Sliding cassette for underwater habitable vessel

Abstract

A kit of parts for a structure for an underwater habitable vessel includes a hull wall section of hollow cross-section with a plurality of first sliders attached to its inner surface, spaced apart around the perimeter of the hull wall section. The kit also includes a cassette configured to be housed within the hollow cross-section of the hull wall section, comprising a cassette body and a plurality of second sliders attached to the cassette body. The second sliders are configured to contact the plurality of first sliders to support the cassette within the hull wall section. The structure allows for easy assembly and adjustments, as well as enhanced reconfigurability.

Description

[0001] Sliding cassette for underwater habitable vessel

[0002] Technical Field

[0003] [1] The present disclosure relates to underwater habitable vessels and their assembly methods, in particular, a cassette for installation within a hull wall section of the underwater habitable vessel.

[0004] Background

[0005] [2] Various types of underwater habitable vessels are known including submarines, submersibles and underwater habitats. Submarines and submersibles are structures that are both able to propel themselves underwater and enable humans to live below the water’s surface for extended periods of time, for example, several hours, weeks, or even months. Underwater habitats are structures that enable humans to live below the water's surface for extended periods of time, for example, several hours, weeks, or even months. Underwater habitats enable scientific research and underwater exploration to proceed much more efficiently than is possible when diving from the surface since there is no need to decompress between excursions from the habitat. Unlike submarines and submersibles, underwater habitats are not typically able to propel themselves and are instead deployed to a stationary location on the sea floor by a support vessel or shore-based crane. The enclosed interior volume of an underwater habitat supports a breathable atmosphere so that humans can work, rest, eat, and / or sleep in the habitat during the course of a mission.

[0006] [3] Underwater habitable vessels are complex structures that require secure assembly and integration of various internal components and systems. These components, which include living quarters, life-support equipment, scientific equipment, etc., must be securely installed within the vessel's hull to ensure the vessel's structural integrity, functionality, and safety.

[0007] [4] One approach to constructing underwater habitable vessels involves assembling the internal components into modules separately from the hull. Towards the end of the construction process, the assembled internal modules are installed within the (nearly) finished hull, before final fit out. This allows for simultaneous fabrication of the hull and the internal modules, potentially reducing construction time and costs. However, this approach presents several challenges related to the installation of the internal modules within the hull. [5] In the prior art, one example of a watercraft system is described in WO2022 / 254183A1 , which includes hull modules and an equipment module. The equipment module is supported by a single mounting rail within the hull module, allowing it to slide along the rail in a direction parallel to the hull's longitudinal axis. While this design allows for some degree of modularity and ease of installation, it has several shortcomings.

[0008] [6] One significant issue with the prior art is the difficulty in accurately aligning and securing large and heavy internal modules within the hull. Misalignment and improper connections can lead to structural and functional problems, potentially compromising the vessel's integrity and safety. In particular, the prior art's single rail support system may not provide sufficient stability for the equipment module, increasing the risk of the equipment module shifting or becoming detached during operation.

[0009] [7] Another challenge not addressed by the prior art is compensating for hull compression. The pressure exerted on the hull when submerged causes it to compress, affecting the alignment and connection of the internal modules, which can result in structural issues.

[0010] [8] In summary, the prior art presents several challenges related to the installation, alignment, and secure attachment of internal modules within the hull of underwater habitable vessels. There is a need for an improved interface and method for installing and aligning internal modules that addresses these challenges and ensures the structural integrity, functionality, and safety of the vessel.

[0011] Summary of the Disclosure

[0012] [9] According to a first aspect of the disclosure, a kit of parts for a structure for an underwater habitable vessel is provided, which includes a hull wall section of hollow crosssection and a plurality of first sliders attached to an inner surface of the hull wall section. The first sliders are angularly spaced apart around the perimeter of the hull wall section. The kit also includes a cassette configured to be housed within the hollow cross-section of the hull wall section, comprising a cassette body and a plurality of second sliders attached to the cassette body. The second sliders are configured to contact the plurality of first sliders to support the cassette within the hull wall section. This arrangement allows for easy insertion and alignment of the cassette, which houses the internal structures and equipment, into a hull wall section of the underwater habitable vessel. Moreover, after completion of a mission, the slidable connection allows for easy removal of a cassette and insertion of a different cassette more suitable for a different mission, thereby facilitating reconfigurability of the system. In addition, providing multiple points of connection between the cassette and the hull wall section increases the security with which the cassette is supported within the hull wall section, thereby increasing the overall safety of the vessel.

[0013]

[0010] In some embodiments, the kit may further comprise a plurality of compensators configured to permit relative movement between the hull wall section and the cassette body along a radius of the hull wall section. This feature allows the hull wall section to compress under pressure without transferring loads to the cassette, and also damps the transfer of vibrations of the hull wall section to the cassette body, improving living comfort for the occupants of the underwater habitable vessel.

[0014]

[0011] In some embodiments, each of the plurality of compensators may comprise a biasing member, such as a coil spring or a resiliently compressible pad. The biasing members can be positioned between the hull wall section and the plurality of first sliders, the cassette body and the plurality of second sliders, or the plurality of first sliders and the plurality of second sliders. Advantageously, the biasing members provide damping of vibrations and / or provide biasing of the cassette towards a centred position within the hull wall section.

[0015]

[0012] In some embodiments, each of the plurality of compensators may comprise an elongate member and a carriage configured to move on the elongate member. The elongate members can be attached to the hull wall section and the carriages attached to the plurality of first sliders, or vice versa.

[0016]

[0013] Optionally in some examples, the elongate member may comprise a screw or a pin, and the carriage may comprise an opening sized to receive the screw or pin slidably. A biasing member, such as a spring or a resilient bush, can be positioned around the screw or pin to bias the carriage relative to the elongate member along the direction of relative movement.

[0017]

[0014] In some embodiments, the plurality of first sliders and the plurality of second sliders may be mutually configured to permit relative movement between the hull wall section and the cassette along a longitudinal axis of the hull wall section.

[0018]

[0015] Optionally in some examples, the plurality of first sliders and the plurality of second sliders may be mutually configured to prevent relative rotational movement between the hull wall section and the cassette about the longitudinal axis of the hull wall section. Thus, placing the pluralities of the first and second sliders into contact with each other advantageously rotationally aligns the cassette with the hull wall section and prevents deviation from that alignment during insertion of the cassette into the hull wall section and during transport and operational deployment of the habitable vessel.

[0019]

[0016] Optionally in some examples, each of the first sliders may comprise a rail and each of the second sliders may comprise a channel or a roller configured to ride on a respective rail of the first sliders, or vice versa. The rails and channels can be arranged parallel to the longitudinal axis of the hull wall section, facilitating the sliding of the cassette into the hull wall section.

[0020]

[0017] Optionally in some examples, the channels may be configured to be releasably fixed in place on the rails to prevent relative movement between the hull wall section and the cassette along the longitudinal axis of the hull wall section. This can be achieved using clamps or screws, ensuring a secure connection between the cassette and the hull wall section.

[0021]

[0018] Optionally in some examples, the rails may each comprise a wear-resistant guide pad configured to interface with a respective one of the plurality of channels. This facilitates the sliding of the cassette into the hull wall section by reducing friction and wear and tear on the rails.

[0022]

[0019] Optionally in some examples, each of the plurality of first sliders may be attached to bosses on the inner surface of the hull wall section, and the first sliders may be uniformly spaced around the perimeter of the inner surface of the hull wall section. This arrangement provides even and secure support for the cassette within the hull wall section.

[0023]

[0020] Optionally in some examples, the cassette body may comprise a deck assembly and / or an equipment support structure. The deck assembly may include floor beams with cutouts or galleries for cables or pipes, allowing for efficient organization and stowage of auxiliary systems within the underwater habitable vessel.

[0024]

[0021] Optionally in some examples, the cassette body may further comprise at least one wall assembly configured to conform to the inner surface of the hull wall section and support cables, pipes, or internal wall features.

[0025]

[0022] According to a second aspect of the disclosure, a method of assembling a structure for an underwater habitable vessel is provided. The method includes providing a hull wall section on a hull wall section jig, providing a cassette on a cassette jig, bringing the cassette into contact and alignment with the hull wall section by adjusting the position of at least one of the hull wall section jig and the cassette jig, and sliding the cassette into the hull wall section. This method allows for efficient assembly of the underwater habitable vessel structure, with the internal structures and equipment being assembled and manufactured separately and simultaneously with the hull wall section.

[0026] Brief Description of the Drawings

[0027]

[0023] Examples are described in more detail below with reference to the appended drawings.

[0028]

[0024] Fig. 1 is a perspective view of the hull of an underwater habitable vessel comprising hull wall sections.

[0029]

[0025] Fig. 2 is a perspective view of a hull wall section with rails attached to bosses on the inner surface.

[0030]

[0026] Fig. 3 is a perspective view of a cassette for insertion into a hull wall section, showing channels and a cassette body.

[0031]

[0027] Fig. 4 is a perspective view of a cassette assembled inside a hull wall section, illustrating the connection between channels and rails.

[0032]

[0028] Fig. 5 is a perspective view of a hemispherical hull wall section with rails attached to bosses on the inner surface.

[0033]

[0029] Fig. 6 is a side view of a step in the assembly process of a segment of the underwater habitable vessel, showing the cassette partially supported on a cassette jig and partially inserted into the hull wall section which is supported on a hull wall section jig.

[0034]

[0030] Fig. 7 is a flow diagram illustrating the method of assembling a segment of an underwater habitable vessel.

[0035] Detailed Description

[0036]

[0031] The detailed description set forth below provides information and examples of the disclosed technology with sufficient detail to enable those skilled in the art to practice the disclosure.

[0037]

[0032] The claimed invention relates to a hull for deployment as an underwater habitable vessel. The description below refers to the components of the hull in both their assembled and disassembled states. It is to be understood that the hull can be provided: in its assembled state; as a kit of parts for assembly into a complete, or partially complete, hull; or in a partially assembled state. Therefore, where two components are said to be attached, it is to be understood that those components may also be provided as part of the kit of parts in a disassembled state but are configured to be attached to each other. Likewise, where two components are said to be configured to be attached to each other, they may be provided in an assembled configuration where they are attached to each other.

[0038]

[0033] Fig.1 shows a hull 1 for deployment as an underwater habitable vessel. The hull 1 is made up of a plurality of hull wall sections 10, 20 joined together by mating rings 30. Fig. 1 shows 5 hull wall sections, however, there may be as few as two hull wall sections 10. Each hull wall section is hollow. In other words, each hull wall section is of hollow crosssection, the cross-section taken as a slice through the hull wall section orthogonal to its longitudinal axis. Hence, when connected together in series, i.e. , end-to-end, the hull wall sections 10, 20 together enclose an interior volume. The interior volume provides space for humans to work, rest, eat, and sleep. In particular, referring to Fig. 4, the interior volume houses a cassette 100 which supports the various structures and equipment necessary for working, resting, eating, sleeping, etc. The cassette 100 and hull wall section are connected via multiple sliding interfaces, which enable easy insertion of the cassette into the hull wall section whilst the multiple points of contact of the cassette with the hull wall section ensure the cassette is securely supported within the hull wall section. The sliding connections comprise first sliders attached to the hull wall section and second sliders attached to a cassette body.

[0039]

[0034] The modular construction allows the hull 1 to be built in different sizes according to mission needs by increasing or decreasing the number of hull wall sections 10, 20 connected together to produce the hull 1. The hull wall sections 10, 20 are detachably connected such that if a habitat is to be redeployed on another mission with different objectives, then the number of hull wall sections 10, 20 can be adjusted as appropriate. Alternatively, the hull wall sections 10, 20 are permanently connected together after assembly, for example, by welding. In alternative embodiments, the hull 1 is not modular and is, instead, hull wall sections, each of a different shape. As will be explained later, one or more cassettes can be inserted into the interior volume.

[0040]

[0035] Where the underwater habitable vessel is a submarine or submersible, it is capable of self-propelled travelling. Where the habitable vessel is an underwater habitat, unlike a submarine or a submersible, but in common with other underwater habitats, the hull 1 is not self-propelled. Instead, the hull 1 is deployed to the floor of a body of water by a surface vessel or shore-based crane. Alternatively, the hull 1 can be deployed using an underwater vehicle rather than a surface mounted crane. Once submerged, the interior volume of the hull is not in atmospheric communication with the surface.

[0041]

[0036] When connected together, the hull wall sections 10, 20 define a pressure hull able to withstand both internal and external pressures (each hull wall section being individually capable of withstanding these pressures). For example, the pressure hull can withstand an external pressure of at least 5 atm such that it can be deployed to a depth of 50 MSW or at least 20 atm such that it can be deployed to a depth of 200 MSW. In one realisation of the habitat, this is achieved by hull wall sections manufactured from 40-80 mm thick steel, preferably 60 mm thick. The interior volume is maintained at surface pressure or a pressure above atmospheric pressure, for example, the ambient pressure at the deployed depth of the habitat. This latter configuration is used for saturation diving missions.

[0042]

[0037] When the hull wall sections 10, 20 are connected together in series, their longitudinal axes are aligned such that hull 1 is arranged along the common longitudinal axis. That is to say, the longitudinal axis passes through the length of the interior volume of the hull 1 and the assembled hull 1 has a generally linear configuration. In other words, the hull 1 is of a generally tubular configuration with closed ends. In cross-section orthogonal to the longitudinal axis, the hull 1 , and the hull wall sections, are generally circular, although other hollow cross-sections are possible, such as square cross-sections.

[0043]

[0038] The hull wall sections 10, 20 are supplied in two different variants, each having a different form factor, i.e. , different shape. The hull wall section 10 at each end of the hull is designed as an end-cap, i.e., is shaped to provide closed ends to the hollow tube of the hull. The remaining hull wall section(s) 20 disposed between the end-caps 10, are designed as intermediate sections 20. In other words, the one or more hull wall sections 20 are hollow tubes, open at each end such that when the hull 1 is assembled, the end-caps 10 and the intermediate sections 20 together define a single enclosed volume. Each endcap 10 is identical, i.e., the shape and dimensions of the end-caps 10 are identical, although the fit out of each end-cap 10 may be different. Likewise, each intermediate section 20 is identical, i.e., the shape and dimensions of the intermediate sections 20 are identical, although the fit out of each intermediate section 20 may be different. Since only two variants of hull wall sections 10, 20 are provided, the size of the habitat can be tailored to the needs of the intended mission without increasing the design or manufacturing complexity; all that needs to be changed is the number of intermediate sections 20 employed and / or the number of complete hulls 1 (each made of the same types of hull wall sections 10, 20). Generally, between 1 and 5 intermediate sections 20 are used per hull 1 although it is possible to produce a hull with end-cap sections only. In some embodiments, the hull wall sections each have a different form factor or length along the longitudinal axis, for example.

[0044]

[0039] The preferred form factor of the end-caps 10 is that of an open-sided hemisphere (see Fig. 5) and that of the intermediate section(s) is a cylinder (see Fig. 2). Both of these shapes are geometrically strong against internal and external pressures thereby enabling the walls to be made thinner for a given pressure requirement than other shapes.

[0045]

[0040] The intermediate hull sections 20 are discussed herein in terms of cylindrical coordinates, regardless of its cross-sectional shape. The axial direction of the coordinate system is coincident with the longitudinal axis of the hull section, which is arranged parallel to the hollow bore of a hull wall and passing through the geometric centre of the hull wall section (which corresponds to the longitudinal axis). The other two coordinate directions are referred to herein as the radial and angular directions.

[0046]

[0041] The end-cap hull wall sections 10 are discussed herein in terms of spherical coordinates having an origin at the geometric centre of the open side of the hull wall section. The longitudinal axis passes through the geometric centre of the open side of the hull wall section and the apex of the opposite side of the hull wall section, i.e., along the axis of rotational symmetry where the end-cap is a hemisphere.

[0047]

[0042] Each hull wall section 10, 20 includes a common internal diameter (the internal diameter being measured across a plane orthogonal to the longitudinal axes of the hull wall sections). The internal diameter is at least 2 m and preferably greater than 3 m. This provides a large interior volume for installation of large quantities of bulky equipment. In some embodiments, the internal diameter is between 2-12 m, 3-8 m, or 4-6m. The length along the longitudinal axis of each section is at least 1 m, and preferably greater than 2 m.

[0048]

[0043] Each hull wall section is made of steel, aluminium, titanium, carbon fibre, acrylic, ceramic, Inconel or Duplex, or combinations thereof. Where combinations of material are used, for example steel and Inconel, the hull wall sections may be formed in layers of each material. Where the sections are made of aluminium, titanium, or, in particular, steel, they are made by an additive manufacturing technique, for example, Wire Arc Additive Manufacturing (WAAM). Hull wall sections manufactured by an additive manufacturing technique have improved structural properties compared to hulls manufactured by traditional fabrication techniques (i.e. , where the hulls are fabricated from forgings or castings). In particular, the improved uniformity of the hull wall created by additive manufacturing has fewer weak points and is less likely to fail at great risk to any human occupants.

[0049]

[0044] The hull wall sections are connected together via identical mating rings 30. A mating ring 30 is placed between each pair of adjacent hull wall sections 10, 20. When assembled into a hull 1 , the hull wall sections are bolted, welded or otherwise attached to the mating rings. Alternatively, the mating rings are dispensed with and adjacent hull wall sections are bolted, welded, or otherwise attached directly together.

[0050]

[0045] Each hull wall section 10, 20 includes at least one aperture 40 through a surface thereof. By aperture is meant a hole through the hull wall that is subsequently sealingly fitted with a component, such as a window. In other words, an aperture is not simply a transparent portion continuous with the rest of the hull wall, i.e., where there is no hole. All of the apertures 40 share identical aperture fittings 41 and dimensions. This enables one of a range of interchangeable components to be fitted to each apertures so that each hull wall section can be reconfigured as needed for a given mission. Examples of such interchangeable components include windows, blanks (i.e., opaque plates that are configured to seal the aperture closed), a connecting structure (i.e., a structure configured to be connected at a first end to an aperture of one hull and to be connected at a second end to an aperture of a second hull, thereby, connecting the hulls together such that a human can pass between the hulls), a hatch (e.g., a door that can be opened and closed, for example, to allow access to an escape pod, submarine, or diving bell releasably attached to the habitat), or a moonpool (i.e., a fitting at the bottom of the hull defining a water surface inside the habitat, thereby allowing divers to enter and leave the habitat and optionally enclosed by a moonpool hood). Moonpools can be fitted with lifts to lift divers and equipment out of the water into the habitat. Each interchangeable component is configured to form a watertight connection with the aperture fitting 41 when fitted to the hull 1 (e.g. via seals). It is understood that a watertight connection can be provided even if a central portion of the interchangeable component allows water therethrough, for example, to define a moonpool.

[0051]

[0046] The apertures 40 in the intermediate sections 20 are regularly arranged around its circumference. This arrangement evenly distributes pressure loads applied on the apertures around the hull wall section thereby avoiding asymmetric pressure loads on the hull. In addition, the rotational symmetry facilitates connecting multiple habitat hulls together. Each aperture 40 has a diameter of at least 1 m such that it is possible for a human wearing diving gear to pass safely through. Preferably, however, the diameter is greater than 2 m so that a human can walk through without needing to bend over.

[0052]

[0047] Fig. 2 shows a cylindrical hull wall section 20. Thus, the hull wall section is of circular cross-section. A plurality of first sliders in the form of rails 22 are attached to bosses 24 on the inner surface of the hull wall section by screws 26. Thus, the first sliders are attached to the inner surface of the hull wall itself. The screws 26 are M 16 screws. The bosses 24 and, hence, the rails 22, are regularly spaced intervals about the circumference of the hull wall section 20. In other words, the rails are regularly spaced angularly about the longitudinal axis of the hull wall section 20. In the embodiment shown, there are six rails regularly arranged around the circumference of the hull wall section. However, two or more rails could be used, and, preferably, four or more, or six or more. The rails 22 are arranged parallel to the longitudinal axis of the hull wall section 20. The rails extend the longitudinal length of the hull wall section. Thus, the rails are at least 1 m long, and generally longer than 2 m. Alternatively, the rails may not extend the entire length of the hull wall section. Instead, multiple shorter rails (optionally in the form of bosses protruding from the hull wall) may be aligned along the length of the hull wall section. The rails 22 serve to support the cassette 100 when it is inserted into the hull wall section 20.

[0053]

[0048] The multiplicity of rails provides many points of support for the cassette from a number of angular positions, thereby supporting the cassette more securely and with less potential for movement within the hull wall section than providing a single rail. As will be explained below, the rails 22 contact respective channels 110 of the cassette 100 and facilitate relative sliding therebetween so that the cassette 100 can easily be slid along the longitudinal axis into the hull wall section 20. Alternatively, instead of rails the first sliders can comprise wheels or rollers along which surfaces, for example the channels 110, of the cassette can roll to facilitate the sliding insertion of the cassette 100 into the hull wall section 20. In general, the first sliders of the hull wall section slidingly contact and support respective second sliders of the cassette, thereby defining contacting pairs of first and second sliders. Thus, as well as providing a secure support structure for the cassette, the sliding interactions of the pairs of first and second sliders enable easy assembly and disassembly of the cassette into and out of the hull wall section.

[0054]

[0049] The rails comprise at least two adjacent flat faces arranged orthogonally to each other. In particular, the rails are shaped such that, when the hull is deployed, one of the faces is arranged horizontally and the other face is arranged vertically. The horizontal face provides a comparatively large, flat surface upon which the mass of the cassette can rest. Thus, the horizontal face is a load-bearing face. The mass of the frame of the cassette may be around 1000-3000 kg, prior to attachment of equipment. The vertical face functions a guide surface which interacts with a corresponding surface of the channel (or a roller) of the cassette to prevent relative rotation between the cassette and the hull wall section. During insertion of the cassette into the hull wall section, this interaction ensures that the channels track correctly along the rails and do not become derailed, which might lead to damage or injury. After insertion, this interaction increases the security of the installation of the cassette within the hull wall section by preventing relative rotation.

[0055]

[0050] The rails are made of a stainless steel such as machined 1.4057 QT800 stainless steel. Other stainless steels can be used, such as 1.4401 and 14404, as can other metals and plastics that are suitable for marine use, for example. The rails comprise wearresistant, low-friction guide pads made of materials such as Tivar, LIHMW Polyethylene, HDPE, LDPE, Nylon, PTFE, PEEK, POM, Teflon, or other suitable materials. The guide pads are mounted on the surface of the rails juxtaposed to the channels of the cassette. These guide pads provide a low coefficient of friction and help to reduce wear and tear on the rails, further enhancing the durability and longevity of the underwater habitable vessel structure. The guide pads are attached to the rails by M6 countersunk screws so as not to interfere with the sliding.

[0056]

[0051] Fig. 3 shows a cassette 100 for insertion into a hull wall section 20. The cassette 100 includes a plurality of second sliders in the form of channels 110. The channels 110 are positioned around the perimeter of the cassette at with the same angular spacing as the rails of the hull wall section so that the channels can align with the rails 22 of the hull wall section 20. The channels are arranged parallel to the longitudinal axis of the cassette, i.e., the hull wall section when assembled. Thus, the channels 110 can rails 22 can be aligned, and the cassette 100 slid into the interior volume of the hull section 20 along the rails such that the cassette 100 is securely held at a plurality of points about its perimeter. Alternatively, instead of channels the second sliders can comprise rollers or wheels attached to the cassette 100. These rollers or sliders can roll along the rails 22 or a channel of the hull wall section to facilitate the sliding insertion of the cassette 100 into the hull wall section 20.

[0057]

[0052] The channels extend the longitudinal length of the cassette. Thus, where the cassette is of approximately the same size as the hull wall section, the channels are at least 1 m long, and generally longer than 2 m. Alternatively, the channels may not extend the entire length of the cassette. Instead, multiple shorter channels may be aligned along the length of the cassette.

[0058]

[0053] The channels are made of a stainless steel such as machined 1.4057 QT800 stainless steel. Other stainless steels can be used, such as 1.4401 and 14404, as can other metals and plastics that are suitable for marine use, for example.

[0059]

[0054] The channels are U-shaped or L-shaped in cross-section. In other words, the channel comprises at least two adjacent flat faces arranged orthogonally to each other. One of the channel’s faces interacts with the horizontal load-bearing face of a respective rail and acts as the main load-bearing face. The other face interacts with the vertical face of the respective rail and acts as a guide face to guide the channel along the rail and prevent relative rotation between the cassette and the hull wall section. A 5 mm clearance is provided between the vertical face of the rail and the guide face of the channel. Alternatively, if the second sliders comprise a roller, for example, the circumference of each roller can comprise a U-shaped or L-shaped profile that functions in the same way as the U-shaped and L-shaped channels. An L-shaped cross-section for the second sliders is preferred since this reduces the alignment burden during assembly.

[0060]

[0055] The overall length of the cassette along the longitudinal axis is approximately the same as that of the hull wall section into which it is inserted. Alternatively, the length of the cassette may be less than that of the hull wall section and multiple cassettes may be inserted into the hull wall section using the same set of first sliders. Alternatively, the length of the cassette may be greater than that of the hull wall section such that the cassette is spans across multiple hull wall sections when assembled therein.

[0061]

[0056] A cassette body 120, which connects to the channels 110, includes at least one deck assembly and / or equipment support structure. The channels 110 may be bolted to the cassette body 120, for example, by bolts inserted through slotted holes in the cassette body to allow height or horizontal adjustment of the cassette body relative to the channels. An upper deck assembly 124 and a lower deck assembly 122 are shown in the embodiment of Fig. 3. The deck assemblies are constructed from a plurality of floor beams 125. Ultimately, the floor beams 125 support a floor on which human users can walk. The deck beams are fabricated from S355 stainless steel. However, other materials can be used.

[0057] Cut-outs 128 are provided through the deck floor beams 125. In addition, the floor beams 125 are supported by support beams 126 attached to the channels 110. The channels 110 may be bolted to the support beams 126 by bolts through slotted holes in the support beams 126 to allow height adjustment of the individual floor beams. Together the floor beams 125 and the support beams 126 define galleries 129 separated from the main volume of the cassette in which human users will operate. These cut-outs 128 and galleries 129 allow for the tidy and secure stowage of auxiliary systems, such as electrical cables and plumbing pipes, out of the workspace and living areas of the vessel. This helps to keep the internal environment of the vessel clutter-free and reduces the risk of accidents or damage to the auxiliary systems.

[0062]

[0058] The cassette body 120 also includes one or more wall assemblies 123 shaped to conform to the inner surface of the hull wall section 20. The wall assembles 123 allow internal wall features to be attached thereto, for example, insulation or equipment such as lighting. In addition, the wall assemblies 123 provide support for cables and / or pipes. The wall assemblies are made from S355 stainless steel. However, other materials can also be used instead.

[0063]

[0059] Instead of a deck assembly, the cassette body includes an equipment support structure, for example a frame used to support scientific or other equipment including mechanical or electrical equipment, or ballast tanks. Some cassette bodies may comprise a mixture of deck assemblies and equipment support structures.

[0064]

[0060] Fig. 4 shows a cassette 100 assembled inside a hull wall section 20 to form a structure for an underwater habitable vessel. Each of the channels 110 is releasably fixed to a respective rail 22 by one or more screws 112. Alternatively, clamps can be used to fix the channels to the screws. Fixing the channels in place, i.e. , fixing the first and second sliders together, prevents the cassette moving longitudinally and rotationally relative to the hull wall section. After a mission is completed and the hull is being refitted, the screws or clamps fixing the rails and channels together can be removed, thereby allowing the cassette to be slid longitudinally out of the hull wall section for replacement or refurbishment.

[0065]

[0061] The screws 112 in Fig. 4 are screwed into threaded holes in the rails 22. The shafts of the screws pass through unthreaded openings within the channels 110. Rubber bushes

[0066] 114 or coil springs are provided around the screws 112, in particular, between the screw heads and the channel 110. For example, the screws may be M16 shoulder screws. The complaint nature of the rubber bushes 114 and springs allows the screw 112, and hence the rail 22 to which the screw is fastened, to move relative to the channel 110. In particular, the screws slide through the openings in the channels. Thus, screws 112 and openings in the channels together define a so-called compensator. Each of the rails and channels may include one or more compensators.

[0067]

[0062] In certain use scenarios, the underwater habitable vessel is submerged underwater and the interior volume is maintained at normal atmospheric pressure. In this case, the pressure of water on the hull wall section, which is assembled into a complete hull, compresses it inwards. This causes the dimensions of the hull wall section to contract. For a cylindrical hull wall section, such as that shown in figures 2 to 4 and discussed in terms of cylindrical coordinates, the contraction of the hull wall is radially inwards towards the longitudinal axis. For a hull wall section of open-sided hemispherical configuration, such as that shown in Fig. 5 and discussed in terms of spherical coordinates, the contraction of the hull wall is radially inwards towards the geometric centre of the complete sphere. At the apex of the hemisphere the radial direction corresponds to a direction along the longitudinal axis of the hull wall section. When the water pressure is removed, for example, when the vessel is returned to the surface, the compression is reversed and the hull wall section expands. Where the hull wall section has a diameter of 5 m with a hull wall thickness of 60 mm steel, the contraction in diameter can be around 10 mm at 200 MSW.

[0068]

[0063] The compensators allow hull wall section to expand and contract relative to the cassette body by permitting relative movement to occur between the inner surface of the hull wall section and the cassette body. For a cylindrical hull wall section 20, the relative movement occurs in a generally radial direction towards and away from the longitudinal axis of the hull wall section. For a hull wall section 10 of open-sided hemispherical configuration, the relative movement occurs in a generally radial direction towards and away from the geometric centre of the complete sphere. The movement is described as “generally” radial since the precise shape and structure of the hull wall section may cause small deviations from contraction / expansion precisely along radial lines. This relative movement for each type of hull wall section may be more generally characterised as a contracting or expanding movement of the hull wall section relative to the cassette body. Alternatively, this same relative movement may be described as a relative movement between the inner surface of the hull wall section and the cassette body along a radius of the hull wall section (it being understood that cylindrical coordinates are used for the intermediate hull wall sections 20 and spherical coordinates are used from the end cap hull wall sections 10).

[0069]

[0064] Allowing this relative movement prevents damage to the cassette body from compressive loads that would otherwise be applied to it by the contracting hull wall section if the cassette body were fixed in position relative to the hull wall section. For example, if the ends of the floor beams 125 of the cassette body were fixedly attached and immovable relative to the hull wall section, the contracting hull wall section would apply a compressive force along the length of the floor beams 125 causing them to bend or buckle and / or cause rupturing of the hull wall section itself. At the same time, the compensator arrangement allows the first and second sliders to support the cassette body within the hull wall section as described above.

[0070]

[0065] Other arrangements for a compensator are possible. However, in each case the compensators are attached to the first sliders and / or the second siders. Thus, relative movement is possible between the hull wall and the first sliders, the first sliders and the second sliders, or the second sliders and the cassette body. This relative movement is generally in the radial direction of the hull wall section. Overall, this enables the relative movement between the hull wall section and the cassette body. The arrangement described above comprising the screw 112 and opening in the channel is of an elongate member and carriage class: the carriage, in the form of the opening, is configured to move along the elongate member, in the form of the screw 112. Elongate members can, alternatively, be configured as rails, pins, posts or channels along which carriages comprising wheels, rollers, openings, or channels can roll or slide. This configuration allows for smooth and controlled movement between the hull wall section and the cassette body along the radius of the hull wall section.

[0071]

[0066] In the arrangement described above, screws / elongate members and respective openings / carriages are attached to the rails / first sliders and channels / second sliders, respectively. Here the relative movement occurs between the rails and the channels in a generally radial direction. Alternatively, the screws can be attached to the channels and the openings can be formed in the rails and the same relative movement would be possible between the rails and the channels. Alternatively, the elongate members can be attached to the hull wall section (in particular, bosses 24 thereon) and the carriages can be attached to the first sliders (i.e., the rails), or vice versa. Here the relative movement occurs between the inner surface of the wall and the rails. Alternatively, the elongate members can be attached to the cassette body (for example, to the support beams 126) and the carriages can be attached to the second sliders (i.e., the channels), or vice versa. Here the relative movement occurs between the cassette body and the second sliders. In each of the above cases, a relative movement in a generally radial direction is enabled between the inner surface of the hull wall section and the cassette body.

[0072]

[0067] As in the arrangement shown in Fig. 4, the elongate member and carriage compensators can include biasing members, such as rubber bushes 114 or springs. The rubber bushes bias the channels relative to the rails along the axes of the screws. In general, the biasing members bias the elongate members relative to the carriages along the direction of relative movement therebetween. These biasing members serve to damp vibrations, which may otherwise cause discomfort to human occupants or interfere with equipment mounted on the cassette body, from being transmitted from the hull wall section to the cassette. In addition, the biasing members of compensators on opposed sides of the cassette body from one another mutually serve to centre the cassette body within the hull wall section, thereby facilitating alignment of the two.

[0073]

[0068] An alternative class of compensator is a simple biasing member type in which the two subcomponents, between which relative movement is desired to facilitate the overall relative movement between the hull wall section and the cassette body, are connected via a biasing member. In this case, the biasing member may be a spring, such as a coil spring, or a resiliently compressible pad. The choice of material for the resiliently compressible pad may include rubber, silicone, or any other resilient compressible material with high load bearing properties.

[0074]

[0069] The biasing members can be positioned in various configurations to permit the relative movement along the radius of the hull wall section. In one example, the biasing members are positioned between the hull wall section and the plurality of first sliders, allowing for relative movement between the hull wall section and the first sliders along the radius of the hull wall section. In another example, the biasing members are positioned between the cassette body and the plurality of second sliders, permitting relative movement between the cassette body and the second sliders along the radius of the hull wall section. For example, where the second sliders are rollers, the axles of each of the rollers can be connected via a spring to the cassette body. Alternatively, the biasing members can be positioned between the plurality of first sliders and the plurality of second sliders, enabling relative movement between the first sliders and the second sliders along the radius of the hull wall section.

[0070] Fig. 5 shows a hull wall section 10 with an open-sided hemispherical configuration. As for the cylindrical hull wall section 20, first sliders in the form of rails 22 are attached to bosses 24 on the inner surface of the hull wall. The rails are curved to conform with the inner surface of the hull wall section. The rails align with support channels of a cassette. The cassette inserted into the hull wall section 10 is shaped differently from that designed for the cylindrical hull wall section 20, in particular, it has a generally hemispherical configuration and the channels are curved to align with the rails. Bosses 24 are positioned in lines arranged perpendicular to each other to support rails in orientations perpendicular to each other. This provides the option for additional attachment points of the cassette to the hull wall section 10, thereby increasing the security of the attachment and enabling a greater variety of cassettes with different load support requirements to be used.

[0075]

[0071] Fig. 6 shows a step of the assembly process of a segment of the underwater habitable vessel. The cassette 100 is shown partially supported on a cassette jig 200 and partially inserted into the hull wall section 20.

[0076]

[0072] During the assembly process, the hull wall section 20 is supported on a hull wall section jig 400. The hull wall section either rests on one or more fixed supporting legs of the jig 400, which may or may not be attached together. Alternatively, the jig 400 comprises rollers on which the hull wall section 20 rests. This arrangement allows the hull wall section 20 to be rotated about its longitudinal axis. This facilitates angular alignment of the hull wall section with the cassette prior to insertion of the latter into the former. In particular, angular alignment of the first and second sliders is facilitated. Equivalent jigs are provided for hull wall sections of other shapes.

[0077]

[0073] The cassette jig 200 comprises a frame 240, mounted on castors 230. Four castors 230 are provided, one at each corner of the cassette jig for maximum stability.

[0078] Alternatively, three or more castors can be used. The castors 230 allow for easy translational movement of the cassette around the floor, facilitating translational alignment of the hull wall section with the cassette prior to insertion of the latter into the former. Furthermore, the castors 230 are jacking castors. This enables the height of the cassette to be adjusted, again to facilitate alignment of the cassette with the hull wall section prior to insertion. The cassette jig 200 also includes third sliders in the form of rails 210. Channels 110 of the cassette 110 are in slidable contact with rails 210 of the cassette jig 200. Thus, once the cassette 100 has been aligned with the hull wall section 20 (i.e. , once the rails 22 of the hull wall section, the channels 110 of the cassette and the rails 210 of the cassette jig have been aligned), the channels of the cassette can be slid along the rails 110 and 210 into the hull wall section such that the cassette is inserted into the hull wall section. Alternatively, the third sliders may comprise wheels or rollers that slidingly support the second sliders of the cassette. The cassette 100 may protrude longitudinally beyond the end of the cassette jig 200 to facilitate insertion into the hull wall section 20.

[0079]

[0074] In some examples, the rails may comprise wear-resistant, low-friction guide pads configured to interface with the channels, reducing friction and wear during the sliding process. The guide pads may be made of materials such as Tivar, LIHMW Polyethylene, HDPE, LDPE, Nylon, PTFE, PEEK, POM, Teflon, or other suitable materials with low coefficients of friction and high wear resistance.

[0080]

[0075] Fig. 7 shows a flow diagram for a method of assembling a segment of an underwater habitable vessel. The method includes providing a hull wall section on a hull wall section jig (step 310), providing a cassette on a cassette jig (step 320), bringing the cassette into contact and alignment with the hull wall section by adjusting the position of at least one of the hull wall section jig and the cassette jig (step 330), and sliding the cassette into the hull wall section (step 340).

[0081]

[0076] In step 310, the hull wall section is positioned in the hull wall section jig 400. For example, the hull wall section is lowered onto the jig by a crane. During this step, the hull wall section is fitted with one or more lift adaptors having lifting slings, spigots or lifting hooks attached thereto and to which a crane can connect. For example, the lift adaptor can be fitted into an aperture or hull stiffener of the hull wall section by bolting. After this step, the adaptor can be removed.

[0082]

[0077] In step 320, the cassette is assembled in the cassette jig 200. The cassette is assembled piece-by-piece in the jig. In some instances, the cassette is not self-supporting and is supported instead by the rails 210 of the cassette jig 200. In other words, without the support provided by the sliders of the cassette jig 200 or the hull wall section, the cassette 100 would fall apart.

[0083]

[0078] In step 330, once the hull wall section and cassette are properly set up on their respective jigs, the assembly process continues with bringing the cassette into contact and alignment with the hull wall section. This is achieved by adjusting the position of at least one or more of the hull wall section in its jig and the cassette in its jig. In some examples, the alignment process may involve aligning the plurality of first sliders on the hull wall section with the plurality of third sliders on the cassette jig. For example, the hull wall section may be rotated on its jig and the cassette jacked up or down in its jig until the two components are aligned.

[0084]

[0079] In step 340, after the cassette 100 is aligned with the hull wall section 20, the assembly process proceeds with sliding the cassette 100 into the hull wall section 20. In one example, the cassette channels are configured to ride on the rails of the hull wall section, allowing for smooth insertion of the cassette into the hull wall section.

[0085]

[0080] Once the cassette is securely inserted into the hull wall section, the assembly process may continue with attaching additional structures, such as mating rings 30 or windows in the apertures 40, if these have not already been attached to the hull wall section.

[0086]

[0081] The process may be repeated to produce additional hull wall sections with cassettes inserted therein. Subsequently, the hull wall sections can be aligned and attached together, for example, by bolting them together via the mating rings 30.

[0087]

[0082] It will be understood that the above description of is given by way of example only and that various modifications may be made by those skilled in the art. Although various embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of this invention.

Claims

Claims1. A kit of parts for a structure (1) for an underwater habitable vessel comprising: a hull wall section (10, 20) of hollow cross-section and comprising a plurality of first sliders attached to an inner surface of the hull wall section, wherein the first sliders (22) are spaced apart around a perimeter of the hull wall section; and a cassette (100) configured to be housed within the hollow cross-section of the hull wall section, the cassette comprising: a cassette body (120); and a plurality of second sliders (110) attached to the cassette body and configured to contact the plurality of first sliders to support the cassette within the hull wall section.

2. A cassette (100) for installation within a hull wall section (10, 20) for an underwater habitable vessel, the hull wall section being of hollow cross-section and comprising a plurality of first sliders (22) attached to an inner surface of the hull wall section, wherein the first sliders are spaced apart around a perimeter of the hull wall section, wherein the cassette comprises: a cassette body (120); and a plurality of second sliders (110) attached to the cassette body and configured to contact the plurality of first sliders to support the cassette within the hull wall section.

3. A hull wall section (10, 20) for an underwater habitable vessel the hull wall section being of hollow cross-section and comprising: a plurality of first sliders (22) attached to an inner surface of the hull wall section, wherein the first sliders are spaced apart around a perimeter of the hull wall section, wherein the first sliders are configured to contact a plurality of second sliders (110) of a cassette (100) to support the cassette within the hull wall section.

4. A structure (1) for an underwater habitable vessel comprising: a hull wall section (10, 20) of hollow cross-section and comprising a plurality of first sliders (22) attached to an inner surface of the hull wall section, wherein the first sliders are spaced apart around a perimeter of the hull wall section; anda cassette (100) housed within the hollow cross-section of the hull wall section, the cassette comprising: a cassette body (120); and a plurality of second sliders (110) attached to the cassette body and in contact with the plurality of first sliders to support the cassette within the hull wall section.

5. The kit of claim 1 , the cassette of claim 2, the hull wall section of claim 3, or the structure of claim 4, further comprising a plurality of compensators configured to permit the hull wall section to expand and contract relative to the cassette body by permitting relative movement between the inner surface of the hull wall section and the cassette body.

6. The kit of claim 5, the cassette of claim 5, the hull wall section of claim 5, or the structure of claim 5, wherein each of the plurality of compensators comprises a biasing member (114).

7. The kit of claim 6, the cassette of claim 6, the hull wall section of claim 6, or the structure of claim 6, wherein the biasing members are positioned between: the hull wall section and the plurality of first sliders are configured to permit relative movement between the hull wall section and the plurality of first sliders; the cassette body and the plurality of second sliders are configured to permit relative movement between the cassette body and the plurality of second sliders; or the plurality of first sliders and the plurality of second sliders are configured to permit relative movement between the plurality of first sliders and the plurality of second sliders.

8. The kit of claim 6 or claim 7, the cassette of claim 6 or claim 7, the hull wall section of claim 6 or claim 7, or the structure of claim 6 or claim 7, wherein the biasing members each comprise a coil spring or a resiliently compressible pad.

9. The kit of claim 5, the cassette of claim 5, the hull wall section of claim 5, or the structure of claim 5, wherein each of the plurality of compensators comprises an elongate member and a carriage configured to move on the elongate member.

10. The kit of claim 9, the cassette of claim 9, the hull wall section of claim 9, or the structure of claim 9, wherein, either the elongate members are attached to the hull wall section and the carriages are attached to the plurality of first sliders, or the elongate members are attached to the plurality of first sliders and the carriages are attached to thehull wall section, such that each of the plurality of compensators is configured to permit relative movement between the hull wall section and the plurality of first sliders.

11. The kit of claim 9, the cassette of claim 9, the hull wall section of claim 9, or the structure of claim 9, wherein either the elongate members are attached to the cassette body and the carriages are attached to the plurality of second sliders, or the elongate members are attached to the plurality of second sliders and the carriages are attached to the cassette body, such that each of the plurality of compensators is configured to permit relative movement between the cassette body and the plurality of second sliders.

12. The kit of claim 9, the cassette of claim 9, the hull wall section of claim 9, or the structure of claim 9, wherein either the elongate members are attached to the plurality of first sliders and the carriages are attached to the plurality of second sliders, or the elongate members are attached to the plurality of second sliders and the carriages are attached to the plurality of first sliders, such that each of the plurality of compensators is configured to permit relative movement between the plurality of first sliders and the plurality of second sliders.

13. The kit of any one of claims 9-12, the cassette of any one of claims 9-12, the hull wall section of any one of claims 9-12, or the structure of any one of claims 9-12, wherein each elongate member comprises a screw (26) or a pin, and each carriage comprises an opening (112) sized to receive the screw or pin slidably.

14. The kit of any one of claims 9-13, the cassette of any one of claims 9-13, the hull wall section of any one of claims 9-13, or the structure of any one of claims 9-13, wherein each of the plurality of compensators comprises a biasing member (114) configured to bias a respective one of the carriages relative to a respective one of the elongate members along a direction of relative movement of the respective elongate member and the respective carriage.

15. The kit of claim 14, the cassette of claim 14, the hull wall section of claim 14, or the structure of claim 14, wherein the biasing members each comprise a spring or a resilient bush.

16. The kit of any one of claims 1 and 5-15, the cassette of any one of claims 2 and 5- 15, the hull wall section of any one of claims 3 and 5-15, or the structure of any one of claims 4-15, wherein the plurality of first sliders and the plurality of second sliders are mutually configured to permit relative movement between the hull wall section and the cassette along a longitudinal axis of the hull wall section.

17. The kit of any one of claims 1 and 5-16, the cassette of any one of claims 2 and 5-16, the hull wall section of any one of claims 3 and 5-16, or the structure of any one of claims 4-16, wherein the plurality of first sliders and the plurality of second sliders are mutually configured to prevent relative rotational movement between the hull wall section and the cassette about the longitudinal axis of the hull wall section, and optionally wherein each of the plurality of first sliders comprises a load-bearing face and a guide face arranged orthogonally to the load-bearing face, and wherein each of the plurality of second sliders comprises a load-bearing face, configured to contact the load-bearing face of a respective first slider, and a guide face arranged orthogonally to the load-bearing face and configured to engage the guide face of the respective first slider.

18. The kit of any one of claims 1 and 5-17, the cassette of any one of claims 2 and 5-17, the hull wall section of any one of claims 3 and 5-17, or the structure of any one of claims 4-17, wherein either: each of the first sliders comprises a rail and each of the second sliders comprises a channel or a roller configured to ride on a respective rail of the first sliders; or each of the second sliders comprises a rail and each of the first sliders comprises a channel or a roller configured to ride on a respective rail of the second sliders.

19. The kit of claim 18, the cassette of claim 18, the hull wall section of claim 18, or the structure of claim 18, wherein the rails are arranged parallel to a longitudinal axis of the hull wall section.

20. The kit of any one of claims 18-19, the cassette of any one of claims 18-19, the hull wall section of any one of claims 18-19, or the structure of any one of claims 18-19, wherein the channels are arranged parallel to a longitudinal axis of the hull wall section.

21. The kit of any one of claims 18-20, the cassette of any one of claims 18-20, the hull wall section of any one of claims 18-20, or the structure of any one of claims 18-20, wherein the plurality of first sliders comprises six rails and the plurality of second sliders comprises six channels.

22. The kit of any one of claims 18-21 , the cassette of any one of claims 18-21 , the hull wall section of any one of claims 18-21 , or the structure of any one of claims 18-21 , wherein the channels comprise U-shaped or L-shaped brackets.

23. The kit of any one of claims 18-22, the cassette of any one of claims 18-22, the hull wall section of any one of claims 18-22, or the structure of any one of claims 18-22, whereinthe channels are configured to be releasably fixed in place on the rails to prevent relative movement between the hull wall section and the cassette along a longitudinal axis of the hull wall section.

24. The kit of claim 23, the cassette of claim 23, the hull wall section of claim 23, or the structure of claim 23, wherein the channels are configured to be releasably fixed in place on the rails by clamps or screws.

25. The kit of any one of claims 18-24, the cassette of any one of claims 18-24, the hull wall section of any one of claims 18-24, or the structure of any one of claims 18-24, wherein the rails each comprise a guide pad configured to interface with a respective one of the plurality of channels.

26. The kit of any one of claims 1 and 5-25, the cassette of any one of claims 2 and 5-25, the hull wall section of any one of claims 3 and 5-25, or the structure of any one of claims 4-25, wherein each of the plurality of first sliders is attached to bosses on the inner surface of the hull wall section.

27. The kit of any one of claims 1 and 5-26, the cassette of any one of claims 2 and 5-26, the hull wall section of any one of claims 3 and 5-26, or the structure of any one of claims 4-26, wherein the first sliders are uniformly spaced around the perimeter of the inner surface of the hull wall section.

28. The kit of any one of claims 1 and 5-27, the cassette of any one of claims 2 and 5-27, the hull wall section of any one of claims 3 and 5-27, or the structure of any one of claims 4-27, wherein the cassette body comprises a deck assembly and / or an equipment support structure.

29. The kit of claim 28, the cassette of claim 28, the hull wall section of claim 28, or the structure of claim 28, wherein floor beams of the deck assembly comprise cutouts or galleries for cables or pipes.

30. The kit of any one of any one of claims 1 and 5-29, the cassette of any one of claims 2 and 5-29, the hull wall section of any one of claims 3 and 5-29, or the structure of any one of claims 4-29, wherein the cassette body further comprises at least one wall assembly configured to conform to the inner surface of the hull wall section and configured to: have one or more internal wall features attached thereto; and / or support cables or pipes.31 . The kit of any one of claims 1 and 5-30, the cassette of any one of claims 2 and 5- 30, the hull wall section of any one of claims 3 and 5-30, or the structure of any one of claims4-30, wherein the hull wall section comprises at least one lift adaptor temporarily attached to an outer surface thereof and configured to receive a lifting sling or lifting hook.

32. A method of assembling a structure for an underwater habitable vessel comprising:(i) providing a hull wall section according to any one of claims 3 and 5-31 on a hull wall section jig;(ii) providing a cassette according to any one of claims 2 and 5-31 on a cassette jig;(iii) bringing the cassette into contact and alignment with the hull wall section by adjusting the position of at least one of the hull wall section jig and the cassette jig;(iv) sliding the cassette into the hull wall section.

33. The method of claim 32, wherein providing the cassette comprises assembling the cassette in the cassette jig.

34. The method of claim 32 or claim 33, wherein the cassette jig comprises a plurality of third sliders configured to contact the plurality of second sliders to support the cassette within the cassette jig.

35. The method of claim 34, wherein bringing the cassette into contact and alignment with the hull wall section comprises aligning the plurality of first sliders and the plurality of third sliders, and sliding the cassette into the hull wall section comprises sliding the cassette along the pluralities of first and third sliders.

36. The method of any one of claims 32-35, wherein the cassette jig is mounted on at least three jacking castors.

37. The method of any one of claims 32-36, wherein at least one end of the cassette protrudes out from the cassette jig.

38. The method of any one of claims 32-37, wherein providing the hull wall section comprises using a crane and at least one sling to lift the hull wall section onto the hull wall section jig.

39. The method of claim 38, wherein the at least one sling is attached to at least one lift adaptor temporarily attached to an outer surface of the hull wall section.

40. The method of claim 38 or claim 39, wherein lifting the hull wall section comprises rotating a longitudinal axis of the hull wall section from a vertical orientation to a horizontal orientation.

41. The method of any one of claims 32-40, wherein providing the hull wall section comprises resting the hull wall section on: removable hull support legs attached to the hull wall section jig and / or rollers configured to allow rotation of the hull wall section about a longitudinal axis thereof.

42. The method of any one of claims 32-41 , further comprising repeating steps (i)-(iv) to produce multiple structures for the underwater habitable vessel.

43. The method of claim 42, further comprising attaching the multiple structures together, optionally via mating rings positioned therebetween.

44. A cassette jig (200) for supporting a cassette for an underwater habitable vessel comprising: a frame (240); and a plurality of third sliders attached to the frame and configured to contact a plurality of second sliders (110) of a cassette (100) to support the cassette on the cassette jig.

Images