as waste material, imparting cost and sustainability losses. In the case of volume shipbuilding, where a facility may produce various ships per year, these costs and labour requirements are amplified by the manufacturer having to re-design and re-construct jigs entirely to suit different models of ship. Further, prior art jig stations are constructed from welded frames. Welding is both expensive and

[0025] can result in frame distortion and scarring, causing errors and undesirable finishes in the completed hull.

[0004] Previous attempts to reduce the labour and cost involved in shell manufacture have used mechanized jigs; however, such mechanized jigs require enormous initial cost, providing a substantial barrier to manufacturers wishing to employ such jigs. Furthermore, mechanized jigs are prone to inaccuracies resulting in a need for further manual finishing and / or adjustment of the shells. Mechanized jigs also require highly skilled workers to operate, resulting in high running costs even after the initial cost of purchase. The ship shells produced by such jigs remain subject to the same weld distortion and scarring issues as conventional jig stations.

[0005] The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

[0006] It is desired to address or ameliorate one or more disadvantages or limitations associated with the prior art, or to at least provide a useful alternative.SUMMARY

[0007] In a first aspect of the present disclosure, there is provided a system for manufacturing shells of a ship, the system comprising: an array of elongate supports; a plurality of diaphragms each configured to extend across (a row or column of) the array of supports, and shaped to receive a shell of a ship to define a selected curvature of the shell, wherein each diaphragm is removably attachable to two or more of the elongate supports to support the corresponding diaphragm.

[0008] In some embodiments, each diaphragm is substantially planar. Each elongate support is configured to support the corresponding diaphragm in tension or in compression. Each elongate support that supports a diaphragm may have a selected or selectable length for engaging that diaphragm. A length of each elongate support may be selectably adjustable in the direction

[0022] of its elongation. Adjustment of an or elongate support may define at least one datum for alignment of the plurality of diaphragms.

[0009] In some embodiments, the system further comprises at least one pull down clip being wherein fastening of the pull down clip draws the shell toward a diaphragm. The or each pull down clip may be configured to retain the shape of the shell when received by the diaphragm. The or each pull down clip may be removably couplable to a diaphragm and fastenable to a stud extending from the shell. The clip may have a slot for receiving the stud, and a nut fastenable about the stud and configured to drive the clip via the slot when fastened. The or each clip may comprise a tab for insertion into a slot of the diaphragm, removably coupling the clip to the diaphragm.

[0010] In some embodiments, the array of elongate supports is a fixed array. Each elongate support may be fixed in position relative to one or more channels in a ground surface. Each elongate support may include a brace for supporting the respective diaphragms, the brace being fastenable to the diaphragms. When detached from the supports, the diaphragms may be stackable together for storage.

[0011] In a second aspect of the present disclosure, there is provided a method for manufacturing shell of a ship, the method comprising: removably attaching a plurality of diaphragms across (rows or columns of) an array of supports, each diaphragm defining a selected curvature; and engaging a shell of a ship with the diaphragms to conform the shell to the selected curvatures.

[0012] In some embodiments, removably attaching diaphragms to the supports includes adjusting a length of each support in the direction of its elongation to engage. Selecting the length of the support may define at least one datum for alignment of the diaphragms.

[0013] In some embodiments, the method further comprises the step of disengaging said shell from said diaphragms, and detaching each diaphragm from the respective supports, and stacking the diaphragms for storage (wherein the diaphragms are substantially planar such that they can be stored in a stacked arrangement). Engaging the shell may further comprise fastening a pull down clip about a stud extending from the shell, the clip being removably coupled to the

[0022] diagram. Engaging the shell may further comprise installing shell frame components to / on the engaged shell, the components being at least one of: a T-Frame, longitudinal bulbs or gussets.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Some embodiments of the present invention will now be described, by way of nonlimiting example only, with reference to the accompanying drawings, in which: a. Figure 1 is an isometric rendering of a system for manufacturing shells of a ship as disclosed herein; b. Figure 2 is an isometric rendering of shell components being installed to / on a shell of the system of Figure 1; c. Figure 3 is an isometric rendering of an array of supports of the system of Figure 1; d. Figure 4 is an isometric drawing of a support of the system of Figure 1; e. Figure 5 is an isometric rendering of a diaphragm on some of the supports of the system of Figure 1; f. Figure 6 is an isometric drawing of a plurality of diaphragms for the system of Figure 1, the diaphragms in a stacked arrangement; g. Figure 7 is a Detail A rendering of datums of the system of Figure 1; h. Figure 8 is a front view drawing of a diaphragm of the system of Figure 1; i. Figure 9 is an isometric drawing of a pull down clip and a diaphragm of the system of Figure 1; j. Figure 10 is a side view drawing of the pull down clip of Figure 8; k. Figure 11 is an isometric rendering of a shell being disengaged from diaphragms of the system of Figure 1; and l. Figure 12 is a flow chart of a method of manufacturing shells of a ship as disclosed herein.DETAILED DESCRIPTION

[0015] Figure 1 shows a system 100 for manufacturing shells of a ship, the system 100 comprising: an array 14 of elongate supports 12; and a plurality of diaphragms 32 each being

[0022] configured to extend across (two or more) supports 12 (of the array 14), and shaped to receive a shell to define a selected curvature of the shell, wherein each diaphragm 32 is removably attachable to two or more of the elongate supports 12 to support the corresponding diaphragm 32.

[0016] Figure 2 shows the system 100, in use with a shell 10 of a ship. The shell 10 is of a substantially rectangular shape, and extends atop the system 100. The system 100 is used with a shell that is substantially planar or flat, such as in the form of a slab, billet, block or sheet (as is the shell 10 shown in Figure 2), before its installation onto / into the system 100. The system 100 may, however, be used with a shell of any shape, dependent on the design or type of ship to which the shell belongs or is intended to be manufactured for. While Figure 2 shows only one shell 10, the system 100 may be configured to hold multiple shells at once, or multiple other shells, or different sized shells. The system 100 is shaped to conform a shell to the requisite (selected) curvature / bending, as will be described later. In exemplary embodiments, the shell 10 received by the system 100 is made of steel, such as for example mild steel, with a substantially constant thickness of between about 6 mm and about 30 mm. The relevant size of the shell 10 may be between about 9 metres and about 13 metres in length, by between about 2.5 metres and about 7 metres in width, e.g., for a rectangular or regularly shaped shell. The shell 10 may be pre-cut to the dimensions required based on the design or type of ship to which the shell belongs or is intended to be manufactured for.

[0017] As shown in Figure 3, the system 100 includes a plurality of elongate supports 12, each extending upwardly from a floor or ground surface 200. The elongate supports 12 are provided in an array 14 of rows and columns across the ground surface 200, and, in at least some embodiments, are equidistantly spaced from one another. As shown in Figure 3, an example of the array 14 can include 7 columns and 18 rows, thus providing 126 points of support (i.e., supports 12) for the diaphragms 32. The supports 12 may be mutually spaced by a selected first intra-support spacing 72 and / or a second intra-support spacing 74 (the first spacing 72 being in a direction corresponding to the rows of the array 14, and the second spacing 74 being in a direction corresponding to the columns of the array 14). The first intra-support spacing 72 and second intra-support spacing 74 may be between about 0.75 metres and about 1 metre, accordingly the example of the array 14 in Figure 3 can have a length of about 12.75 metres and

[0022] a width of about 6 metres, depending on the intra-support spacing 72, 74. The length and width of the array 14 are interchangeable based on the design or type of ship to which the shell belongs or is intended to be manufactured for.

[0018] The array of elongate supports 12 is a fixed array 14, relative to the ground surface 200, thus even as the shell 10 is replaced with another shell to begin manufacturing in the system 100, the position of the supports 12 in the array 14, relative one another, remains unchanged.

[0019] Each elongate support 12 is fixed in position, during manufacturing, relative to one or more channels 16 in a ground surface 200. In this way, the array 14 may be referred to as a fixed array as each of the elongate supports 12 of the array 14 are fixedly attached to the ground surface 200 by the provision of rows or columns of the channels 16 in the surface 200. The fixed array 14 creates consistency during manufacture, reducing tolerances between shells manufactured thereby and thus increasing the quality of the manufactured shells. In some embodiments, the channels 16 are installed downwardly or 'sunk' into the surface 200 such that attachment of the supports 12 thereto results in the supports 12 being substantially flush with the surface 200. Accordingly, the 'sunk' installation of the channels 16 means that the channels 16 are not a tripping hazard (or similar other hazard) to workers. In some embodiments, the supports 12 may be attached to the channels 16 by welding the support base 18 to the channels 16. In other embodiments, however, attachment of the supports 12 to the channels 16 may be provided by way of fasteners, clamps or by corresponding geometries in the channel 16 and support 12.

[0020] The elongate supports 12 have an elongation extending from a lower end (the base 18 of the support 12), which is configured for attachment to the channels 16 as described, toward a brace 20 of the support 12. The elongation pictured in Figure 4 is a round tubular elongation. The round tubular elongation is provided for its strength characteristics, being capable of withstanding higher loads relative to material required, and for its ease of manufacture. The elongation may instead be a different shape, including, for example, a square, rectangular or polygonal tube or extrusion.

[0021] The base 18 of the support 12 includes a plate positioned perpendicularly to the length of the support 12, the plate 28 is configured for attachment to the channel 16 as described. In preferred embodiments, the base 18 additionally includes at least one gusset 30, providing

[0022] additional attachment of the plate 28, and strength of that attachment, to the support 12 by extension along the plate 28 in the direction of the ground surface 200, and by extension along the support 12 in a direction toward the brace 20. Exemplary gussets 30 include central holes such as those manufactured through use of a dimple die or punch. The central holes in the gussets 30 are provided as provisions for a tie down point for lashing the supports 12 to the shell 10 where required, such as, for example, where significant distortion of the shell 10 is likely to occur. Therefore, lashing the supports 12 to the gussets 30 assist the brace 20 of the support 12 in retaining the shell 10 thereto (via the diaphragm 32). In other examples, the lashing may occur between the supports 12 and the ground surface 200, or channels 16, for example where large forces will be exerted on the supports 12 in the case of use of large shells 10, whereby there is a possibility of dislodging the supports 12 from the channels 16. The central holes of the gussets 30 may additionally serve to reduce the weight of each gusset 30, and thereby reduce the overall weight of the support 12. Even more exemplary gussets 30 include a fillet or rounding positioned along the lower length of the gusset 30 aligned with the plate 28 to provide ease of installation of the gusset 30 by reducing potential interference with the plate 28.

[0022] As shown in Figure 4, each elongate support 12 includes a brace 20 for supporting the diaphragm 32, the brace 20 being fastenable to the diaphragm 32. The brace 20 is positioned at the opposite end of the support 12 to the base 18, and is configured to support a diaphragm 32 thereatop. Although not pictured in the Figures, the base 18 may be painted or coated in a high- visibility material, such as a reflective or fluorescent paint or coating. This paint or coating ensures that the base 18 of the support 12 is not a hazard to workers, being easily visible and reducing the likelihood of tripping. Exemplary braces 20 include a means for fastening to the diaphragms 32, in this embodiment being a pair of captive nuts 34, which receive fasteners thread through an aperture 42 in the diaphragm 32. Along with the captive nuts 34, the brace 20 is shaped to support the diaphragm 32, having a lipped channel 36 which the diaphragms 32 may seat into for support. For strength, the brace 20 extends from the elongation in the form of an L- shaped plate or steel 'angle'.

[0023] Each elongate support 12 can have a selected or selectable length to engage a respective diaphragm 32 (for removable attachment thereto). The length of each elongate support 12 is selectably adjustable in the direction of its elongation. The support 12 is adjustable along its

[0022] elongation to provide a selectable length thereof in the direction of that elongation (i.e., to extend the distance between the brace 20 and base 18). Length adjustment of the support 12 is provided by relative sliding movement between an inner tube 22 and outer tube 24 thereof, the relative sliding movement being configured to increase the distance between the base 18 and the brace 20. The inner tube 22 includes a series of spaced inner tube apertures 58 along its length, each aperture 58 configured to receive a pin 26, the pin 26 being insertable through an outer tube slot 56 and through a selected one of the inner tube apertures 58 to coarsely adjust the support 12 length. The pin 26 is coupled about the outer tube 24, and incudes a loop 62 such that the pin 26 is retained proximate the support 12 even when not in place (inserted through the slot 56 and aperture 58 as described). By configuring the supports 12 to be adjustable along their respective elongations, the supports 12 provide a modularity to the system 100, allowing the system 100 to be used with a variety of shell shapes, for the same ship and for other ships, without substantial modification.

[0024] Each elongate support 12 includes a collar 38 configured to rotate about a screw thread 60 of the elongate support 12 to provide fine adjustment of the length of the support 12. The collar 38 is provided surrounding the outer tube 24 of the support 12, and positioned proximate the brace 20 end of the outer tube 24. The collar 38 is fitted to outer tube screw threads 60 (not shown) provided on an exterior of the outer tube 24. The screw threads 60 extend down the outer tube 24 a distance equal to that of the length of the slot 56. Upon positioning the tubes 22, 24 in their coarsely adjusted positions, rotation of the collar 38 about the screw threads 60 provides incremental increase in the length of the support 12. Exemplary embodiments may further include a second collar 40 abutting the first collar 38. Shown in Figure 4, the second collar 40 serves as a locking mechanism which prevents the inner tube 22 from moving vertically relative the outer tube slot 56. What is meant by this is that the collars 38, 40 together 'sandwich' the inner tube 22 making it less prone to unwanted movement caused, for example, by vibration and impacts during manufacturing (i.e., use of the system 100).

[0025] Each elongate support 12 is configured to support the corresponding diaphragm in tension or in compression. The pair of collars 38, 40 together provide the ability to further fine adjust the length of the support 12 in either direction, thus increasing or decreasing the height of the support 12 in a 'push-pull' configuration, wherein each elongate support 12 thereby is

[0022] fastenable against a respective diaphragm 32 in tension or in compression. For example, distortion caused by heat during welding of the shell 10 can be accounted for by both increasing and decreasing the height of the support 12 using the collars 38, 40. The first (lower) collar 38 can be rotated to extend the length of the support 12, and thus force the height of the diaphragm 32 to increase. Alternatively, the second (upper) collar 40 can be rotated to decrease the length of the support 12, and thus force the height of the diaphragm 32 to decrease. In the same manner, unevenness in the ground surface 200 or the diaphragm support / lower edge 52 can be accounted for by the use of two collars 38, 40. In this way, the inclusion of two collars 38, 40 provides the support 12 the functionality to operate both as a compressive and tensile force on the diaphragm 32 to which it is attached. In some embodiments, at least one of the elongate supports 12 of the array 14 is in tension during manufacturing of the shell (i.e., use of the system 100).

[0026] Looking to Figure 5, one of the set of diaphragms 32 can be seen positioned above the array 14 of supports 12. The diaphragm 32 is in the form of a relatively flat (being thinner than it is wide, meaning that, in use, the diaphragm 32 extends further vertically, in a direction perpendicular to the ground surface 200, than it extends horizontally, in a direction parallel to the ground surface 32) structural beam. Advantageously, the planar or flat nature of the diaphragms 32 allows them to be efficiently stacked together to achieve a small volume (an overall envelope size) for storage when not in use in the system 100, as is exampled by Figure 6. Accordingly, when detached from the supports 12, the diaphragms 32 are stackable together for storage. In some embodiments, the system 100 comprises a plurality of diaphragms 32 which are each configured to be received by a number, typically 3 or more, of the supports 12 at a lower edge ('support edge') 52, and to receive a shell at an upper edge ('shell edge') 54. In exemplary embodiments, the system 100 comprises at least 2 diaphragms 32. The shell edge 54 of the diaphragm 32 is shaped accordingly to the desired shape of the manufactured shell. The shape may be substantially flat (e.g., for a deck shell of the ship) or have / include a selected curvature (e.g., for a side shell of the ship). The diaphragms 32 may be interchangeable and / or replaceable such that they can be used multiple times in the system 100. When a shell is engaged with each diaphragm 32, the system 100 conforms the shell to the shape of the diaphragm 32. Each diaphragm 32 is configured to extend across at least two or three supports 12. In some embodiments, the diaphragms 32 are straight, and extend across at least two supports 12 of a single row or column of the array 14 of supports 12. To support the diaphragm 32, the supports

[0022] 12 can be adjusted in length, as described, such that they each respectively engage the diaphragm 32. Figure 8 shows an example of this adjustment, which provides that the diaphragm may be of any shape across its lower edge, and that the system 100 as a whole may be adjusted to dictate the height at which the diaphragms 32 are held relative to the ground surface 200. In this way, the adjustability of the system 100 also allows the supports 12 and diaphragms 32 to provide / define at least one reference point, preferably two reference points, based on their positions (i.e., acting as datums), which can be used, for example, during for construed on / assembly of the system 100, and during the manufacture of shells by the system.

[0027] The array 14 of elongate supports 12 provides / defines two datums A, B for alignment of the diaphragms 32. Figure 7 shows the datums, or 'reference' lines, provided by way of the arrangement of the present disclosure. The positioning of the supports 12 and diaphragms 32 creates two standardized planes which can be referenced by workers during use of the system 100. Datum A references the support edge 54 of the diaphragm 32 and the brace 20 of the support 12, providing a fixed line across the multiple supports 12 or diaphragms 32. Datum A provides workers a reference point to assist in achieving the required adjustment of the length of the supports 12 to suit the shell being manufactured. Datum B spans the outer edge of the diaphragms 32, providing reference for alignment of each diaphragms extension across the array 14 (rows or columns) of supports 12 as they are installed. Beneficially, both Datum A and Datum B can be acquired and referenced even before the shell is received by the system 100. The datums A, B allow a worked to measure only a first support 12, for its height and positioning in the array 14. The further supports 12 in the system 100 can then be positioned and adjusted utilised the datum reference lines provided by the first support 12 installed. This allows significantly decreased setup time, as the workers do not have to spend time measuring each of the supports 12, and thus the datums A, B provide for resultantly low manufacturing labour costs.

[0028] The diaphragms 32 may be made similarly to the shells 10, but are provided to the system 100 perpendicularly thereto. The diaphragms 32 are provided perpendicularly and with thicknesses selected to support the vertical loading / forces applied thereon by the shell 10 during manufacture, and to pull the shell 10 to their (the diaphragm's) curvature, if there is any. In the embodiment shown, the diaphragm thickness is 10mm for this purpose. . Turning back now to

[0022] Figure 8, wherein the embodiment of the diaphragm 32 shown includes apertures 42 for fitment to captive nuts 34 in the support 12. Fasteners can be driven through the apertures 42 in the diaphragm 32, and fastened against or through the captive nuts 34 in the support 12, to thereby fasten the diaphragm 32 against the support 12. The diaphragm 32 may additionally include a diaphragm upstand 76 and or a diaphragm notch 78, each provided to assist in visually indicating the end points of the shell 10 to a worker, and thus allow the worker to more easily accurately install the diaphragm 32 by reference thereto. The diaphragm may also include slots 44 along its length. The slots 44 allow fitment of a pull down clip 46.

[0029] The system 100 further includes at least one pull down clip 46 being removably couplable to a diaphragm 32 and fastenable to a stud 48 extending from the shell 10, wherein fastening of the clip 46 draws the shell 10 toward the diaphragm 32. Embodiments disclosed herein include at least one pull down clip 46 for each diaphragm 32 in the system 100. Exemplary embodiments, like those shown in Figure 1, include at least 3 pull down clips 46 in each diaphragm 32, or a pull down clip 46 at each slot 44 in each diaphragm 32. The number of pull down clips 46 required for each diaphragm 32 is dependent on the shape and size of the shell / s 10 being utilised in the system 100. In other embodiments, more than 3 pull down clips 46 may be used, such as, for example, when there is a large number of frame components 50 being attached to the shell 10. A minimum number of 3 pull down clips 46 may be a useful minimum number of pull down clips 46 in view of the shell 10 shown in the Figures; however, a minimum of 1 pull down clip 46 may be sufficient, or any number of pull down clips 46 may be utilised, e.g., as many as possible to fit in / on the diaphragm 32. The pull down clips 46 are provided to assist the system 100 in receiving the shell 10. Turning now to Figures 9 and 10, a pull down clip 46 in accordance with an embodiment of the present invention is shown. The / each pull down clip 46 is configured to retain the shape of the shell 10, or to pull the shell 10 to the shape (curvature) of the diaphragm, when received by the diaphragm 32. The clip 46 ensures that the shell 10 maintains its shape on the diaphragms 32 during manufacture, for example, while 'hot work' (such as welding) occurs, by acting to pull down the shell 10 to the diaphragm 32. The / each pull down clip 46 comprises a tab 70 for insertion into an aperture 42 of the / each diaphragm 32, removably coupling the clip 46 to the diaphragm 32. Looking to Figure 10, the clip 46 shown includes a main body in an L-shaped angle. The clip 46 is removably couplable to the diaphragm 32 by insertion of one end of the angle, being the pull down clip tab 70 portion, into the slot 44

[0022] of the diaphragm, the angle retaining the clip 46 in the diaphragm 32. In position, the clip 46 extends downwardly against the diaphragm 32 on one side, and perpendicularly away from the diaphragm at the other side. The removably couplable arrangement of the clip 46 provides simple installation of the pull down clip 46 into the system 100. The clip 46 has a slot 68 for receiving the stud 48, and a nut 66 fastenable about the stud 48 and configured to drive the clip 46 via the slot when fastened. The slot 68 in the clip 46 allows fastening of the shell 10 to the diaphragm 32. The notch extends from an outer edge of the perpendicular side of the clip 46 towards approximately the centre of that side. The notch is configured to receive a stud 48 affixed to the shell 10, and to fasten against that stud to draw the shell 10 towards diaphragm 32. The stud 48 may be fastened in a variety of a manners. In the embodiment shown, the stud 48 is a threaded stud, and a fastener 66 of the pull down clip 46 is able to be fastened from the underside of the clip 46 around the stud 48.

[0030] The stud 48 is affixed to extend from an underside of the shell 10. In some embodiments, the stud 48 extends from the shell 10 by virtue of a 'lollipop' 64. What is meant by this is that the shell 10 includes a flat plate or gusset which extends downwardly from the underside of the shell 10, the plate or gusset providing the attachment point for the stud 48. Attachment of the stud 48 may be by bolting or welding. Attachment of the stud 48 to the shell 10 utilising a lollipop 64 and a by bolted or welded connection thereto reduces scarring of the shell 10 caused by direct attachment of the stud 48, and is better suited to meet enforced shipbuilding regulations. Alternatively, the stud 48 may be welded directly to the shell 10, or integrally formed therewith. Advantageously, the stud 48 is a sacrificial but reusable component of the system 100, in that upon completion of manufacture of a shell, the stud 48 may be removed, such as by cutting, from the shell, and reattached to another shell.

[0031] Turning now to Figure 11, once the system 100 has received a shell 10, and the shell 10 is optionally being retained by at least one pull down clip 46, e.g., preferably by at least 3 pull down clips 45, further manufacturing operations may take place to complete the shell 10. With the system 100 conforming the shell 10 to take the requisite shape, frame components 50 such as a T-Frames, longitudinal bulbs or gussets may be attached. These components 50 have the purpose of internally stiffening the shell 10, or may be simply provided for the attachment of other ship components such as hull parts or interior structures.

[0022]

[0032] A method 300 for manufacturing shells 10 of a ship, using the system 100, will now be described with reference to Figure 12.

[0033] The method 300 includes the steps of: removably attaching a plurality of diaphragms 32 to extend across an array 14 of supports 12, each diaphragm 32 defining a selected curvature; and engaging a shell 10 of a ship with the diaphragms 32 to conform the shell 10 to the selected curvatures (shape of the diaphragms 32).

[0034] Engaging the shell 10 can include fastening a pull down clip 46 about a stud 48 extending from the shell 10. Engaging the shell 10 may further include installing shell frame components 50 to / on the engaged shell 10.

[0035] The method 300 may further include disengaging said shell 10 from said diaphragms 32, and detaching each diaphragm 32 from the respective supports 12, wherein the diaphragms 32 are substantially planar such that they can be stacked (together) for storage (i.e., stored in a stacked arrangement).

[0036] In a first step ('removably attaching step') 310, the supports 12 are provided (in a set) in an array 14. The array 14 can be an array of any number of rows and columns, the number of rows and columns being dependent on the shell being manufactured. In this embodiment shown in the Figures, the array 14 is a fixed array comprising 18 rows and 7 columns. Prior to undertaking the method 300, the supports 12 may be stored separately, and provided in the array 14 by their attachment to channels 16 in the ground surface 200 at the relevant time.

[0037] A first diaphragm 32 (being any one of a set of diaphragms 32) can then be attached to the supports 32. The diaphragm 32 may be craned onto the supports or hoisted into place by way of a suitable block and tackle or pulley system. In exemplary embodiments, craning the diaphragms 32 includes the use of soft slings. Alternatively, the diaphragm 32 may be manually positioned atop the supports 12 by workers (where safe to do so dependent on the diaphragm 32 weight and size), or moved into place by any relevant mechanical aid.

[0022]

[0038] Removably attaching diaphragms 32 to the supports 12, as in step 310 may include adjusting a length of each support 12 in the direction of its elongation. Adjustment of the supports 12 occurs such that each support 12 over which a given diaphragm 32 extends is engaging that diaphragm 32. The adjustment of the supports 12 is completed by manual rotation of the collars 38, 40 about the screw threads 60.

[0039] Adjusting / selecting the length of the supports 12 defines at least one datum for alignment of the diaphragms. Adjustment of the length of the supports 12 can, therefore, be provided before any diaphragms 32 are attached, when the first diaphragm 32 is attached, or when multiple or all of the diaphragms 32 are attached. The adjustment provides at least one datum (by defining that datum), in the Figures being the two datums: Datum A; and Datum B, which can be referenced during installation (i.e., removable attachment) of the diaphragms 32.

[0040] Reference of the datum during the step 310 ensures the diaphragms are installed in accurate positions, being aligned with the one another and / or at the requisite positions required by the system 100.

[0041] In a second step ('engaging step') 320, a shell 10 is placed atop the diaphragms 32. The shell 10 is placed atop the diaphragms in a manner similar to that of the diaphragms 32. The shell 10 is forced downwardly onto the diaphragms 32, conforming it to the shape of the shell edge 54 thereof. The engaging step 320 includes pulling the shell 10 down onto the diaphragms 32 to conform it thereto.

[0042] In exemplary embodiments, pull down clips 46 are utilised to conform the shell 10 to the diaphragms 32. The engaging step 310 may instead, or also, include temporarily welding the shell 10 to the diaphragms 32. This is achieved by fastening the pull down clip 46 against a stud 48 of the shell 10. In exemplary embodiments, step 330 additionally includes installing frame components 50 to the shell 10 once it has engaged and been conformed to the diaphragms 32. The frame components 50 are typically welding to the shell 10, however, it is understood that any further manufacturing processes required for the installation of frame components 50 is considered.

[0022]

[0043] The method 300 may additionally include a third step ('disengaging step') 330. This step can take place following the completion of installation of frame components 50. In this step 330, the shell 10 is disengaged from the diaphragms 32 by unfastening the pull down clips 46 from the studs 48. Following this, the shell 10 is removed entirely from the system 100, and thus relocated for later installation to the ship during hull assembly. The shell 10 may include lifting lugs, attachment to which allows the diaphragms to be transported, for example by crane or hoist, to a next build station or further system location. Transportation may be via a suitable block and tackle or pulley system.

[0044] A fourth step 340 ('removing step') may additionally be undertaken in method 300. Step 340 includes removing the fasteners from the captive nuts 34 of the brace 20 of the supports 12 and from the diaphragm apertures 42. The diaphragms 32 are then also able to be detached and removed from the system 100, and stored in a stacked arrangement by virtue of their planar or flat shape.

[0045] The removing step 340 can be undertaken for the purpose of removing the diaphragms for repair of replacement thereof, such as, for example, in the case of damage thereto. The removing step 340 can also be undertaken for the purpose of removing other components of the system 100, such as the diaphragms 32 or pull down clips 46 for repair or replacement. In step 340, the supports 12 may also be removed from the channels 16 in the ground surface 200, such that the channels can be repaired or replaced.

[0046] Summarily, it is to be understood that the system described herein provides a number of advantages in operation over existing shell manufacturing apparatuses and methods. Namely, the modularity and reusability of the components of the system results in a system which can be deployed in the manufacture of a wide range of shells in a wide range of shipbuilding. For example, the supports are adjustable in height, the diaphragms and pull down clips reusable and the studs able to be cut and reattached to other shells. This results in a system that produces significantly less material waste in its construction and in the manufacture of shells for a ship. Further still, the system disclosed creates consistency in volume manufacturing through the use of datum reference points. This consistency provides efficiency in manufacturing, reducing labour costs and lead times. The use of a standardized fixed array furthers this intention, while additionally increasing the quality and tolerance of parts produced by the system.

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[0047] The embodiments described relate to a Type 26 Global Combat ship (also referred to as a city-class frigate), however, it is understood that the invention has a wide variety of uses. The invention is useful primarily in volume shipbuilding, such as military shipbuilding and thin- shelled construction ships, but its uses are limited only to the manufacture of ships having a shell construction. The invention relates to a system and method for manufacturing the shells of such a ship, which is an integral process executed in the manufacture of all relevant shell construction ships.

[0048] As used herein, the term “set” corresponds to or is defined as a non-empty finite organization of elements that mathematically exhibits a cardinality of at least 1 (i.e., a set as defined herein can correspond to a unit, singlet, or single element set, or a multiple element set), in accordance with known mathematical definitions (for instance, in a manner corresponding to that described in An Introduction to Mathematical Reasoning: Numbers, Sets, and Functions, "Chapter 11 : Properties of Finite Sets" (e.g., as indicated on p. 140), by Peter J. Eccles, Cambridge University Press (1998)). Thus, a set includes at least one element. In general, an element of a set can include or be one or more portions of a system, an apparatus, a device, a structure, an object, a process, a procedure, physical parameter, or a value depending upon the type of set under consideration.

[0049] While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. It will be apparent to a person skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the present invention should not be limited by any of the above described exemplary embodiments.

[0050] Throughout this specification and the claims which follow, unless the context requires otherwise, the word ‘comprise’, and variations such as ‘comprises’ and ‘comprising’, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.LIST OF REFERENCE SIGNS

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Claims

THE CLAIM DEFINING THE INVENTION ARE AS FOLLOWS:

1. A system for manufacturing shells of a ship, the system comprising: an array of elongate supports; and a plurality of diaphragms each configured to extend across the array of supports, and shaped to receive a shell of a ship to define a selected curvature of the shell, wherein each diaphragm is removably attachable to two or more of the elongate supports to support the corresponding diaphragm.

2. The system of claim 1, wherein each diaphragm is substantially planar.

3. The system of claim 1 or 2, wherein each elongate support is configured to support the corresponding diaphragm in tension or in compression.

4. The system of claim 3, wherein at least one of the elongate supports is in tension during manufacturing of the shell.

5. The system of any one of the preceding claims, wherein each elongate support that supports a diaphragm has a selected or selectable length for engaging that diaphragm.

6. The system of claim any one of the preceding claims, wherein a length of each elongate support is selectably adjustable in the direction of its elongation.

7. The system of claim 6, wherein adjustment of an or each elongate support defines at least one datum for alignment of the plurality of diaphragms.

8. The system of any one of the preceding claims, further comprising at least one pull down clip, wherein fastening of the pull down clip draws the shell toward a diaphragm.

9. The system of claim 8, wherein the or each pull down clip is configured to retain the shape of the shell when received by the diaphragm.

10. The system of claim 8 or 9, wherein the or each pull down clip is removably couplable to a diaphragm and fastenable to a stud extending from the shell.[0022]11. The system of claim 10, wherein the or each pull down clip has a slot for receiving the stud, and a nut fastenable about the stud and configured to drive the clip via the slot when fastened.

12. The system of any one of claims 8 to 11, wherein the or each pull down clip comprises a tab for insertion into a slot of the diaphragm, removably coupling the clip to the diaphragm.

13. The system of any one of the preceding claims, wherein the array of elongate supports is a fixed array.

14. The system of claim 13, wherein each elongate support is fixed in position relative to one or more channels in a ground surface.

15. The system of any one of the preceding claims, wherein each elongate support includes a brace for supporting the respective diaphragm, the brace being fastenable to the diaphragm.

16. The system of any one of the preceding claims, wherein, when detached from the supports, the diaphragms are stackable together for storage.

17. A method for manufacturing shells of a ship, the method comprising: removably attaching a plurality of diaphragms across an array of supports, each diaphragm defining a selected curvature; and engaging a shell of a ship with the diaphragms to conform the shell to the selected curvatures.

18. The method of claim 17, wherein removably attaching the diaphragms to the supports includes selecting a length of each support in the direction of its elongation.

19. The method of claim 18, wherein selecting the length of each support defines at least one datum for alignment of the diaphragms.

20. The method of any one of claims 17 to 19, further comprising disengaging the shell from the diaphragms, detaching each diaphragm from the supports, and stacking the diaphragms for storage.[0022]

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