Rescue appliance

Abstract

A rescue appliance has at least one sheet of flexible material (401, 402) that includes graphene The rescue appliance may be inflatable, for example an inflatable survival craft such as a liferaft, single seat liferaft, multiple seat liferaft, lifeboat or marine escape system, MES. The rescue appliance may be an escape slide or escape chute. The sheet of material further may include a polyurethane, PU, or thermoplastic polyurethane, TPU. The rescue appliance may include two sheets of material, one of which is provided to support the other and to form an inflatable bladder. The sheet of material may be formed from fibres, threads or yarn that contains graphene.

Description

09866 1RESCUE APPLIANCETECHNICAL FIELD

[0001] The present invention relates to rescue appliances, such as inflatable survival crafts and escape slides .BACKGROUND TO THE INVENTION

[0002] It is known to form rescue appliances, such as inflatable survival craft and escape slides, using flexible polymer films (e . g . polyurethane, PU, or thermoplastic polyurethane, TPU) to create waterproof and gas (e . g . air) holding materials .

[0003] The rescue appliances may include an inflatable bladder . In some cases the bladders are made of a textile (nylon or polyester) which is coated with an air-holding layer of an air impermeable material such as synthetic rubber (e . g . neoprene) or thermo-plastic materials such as polyurethane ( PU) and thermoplastic polyurethane (TPU) . Most bladders are now made of a TPU coated fabric type because TPU is a thermo-plastic material which can be easily welded using high frequency or radio frequency or ultrasonic welding . The disadvantage of this type of bladder construction is that the bladders have poor characteristics in respect of weld strength, tear and tensile strength and are not Fire Resistant ( FR) and also may not be Moisture Vapour Permeable (MVP) .

[0004] Inflatable rescue appliances may also include an interior and exterior sheet of material, in which the inflatable bladder is contained. This sheet of material should be strong and fire resistant .

[0005] Rescue appliances are used in many safety-critical roles - for example by aircrew and persons onboard ships and other vessels . Aircrew and their flight equipment is subjected to extremes of potential for damage which include the following :09866 2• Wear and tear as a result of the frequency of use and servicing .• If the pilot ej ects from the aircraft this can place great strain on the materials . The equipment may be required to be able to withstand the "air blast" resulting from meeting up to 700 knots air speed and unless the materials are strong enough they can be torn open. Also during "air blast" the blast can include fragments of materials that can penetrate the equipment and puncture it resulting in it failing in use .• On landing on the ground and if escape and evasion is required then damage can be caused by the environment tearing or puncturing the liferaft .SUMMARY OF THE INVENTION

[0006] According to one aspect of the invention, there is provided a rescue appliance having at least one sheet of flexible material that includes graphene .

[0007] The rescue appliance in some embodiments is inflatable . The rescue appliance may be an inflatable survival craft, such as a liferaft (e . g . a single seat liferaft or multiple seat liferaft ) , a lifeboat or a marine escape system, MES . The rescue appliance may be an escape slide or escape chute, such as an inflatable escape slide or escape chute . The invention provides an inflatable survival craft having at least one sheet of flexible material that includes graphene . The invention provides an escape slide or escape chute having at least one sheet of flexible material that includes graphene .

[0008] Survival craft and the like rescue appliances (e . g . boats and escape slides etc . ) are typically manufactured from a flexible material that is impervious to air to create an air holding buoyancy system which can be inflated from a compressed gas source (or other inflation means ) . Typically such survival craft and escape slides are packed into a small container or pack so as to occupy the minimum volume when uninflated. The09866 3packed size of the survival craft and escape slides , and its weight, are important in many applications, and incorporating graphene into the air holding materials has been shown to achieve these benefits in many applications . A thinner and lighter material that incorporates graphene but at the same time maintains the same strength characteristics is a major advantage . Survival crafts and escape slides are typically folded and compressed when being packed and the thinner the material the less packed volume it will occupy. On being inflated it is beneficial that the material is thinner and less stiff and this results in faster unfolding and inflation compared to a thicker material . Additionally the weight is critical in many applications as this affects the type of equipment needed to support and launch the survival craft and escape slides . Examples will be described of different types of survival craft and escape slides where graphene is incorporated into the device (e . g . into the buoyancy material) . For example, single seat or multiseat liferafts can be manufactured in different ways and these would benefit from materials being reinforced with graphene .

[0009] Graphene can be defined as a lattice of hexagonal carbon atoms having a single layer of atoms arranged in a honeycomb planar nanostructure . Graphene Nano Platelets (GNPs ) can be defined as platelet-shaped sheets of graphene stacked on top of one another . These graphitic stacks may have an average thickness of 1-2 nanometres . GNPs may possess many of the same properties as graphene . The graphene in the at least one sheet of flexible material, according to various embodiments of the invention, may be in the form of GNPs or other forms of graphene, including pure graphene .

[0010] The sheet of material may also include polyurethane, PU, and / or thermoplastic polyurethane, TPU . Graphene may be dispersed into PU / TPU at the melt stage in the form of GNPs .

[0011] The sheet of material may be formed from fibres , threads or yarn that contains graphene . The fibres, threads or09866 4yarn may be woven together to form the sheet of material . The fibres, threads or yarn may also include polyurethane, PU, and / or thermoplastic polyurethane, TPU . Graphene may be dispersed into PU / TPU at the melt stage in the form of GNPs .

[0012] Embodiments of the invention may provide inflatable survival crafts and escape slides using flexible polymer films (e . g . PU or TPU) incorporating graphene to create waterproof and / or gas (e . g . air) holding materials . Such incorporation of graphene into the PU / TPU film may increase its strength and contributes to the overall performance of the equipment .

[0013] Embodiments of the invention may provide inflatable survival crafts and escape slides using one of more sheets of material, e . g . including PU or TPU, and incorporating graphene . Such incorporation of graphene into the sheet of material may increase its strength and flame retardance, and contributes to the overall performance of the equipment .

[0014] The sheet of material may be fluid impermeable . This allows the sheet of material to form a pressure holding inflatable item. Pressure holding inflatable items are normally referred to as "bladders" . Inflatable bladders can be inflated orally by mouth or from a compressed gas source such as a cylinder of compressed CO2 .

[0015] For example, inflatable survival craft and escape slides may utilise a film of a flexible polymer typically for example PU or TPU in order to provide a barrier against a pressurised gas in the creation of inflatable structures .

[0016] The sheet of material may have a thickness of between 100 and 150pm.

[0017] The sheet of material may include between 1 and 10% graphene (by weight ) , preferably 1.5% graphene by weight . Samples of a number of different percentages of graphene by weight ranging from 1% to 5% were tested in four ways - being breaking force, puncture resistance, weld strength and tear09866 5strength. The most effective percentage of GNPs within the TPU was found to be 1.5% .

[0018] The sheet of material may be moisture-vapour permeable . This may improve comfort if the sheet of material is positioned against the wearer' s body and allow the passage of perspiration through the material .

[0019] The sheet of material may be flame retardant (e . g . it will be less damaged by fire than a non-graphene including sheet of material) .

[0020] The inflatable survival crafts and escape slides may have at least one further non-graphene sheet of material (i . e . a sheet of material that does not contain graphene) . The non-graphene sheet of material may support the sheet of flexible material that includes graphene . The sheet of flexible material that includes graphene may have a lower modulus of elasticity the non-graphene sheet of material . The non-graphene supporting sheet of material may limit the expansion or stretching of the sheet of flexible material that includes graphene (e . g . as a bladder incorporating the sheet of flexible material that includes graphene ) . The non-graphene supporting sheet of material may protect the sheet of flexible material that includes graphene from abrasion or other damage . Alternatively, the supporting sheet of material may include graphene, and the sheet of material supported by the supporting sheet of material may or may not include graphene .

[0021] Inflatable survival crafts and escape slides comprising conventional films or sheets of material (without graphene reinforcement) have a number of disadvantageous features ; these include limited tensile strength, limited resistance to impact damage, low modulus (modulus of elasticity) , low thermal stability and poor flame retardancy. Studies have shown that by incorporating graphene into a sheet or film (e . g . a PU / TPU film) it is possible to improve a number of characteristics of the sheet or film to the overall advantage09866 6of the equipment' s performance . For example see : "Chemical Engineering Journal" Vol 482 15thFebruary 2024 "The Reinforcement of Polyurethane by Mini-Sized Graphene with Superior Performances" . Such laboratory studies have indicated that the inclusion of graphene in PU material can provide the following benefits to the PU film and therefore to the equipment :Improved tensile strength by up to 80%Modulus by up to 126%Increased mechanical performanceIncreased shape memoryThe PU film can be fire retardant and generate limited smoke

[0022] Bladders incorporating graphene (and e . g . PU / TPU) , according to embodiments of the invention have been manufactured and tested and found to have the following improvements over the same non-Graphene bladders :Average breaking force increased by 40%Average puncture resistance improved by 10%Average weld strength improved by 39%Average tear strength improved by 10%

[0023] Reducing the weight of the product is very advantageous both for personal safety equipment (e . g . inflatable survival crafts and escape slides ) . The thickness and therefore the weight of the PU / TPU film can be reduced while still achieving the same or better strength characteristics of the non-graphene PU film.

[0024] Additionally reducing the thickness of a grapheneincluding PU / TPU sheet or film may make it more flexible and therefore easier to pack into a more compact space thereby further saving space and weight .

[0025] According to another aspect of the invention, there is provided a rescue appliance having at least one part that includes graphene . The part may be a rigid part . The part my be an uninf datable part .

[0026] Some embodiments of the invention relate to an inflatable liferaft . This liferaft may be provided including a floor, and an inflatable structure having an inner layer and an outer layer, wherein the inner layer is separable from the outer layer, and wherein the floor is connected to the inflatable structure . The floor, inner layer and / or outer layer may include a sheet of material that includes graphene, which may improve strength or compactness . The inflatable structure may comprise a buoyancy tube at the periphery of the liferaft . The buoyancy tube may include a sheet of material that includes graphene . The floor may be connected to the outer layer of the inflatable structure at a position that is above the waterline of the liferaft in use . The floor may be connected to an upper region of the outer layer of the inflatable structure . The liferaft may comprise a further layer (e . g . including graphene ) for creating a water pocket at the underside of the liferaft in use . The inner layer may include a flange portion that extends through the outer layer and is connected to the floor . A survival system may be provided including an inflatable chamber having an inner layer laminated to an outer layer, wherein the arrangement is such that the inner and outer layers partially de-laminate when the chamber is inflated . The chamber may be formed by an upper laminated sheet and a lower laminated sheet, each forming part of the inner layer and the outer layer, wherein the upper laminated sheet and the lower laminated sheet are attached to one another around their periphery. The upper laminated sheet and the lower laminated sheet may be attached to one another around their periphery by stitching . The upper laminated sheet and the lower laminated sheet may be attached to one another around their periphery by welding . The inner layer may delaminate from the outer layer in the region of the weld to thereby form an inflatable bladder within the outer layer that is at least partially separated from the outer layer . A method of manufacturing a survival system may be provided including an inflatable chamber (e . g . including graphene ) , the method including laminating an inner layer to an outer layer such that the inner and outer layers partially de-laminate when thechamber is inflated . The method may include forming the chamber by an upper laminated sheet and a lower laminated sheet, each forming part of the inner layer and the outer layer, and attaching the upper laminated sheet and the lower laminated sheet around their peripheries . The method may include attaching the upper laminated sheet and the lower laminated sheet around their peripheries by stitching . The method may include attaching the upper laminated sheet and the lower laminated sheet around their peripheries by welding . The inner layer may de-laminate from the outer layer in the region of the weld to thereby form an inflatable bladder within the outer layer that is at least partially separated from the outer layer . A method of deploying a survival system may be provided including inflating the chamber and causing the inner and outer layers partially delaminate . A liferaft may be provided including a floor and an inflatable chamber, wherein the floor and the inflatable chamber are formed by joining together two sheets of material . The two sheets of material may form, respectively, an upper surface of the floor and the inflatable chamber, and a lower surface of the floor and the inflatable chamber . The two sheets of material may be j oined around their edges to form an outer side of the inflatable chamber, and wherein the two sheets of material are joined at a region spaced inwardly from their edges to form an inner side of the inflatable chamber . The floor may extend from the inner side of the inflatable chamber . A method of manufacturing a liferaft may be provided including a floor and an inflatable chamber, the method including forming the floor and the inflatable chamber by j oining together two sheets of material . The two sheets of material may form, respectively, an upper surface of the floor and the inflatable chamber, and a lower surface of the floor and the inflatable chamber . The two sheets of material may be joined around their edges to form an outer side of the inflatable chamber, and wherein the two sheets of material may be joined at a region spaced inwardly from their edges to form an inner side of the inflatable chamber . The floor may extend from the inner side of the inflatable chamber .

[0027] Some embodiments of the invention relate to a survival craft . This survival craft includes inflatable members , the survival craft comprising : a hull formed from the inflatable members and including a floor; a rigid pod configured to carry at least one powered propulsion unit; and an inflatable wall formed from the inflatable members for mounting the rigid pod to the hull . The inflatable members, the hull, the floor, the rigid pod and / or the inflatable wall may include graphene . In one embodiment the floor has a recess therein at a stern end thereof to provide an opening; the inflatable wall surrounds the recess ; the pod is formed in a shape complimenting the recess ; the pod is supported by and securely mounted to the inflatable wall by a hinged fabric attachment (e . g . including graphene ) , by bonding and / or by an interference fit between the side walls of the pod and the inflatable wall; the inflatable wall is configured to facilitate the application of motive power from the propulsion unit to the hull to move the hull in water; the floor is formed by a plurality of modular inflatable chambers (e . g . including graphene ) ; and a combination of the modular inflatable chambers of the floor, and the inflatable members of the hull and the wall, acts a transom to transfer power from the pod to the hull to propel the craft forward. At least one of the inflatable members may be formed from a drop thread material and may comprise a sheet of material including graphene and / or threads including graphene . A canopy support structure (e . g . including graphene ) may be carried by the hull and formed from the inflatable members, wherein, optionally, the canopy support structure is formed by elongate inflatable members positioned in a cross-hatched arrangement . The plurality of modular inflatable chambers of the floor may be in a cross laid arrangement and / or with multiple layers . The floor may support the inflatable wall . The inflatable members of the hull may comprise inflatable tubes (e . g . including graphene) or vertical inflatable panels (e . g . including graphene ) , wherein, optionally, the vertical inflatable panels are formed by a plurality of modular inflatable chambers . The hull may include at least one elongate central inflatable tube (e . g . including09866 10graphene) along the floor providing longitudinal rigidity to the hull . The hull may include at least one inflatable tube (e . g . including graphene) that extends from the elongate central tube to the edge of the hull Edges of the under surface of the hull may comprise inflatable sleeves (e . g . including graphene) that define a space of triangular cross section to retain water . The survival craft may comprise an inclined or vertical passenger transfer system (e . g . including graphene ) attachable to the craft . The hull may be formed of vertical inflatable panels and comprises a door (e . g . including graphene) arranged for assisting passengers to board from the water . The survival craft may include an inflatable fin or spine (e . g . including graphene ) extending from the underside of the hull . The survival craft may include seating (e . g . including graphene) formed by the inflatable members . The inflatable wall may be formed by a plurality of the inflatable members (e . g . including graphene ) . The rigid pod may be configured to carry, in a deflated state, the survival craft, and the rigid pod being coupled to the hull when the survival craft is in an inflated state . The rigid pod may be securely attached to the wall by a fastening means (e . g . including graphene ) and / or an interference fit . The powered propulsion unit may be attached to the rigid pod with a lowering mechanism. The rigid pod may carry a source of energy for the powered propulsion unit . The rigid pod may carry an inflation system for inflating the craft .

[0028] Some embodiments of the invention relate to an inflatable evacuation slide . This inflatable evacuation slide, for evacuating people from a first structure to a second structure, comprises : at least three longitudinal beams, including two lateral lower beams and an upper beam, spaced apart transversally over their length and substantially parallel to each other in the inflated state, each beam comprising at least one inflatable longitudinal tube; and a plurality of inflatable lateral panels connected to said upper beam and to said lateral lower beams; wherein the inflatable lateral panels comprise drop stitch material . The beams, the inflatable09866 11longitudinal tubes , and the inflatable lateral panels may include graphene . The inflatable longitudinal tube may comprise a braid tube ( e . g . including graphene ) . The braid tube may be formed of a plurality of substantially inelastic fibres ( e . g . including graphene ) . The braid tube may include at least one longitudinally extending element ( e . g . including graphene ) for constraining the maximum longitudinal extension of the braid tube . Each of the inflatable longitudinal tubes may include at least one end plate ( e . g . including graphene ) positioned at an end of the tube . The end plates may include a clamping mechanism ( e . g . including graphene ) for clamping the braid tube of the inflatable longitudinal tubes thereto . The inflatable longitudinal tubes of each beam may be coupled together by a sleeve ( e . g . including graphene ) ) . The slide may comprise a plurality of inflatable floor panels ( e . g . including graphene ) connected to said lateral lower beams . The slide may comprise drop stitch material and may comprise a sheet of material including graphene and / or threads including graphene . The slide may include a flexible chute ( e . g . including graphene ) for supporting people during their evacuation via the slide , said chute including a floor part ( e . g . including graphene ) extending between said two lateral lower beams and at least one partitioning wall ( e . g . including graphene ) extending between the floor part and the upper beam for defining at least two slide paths for the people during evacuation . Rach beam may comprise at least two inflatable longitudinal tubes , said tubes connected side by side , and adj acent along their length . The inflatable longitudinal tubes may comprise an inflatable bladder ( e . g . including graphene ) , the volume of which is constrained by the braid tube . The braid tube may be contained in a sleeve ( e . g . including graphene ) suitable for being adhesively connected to the inflatable lateral panel .

[0029] Some embodiments of the invention relate to an inflatable evacuation slide . This inflatable evacuation slide , for facilitating evacuation from a structure to water , comprises at least one helical inflatable path . The helical inflatable09866 12path may be formed from a sheet of material that includes graphene . The or each helical inflatable path may be configured to extend generally vertically between the structure and the water . The slide may comprise a plurality of helical inflatable paths . First of said helical inflatable paths and a second of said helical inflatable paths may have a common central axis . A first of said helical inflatable paths and a second of said helical inflatable paths may have a double helix configuration. The first of said helical inflatable paths and the second of said helical inflatable paths may be interlaced . Two of said helical inflatable paths a may be arranged side by side with spaced apart and substantially parallel central axes . The slide may comprise spacing means (e . g . including graphene) for controlling the pitch between helix turns of the or each of the helical inflatable paths . The spacing means may comprise a plurality of hollow cylinders formed of drop stitch material and may comprise a sheet of material including graphene and / or threads including graphene . The spacing means may be operable to set a minimum distance between two adjacent helix turns of the or each of the helical inflatable paths . The spacing means may comprise a plurality of tubular parts (e . g . including graphene) attached to the slide, the gap between adj acent ones of the tubular parts varying with the pitch between the helix turns, and the abutment of adjacent tubular parts preventing the distance between two adj acent helix turns falling below said minimum distance . The spacing means may be operable to maintain a substantially equal distance between adjacent helix turns of the or each of the helical inflatable paths . The spacing means may comprise a plurality of elastically deformable cables extending (e . g . including graphene) along the slide, the cables being attached to the slide at spaced apart locations along the length of the slide and being held in tension. The spacing means comprises a winch or pulley system. The slide may include a plurality of bowsing attachment parts spaced apart along the slide between an entrance to the slide at the structure and the water . The slide may include at least one exit (e . g . including graphene ) configured to allow evacuees from the structure to09866 13transfer from the slide to at least one craft . A platform (e . g . including graphene ) for floating on the water may be provided, the platform being attached to the slide . The platform may be configured to secure thereto the or each craft during boarding of the evacuees . The or each helical path may be formed by a plurality of partially overlapping sections (e . g . including graphene ) . Each of said sections may have an upper surface having an exposed portion and an overlapped portion that is overlapped by the one of the sections above, the exposed portions of the upper surfaces of the sections being arranged to define the helical path . The slide may include a linear path portion that extends from the helical inflatable path . The linear path portion may extend obliquely to a central axis of the helical inflatable path . An exit (e . g . including graphene) of the slide may be formed at an end of the linear portion . The slide may comprise inflatable drop stitch material and may comprise a sheet of material including graphene and / or threads including graphene . The dimensions of the slide may be so chosen that evacuees from the structure travel along the helical path at a speed of between 1 and 10 kph . One of the dimensions may be a diameter of a substantially cylindrical space around which the or each helical path extends . One of the dimensions may be a pitch of the or each helical path. One of the dimensions may be a length of the slide . The slide may include a substantially cylindrical outer wall (e . g . including graphene ) extending around an outer periphery of the or at least one of the helical paths, the outer wall being longitudinally elastically deformable to accommodate changes in distance between an entrance to the or each slide at the structure and the water . The slide may include a substantially cylindrical inner wall (e . g . including graphene ) extending around an inner periphery of the or at least one of the helical paths, the inner wall being longitudinally elastically deformable to accommodate changes in distance between an entrance to the or each slide at the structure and the water . An escape system may be provided comprising a slide for facilitating evacuation of from a structure to water, wherein the slide comprises at least one09866 14helical path, wherein the or each helical path is formed by a plurality of partially overlapping sections (e . g . including graphene ) . Each of said sections may have an upper surface having an exposed portion and an overlapped portion that is overlapped by the one of the sections above, the exposed portions of the upper surfaces of the sections being arranged to define the helical path . A marine escape system may be provided comprising the escape system defined above, and further including at least one craft coupleable to said slide for receiving evacuees from the structure . The or each liferaft may be inflatable . A bowsing arrangement may be provided for an escape system that has a slide for facilitating evacuation of from a structure to water, the bowsing arrangement including a plurality of retractable or removable bowsing attachment parts for being mounted spaced apart to the structure and for attachment to corresponding attachment parts spaced along the slide between an entrance to the slide at the structure and the water . The bowsing attachment parts may be configured to be magnetically coupled to the structure . The bowsing attachment parts may include an inflatable portion (e . g . including graphene ) . The bowsing attachment parts may comprise a plurality of sections moveable between a deployed configuration and a retracted configuration . The attachment part sections may be configured foldable or mounted for telescopic relative movement . The bowsing attachment parts may be configured to be coupled to the structure by suction .BRIEF DESCRIPTION OF THE DRAWINGS

[0030] For a better understanding of the present invention embodiments will now be described by way of example, with reference to the accompanying drawings , in which :Fig . 1 is a cross-section of an inflatable personal flotation device;Figs . 2 to 7 are partial views at points around the circumference of the inflatable personal flotation device of Fig . 1 - e . g . at points A, B or C - showing different forms of pieces of material that may be used to form the inflatable09866 15personal flotation device;Figs . 8 , 9 and 10 are partial views at points around the circumference of the inflatable personal flotation device showing how two pieces of material and may be sealed at their seams in various different ways ;Fig . 11 shows is a perspective view of an inflatable liferaft ;Fig . 12A shows an overhead plan view of one configuration of liferaft;Fig . 12B shows a cross-section taken along line A-A of Fig . 12A;Fig . 13A shows an overhead plan view of another configuration of liferaft;Fig . 13B shows a cross-section taken along line A-A of Fig . 13A;Fig . 14A shows a cross-sectional view taken of the inflatable chamber of the liferaft;Fig . 14B shows a close up detailed view of the material forming the layer of the inflator chamber of Fig . 14A;Fig . 14C shows an enlarged detailed view of the inflated chamber at a seam region;Fig . 16A shows an overhead plan view of another configuration of liferaft;Fig . 16B shows a cross-section taken along line A-A of Fig . 16A;Fig . 17A shows a cross-sectional view of an inflatable chamber having two separate layers;Fig . 17B shows an enlarged detailed view of the layers of the inflatable chamber of Fig . 17A;Fig . 17C shows an enlarged view of the inflatable chamber of Fig . 17A where the upper and lower layers are connected together;Fig . 18A shows a cross-sectional view of a liferaft in accordance with another configuration of liferaft;Fig . 18B shows a detailed view of a buoyancy tube of the liferaft of Fig . 18A;Fig . 18C shows a detailed view of a connection between09866 16a floor and a buoyancy tube of the liferaft of Fig . 18A;Fig . 19 shows a cross-sectional view of a modification to the liferaft of Figs . 18A-C;Fig . 20A shows a cross-sectional view of another modification to the liferaft of Figs . 18A-C;Fig . 20B shows a detailed view of a connection between a floor and a buoyancy tube of the liferaft of Fig . 20A;Fig . 21 shows a cross-sectional view a laminated sheet of material for use with an embodiment of the invention;Fig . 22 shows a partial overhead plan view of a buoyancy tube in accordance with an embodiment of the invention;Fig . 23A shows a partial cross-sectional view along line A-A of the buoyancy tube of Fig . 22 prior to inflation;Fig . 23B shows a partial cross-sectional view along line A-A of the buoyancy tube of Fig . 22 after inflation;Fig . 24 shows an overhead plan view of a liferaft according to an embodiment of the invention;Fig . 25 shows a cross-section taken along line A-A of Fig . 24 ;Fig . 26 shows a cross-sectional view of a device for making a liferaft in accordance with the embodiment of Fig . 24 ; andFig . 27 shows perspective views of the layers of the liferaft and the manufacturing process ;Fig . 28 is a perspective view of a survival craft showing a hull a the pod attached thereto;Fig . 29 is a perspective view of the survival craft of Fig . 28 illustrating the canopy support structure carried by the hull;Fig . 30 is a cross-sectional view of the survival craft of Fig . 28 focusing on the rear of the craft;Fig . 31 is a similar view to Fig; 30 showing an alternative arrangement of the modular floor;Fig . 32 is a perspective view showing a spine and stiffener structure along the floor of the craft;Fig . 33 illustrates the canopy support structure supporting a flexible material covering the craft;09866 17Fig . 34 is a front elevational view from the front of the craft showing the sleeves attached to the underside of the hull;Fig . 35 is front elevational view of the pod front the front, showing the power units in a lowered position and a raised position;Fig . 36 shows another view of the pod support an inflation tray;Fig . 37 shows a third perspective view of the pod carrying an inflation tray and an uninflated survival craft;Fig . 38 is a similar view to Fig . 34 showing inflation cylinders arranged on the underside of the hull;Fig . 39 is another view of Fig . 38 showing the inflation cylinders along the centreline and the pod attached to the craft;Fig . 40 shows the cylinders of Figs . 38 and 39 enclosed by a cover;Fig . 41 shows a side view of an inflated survival craft with pod attached thereto;Fig . 42 is a perspective view of an alternative survival craft;Fig . 43 is a perspective view of the alternate survival craft illustrating the canopy support structure carried by the hull;Fig . 44 is a cross-sectional view of the survival craft focusing on the rear of the craft;Fig . 45 is a similar view to Fig . 44 showing a modular arrangement of the vertical inflatable panels ;Fig . 46 is a perspective view of the hull including an opening and a door arrangement to assist in boarding persons from the water into the craft, along with the retrieval of casualties from the water;Figs . 47 and 48 are, respectively, a side elevation and an overhead plan view of a craft in accordance with another embodiment of the invention;Fig . 49 is a perspective view of a modified survival craft showing the hull;09866 18Fig . 50 is a partial perspective view of the stern of a modified survival craft;Fig . 51 is a perspective view of a modified survival craft showing underside of the hull;Fig . 52 shows schematically two joined drop thread panels ;Fig . 53 shows a side elevation of the bow of a vessel where the butt ends of the drop stitch panels (that would otherwise extend perpendicularly to the direction of travel of the craft in water) are skinned to form a smooth surface;Fig . 54 is a partial perspective view of the stern of a modified survival craft showing the structure of the inflatable wall;Fig . 55 shows a side elevational view of a slide extending between a ship and a lifeboat;Fig . 56A shows a perspective view of a slide of Fig .55 ;Fig . 56B shows an overhead plan view of the slide of Fig . 56A;Fig . 56C shows a side elevational view of the slide of Fig . 56A;Fig . 56D shows a front elevational view of the slide of Fig . 56A (viewed from the exit, life raft end) ;Fig . 56E shows a rear elevational view of the slide of Fig . 56A (viewed from the entry, ship end) ;Fig . 56F shows a plan view of the underside of the slide of Fig . 56A;Fig . 57A shows a close-up view of one arrangement of the upper beam of the slide;Fig . 57B shows an alternative arrangement of the upper beam of the slide;Fig . 57C shows an arrangement of a lateral beam of the slide;Fig . 57D shows a first arrangement of material strips for connecting the tubes of a beam of the slide;Fig . 57E shows a second arrangement of material strips for connecting the tubes of a beam of the slide;09866 19Fig . 58A shows a side elevational view of an inflatable side panel of the slide ;Fig . 58B shows a perspective view of the side panel of Fig . 58A;Fig . 58C shows a front elevational view of the side panel of Fig . 58A;Fig . 59 shows a perspective view of a drop stitch material ;Fig . 60A shows a side elevational view of a floor panel of the slide ;Fig . 60B shows a perspective view of a floor panel of Fig . 60A;Fig . 60C shows a front elevational view of the floor panel of Fig . 60A;Fig . 61 shows a transverse cross-sectional view of one of the tubes used in upper or lateral beams of the slide ;Fig . 62A shows a perspective view of a braid material used in the tubes of the beams of the slide ;Fig . 62B shows a schematic view of the arrangement of a longitudinal element of the braid material ;Fig . 63A shows a perspective view of a rigid end cap assembly provided at each end of the tubes ;Fig . 63B shows the end cap assembly of Fig . 9A in exploded form;Fig . 63C shows a rear elevational view of the end cap assembly of Fig . 63A;Fig . 63D shows a side elevational view of the end cap assembly of Fig . 63A;Fig . 63E shows a cross-section taken along the line A-A of Fig . 63C;Fig . 63 F shows an enlarged view of the encircled portion B of Fig . 63E ;Fig . 64A shows a perspective view of the end plate of the end cap assembly of Fig . 63A;Fig . 64B shows rear elevational view of the end plate of Fig . 64A;Fig . 64C shows a side elevational view of the end09866 20plate of Fig . 64A;Fig . 64D shows a cross-section taken along the line A-A of Fig . 10B;Fig . 64E shows an enlarged view of the encircled portion B of Fig . 64D .Fig . 65A shows a perspective view of the outer spacer of the end cap assembly of Fig . 63A;Fig . 65B shows a rear elevational view of the outer spacer of Fig . 65A;Fig . 65C shows a side elevational view of the outer spacer of Fig . 65A;Fig . 65D shows a cross-section taken along the line A-A of Fig . 65B;Fig . 65E shows an enlarged view of the portion B of Fig . 65D;Fig . 66A shows a perspective view of the clamp ring of the end cap assembly of Fig . 63A;Fig . 66B shows an elevational view of the clamp ring of Fig . 66A;Fig . 66C shows a cross-section taken along the lines A-A of Fig . 66B .Fig . 67A shows a perspective view of the inner spacer of the end cap of Fig . 63A;Fig . 67B shows a front elevational view of the inner spacer of Fig . 67A;Fig . 67C shows a side elevational view of the inner spacer of Fig . 67 ;Fig . 67D shows a cross-section taken along the line A-A of Fig . 67B;Fig . 67E shows an enlarged view of the encircled portion B of Fig . 67D;Fig . 68 is a cross-sectional view of the inflation valve mounting;Fig . 69 shows a close-up view of an alternative arrangement of the upper beam of the slide ;Fig . 70 shows a perspective view of a vessel with an escape system including a slide for evacuating passengers to09866 21crafts ;Fig . 71 shows a close up perspective view of a slide having two side-by-side slide assemblies providing helical escape paths for passengers ;Fig . 72 shows a perspective view of a first spacing arrangement for the helix turns of a slide assembly;Fig . 73 shows a perspective view of a second spacing arrangement for the helix turns of a slide assembly;Figs . 74A and 74B show a simplified side elevational view of a third spacing arrangement for the helix turns of a slide assembly;Fig . 74C shows a simplified perspective view of the third spacing arrangement for the helix turns of a slide assembly;Figs . 75A and 75B show a simplified side elevational view of a fourth spacing arrangement for the helix turns of a slide assembly;Fig . 75C shows a simplified perspective view of the fourth spacing arrangement for the helix turns of a slide assembly;Fig . 76 shows a perspective view of a fifth spacing arrangement for the helix turns of a slide assembly;Fig . 77A shows a simplified side elevational view of the fifth spacing arrangement for the helix turns of a slide assembly in an expanded state;Fig . 77B shows a partial view of the fifth spacing arrangement for the helix turns of a slide assembly in an expanded state;Fig . 78A shows a simplified side elevational view of the fifth spacing arrangement for the helix turns of a slide assembly in a contracted state;Fig . 78B shows a partial view of the fifth spacing arrangement for the helix turns of a slide assembly in a contracted state;Fig . 79 shows a close up perspective view of a slide having one slide assembly providing helical escape paths for passengers having twin tracks for passengers ;09866 22Fig . 80 shows a close up perspective view of a slide having one slide assembly providing helical escape paths for passengers but ending in an inclined linear slide section;Fig . 81 shows a close up perspective view of a bowsing line fixture point;Fig . 82A shows a perspective view of an example arrangement having two side-by-side slide assemblies ;Fig . 82B shows a side elevational view of an example arrangement having two side-by-side slide assemblies of Fig .82 A;Fig . 83A shows a partial side elevational view of an alternative helical path arrangement;Fig . 83B shows a partial perspective view of the alternative helical path arrangement of Fig . 83A;Fig . 83C shows a partial enlarged perspective view of the alternative helical path arrangement of Fig . 83A;Fig . 84A shows a partial side elevational view of another alternative helical path arrangement;Fig . 84B shows a partial perspective view of the alternative helical path arrangement of Fig . 84A;Fig . 85A shows a partial side elevational view of yet another alternative helical path arrangement;Fig . 85B shows a partial perspective view of the alternative helical path arrangement of Fig . 85A;Fig . 86A shows an overhead plan view of a platform for attachment to the slides and crafts ;Fig . 86B shows a front elevational view of the platform of Fig . 86A; andFig . 86C shows a side elevational view of the platform of Fig . 86A.

[0031] In the drawings , like elements are generally designated with the same reference signs .DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0032] A rescue appliance according to various embodiments has at least one sheet of flexible material that includes09866 23graphene . The sheet of flexible material may also include a flexible polymer - such as polyurethane, PU, and / or thermoplastic polyurethane, TPU.

[0033] A rescue appliance according to various embodiments has at least one piece of material that includes graphene .

[0034] The rescue appliance in some embodiments is inflatable . The rescue appliance may be an inflatable survival craft, such as a liferaft (e . g . a single seat liferaft or multiple seat liferaft ) , a lifeboat or a marine escape system, MES . The rescue appliance may be an escape slide or escape chute, such as an inflatable escape slide or escape chute . The rescue device is not worn by the user when inflated and is not a garment, a lifejacket or a life preserver unit, LPU .

[0035] The sheet of flexible material may be formed by dispersing graphene in the form of Graphene Nano Platelets (GNPs ) into PU / TPU at the melt stage . The sheet of material may have a thickness of between 100 and 150pm. The sheet of material may include between 1 and 10% graphene by weight, preferably 1.5% graphene by weight .

[0036] The sheet of material may be formed from fibres , threads or yarn that contains graphene . The fibres, threads or yarn may be woven together to form the sheet of material . The fibres, threads or yarn may also include polyurethane, PU, and / or thermoplastic polyurethane, TPU . Graphene may be dispersed into PU / TPU at the melt stage in the form of GNPs to from the fibres , threads or yarn .

[0037] Embodiments of the invention may provide escape slides and inflatable survival craft using flexible polymer films (e . g . PU or TPU) incorporating graphene to create waterproof and / or gas (e . g . air) -holding materials . Such incorporation of graphene into the PU / TPU film may increase its strength and flame retardancy, and may contribute to the overall performance of the equipment .09866 24

[0038] The graphene-including sheet of material may be fluid impermeable . This allows the sheet of material to form a pressure-holding inflatable item and / or to form a waterproof garment / item.

[0039] Pressure-holding inflatable items are often referred to as "bladders" . Inflatable bladders can be inflated orally by mouth or from a compressed gas source such as a cylinder of compressed CO2 .

[0040] Embodiments of the invention may provide escape slides and inflatable survival craft using one of more sheets of material . The sheet of material may be formed from fibres , threads or yarn that contains graphene . The fibres, threads or yarn may be woven together to form the sheet of material . The fibres, threads or yarn may include PU or TPU, and incorporate graphene . Such incorporation of graphene into the fibres , threads or yarn of the sheet of material may increase the strength of the sheet and flame retardancy, and contributes to the overall performance of the equipment .

[0041] Inflatable survival craft and escape slides may include inflatable structures . An inflatable survival craft and an escape slide may be sealed against water ingress .

[0042] A graphene-including flexible sheet of material may be incorporated into an escape slide and inflatable survival craft in a number of ways . By way of example, such an inflatable device (or part thereof ) 10 is shown in Fig . 1. The device 10 includes two pieces of flexible material 12A and 12B . The pieces of flexible material 12A and 12B are connected to each other along opposite sides by a first seam 14A and a second seam 14B . The pieces of flexible material 12A and 12B form an inflatable bladder 16. The inflatable bladder 16 may be inflated, for example, by a gas inflation system 18 or by an oral inflation device 20. The inflatable bladder 16 may be circular in crosssection but may also have other cross-sectional shapes , such as elliptical .09866 25

[0043] Figs . 2 to 7 show different ways in which a grapheneincluding flexible sheet of material may be incorporated into the inflatable device 10. Figs . 2 to 7 are partial views at any point around the circumference of the inflatable device 10 of Fig . 1 - e . g . at points A, B or C .

[0044] In Fig . 2 each of the two pieces of flexible material 12A and 12B may be formed by a graphene-including flexible sheet of material 22 that is coated or laminated onto an inner face 24 of a supporting substrate 26 such as a woven textile (e . g . coated or laminated onto the entire inner face 24 of the supporting substrate 26 ) . The flexible sheet of material 22 creates a barrier to gas when the bladder 16 is filled and pressurised with gas . The outer textile supporting substrate 26 provides strength, abrasion resistance and limits the elasticity of the bladder 16 to create a dimensionally stable structure . The supporting substrate 26 may be a non-graphene sheet of material (i . e . a sheet of material that does not contain graphene) .

[0045] The supporting substrate 26 of Fig . 2 may be a graphene-containing sheet of material . The supporting substrate 26 may be formed by weaving together fibres , threads or yarn that contain graphene . In an arrangement where the supporting substrate 26 of Fig . 2 is a graphene-containing sheet of material, the flexible sheet of material 22 may be formed by a graphene-including flexible sheet or may be formed by a non-graphene sheet ( i . e . a sheet of material that does not contain graphene) .

[0046] In Fig . 3 each of the two pieces of flexible material 12A and 12B may be formed by a graphene-including flexible sheet of material 22 that is coated or laminated onto an outer face 28 of an inner supporting substrate 26A, such as a woven textile (e . g . coated or laminated onto the entire outer face 28 of the inner supporting substrate 26A) . The flexible sheet of material 22 creates a barrier to gas when the bladder 16 is filled and09866 26pressurised with gas . The inner supporting substrate 26A provides strength and limits the elasticity of the bladder 16 to create a dimensionally stable structure . The inner supporting substrate 26A may be a non-graphene sheet of material (i . e . a sheet of material that does not contain graphene) . The flexible sheet of material 22 may protect the inner supporting substrate 26A from damage . The flexible sheet of material 22 may provide an outer surface onto which other items formed of PU / TPU may be readily attached - e . g . by high-frequency welding .

[0047] The inner supporting substrate 26A of Fig . 3 may be a graphene-containing sheet of material . The inner supporting substrate 26A may be formed by weaving together fibres, threads or yarn that contain graphene . In an arrangement where the inner supporting substrate 26A of Fig . 3 is a graphene-containing sheet of material, the flexible sheet of material 22 may be formed by a graphene-including flexible sheet or may be formed by a non-graphene sheet (i . e . a sheet of material that does not contain graphene) .

[0048] In Fig . 4 each of the two pieces of flexible material 12A and 12B may be formed by a graphene-including flexible sheet of material 22 that is coated or laminated onto an inner face 24 of an outer supporting substrate 26B ( such as a woven textile ) and coated or laminated onto an outer face 28 of an inner supporting substrate 26A ( such as a woven textile ) . For example, the flexible sheet of material 22 is coated or laminated onto the entire inner face 24 of an outer supporting substrate 26B and coated or laminated onto the entire outer face 28 of an inner supporting substrate 26A. The flexible sheet of material 22 is sandwiched between an inner and outer supporting substrates 26A, 26B . The flexible sheet of material 22 creates a barrier to gas when the bladder 16 is filled and pressurised with gas . The inner supporting substrate 26A provides strength and limits the elasticity of the bladder 16 to create a dimensionally stable structure . The outer supporting substrate 26B provides strength, abrasion resistance and limits the elasticity of the bladder 16 to create a dimensionally stable09866 27structure . Such an arrangement may be used, for example, as part of a large liferaft, inflatable slide or boats, etc (e . g . the survival craft as described in W02017 / 140890 ) . The inner supporting substrate 26A and / or the outer supporting substrate 26B may be a non-graphene sheet of material (i . e . a sheet of material that does not contain graphene) .

[0049] The inner supporting substrate 26A of Fig . 4 may be a graphene-containing sheet of material . The inner supporting substrate 26A may be formed by weaving together fibres, threads or yarn that contain graphene . Alternatively, or additionally, outer supporting substrate 26B of Fig . 4 may be a graphenecontaining sheet of material . The outer supporting substrate 26B may be formed by weaving together fibres , threads or yarn that contain graphene . In an arrangement where the inner supporting substrate 26A and / or the outer supporting substrate 26B of Fig .4 is a graphene-containing sheet of material, the flexible sheet of material 22 may be formed by a graphene-including flexible sheet or may be formed by a non-graphene sheet (i . e . a sheet of material that does not contain graphene) .

[0050] In Fig . 5 each of the two pieces of flexible material 12A and 12B may be formed by an inner graphene-including flexible sheet of material 22 and an outer sheet 30 such as a woven textile (similar to the supporting substrate 26 of Fig . 2 ) . However, in this embodiment, the flexible sheet of material 22 is not attached to outer sheet 30 but is unsupported. The flexible sheet of material 22 may be within but completely separate from the outer sheet 30. The flexible sheet of material 22 may be connected to the outer sheet 30 at one or more points which form a minority of the surface area of the outer sheet 30. The outer sheet 30 forms a non-elastic outer "restrainer" which has smaller dimensions than the potential dimensions of the chamber formed by the flexible sheet of material 22 when expanded . The non-elastic outer "restrainer" retains its dimensional stability so that it does not expand when the chamber formed by the graphene-including flexible sheet of material 2209866 28is inflated . Such an arrangement may be used, for example, as part of a small liferaft that needs to be very compact when deflated and packed . The outer sheet 30 may be a non-graphene sheet of material ( i . e . a sheet of material that does not contain graphene) .

[0051] The outer sheet 30 of Fig . 5 may be a graphenecontaining sheet of material . The outer sheet 30 may be formed by weaving together fibres, threads or yarn that contain graphene . In an arrangement where the outer sheet 30 of Fig . 5 is a graphene-containing sheet of material, the flexible sheet of material 22 may be formed by a graphene-including flexible sheet or may be formed by a non-graphene sheet (i . e . a sheet of material that does not contain graphene) .

[0052] In Fig . 5 the chamber formed by the flexible sheet of material 22 may be made to be oversize or made from a material that can stretch and so that any join in the chamber (e . g . welds or seams between multiple flexible sheets of graphene-containing material ) never comes under tension . Although the chamber may be of generally the same shape as the non-elastic outer "restrainer", the chamber may be of generally larger size . The chamber may be made of a sufficiently large size so that, when inflated within the non-elastic outer "restrainer", the chamber fills the internal volume of the non-elastic outer "restrainer" without any stretching of the chamber occurring, and the tension is taken up by the non-elastic outer "restrainer" . If the chamber is made oversized, the chamber may be made of an inextensible and / or inelastic material . It is advantageous for the tension to be taken up by the non-elastic outer "restrainer", as it may generally be stronger than the chamber .

[0053] In Fig . 6 each of the two pieces of flexible material 12A and 12B is formed by a graphene-including flexible sheet of material 22. In this embodiment graphene-including flexible sheet of material 22 is not supported in any way and forms a single layer pressurised bladder (no sheet such as a woven textile or the like is provided) . The graphene-including09866 29flexible sheet of material 22 may provide an outer surface onto which other items formed of PU / TPU may be readily attached -e . g . by high-frequency welding .

[0054] In Fig . 7 each of the two pieces of flexible material 12A and 12B may be formed by two graphene-including flexible sheets of material 22A and 22B . Inner flexible sheet of material 22A is coated or laminated onto an inner face 24 (e . g . onto the entire inner face 24 ) of a supporting substrate 26 ( such as a woven textile) . Outer flexible sheet of material 22B is coated or laminated onto an outer face 28 (e . g . onto the entire outer face 28 ) of the supporting substrate 26. The supporting substrate 26 is "sandwiched" between the inner and outer flexible sheets of material 22A and 22B . The flexible sheets of material 22A and 22B create barriers to gas when the bladder 16 is filled and pressurised with gas . The supporting substrate 26 provides strength and limits the elasticity of the bladder 16 to create a dimensionally stable structure . The flexible sheets of material 22A and 22B provide redundancy, so that the gastight nature of the bladder may be maintained when one of the flexible sheets of material 22A and 22B is damaged. The supporting substrate 26 may be a non-graphene sheet of material ( i . e . a sheet of material that does not contain graphene ) . The outer flexible sheet of material 22B may protect the supporting substrate 26 from damage . The outer flexible sheet of material 22B may provide an outer surface onto which other items formed of PU / TPU may be readily attached - e . g . by high-frequency welding .

[0055] The supporting substrate 26 of Fig . 7 may be a graphene-containing sheet of material . The supporting substrate 26 may be formed by weaving together fibres , threads or yarn that contain graphene . In an arrangement where the supporting substrate 26 of Fig . 7 is a graphene-containing sheet of material, the flexible sheets of material 22A and 22B may be formed by a graphene-including flexible sheet or may be formed by a non-graphene sheet (i . e . a sheet of material that does not contain graphene) .09866 30

[0056] Although in the arrangements described above, each of the two pieces of flexible material 12A and 12B may be formed by a graphene-including flexible sheet of material 22 , it should be understood that only one of the pieces of flexible material 12A and 12B may formed by a graphene-including flexible sheet of material 22 (the other piece of flexible material may be gas-impermeable but not include graphene ) .

[0057] An inflatable survival craft and escape slide may use a graphene-including flexible sheet of material 22 to create a barrier to water or other liquids when used for example in immersion survival suits . The graphene-including flexible sheet of material can be incorporated into the equipment structure in one of the six ways above in Figs . 2 to 7 .

[0058] An inflatable survival craft and escape slide may use a graphene-including flexible sheet of woven material 26, 26A, 26B to improve strength, flame retardancy, and / or abrasionresistance when used for example in immersion survival suits . The graphene-including flexible woven sheet of material can be incorporated into the equipment structure in one of the six ways above in Figs . 2 to 7 .

[0059] The graphene-including flexible sheet of material 22 can be made MVP (Moisture Vapour Permeable ) , termed "breathable", if required . For example, the graphene-including flexible sheet of material 22 may have a molecular structure that allows moisture vapour to pass through but that does not allow water to pass through .

[0060] Typically, such inflatable survival craft and escape slides are formed from a plurality of pieces of flexible material, such as the pieces of material 12A and 12B of the inflatable survival craft or escape slide 10 described above . The pieces of material may include (or consist of ) grapheneincluding flexible sheets of material, such as the grapheneincluding flexible sheet of material 22 and / or flexible sheet09866 31of woven material 26, 26A, 26B of the inflatable survival craft or escape slide described above . Edges of one or more pieces of material may be connected together to form an inflatable survival craft or escape slide .

[0061] Pieces of material 12A and 12B may be sealed at their seams ( such as the seams 14A and 14B described above) in various ways . Pieces of material may be sealed at their seams by being glued or welded (e . g . welded together by high frequency welding) . The seams can be "in shear", peel or peel and shear, as shown in Figs . 8 , 9 and 10, respectively.

[0062] By way of example, Fig . 8 shows a partial view of the inflatable survival craft or escape slide 10 described above in the region of the seam 14B . The two generally semicircular ( in cross-section) pieces of material 12A and 12B are brought together, with edges 40A and 40B of the pieces of material 12A and 12B extending radially outwardly with respect to the generally circular (in cross-section) inflated body of the inflatable survival craft and escape slide 10 so that they lie adjacent to one another and in parallel . The seam 14B is formed by welding or gluing (or otherwise fixing together) the edges 40A and 40B of the pieces of material 12A and 12B . The weld (or adhesive) between the edges 40A and 40B of the pieces of material 12A and 12B is designated 42. The seam 14A may be formed in the same way. Such seams as shown in Fig . 8 can be referred to as "in peel" .

[0063] By way of example, Fig . 9 shows a partial view of the inflatable survival craft or escape slide 10 described above in the region of the seam 14B . The two generally semicircular ( in cross-section) pieces of material 12A and 12B are brought together, with edges 40A and 40B of the pieces of material 12A and 12B overlapping . The upper piece of material 12A has an outer surface 43A and an inner surface 43B . The lower piece of material 12B has an outer surface 45A and an inner surface 45B . The pieces of material 12A and 12B are connected at an edge region 40A and 40B of each of the pieces of material 12A and 12B09866 32so that the distal inner surface of one of the pieces overlaps the distal outer surface of the other one of the pieces . In the arrangement shown the distal outer surface 43A of the upper piece of material 12A is positioned to face the distal portion of the inner surface 45B of the lower piece of material 12B .

[0064] The seam 14B is formed by welding or gluing (or otherwise fixing together) the edges 40A and 40B of the pieces of material 12A and 12B . The weld (or adhesive) between the edges 40A and 40B of the pieces of material 12A and 12B is designated 42. The seam 14A may be formed in the same way. Such seams as shown in Fig . 9 can be referred to as "in shear" .

[0065] By way of example, Fig . 10 shows a partial view of the inflatable survival craft or escape slide 10 described above in the region of the seam 14B . The two generally semicircular ( in cross-section) pieces of material 12A and 12B are brought together, with edges 40A and 40B of the pieces of material 12A and 12B extending radially inwardly with respect to the generally circular (in cross-section) imflated body of the inflatable lif survival craft eraft or escape slide 10 so that they lie adjacent to one another and in parallel . The seam 14B is formed by welding or gluing (or otherwise fixing together) the edges 40A and 40B of the pieces of material 12A and 12B, and by welding or gluing (or otherwise fixing) a strip of material 47 over the outer surface of the inflatable survival craft or escape slide 10 in the region where the pieces of material 12A and 12B meet . The weld (or adhesive ) between the edges 40A and 40B of the pieces of material 12A and 12B, and between the strip of material 47 over the outer surface of the inflatable survival craft or escape slide 10 in the region where the pieces of material 12A and 12B meet, is designated 42. The seam 14A may be formed in the same way. Such seams as shown in Fig . 10 can be referred to as "in peel" and "in shear" .

[0066] Conventionally, inflatable liferafts, inflatable boats and inflatable MESs (marine escape systems ) are manufactured from a material which is the supporting textile09866 33such as nylon of polyester coated with a TPU layer which provides the seal against internal air pressure and external water pressure .

[0067] As shown in Figure 11 , the structure made be made using an inflatable tubular system or can be made also in combination using an inflatable "drop thread" or "spacer" material which consists of two layers of textile spaced apart by threads which keep the internal space between the layers uniform. The external faces of the textiles and the side walls are coated with a TPU.

[0068] Referring first to Fig . 11, a survival craft comprises a hull 310 and a superstructure 311 carried on the hull 310. The structure may be as described in WO-A-2015 / 107019 .

[0069] The hull 310 is formed by port and starboard inflatable tubes 312 , 313 that extend along the gunwales of the hull 310 and extend upwardly while converging to meet at a shaped bow 314 . At the stern 315 , the tubes 312 , 313 are spaced by a stern member 316. A floor 317 extends between the gunwale tubes 312 , 313 and the stern member 316 and is formed by spaced sheets of air-impervious fabric forming an inflatable chamber . The spaced sheets may be formed by a drop thread material . In addition two longitudinal inflatable floor tubes 342 , 343 may extend from the stern 215 to the bow 314 . These tubes 342 , 343 may also be formed of a drop thread material to give these tubes 342 , 343 increased rigidity.

[0070] The floor 317 carries a powered propulsion system for the survival craft . This may be an electrical system with a generator (not shown) , which may be a diesel power unit, mounted within the survival craft and electrical connections to fore and aft thrusters located beneath the floor 317 .

[0071] The superstructure 311 is formed by a roof and port and starboard sidewalls . Each sidewall is formed by an upper09866 34elongate inflatable tube 325 , 326 extending along the length of the hull 310 generally parallel to the associated gunwale tubes 312 , 313 with the upper tubes converging and meeting above the bow 314 . At the stern 315 , the upper tubes 325 , 326 are separated by an upper stern spacer 327 . The upper tubes 325 , 326 are spaced by lateral inflatable spacer tubes 344 at spaced intervals along the upper tubes 325 , 326. A sheet 328 of flexible water-impervious material (only half of which is shown, so as not to obscure the internal parts of the survival craft) extends between the upper tubes 325 , 326 and forms a roof . Again, any or all of the tubes may be made from a drop thread material .

[0072] The side walls (only one of which, 323, can be seen) are formed by inflatable side spacer tubes 329a - 329i that extend between the gunwale tubes 312 , 313 and the associated upper tubes 325 , 326. The side spacer tubes 329a - 329i are arranged in a zigzag configuration along the gunwale tubes 312 , 313 with successive side spacer tubes 329a - 329i being inclined in respective opposite directions relative to the gunwale tubes 312 , 313. In addition, two inflatable stern tubes 330a, 330b extend in a V-conf iguration between the stern member 316 and the upper stern spacer 327 . The inflatable side spacer tubes 329a -329i may be formed by consecutive sections of a single tube or by separate tubes . The tubes 329a - 329i may be formed of a drop thread material . Sheets of flexible water-impervious material (not shown, so as not to obscure the internal parts of the survival craft ) cover the sides of the superstructure 311 and the end of the superstructure 311 and are provided with door and window openings .

[0073] In this way, the superstructure 311 forms a truss structure carried by the hull 310 that provides the hull 310 with increased longitudinal rigidity, resisting any tendency of the hull 310 to bow. In addition, it forms a protective shelter for occupants of the survival craft .09866 35

[0074] In use, the survival craft is deflated and packed in a container (not shown) that may be rigid or flexible . The container includes an inflation system (not shown) of any suitable known type . The container is carried by a deployment system that is for mounting on a marine structure such as a rig or a ship . The system may carry more than one such container .

[0075] When required for use, the system releases the container into the water . On reaching the water, the inflation system commences inflation of the survival craft and the container opens, so allowing the survival craft to complete inflation and deploy. People from the marine structure can then enter the survival craft .

[0076] As mentioned above, conventionally, inflatable liferafts, inflatable boats and inflatable MESs are manufactured from a material which is the supporting textile such as nylon of polyester coated with a TPU layer which provides the seal against internal air pressure and external water pressure . Such a material may be used for the floor, panels and tubes .

[0077] The systems using these structures rely on the TPU coating to be extremely strong and robust as this not only provides the air pressure retention but also must be sufficiently strong and durable to withstand the possible damage caused during boarding and use where multiple impacts and scraping of the structure may occur . Additionally, the material has to withstand extended sea trials , UV and saltwater exposure and hot and cold temperature extremes .

[0078] According to this embodiment of the invention, the inflatable liferafts, inflatable boats and / or inflatable MESs include at least one sheet of flexible material that includes graphene, of the type / composition as discussed above . The sheet of flexible material that includes graphene may be a woven sheet formed of graphene-including fibres, threads or yarn. The sheet of flexible material may also include a flexible polymer such09866 36as PU and / or TPU, as discussed above . Such a material may be used for the floor, panels and tubes .

[0079] Although this embodiment has been described in relation to a craft as shown in Fig . 11 , it should be appreciated that least one sheet of flexible material that includes graphene may be advantageously incorporated into many other forms of craft .

[0080] Conventional inflatable liferafts, inflatable boats and inflatable MESs made from TPU without graphene reinforcement may fail earlier in their lifetime than those with a grapheneincluding sheet .

[0081] The sheet of flexible material that includes graphene may be on the outside face of the structures of the survival craft, as in Figs . 3 and 8 , and sealed as in Fig . 10. Such a sheet of material may be air impermeable and / or waterproof .

[0082] The sheet of flexible material that includes graphene may be formed of graphene-including fibres, threads or yarn may be an internal part of the structures of the survival craft, as in Figs . 3 , 7 and 8.SINGLE SEAT LIFERAFTS

[0083] These liferafts are designed for single person occupancy and examples are a liferaft carried in the survival pack that is typically located under the ej ector seat of a combat aircraft . The packed size is very important as it dictates what other equipment can be carried in the survival pack - for example more survival aids or a weapon. The weight is also critical as the ejector seat when being ejected from the aircraft is weight critical with regards to the ej ector "guns" . Another example is the single seat liferaft carried on a Submarine Escape Suit . Here the liferaft is packed into a pack that is mounted onto the Submarine Escape Suit which is donned by a person prior the entering the Escape Chamber . The smaller and lighter the packed liferaft then the easier it is to escape through the confined09866 37space of the Escape Chamber . Another type of Single Seat Liferaft is a Leg Mount Liferaft that is worn by aircrew typically in a helicopter where rapid egress without restriction or obstruction is vital, as described for example in WO 2025 / 202207 Al (our ref : 09330 ) .

[0084] Single seat or multi-seater inflatable life rafts are important safety equipment . The following discussion in this section relates mainly to single seat inflatable life rafts, although the principles are also applicable to multi-seater inflatable life rafts and other survival equipment .

[0085] There are three main types of single seat life raft and for all these applications the reduction of weight and bulk when packed is very important . The life rafts are inflated by activating the release of gas from a compressed gas cylinder attached to the life raft but can be orally topped up as well . The life rafts can have either a single layer canopy or floor or the floor and / or canopy can be of an inflatable type to assist in thermal protection and which can be inflated orally through an oral inflation valve .

[0086] Single seat life rafts can be kept ready for deployment in various ways, such as :• The single seat life raft that is stowed on the underside of an ej ection seat in a fast j et aircraft . Here packed weight and bulk is very critical as the size has to fit in limited space under the seat and weight is critical as it affects the ej ection sequence of the seat . When the airman ejects from the aircraft in the seat, the life raft remains attached to the airman and when he lands on water the life raft can be inflated and the survivor climbs into it . • The single seat life raft that is worn folded down into a small pack which is attached to the survival suit on the hip of a submariner (see EP2066557 for "Submarine Escape Suit Assemblies" in the name of Survitec Group Ltd) , when used as part of the SEIE (Submarine Escape Immersion Equipment ) . Low weight and small packed size are important09866 38as the escaping submariner has to fit into the confined space of an escape chamber . After leaving the submarine escape chamber and when the survivor surfaces he can then inflate the life raft and climb into it .• The single seat life raft that is worn as a back-pack by aircrew and other such persons, that, following the escape from a ditched aircraft, the survivor can then inflate the life raft and climb into it . It is important that the life raft back-pack is of low bulk otherwise it would hinder the entry and escape from the aircraft .

[0087] Figures 12A-B and 13A-B show two typical liferafts . The liferafts include a buoyancy tube 401, a floor 402 (which can be single layer or two layer and inflatable) and a canopy 403 (which can be single layer or two layer and inflatable) . The buoyancy tube 401, floor 402 and / or canopy 403 may include at least one sheet of material that includes graphene .

[0088] As shown in Figures 14A, 14B, and 14C, inflatable lifesaving equipment, such as a liferaft or lifejacket, may use a single layer of material 420 that consists of a textile supporting sheet 422 (for example nylon or polyester) coated or laminated on the inside with a sheet 424 of flexible, air impermeable polymer such as neoprene or polyurethane . The coated two-layer material is typically stiff because of the relative thickness of the material and it is typically joined at its edges by welding or gluing the material together to form a seam 426. The resistance of the bladder to bursting from over pressure is dependent on the strength of the weld in peel and the strength of the welded or glued seam 426 is only as strong as the bonding of the polymer layer 424 to the supporting textile 422 . Furthermore, when the outer textile 422 is coated with the polymer 424 its tear strength is greatly reduced and therefore a stronger and thicker textile may need to be used . The use of graphene in the textile supporting sheet 422 may increase its strength, and so its thickness (for a given strength) may be reduced. The use of graphene in the sheet 424 of flexible, air09866 39impermeable material may increase its strength, and so its thickness ( for a given strength) may be reduced .

[0089] A polyurethane ( PU) film 432 can be attached to a textile substrate 434 as shown in Figure 15. A welded seam 436 is also stitched 438. The film 432 and or the textile substrate 434 may include graphene .

[0090] Typically, life rafts are constructed from a number of panels which are joined together by welding or gluing or a combination of these . Figures 16A and 16B show a typical single seater raft . The buoyancy chamber 431 is typically made up from textile substrate coated with a thermoplastic polymer (such as polyurethane) to make it air tight . The textile substrate coated with the thermoplastic polymer ( such as polyurethane ) may include graphene . A floor 435 is attached to the buoyancy chamber 431 and a canopy 433 is attached to the upper part of the buoyancy chamber 431 tube . Both the floor 435 and the canopy 433 are typically inflatable to give additional insulation to the occupant . Assembling the life raft requires multiple seams to be sealed denoted by "X" Figures 16A and 16B . The floor 435 and the canopy 433 may include graphene .

[0091] Instead of using a single layer of material that consists of a textile supporting sheet (for example nylon or polyester containing graphene) coated or laminated on the inside with a sheet of flexible air impermeable polymer such as neoprene or polyurethane containing graphene as described above with reference to Figures 14A, 14B, and 14C, two separate layers may be provided (i . e . a textile outer layer and the separate inner polymer layer) .

[0092] The use of two separate layers to make an inflatable structure, results in a bladder construction that is lighter, more compact when packed and stronger . The textile outer layer and / or the separate inner polymer layer may include graphene .

[0093] As shown in Figures 17A-C, a textile outer layer restrainer09866 40452 ( for example nylon or polyester including graphene ) may be formed of two sheets of material that are stitched together in a similar manner to that describe in relation to Figure 9. An upper sheet of material 453A has an outer surface 457A and an inner surface 457B . The lower sheet of material 453B has an outer surface 458A and an inner surface 458B . The sheets 453A and 453B are connected at an edge region 459 of each of the sheets so that the distal inner surface of one of the sheets overlaps the distal outer surface of the other one of the sheets , the distal surfaces being stitched together, as indicated at 461. In the arrangement shown the distal inner surface 457B of the upper layer 457A is positioned to face the distal portion of the outer surface of the lower layer 453B, these layers being held in contact by the stitching 461.

[0094] The bladder 409 is formed by two sheets 454 of flexible air impermeable material . The two sheets are j oined by a weld .

[0095] In this arrangement the outer textile 452 can be stitched ( in sheer) around its edge and this creates a much stronger seam than the welding . The bladder 409 is made to be oversize or made from a polymer (e . g . including graphene) that can stretch and so the welded edge 456 never comes under tension . Although the bladder 409 may be of generally the same shape as the outer textile 452 , the bladder 409 may be of generally larger size . The bladder 409 may be made of a sufficiently large size so that, when inflated within the outer textile 452 , the bladder 9 fills the internal volume of the outer textile 452 without any stretching of the bladder 409 occurring, and the tension is taken up by the outer textile 452. If the bladder 409 is made oversized, the bladder 409 may be made of an inextensible and / or inelastic material . It is advantageous for the tension to be taken up by the outer textile 452 , as it is stronger than the bladder 409.

[0096] The outer textile layer 452 may made from a lightweight "ripstop" material and is coated with a lubricant such as silicon. The outer textile layer 452 may made from a lightweight09866 41material that includes graphene and is coated with a lubricant such as silicon. This produces an extremely strong material with high tear strength, and also, because the surface has a very low surface friction, the inner polymer layer will slide easily over it which results in a very compact liferaft .

[0097] Ripstop fabrics are woven fabrics, e . g . made of nylon, using a special reinforcing technique that makes them resistant to tearing and ripping . During weaving, relatively thick reinforcement threads are interwoven at regular intervals in a crosshatch pattern . The intervals are typically 5 to 8 mm. Thin and lightweight ripstop fabrics have a 3-dimensional structure due to the thicker threads being interwoven in thinner cloth .

[0098] Another embodiment involves the use of a two layer inflatable structure (similar to that shown in Figures 17A-C) where the internal bladder is separate to outer restainer but in this case there is a floor which is attached to a buoyancy tube such that there is a waterproof seal between the buoyancy tube and floor . It has been found that by using a lightweight but very strong outer restrainer that is stitched together and a separate inner bladder it is possible to make a much lighter and more compact (when packed) liferaft . Advantageously, if the outer restrainer and / or the separate inner bladder include graphene, this will further enhance the strength and / or lightness and / or compactness .

[0099] As shown in Figures 18A-C, a buoyancy tube 500 is made up of an outer stitched (at 530 ) restrainer 505 with a separate inner bladder 504 (in a similar manner to the inflatable structure of Figures 17A-C) . The outer restrainer 505 may be a lightweight nylon or polyester or "ripstop" type fabric that has high tear strength and in the order of 50 to 100 gms / m2and preferably may also be silicone coated to make it water resistant and more "slippy" and therefore easier to pack . The outer restrainer 505 may be a lightweight nylon or polyester fabric that has high tear strength and includes graphene, and preferably may also be silicone coated to make it water resistant09866 42and more "slippy" and therefore easier to pack. The separate inner bladder 504 may be formed from TPU / PU incorporating graphene .

[0100] The floor 502 in this embodiment is an inflatable floor made by welding together the two layers at certain points to create a "quilted" or "pillow" effect when inflated . The floor material is a coated fabric, typically a nylon or polyester textile (e . g . including graphene ) coated with a polyurethane film (e . g . including graphene) to seal it . The polyurethane coating can be welded together with a high frequency, or ultrasonic, welding system. The floor panels can be stitched and then sealed by taping them together or they can be welded together . In Figure 18A the waterproof floor 502 is shown whereby it is attached to the top centre line of the buoyancy tube 500 and such is above the waterline of the liferaft .

[0101] The canopy 503 , like the floor 502 , can be single layer or inflatable and may include graphene .

[0102] The bladder 504 is typically a weldable polyurethane film (e . g . including graphene ) in the order of 100 to 200 microns thickness .

[0103] The outer restrainer 505 is typically a woven textile of nylon or polyester (e . g . including graphene) in the order of 50 to 100 gms per m2. This can be a "ripstop" material whereby additional stronger threads are incorporated in the weave in both warp and weft this increases tear strength substantially. The textile can also be silicon coated that makes it "slippery" and can be packed and folded into a more confined space and also makes it water resistant .

[0104] The gas inflation system 506 typically uses compressed carbon dioxide that is released into the liferaft bladder 504 via an inflation valve . The bladder 504 is fitted with oral inflation valves 507 as is the floor (at 507a) and canopy (at 507b) , if inflatable, such that it can be "topped up" by mouth .09866 43

[0105] Water pockets 508 can be attached to the underside of the buoyancy tube 500 or floor 502 and help to stabilise the raft on the water surface .

[0106] A connection strip 509 links the edge of the waterproof floor to the underside of the buoyancy tube 500. An optional bailer funnel 532 may be provided in the floor 502 .

[0107] Figure 19 shows how a piece of material 510 can be attached around the underside of the buoyancy tube 500 and has holes 512 in it such that it creates a single large water pocket 514 . This can be further assisted by an inflatable "bolster" 516 positioned under the floor 502 that pushes the water pocket down into the water (as shown by dashed lines 518 ) . The piece of material 510 may include graphene .

[0108] Figures 20A and 20B show another way of attaching the floor 502 such that it is waterproof . The bladder 504 is stitched (at 520 ) into the seam of restrainer 505 and projects beyond it and is welded (at 522 ) to the floor 502 around its edge . The stitching 520 is then sealed over by a waterproof tape 524 or by applying sealant over the stitching 520. The waterproof tape 524 may include graphene .

[0109] The attachment of a polyurethane ( PU) film 432 (e . g . including graphene ) to a textile substrate (e . g . including graphene) 434 , as discussed above in relation to Figure 15 , can be problematic . A welded seam 436 that is also stitched 438 can fail because the polyurethane film 432 is strongly bonded to the textile 434 and peels open (at 39 ) before the stitching 38 holds it, and so gas can leak through the stitching .

[0110] According to this embodiment, as shown in Figures 21 to 23B, there is provided a weak attachment (or lamination) 554 of a PU film 550 to a textile substrate 552 such that we can create a laminated sheet 556 with strong seam but with a lightweight material . The concept is based on the fact that a stitched seam can be much stronger than a welded seam in "peel", but if you try and create a welded seam that is also stitched then this09866 44fails because the polyurethane film is strongly bonded to the textile and peels open before the stitching holds it and so leaks through the stitching .

[0111] As shown in Figure 21 , the PU film 550 may be a 175 micrometre thick weldable layer, for example as available from Porcher . The textile substrate 552 may be 60 to 80gr nylon ripstop material with very small ripstop indices (squares ) to maximise sewing tear strength. The ripstop material may be of the type described in relation to the previous embodiment . A weak adhesive 554 provides a weak bond between the PU film 550 and the textile substrate 552 , so that there is a weak lamination between the PU film 550 and the textile substrate 552. The film 550 and / or the textile substrate 552 may include graphene .

[0112] Figure 22 shows a partial overhead plan view of an inflatable part of survival equipment - for example, similar to the buoyancy tube 500 of Figure 19. An upper laminated sheet 556a is attached to a lower laminated sheet 556b at a seam 558. The seam 558 comprises an inner 5mm RF weld 560 and an outer stitch line 562 , spaced 3mm from the weld 160. The stitching of the stitch line 562 may be lock stitch with 10-12 stitches per 25mm.

[0113] The PU film (e . g . including graphene) 550 is more elastic than the textile substrate 552 (e . g . including graphene ) , and is only weakly attached to the textile substrate 552 .

[0114] In order to assemble the buoyancy tube 100 (or other inflatable part ) , the lower laminated sheet 556b is laid out flat on a surface, with the PU film 550 facing upwards . The upper laminated sheet 556a is then placed over the lower laminated sheet 556b, with the PU film 550 facing downwards . The upper laminated sheet 556a and the lower laminated sheet 556b are then stitched together along the stitch line 562 . The upper laminated sheet 556a and the lower laminated sheet 556b are welded together to form the weld 560. The stitch line 562 may be formed before or after the weld 560. In addition to the peripheral weld 560, a plurality of discrete welds, inwardly of09866 45the periphery, may be formed between the upper laminated sheet 556a and the lower laminated sheet 556b at certain points to create a "quilted" or "pillow" effect when inflated .

[0115] Figures 23A and 23B show a cross-section taken along the line A-A of Figure 22. Prior to inflation, as shown in Figure 23A, the upper laminated sheet 556a is attached to a lower laminated sheet 556b at the seam 558 , by the weld 560 and the stitch line 562 .

[0116] During inflation the weld 560 is partially broken - and the textile substrate 552 of the upper laminated sheet 556a partly de-laminates from the PU film 550 (e . g . including graphene) of the upper laminated sheet 556a, and, similarly, the textile substrate 552 of the lower laminated sheet 556b partly de-laminates from the PU film 550 (e . g . including graphene) of the lower laminated sheet 556b . However, the part of the weld 560 between the films 550 of the upper laminated sheet 556a and lower laminated sheet 1556b the remains intact, thereby forming an inner bladder .

[0117] The part of the PU film 550 of the upper laminated sheet 556a and the part of the PU film 550 of the lower laminated sheet 556b through which the stitch line 562 passes tears away from the maj or of the film 550 of the upper laminated sheet 556a and of the lower laminated sheet 556b . The stitch line 562 remains connecting the textile substrate 552 (e . g . including graphene) of the upper laminated sheet 556a, the torn away part of the film 550 of the upper laminated sheet 556a, the torn away film 550 of the lower laminated sheet 556b and the textile substrate 552 of the lower laminated sheet 556b . The major parts of the film form the inner bladder that is not connected to the stitch line 562 .

[0118] After inflation, while the weld 560 only holds together the films 550 of the upper laminated sheet 556a and the lower laminated sheet 556b, the stitch line 562 connects the textile substrates 552 of the upper laminated sheet 556a and the lower laminated sheet 556b .09866 46

[0119] As mentioned above in relation to Figures 16A and 16B, typically, life rafts are constructed from a number of panels which are joined together by welding or gluing or a combination such technique . Assembling the known life raft requires multiple seams to be sealed. This embodiment is a method to reduce the multiple seams by welding two halves of the life raft and the floor (and also optionally the canopy) in a "single shot" .

[0120] Figure 25 shows a section through the life raft of Figure 24 made using the "single shot" process . The complete buoyancy tube 401 and floor 402 is cut from only two pieces (sheets ) of coated material (e . g . including graphene ) , one forming the upper section 584 of the buoyancy tube 401 and floor 4022 and one forming the lower section 585 of the buoyancy tube 401 and floor 402. This greatly reduces cutting and handling time as there are only two panels rather than many.

[0121] The coated material may be coated with polyurethane or a weldable thermoplastic polymer and may include graphene .

[0122] The upper 584 and lower 585 panels are then laid onto the single welding tool which is shown in section in Figure 26.

[0123] The welding tool comprises two electrodes, an upper 586 and lower 587 tool that create the series of welds when they are brought together squeezing the two layers of material 584 , 585 together (with polyurethane faces of the coated material together e . g . including graphene) and power is applied across them. Retractable location pins 588 are arranged around the edge of the welding tool which align with holes punched around the edge of the two panels 584 , 585 and which hold the panels 584 , 585 in place as the upper 586 and lower 587 welding tools come together .

[0124] Prior to putting the two panels 584 , 585 onto the welding tool, preformed "bends" may be created in the panels 584 , 585 by making a welded "pinch pleat" in the corners of the panels . It is also possible to attach a canopy around the edge of the09866 47life raft in the same single shot weld .

[0125] Figure 27 shows the layers of the life raft and the manufacturing process .

[0126] The life raft may have the following features :

[0127] The buoyancy tube 401 and floor 402 assembly may be fully manufactured from a total of two cut panels 584 , 585 (e . g . containing graphene) by a single hit weld ( following attachment of any gas inflation inlet ports ) .

[0128] The design of the pattern for the buoyancy tube 401 / floor panel 402 (e . g . containing graphene ) may include an integral inflatable tube which inflates with the buoyancy to support the canopy. The cylinder retaining pocket and canopy retaining ties may also be an integral part of the two buoyancy tubes 401 / floor panels 402 .

[0129] An inflatable floor 402 may be incorporated as part of the two cut panels 584 , 585 or could be fitted as an option separately following manufacture of the life raft as dictated by the customer requirement . No additional material may be needed for the inflatable floor 402 as it may be cut from the remainder of the material from the top buoyancy panel 584 (it may just require an additional gas inflation inlet port ) .

[0130] The welded design of the buoyancy tube 401 manufacture may leave a flanged area all around the buoyancy tube 1 where the top and bottom panels 584 , 585 are j oined which may accommodate the sewing attachment for the canopy. The cut panels 584 , 585 may also include canopy retaining ties in the flanged area which may be tied in simple bows to retain the folded canopy. When the canopy is folded / rolled up and secured to the buoyancy tube 401, the rolled up canopy may be robust and could double up as hand grips along the length of the raft to assist boarding and negate the need for separate hand hold patches and webbing .

[0131] As the floor panel 402 may be partially suspended between the two buoyancy tubes 401 , and will initially be positioned clear of the water surface on inflation, it is considered that a vacuum effect may potentially be created against the underside09866 48of the floor panel and the surface of the water which would stabilise the life raft and potentially negate the need for separate water pockets .

[0132] A reduced packed bulk may be further achieved by using lighter weight buoyancy material and ultra lightweight rip-stop canopy material (e . g . of the type described above ) .

[0133] To further reduce the bulk and provide a level of flexibility to the finished shape of the packed unit a twin cylinder inflation system may also be adopted using standard low cost life j acket inflation units to distribute the bulk more evenly within the packed life raft but this approach would need to consider the potential benefits against the costs of a twin inflation system.

[0134] Whilst a smaller, lighter and more compact single seat life raft would benefit the current products used in conjunction with the current single seat life raft, the principles may also be applied to a waist mounted life raft which could be worn in conjunction with a life jacket to provide optimum protection to the wearer in an abandonment situation.

[0135] These embodiments can be used in a life raft (or other inflatable survival equipment) singly or combined in any combination .MULTI SEAT LIFERAFTS AND BOATS

[0136] Figure 12A shows a typical circular Multi Seat Liferaft . Liferafts like this will benefit from a reduced bulk ( so that it will fit into a smaller size of liferaft container or pack) . According to one embodiment, the materials of a liferaft are reinforced with graphene to provide a reduced bulk for a given strength of the liferaft . Also, because the material incorporating graphene (for a given strength) is thinner and lighter, it will inflate more rapidly, particularly in a cold temperature .

[0137] Another inflatable liferaft will now be described with reference to Figure 28 to 54 .09866 49

[0138] Referring first to Figures 28 and 29 the survival craft comprises a hull 610, a canopy support structure 620 carried on the hull 610 and a wall 611. The craft may have a capacity of e . g . from 25 to over 400 persons .

[0139] The hull 610 is formed by first port and starboard inflatable tubes 612 , 613 that extend along the gunwales of the hull 610 and extend upwardly while converging to meet at a shaped bow 614 , and second port and starboard inflatable tubes 612a, 613a that extend along the first port and starboard inflatable tubes extending upwardly while converging to form an archtube 616. The first and second port and starboard inflatable tubes 612 , 613, 612a, 613a may also extend along the stern 615 leaving an opening 618 . One or more of first and second port and starboard inflatable tubes 612 , 613, 612a, 613a, and archtube 616 may include at least one sheet of material that includes graphene . For example, any of first and second port and starboard inflatable tubes 612 , 613 , 612a, 613a, and archtube 616 may be formed as described with reference to one or more of Figures 28 to 37 .

[0140] A floor 617 extends between the tubes 612 , 613, 612a, 613a and is formed by spaced sheets of air-impervious fabric forming an inflatable chamber . The spaced sheets of air-impervious fabric forming an inflatable chamber may include at least one sheet of material that includes graphene . The spaced sheets may be formed by or connected by a drop thread material which provides an inherent strength . The floor advantageously provides a smooth flat surface for the passengers . The air gap between the sheets of air-impervious fabric also provides thermal insulation.

[0141] The floor 617 has a rectangular recess 618a formed therein at the stern end thereof to provide an opening 18 .

[0142] As seen in Figure 30 , the hull 610 comprises a U-shaped wall 611 that surrounds the recess 618a at the stern 615 .09866 50The wall 611 is formed by an inflatable chamber coupled to the floor 617 of the craft and may be formed using a drop thread material . The wall 611 may include at least one sheet of material that includes graphene . The inflatable chamber may be a circular tube or vertical flat sheet panels . The wall 611 may rest on the upper surface of the floor 617 or may abut the edges of the floor 617 that define the opening 618 . The wall 611 may be bonded to the floor 17.

[0143] The wall 611 , when inflated, acts as a bund and an extension to the gunwale formed by the tubes, 612 , 613 , 612a, 613a . The wall 611 may be bonded to the tubes 612 , 613, 612a, 613a to provide a water-tight barrier . The wall 611 may abut the tubes 612 , 613 , 612a, 613a to provide a water-resistant barrier .

[0144] As seen in Figures 30 and 31 , the floor 617 may be formed by modular inflatable chamber portions . Each inflatable chamber portion is preferably isolated from the other inflatable chamber portions after inflation, so that, if one inflatable chamber portion is damaged, the intact inflatable chamber portions are sufficient to provide a functional floor 617. This also allows replacement of damaged inflatable chamber portions .

[0145] As also seen in Figure 30 and 31 , the floor 617 may be formed by two layers, one lying on top of the other . More than two layers may be provided. Each layer may comprise a plurality of the modular inflatable chamber portions . The modular inflatable chamber portions of adjacent layers may be in a staggered arrangement or any other arrangement so that one or more edges of the inflatable chamber portions are not aligned in adjacent layers (e . g . the portions are in a cross laid arrangement ) . This may provide additional stiffness to the craft . Such an arrangement may be particularly advantageous when the modular inflatable chamber portions of floor 617 include at least one sheet of material that includes graphene, as the graphene may increase the strength and / or ease of inflation of the modular inflatable chamber portions .09866 51

[0146] As shown in Figure 32 , a longitudinal floor tube 651 may extend from the wall 611 to the bow 614 along the floor 617 to form a central spine of the craft and additional floor tubes 652 extending (e . g . perpendicularly) from the spine to tubes 612 , 613 may be used as stiffeners to increase rigidity of the structure . These tubes 651 , 652 may also be formed of a drop thread material . The tubes 651 , 52 may be inflatable . One or more of floor tubes 651, 652 may include at least one sheet of material that includes graphene . For example, any of floor tubes 651, 652 may be formed as described with reference to one or more of Figures 1 to 10.

[0147] The canopy structure 620 is formed by a network of elongate inflatable tubes 621 , 621A arrangement along the length of the hull and supported by the archtube 616. The network of inflatable tubes comprises a series of (e . g . six) spaced apart longitudinal tubes and a series of (e . g . six) transverse tubes 621A. The tubes 621 and 621A are interconnected. The tubes 621 and 621A may have a generally arched shape . A sheet 660 of flexible water-impervious material over the archtube 616 and canopy structure 620 to form a canopy, as shown in Figure 33. The generally arched shape of the tubes 621 and 621A holds the sheet 660 apart from the floor 617 to define a passenger space that is protected from the elements . Again, any or all of the tubes may be made from a drop thread material . One or more of elongate inflatable tubes 621, 621A may include at least one sheet of material that includes graphene . For example, any of elongate inflatable tubes 621, 621A may be formed as described with reference to one or more of Figures 1 to 10. The sheet 660 may include at least one sheet of material that includes graphene .

[0148] In this way, the canopy support 620 may form a truss structure carried by and is supported by the hull 610 that provides the hull 610 with increased rigidity, resisting any09866 52tendency of the hull 610 to bow. In addition, it forms a protective shelter for occupants of the survival craft .

[0149] A sheet 660 of flexible water-impervious material covers the sides of and the ends of the canopy structure 620 and is provided with door and window openings 661.

[0150] As seen in Figure 34 , longitudinally extending sleeves 670 may be fitted towards the outer side edges of the under surface of the hull 610. The sleeves 670 comprise a sheet of flexible material 670A that is connected at one end to an outer side edges of the under surface of the hull 610. At the other end, the sheet of flexible material 670A is connected to a first side of an inflatable tube 670B . The inflatable tube 670B extends longitudinally and is bonded at a second side, opposite to the first side, to the under surface of the hull 610. Once the inflatable tubes 670B are inflated, the sleeves 670 define a space of substantially triangular cross section 671 which retains water to add weight to the craft, thereby providing stability. One or more of inflatable tubes 670B may include at least one sheet of material that includes graphene . For example, any of inflatable tubes 670B may be formed as described with reference to one or more of Figures 1 to 10. The sheet of flexible material 670A may include graphene .

[0151] The survival craft may also comprise a rigid pod structure 619 (see e . g . Figures 28 and 30 ) . The pod 619 is supported by and securely mounted to the wall 611 by a hinged fabric attachment 611a (e . g . by lacing) , by bonding and / or by an interference fit between the side walls of the pod 619 and the wall 611. The pod 619 acts as the transom. The pod 619 is an integral component of the craft . The pod structure 619 may be made from a drop thread material, aluminium, glass fibre reinforced plastics (GRP) or steel . The pod 619 structure may float in water . The pod 619 may include includes graphene . The fabric attachment 611a may include at least one sheet of material that includes graphene .09866 53

[0152] The pod 619 may be formed in a substantially rectangular shape or any other shape complimenting the recess 618a . The pod 619 may include an inclined surface 692 to provide hydrodynamic support when attached to the craft and in use . The pod 619 may also include an additional protruding section 704 which acts as a protective fender for the propulsion unit . Additionally, the pod 619 may include a skeg 685 ( Figure 35 ) which improves the directional stability of the craft and may also have an inclined edge to improve hydrodynamics . Figure 38 illustrates the craft once the pod is attached .

[0153] As shown in Figures 35 , 36 and 37 , a powered propulsion unit 680 for the survival craft is attached to or enclosed within the pod 619. The powered propulsion unit 680 may be motor 861 driving a shielded propeller 682 . The craft may be steerable from within the hull 610. The powered propulsion unit may use petrol, diesel, electric or any combination as a fuel source . The pod 619 may also house a starter for the propulsion unit ( if applicable) and a battery / cell ( if applicable ) . The pod 619 may also store the fuel source for the propulsion unit 680. Fuel may alternatively (or additionally) be stored within bladders located inside the craft, exterior to the craft, or a combination of both .

[0154] As shown in Figure 35 , more than one powered propulsion unit 680 may be attached to the pod 619. The propellers 82 may be replaced by, for example, a water j et .

[0155] The powered propulsion unit 680 may be attached to the pod 619 with a lowering mechanism. Thus , when the craft is stored, the propulsion unit 680 may be in a raised position 683 and when in use, lowered into a driving position 684 . The lowering mechanism may be automatic or manually controlled .

[0156] Additional equipment such as a compressor for back inflation air, an osmosis pump for fresh water, heating units09866 54or a ventilation unit as backup air supply may be positioned inside the pod 619 and powered by the powered propulsion unit 680 .

[0157] Advantageously, the combination of the modular inflatable chambers (of the floor) , the inflatable members of the hull and the wall 611, acts a transom to transfer power from the pod 619 to the hull 610 to propel the craft forward . By forming any of these parts with a sheet of material that includes graphene, the strength of these parts may be increased and thereby improve the transfer power from the pod 619 to the hull 610 .

[0158] Referring to Figures 36 and 37 , the pod 619 carries an inflation system. The inflation system is provided in the form of an inflation tray 690 and is mounted on top of the pod 619. The inflation tray 690 may be formed and manufactured from angular or flat sheet aluminium or steel to provide a rigid frame . The inflation tray 690 may include gas cylinders and hoses 691 for storing gases and for providing gases to the modular inflatable chambers (of the floor) , tubes 651, 652 (of the floor) , tubes 612 , 613 , 612a and 613a (of the hull ) , and tubes 621 , 621A (of the canopy) (any of which may include graphene) in order to inflate them. The gases used for the inflation system may be any combination of carbon dioxide, nitrogen, helium and air . In order to allow easy servicing, the inflation tray 690 can be easily separated from the pod .

[0159] The pod structure 619 may include a compressor to provide inflation gas instead of the gas cylinders, or in addition thereto .

[0160] The pod 619 may include a diagnostic port that allows the status of services (e . g . fuel capacity, battery status , inflation system status ) of the survival craft to be checked . A processor may be provided in the pod 619 to record this data and09866 55make it available via the diagnostic port . The diagnostic port may be a USB port .

[0161] The pod 619 may include a separate container the stores "lifed" items - i . e . items that have a limited useful lifespan. The container may store items such as sea sickness tablets and other medication. The container is readily replaceable, which eases servicing of the survival craft .

[0162] The rigid pod 619 may be configured to carry required emergency equipment - e . g . flares first aid kit etc, along with food and water . The pod 619 may be configured to support back up services e . g . a reverse osmosis pump, inflation pumps , etc . The power for the support services may be taken from the propulsion unit 680.

[0163] As seen in Figures 39 and 40 , in addition to the skeg of the pod 619, or alternatively, inflation cylinders may be mounted along the centreline of the underside of the hull 720 forming a keel . The cylinders may be enclosed within a sleeve arrangement 730 so that they are streamlined. The sleeve arrangement 730 may include at least one sheet of material that includes graphene . This keel arrangement aids the stability and steering of the craft . The inflation cylinders may be the cylinders held by the inflation tray or external cylinders .

[0164] When stored, the inflatable members of the survival craft are deflated and packed into a valise 701 which may be rigid or flexible, and may include at least one sheet of material that includes graphene . The deflated assembly 702 is mounted on top of the inflation tray 690 which may also be removed from the inflation tray to easily allow regular maintenance works and / or servicing . As seen in Figure 37 , in the deflated state, the survival craft comprises the deflated assembly 702 , the inflation tray 690 and the pod 619. The deflated assembly 702 may carried by the pod 619 in other ways . The deflated assembly09866 56702 may be attached to an outer surface of the pod 619 - e . g . a top, side or bottom surface .

[0165] The survival craft in its deflated state may be carried by a deployment system on a marine structure of a known type and when required for use, the system releases the deflated survival craft into the water . The deployment system may include parts comprising graphene . On reaching the water, the inflation system commences inflation of the survival craft and the assembly 702 opens , allowing the survival craft to complete inflation and deploy. The inflation may be automatic or manual .

[0166] People from the marine structure can then enter the survival craft through an inclined transfer system - e . g . including an evacuation passage ( such as an escape slide) , of a known type or of a type described herein, which may be attached to the craft by a series of patches mounted on the pod 619 or on the bund 611. The inclined transfer system may include a transfer platform or the transfer may be direct to the craft . A vertical transfer system may be directly into the craft, or may be via a transfer platform. The side may optionally remain attached to the survival craft (or platform) after the passengers have boarded to provide additional passenger space or storage space . Alternatively, vertical evacuation passages of known type or of a type described herein may be attached to any location of the craft (or platform) by means of a suitable inflatable frame . In Figure 37 an evacuation passage 703 is shown positioned above the stern end of the pod 619, for allowing passengers to enter the survival craft . Types of evacuation passages 603 may include chutes or slides .

[0167] It is safer to have people enter a survival craft after it is on the water, rather than lowering a full craft into the sea .

[0168] The propulsion system 680 may be used to move the survival craft clear of the structure and to steer it .09866 57

[0169] The provision of a rigid floor 617 and the inflatable sleeve 670 reduces the tendency of the floor 617 to crease as the hull 610 travels through water so reducing the drag on the hull 610. The use of graphene in the rigid floor 617 and the inflatable sleeve 670 may improve strength and may further reduce the tendency of the floor 617 to crease as the hull 610 travels through water .

[0170] Figures 42 and 43 show an alternate construction of the survival craft . The inflatable tubes 612 , 613 , 612a, 613a that form the periphery of the craft may be replaced by vertical inflatable panels which may be of a drop stitch material . The hull 750 of this craft is formed by port and starboard vertical inflatable panels 751, 752 that extend along the gunwales of the hull while converging to meet at a shaped bow 753. The panels 751 , 752 may each include at least one sheet of material that includes graphene .

[0171] As seen in Figure 44 , in this embodiment, the stern end 755 of the craft is formed of an inflatable wall 754 extending between the port and starboard vertical inflatable panels 751 , 752 and around the recess 618a of the floor 617 . The inflatable wall 754 may include at least one sheet of material that includes graphene .

[0172] Similar to the construction of the floor 617 , the vertical inflatable panels of the craft may also be formed by modular inflatable chamber portions as seen in Figure 45. Each inflatable chamber portion is preferably isolated from the other inflatable chamber portions after inflation, so that, if one inflatable chamber portion is damaged, the intact inflatable chamber portions are sufficient to provide a functional periphery of the hull . This also allows replacement of damaged inflatable chamber portions, although the use of graphene in the inflatable chamber portions is likely to reduce the likelihood of damage .09866 58

[0173] Additionally, Figure 46 shows a portion of the hull being arranged to serve as a door 790 allowing persons in the water to board the craft or assist in the retrieval of casualties from the water . The door 790 may be pivotally attached to the hull providing an opening 791. The opening and door arrangement maintains , as far as practical, the integrity of the hull . The door may include graphene .

[0174] The survival craft may be provided with a fire suppression system, such as a deluge pump for spaying water over the canopy in the event of a fire . The survival craft may be provided with lighting . Such lighting may be configured to relive sea sickness . Lighting (e . g . LED lighting) may be provided in the floor to guide passengers to / from the exit / entrance . The survival craft may be equipped with display screens for providing information to the passengers, such as safety information. The display screens may be foldable from a stowed position to a deployed position by a suitable mechanism. The survival craft may be equipped with GPS navigation, radar and / or navigation lights . The survival craft may be self-righting .

[0175] Figures 47 to 54 show an alternative construction of the survival craft .

[0176] As shown in Figure 47 , the craft may be fitted with fins 800 to assist with the steering and control of the craft . These fins 800 may be fitted either on the underside of the hull 810 or dropped / lowered down from a sidewall 820. If dropped / lowered down from the sidewall 820 , they may be a pair - one port, one starboard . If fins are fitted to the underside of the hull 810, they may be spaced evenly across the width of the hull 810 in the front . There may normally be in combinations of two or four fins 800. The fins 800 may be used with other configurations of craft .09866 59

[0177] The fin ( s ) 800 as described above will normally be fabricated from a rigid material, which may include graphene . Alternatively, an inflatable version of the fin ( s ) 800 may be used - e . g . using a drop thread material . The fin (s ) 800 may include at least one sheet of material that includes graphene .

[0178] The hull 810 may be constructed using drop stitch panels mounted vertically (substantially perpendicularly to the horizontal floor of the hull 810 ) . This provides additional stiff ness / rigidity to the structure, creating a series of spines 830 - see Figure 50. The vertical panels can either be in the central portion of the craft or can be the side walls 820 of the craft or combinations thereof . The vertical panels either in the central portion of the craft or the side walls 820 may include at least one sheet of material that includes graphene .

[0179] These vertically mounted panels can be extended through the floor of the hull, and protrude a short distance (typically 150mm) below the floor . These protrusions 840 may assist in the steering and control of the craft . They may be an alternative to the fins 800. The panels preferably extend below the hull in the forward 2 / 3 of the craft (at the bow end) . Additionally, or alternatively, the side walls 820 may protrude a short distance (typically 150mm) below the floor, as shown at 845 .

[0180] The vertically mounted panels / spines 830 inside the craft side walls 820 can also be utilised for seating 850 inside the craft - see Figure 49.

[0181] Additional seating can be provided inside the craft by using drop stitch panels mounted either vertically or horizontally. These panels mounted either vertically or horizontally may include at least one sheet of material that includes graphene . As well as providing seating, these panels will provide additional stiffness for the craft .09866 60

[0182] The seating arrangements can run either longitudinal along the craft or transverse across the craft .

[0183] The drop stitch panels can be assembled by a number of different methods . A fabric panel may be enclosed to make it air holding, and this is then j oined to another air holding panel to form the required structure . Alternatively, the fabric panel can be joined to another fabric panel and then enclosed to make an air holding structure . The panels may include an end cap . Fig 52 shows two joined drop stitch panels 860A and 860B with a shared end cap 870 at each end . The fabric panels may include at least one sheet of material that includes graphene . The end caps 870 may include at least one sheet of material that includes graphene .

[0184] In certain key areas of the hull 810 , in order to minimise drag, the butt ends of the drop stitch panels (that would otherwise extend perpendicularly to the direction of travel of the craft in water) are skinned to form a smooth surface as shown at 880 in Figure 53. The skinned ends 880 typically would be at the bow and side wall areas .

[0185] In order to support the bow panels a stepped reinforcing arrangement 890 may be added to inside face of the bow. The stepped reinforcing arrangement 890 provides access to the bow windows of the craft to assist in steering and towing arrangements - see Figure 49. The stepped reinforcing arrangement 890 may include at least one sheet of material that includes graphene .

[0186] The construction of the inflatable transom wall area 900 may be such that it is laminate in structure allowing it to be reinforced by cross linking different panels - see particularly Figure 54 . Some of the panels may extend vertically and others may extend horizontally. The rear area of the inflatable transom 900 may have cut outs 910 provided to allow easy access into the craft from the water - see particularly09866 61Figure 49. The rear area of the inflatable transom 900 may be extended as shown at 920 in Figure 49 to have a sufficient length to protect the engines and the rigid pod from contacting the side shell of the vessel that the craft is deployed from. The inflatable transom 900 may include at least one sheet of material that includes graphene .

[0187] The survival craft described above with reference to the drawings is more compact than rigid survival crafts and so occupies less space on a marine structure . This can be important on passenger ships where outside space to the sides of the ship is at a premium. At the same time, the survival craft has the advantage over unpowered inflatable life rafts that it is powered and steerable and so can be used to move persons clear of the marine structure .

[0188] "Drop thread" (also sometimes referred to as "drop stitch" ) material is made by weaving "three dimensionally" on a special loom. An outer and inner textile layer is woven in a conventional manner but the loom is able to weave threads vertically at 90° between the inner and outer layers of textile . These vertical threads are termed "drop threads" . The inner and outer layers of textile may include at least one sheet of material that includes graphene . The drop treads may comprise graphene to improve their strength / lightness .INFLATABLE ESCAPE SLIDES

[0189] An inclined escape slide is disclosed in WO 2018 / 078041 Al (our ref : 07088 ) . A vertical escape slide is disclosed in WO 2019 / 007962 Al (our ref : 07306) . Embodiments will now be described of escape slides that include graphene in various materials, fabrics , textiles , coatings and rigid components . This may result in the slides having a lower mass and more compact size . The lighter and more compact size of the slide may benefit the stowage system of the slide as the stowage system can be smaller and / or less complicated. The lighter and more compact size of the slide may benefit the launching apparatus09866 62as the launching system can be smaller and / or less complicated. Further, the thinner and lighter weight materials that can be used if graphene is used may contribute to faster inflation.

[0190] FIG . 55 shows an inflatable evacuation slide 1001, in deployed and inflated configuration between a ship 1003 and an inflatable survival life raft 1005. The life raft 1005 is deployed and inflated, and releasably attached to the lower or exit end of the slide 1001 by deformable releasable slide / raft interface coupling devices . Although the inflatable evacuation slide 1001 is deployed between a ship 1003 and an inflatable survival life raft 1005 in this embodiment, it should be understood that that the slide 1001 can extend from between any two structures, such as inflatable structures, platforms, life rafts, e . g . an inflatable life raft, lifeboats etc . The life raft 1005 may be of one of the types described above .

[0191] The other end of the slide 1001, which is its upper or entry end, is connected to a storage and launching cradle 1007 , mounted on the ship 1003, for storing the assembly constituted by the slide 1001 , folded in a deflated state, and the life raft 1005 , also deflated and folded in a container (not shown) , around which the slide 1001 is wrapped in the storage configuration, before launching, on a deck of the ship 1003.

[0192] As shown on a larger scale in FIGS . 56A to 56E, the structure of the slide 1001 comprises a framework including three longitudinal triple beams , one of which is an upper beam 1009, in a substantially central position above the other two, which are lateral lower beams 1011, between which is fixed and stretched over the whole length of the slide 1001, a flexible chute 1013.

[0193] Each of the three longitudinal triple beams 1009 and 1011 comprises three longitudinal tubes 1015A-C, each in the form of an elongated cylinder having a substantially circular cross-section, individually inflatable ( i . e . each inflatable independently of the others ) , stacked one ( 1015A) above the09866 63other two ( 1015B, 1015C) so that they are tangential two by two over their length, and thus connected together adjacent and side by side . The tubes 1015A-C may be connected intermittently or continuously over their length, for example by an adhesive or by high-frequency welding, so that the cross-section of each beam 109 or 1011 has substantially the shape of an equilateral triangle in the inflated state .

[0194] Although in the embodiment longitudinal beams 1009 and 1011 each comprise three longitudinal tubes 1015A-C are provided, it should be understood that the beams 1009 and 1011 may comprise only a single longitudinal tube or any number of longitudinal tubes .

[0195] The framework of the slide 1001 also comprises a plurality of stiffening modules 1017 , which are inflatable, but pneumatically and mechanically independent of each other, and arranged side by side at their base, from the entry end to the exit end of the slide 1001, and each mechanically connected to the longitudinal tubes 1015A-C of the longitudinal beams 1009 and 1011 by connection means, and inflated from the longitudinal tubes 1015A-C of the longitudinal beams 1009 and 1011 by inflation means, so that, in the inflated state of the slide 1001 , they can brace and stay the beams 1009 and 1011, keeping them spaced apart transversally to their length, and so that they extend substantially parallel to each other, in order to give the inflated slide 1001 a cross-section (perpendicular to the beams 1009 and 1011 ) having substantially the shape of an isosceles or equilateral triangle .

[0196] Each stiffening module 10017 includes two symmetrical halves 1019a and 1019b ( Figure 56B) , each being composed of two inflatable side panels 1021a, b connected together at the top, before assembly of the two halves . As the two symmetrical halves 1019a and 1019b are identical to each other, and arranged face to face, it is sufficient to describe one of them.09866 64

[0197] Each of the side panels 1021a / b has a generally hexagonal shape, as shown in Figures 58A-4C . The side panel 1021a / b has two oppositely facing long side walls 1023a, b, identical to each other, two oppositely facing intermediate length side walls 1025a, b, identical to each other, and two oppositely facing short side walls 1027a, b, also identical to each other . A corner connector 1028 joins each two adjacent side walls . The side walls extend between two opposite faces 1029a, b of the side panel 1021a / b . The side panel 1021a / b may comprise graphene . The two oppositely facing long side walls 1023a, b, two oppositely facing intermediate length side walls 1025a, b, and / or two oppositely facing short side walls 1027a, b may comprise a sheet of material that includes graphene . The corner connectors 1028 may comprise graphene .

[0198] The side panels 1021a and 1021b of each half 1019a and 1019b of the stiffening module are j oined to each other at the upper ends at the intermediate side walls 1025a .

[0199] The side panels 1021a / b are formed from drop stitch (or drop thread) material, which has the general form shown in Figure 59. In such a material, thousands of (e . g . nylon) threads connect the two opposite faces 1029a, 29b to keep side panels 1021a and 1021b in the desired shape when inflated and to provide rigidity. The two opposite faces 1029a, 29b may include a sheet of material that contains graphene . The threads connect the two opposite faces 1029a, 29b may include graphene .

[0200] Each stiffening module 1017 has, in the inflated state, the general outer shape of a hollow truncated pyramid with a square or rectangular base, the inclined edges of which are formed by two pairs of side panels 1021a, 21b thus comprising four independent inflatable structures .

[0201] Although the stiffening modules 1017 are not mechanically coupled to each other, or connected to each other by inflation means, each of them is however connected to09866 65longitudinal tubes 1015A-C of the three longitudinal beams 1009 and 1011 by connection means, as well as optionally to some of the longitudinal tubes 1015A-C of these beams 1009 and 1011 by inflation means . However, it is preferred that the stiffening modules 1017 and the longitudinal tubes 1015A-C are inflated separately .

[0202] Each of the four independent inflatable side panels 1021a and 1021b of each of the stiffening modules 1017 may be connected to inflation means, and, moreover, with respect to any pair of two immediately adjacent stiffening modules 1017 , a majority of independent inflatable side panels 1021a and 1021b of one of these two modules is connected to inflation means that are different from those to which the homologous inflatable structures of the other one of these two modules are connected.

[0203] The base of the slide 1001 ( Figure 56F) comprises a plurality of abutting but independent floor panels 1030. The floor advantageously provides a smooth flat surface .

[0204] Each of the floor panels 1030 has a generally rectangular shape, as shown in Figures 60A-6C . Each of the floor panels 1030 may include graphene . The panel 1030 has two oppositely facing long side walls 1032a, b, identical to each other, and two oppositely facing short side walls 1034a, b, also identical to each other . A corner connector 1036 joins each two adjacent side walls . The side walls extend between two opposite faces 1038a, b of the panel 1030. The two oppositely facing long side walls 1032a, b, and / or two oppositely facing short side walls 1034a, b may comprise a sheet of material that includes graphene . The corner connectors 1036 joins may include graphene .

[0205] The adjacent floor panels 1030 of abut each other at the upper ends at the short sides walls 1034a, b .09866 66

[0206] The floor panels 1030 are formed from drop stitch (or drop thread) material, which has the general form shown in Figure 59. In such a material, thousands of (e . g . nylon) threads connect the two opposite faces 1038a, 1038b to keep the floor panel in the desired shape when inflated and to provide rigidity. The threads that connect the two opposite faces 1038a, 1038b may comprise graphene . The air gap between the opposite faces 1038a, 1038b also provides thermal insulation. The opposite faces 1038a, 1038b may comprise a sheet of material that includes graphene .

[0207] The bottom of the slide 1001, atexit end comprises a downstream end that is connectable to the life raft 1005 (or other structure ) .

[0208] Referring now to Figure 57A, the arrangement of the inflatable tubes 1015A-C that form the upper beam 109 is shown . Each of the tubes is connected to the two adjacent tubes by adhesive 1060 which is applied preferably along the entire length of each of the tubes over a portion of the circumference of the tube that will abut the two adjacent tubes . The adhesive 1060 connects the tubes 1015A-C together to form a generally triangular structure, with the tube 1015A sitting above the two lower tubes 1015B and 1015C . The upper beam 1009 formed by the tubes is connected to the inflatable side panels 1021a, b of each stiffening module 10017 by adhesive, as shown in Figure 57A. In particular, the upper tube 1015A has two regions of adhesive 1062 provided preferably along the entire length of the tube in a region that contacts the interior faces 1029a and 1029b of oppositely facing inflatable side panels 1021a and 1021b . Each of the lower tubes 1015B and 1015C includes a region of adhesive 1064 extending preferably along its entire length in the region that comes into contact with the interior faces 1029a and 1029b .

[0209] As an alternative to the direct connection between the adjacent tubes , and interior faces 1029a, 1029b, a strip or09866 67strips of material may extend between these elements and be adhered to adjacent ones of the elements by adhesive . Figure 57D shows a "large mounting" form of such strips of material, comprising a two spaced apart V-shaped strips 1068 , the limbs of which are adhered to adjacent tubes 1015 (i . e . two of tubes 1015A / B / C) . Figure 57E shows a "small mounting" form of such a strip of material, comprising an X-shaped strip 1067 , the limbs of which are adhered to adjacent tubes 1015 (i . e . two of tubes 1015A / B / C) . The "X" may be formed by two stitched together pieces of material ) .

[0210] A further alternative arrangement of the upper beam 1009 is shown in Figure 57B . The arrangement of the tubes 1015A-C is the same as in Figure 57A. However, a beam sleeve 1066 is fixed around the tubes 1015A-15C in order to hold the tubes together ( in addition to the adhesive 1060 ) . In this embodiment, an adhesive region which preferably extends along the entire length of the upper tube 1009 secures the outer face 1070 of the beam sleeve 1066 to the inner faces 1029a and 1029b of the side panels 1021a and 1021b . A continuous beam sleeve 1066 may be provided along the length of the upper beam 1009.

[0211] Rather than directly coupling the tubes 1015A-15C together by adhesive 1060, as shown in Figure 57B, a material strip arrangement may also be provided, as described in relation to Figures 57D and 57E .

[0212] Figure 57C shows the arrangement of a lateral lower beam 1011. The tubes 1015A-15C of the lower beam 1011 are connected to each other by adhesive 1060 , in the same way as shown in Figure 57A (although material strips could be used alternatively as described in relation to Figures 57D and 57E) . The tubes 1015A and 1015B are connected to the face 1029a of the side panel 1021a by adhesive region 1062 and 1064 , respectively, in the same manner as described in relation to Figure 57A (although material strips could alternatively be used) . The tubes 1015B and 1015C are connected to the inner face 1038a of09866 68the floor panel 1030 by adhesive regions 1072 which preferably extend along the entire length of the tubes 1015B and 1015C round a portion of the circumference thereof that is adjacent to the floor panel 1030 (although material strips could alternatively be used) .

[0213] As in Figure 57B, a beam sleeve may be fitted around the tubes 1015A-1015C of a lateral lower beam 1011 to secure them together .

[0214] With regard to coupling the slide 1001 by its upper end to the storage cradle 1007 mounted on the ship 1003, this can be carried out as in the rescue equipment of the state of the art . However, the rescue equipment of the embodiment preferably comprises a storage and launching cradle 1007 for the assembly constituted by a container, containing at least one life raft such as 1005 and its inflation means, and the slide 1001 wrapped around the container . The cradle 1007 may comprise graphene .

[0215] The chute 1013 has a generally flat floor 1039 formed of flexible material that extends between the lateral lower beams 1011 over the whole length of the slide 1001. In order to increase the speed of evacuation via the slide 1001, it is advantageous to subdivide the chute 10013 into three adjacent tracks 1040a and 1040b and 1040c (as best seen Figures 56A, 56D and 56E) by a flexible separating partitions 1042a and 1042b supporting the mid part of the chute floor 1039 and suspended from the upper beam 1009, over the whole length of the slide 1001. The separating partitions 1042a and 1042b may be formed by a netting material and / or may comprise graphene . This variant is advantageous for ships carrying a large number of passengers . The chute 1013 may comprise graphene . The flat floor 1039 may comprise a sheet of material including graphene .

[0216] In the embodiments of the invention each inflatable tube 1015A-C is constructed from a bladder 1050 and a surrounding09866 69braid tube 1052 . Figure 62A shows a biaxial braid tube 1052 , having two intertwined strands of inextensible material, each extending at an angle inclined to the central, longitudinal axis of the tube . The strands of inextensible material may comprise graphene . Preferably, the braid tube used in the embodiments has an additional, third element that extends substantially parallel to the longitudinal axis of the tube that constrains longitudinal extension of the tube ( so that the tube has a predetermined maximum length when inflated) . The longitudinal elements may be fibres, filaments, ropes or webbings etc . and may comprise graphene . The longitudinal elements may be attached to a biaxial braid tube to constrain longitudinal extension of the tube . Alternatively, the longitudinal elements may be integrated into the braid tube to form a triaxial braid tube, which is a tube formed by intertwining three strands of an inextensible material, the third strand extending longitudinally, substantially parallel to the central axis of the tube .

[0217] The arrangement of the third elements ( 3 ) is shown in Figure 62B . The third elements (3 ) extend axially, in contrast to the biaxial fibres ( 2 ) to which they are attached. The scissor angle ( 1 ) is selected in the uninflated state to be large enough so that, at maximum radial extension (when in the inflated state ) , the third elements (3 ) constrain the maximum longitudinal extension,

[0218] The strands of an inextensible material forming the braid may be Vectran® ( formed from a liquid crystal polymer, LCP) , Kevlar®, or other aramids , polyesters or Ultra-high-molecular-weight polyethylenes (UHMWPEs ) . Strands of inextensible material may also include graphene in combination with these materials .

[0219] The bladder 1050 can be formed integrally with the braid tube 1052 by, for example by coating the braid tube 1052 with a flexible polymeric material such as silicone or a flexible09866 70plastic such as polyurethane, or neoprene . The coating of the braid tube 1052 may include graphene .

[0220] Alternatively (as shown) the braid tube 1052 can retain within it a sealed bladder 1050 made from a flexible material such as silicone or polyurethane or a synthetic rubber or neoprene . The sealed bladder 1050 may include graphene and may be formed as described in relation to any one of Figures 1 to 10. It is preferred to use a bladder 1050 within the braid tube 1052 that is made "over size" having a length that is at least as long as the maximum length of the braid tube 1052 and a diameter that is at least as large as the maximum diameter of the braid tube 1052 when expanded . In this way, the bladder 1050 is unstressed as it fills and empties .

[0221] That is, although the bladder 1050 may be of generally the same shape as the braid tube 1052 , the bladder 1050 may be of generally larger size . The bladder 1050 may be made of a sufficiently large size so that, when inflated within the braid tube 1052 , the bladder 1050 fills the internal volume of the braid 1052 without any stretching of the bladder 1050 occurring, and the tension is taken up by the braid tube 1052 . If the bladder 1050 is made oversized, the bladder may be made of an inextensible and / or inelastic material . It is advantageous for the tension to be taken up by the braid tube 1052 , as it is stronger than the bladder .

[0222] When the braid tube 1052 and the bladder 1050 are separate, there may be relative movement between the braid tube 1052 and the bladder 1050. In order to reduce wear on the bladder 1050 from such relative movement, the braid may be formed or coated with a low friction material . Alternatively, a low friction material could be placed between the braid tube 1052 and the bladder 1050. The bladder 1050 could be formed with a double skin with a lubricant between the two skins .

[0223] The bladder 1050 may be elastic but this is not essential .09866 71

[0224] The bladder 1050 and braid tube 1052 are preferably contained within a protective outer bladder sleeve 1054. The outer bladder sleeve 1054 protects the braid 1052 from damage . The outer bladder sleeve 1054 also allows the inflatable tubes 1015A-C to be glued to other parts of the slide 1001 ( it is not possible to reliably attach braid 1052 by glue ) . The protective outer bladder sleeve 1054 may comprise graphene .

[0225] The use of braid 1052 in the tubes 1015A-15C allows the tubes to be inflated to much higher pressure than was previously possible . Pressures of lOOpsi and above are possible .

[0226] The combination of the drop stitch panels 1021a / b, 1030 and the braid 1052 in the tubes 1015A-15C is highly advantageous . The rigidity of the drop stitch panels (and particularly their ability to resist deformation in response to shear stress ) resists the bending / collapse of the inflatable beams 1009 and 1011 , and provides a significant advantage over the prior art . The use of graphene allows these parts to be thinner and lighter ( for a given strength) .

[0227] The tubes 1015A-15C are provided at each end with a rigid end cap assembly as shown in the assembled form in Figure 63A and in exploded form in Figure 63B . The end cap assembly 1090 includes an outer, generally circular end plate 1092 having an aperture 1093 formed therein for mounting an inflation valve . A circular outer spacer 1094 and a circular inner spacer 1096 are provided either side of a clamp ring 1098 . The end plate 1092 , outer spacer 1094 and inner spacer 1096 are fixed together by a plurality of nuts and bolts . The end plate 1092 , outer spacer 1094 , inner spacer 1096 and / or clamp ring 1098 may comprise graphene .

[0228] A rear elevational view of the end cap assembly 1090 is shown in Figure 63C . A side elevational view of the end cap assembly 1090 is shown in Figure 63D. Figure 63E shows a cross-09866 72section taken along the line A-A of Figure 63C . Figure 63F shows an enlarged view of the end circled portion B of Figure 63E .

[0229] Figure 64A shows a perspective view of the end plate . Figure 64B shows a rear elevational view of the end plate 1092 . Figure 64C shows a side elevational view of the end plate 1092 . Figure 64D shows a cross-section taken along the line A-A of Figure 64B . Figure 10E shows an enlarged view of the encircled portion B of Figure 64D.

[0230] Figure 65A shows a perspective view of the outer spacer . Figure 65B shows an inward plan view of the outer spacer 1094 . Figure 65C shows a side elevational view of the outer spacer 1094. Figure 65D shows a cross-section taken along the line A-A of Figure 65B . Figure 65E shows an enlarged view of the lower portion of Figure 65D.

[0231] Figure 66A shows a perspective view of the clamp ring 1098 . Figure 66B shows a plan view of the clamp ring 1098. Figure 66C shows a cross-section taken along the lines A-A of Figure 66B .

[0232] Figure 67A shows a perspective view of the inner spacer 1096. Figure 67B shows front elevational view of the inner spacer 1096. Figure 67C shows a side elevational view of the inner spacer 1096. Figure 67D shows a cross-section taken along the line A-A of Figure 67D. Figure 67E shows an enlarged view of the lower portion of Figure 13D.

[0233] The end plate 1092 includes an inner, generally cylindrical portion 1100 having a greater thickness in the longitudinal direction of the tube than the outer, generally annular portion 1102. The difference in thicknesses results in a circumferential flange 1104 being formed around the periphery of the end plate, providing a recess 1106 for receiving the inner and outer spacers 1094 and 1096, and the clamp ring 109809866 73( see, for example, Figure 63F) . The outer spacer 1094 is of generally annular form such that it can be accommodated within the recess 1104 of the end plate 1092 , as is the inner spacer 1096. The outer spacer 1094 includes a circumferential recess 1110 (see, for example, Figure 65E) , which is of generally semicircular cross-section. The inner spacer 1096 includes a corresponding circumferential recess 1112 (see, for example, Figure 67E) which is also of generally semi-circular crosssection . When assembled, the outer 1094 and inner 1096 spacers face each other such that their recesses 1110 and 1112 face one another in order to define a generally circular space for accommodating the clamp ring 1098 (as best shown in Figure 63F) .

[0234] A purpose of the end cap assembly 1090 is to provide a strong attachment point for each of the opposite ends of the tubes 1015A-15C (as they are carrying the forces ) . The material 1113 of the tubes 1015A-15C is shown by a dash line in Figure 63F. At each end of the tubes the material 1113 is wrapped around the clamp ring 1098. The clamp ring 1098 , together with the wrapped around material 1113 of the tube is then placed in the recesses 1110 and 1112 of the outer and inner spacerslO 94 and 1096. A bolt 1114 fastens the outer spacer 1094 to the inner spacer 1096 to one another, thereby clamping the clamp ring 1098 and the material 1113 between the spacers . The bolt 1114 cooperates with nut 1116 to additionally secure the spacers 1094 and 96 to the end plate 1092. The bolt is tightened sufficiently to provide an air-tight seal .

[0235] The material 1113 of the tube 1015A-15C may comprise each of the layers of the tube which, as describe with reference to Figure 61, and so may include the bladder 1050 , the braid 1052 and the outer bladder sleeve 1054. Such an arrangement is applicable to a tube where the bladder 1050 is formed integrally with the braid tube . In such an arrangement the end cap assembly 1090 may provide an air-tight seal .09866 74

[0236] However, in a preferred embodiment, the materiall 113 of the tube 1015A-15C comprises the braid tube 1052 (and optionally the outer bladder sleeve 1054 ) . In such an arrangement the bladder has its volume constrained radially by the braid tube 1052 , and longitudinally the end cap assemblies 1090 - for which the maximum separation is advantageously controlled by the resistance to longitudinal extension of the braid tube 1052 .

[0237] The floor panels 1030 may each be inflated by a gas connection with one of the tubes 1015A-15C of lower beams 1011. However, it is preferred that the floor panels 1030 are inflated by a different gas connection to the tubes 1015A-15C . Advantageously, the floor panels 1030 are inflated in parallel, but adjacent panels are inflated by gas from different gas connectors .

[0238] Figure 68 shows an example arrangement at one end of a bladder 1050. An end opening 1200 of the bladder 1050 is partially closed by e . g . PU glue 1202 and e . g . neoprene glue 1204. Embedded within the neoprene glue 1204 is an e . g . neoprene moulding 1206 into which is fitted an e . g . metal female tread insert 1208. To inflate the bladder a high pressure hose 1210 having an e . g . male treaded portion 1212 is screwed into the female tread insert 1208 and sealed thereto by O-ring 1214. The hose 1210 may pass through the aperture 1093 in the end plate 1092. It should be understood that this is just one example of an inflation arrangement for the bladder, and many alternatives may be used . Any of these components may comprise graphene .

[0239] Preferably the longitudinal beams 1009 and 1011 are be inflated independently from the side panels 1021a, 1021b (and are not connected via an inflation means ) as beams 1009 and 1011 are inflated up to 100 psi SWP (Safe Working Pressure ) whereas the side panels 1021a, 1021b are only inflated up to 10 psi SWP . However, it should be understood that this is merely one09866 75inflation arrangement and the invention is not restricted to any particular type of inflation arrangement .

[0240] An ambient venturi valve may be used to augment high pressure inflation to provide an initial fill of the tubes 15A-15C (and the connected panels ) . This is where a high-pressure gas supply (e . g . from a cylinder) will be augmented by air being drawn in through a venturi valve arrangement . The gas used to inflate the tubes 10115A-1015C (and the connected panels ) preferably comes from a gas supply system on the vessel 3, provided by e . g . compressors , air pumps , charged gas cylinders, chemical gas generators etc .

[0241] The use of the braid 1052 in the tubes 1015A-15C provides for great strength, and allows the tubes to be inflated at very high pressure, so the tubes , when inflated, are highly rigid. The end cap assemblies 1090 are configured to work effectively at the high pressures used to inflate the bladders 50 within the braided tubes . The configuration of the tubes in three multiple groups (in the embodiment, groups of three) , further enhances rigidity of the slide 1001 , and also provides redundancy in the event that a tube should become damaged . Further, the use of drop stitch material in the side panels 1021a, b and the floor panels 1030 allows these panels to withstand high inflation pressures whilst maintaining the desired shape as shown in the drawings and rigid surfaces . The use of graphene allows the components to be thinner / lighter for a given strength .

[0242] In an alternative embodiment, two or more bladders 1050 may be enclosed in a single braid tube 1052 . This provides redundancy, so that, should one of the bladders 1050 burst, the remaining bladder ( s ) are able to fill the space within the braid tube 1052 . Each bladder may include a sheet of material that includes graphene .09866 76

[0243] In the embodiments described above, each of the three longitudinal triple beams 1009 and 1011 comprises three longitudinal tubes 1015A-C . Figure 69 shows an alternative arrangement in which each of the three longitudinal triple beams 1009 and 1011 comprises six longitudinal tubes 1015A-F, each in the form of an elongated cylinder having a substantially circular cross-section, individually inflatable ( i . e . each inflatable independently of the others ) , stacked one ( 1015A) above two ( 1015B, 1015C) and two ( 1015B, 1015C) above three ( 1015D, 1015E, 1015F) so that they are tangential two by two over their length, and thus connected together adjacent and side by side . The tubes 1015A-F may be connected intermittently or continuously over their length, for example by an adhesive or by high-frequency welding, so that the cross-section of each beam 1009 or 1011 has substantially the shape of an equilateral triangle in the inflated state . Figure 15 shows the upper beam 1009. The lower beams 1011 may have the same general configuration of the upper beam 1009.

[0244] Each of the tubes is connected to the two adjacent tubes by adhesive 1060 which is applied preferably along the entire length of each of the tubes over a portion of the circumference of the tube that will abut the two adjacent tubes . The adhesive 1060 connects the tubes 1015A-F together to form a generally triangular structure, with the tube 1015A sitting above the two middle tubes 1015B and 1015C, and the two middle tubes 15B and 15C sitting above the three lower tubes 1015D, 1015E and 1015F. The upper beam 1009 formed by the tubes is connected to the inflatable side panels 1021a, b of each stiffening modules 1017 by adhesive 1060 , as shown in Figure 69. In particular, the upper tube 1015A has two regions of adhesive 1062 provided preferably along the entire length of the tube in a region that contacts the interior faces 1029a and 1029b of oppositely facing inflatable side panels 1021a and 1021b . Each of the middle tubes 1015B and 1015C includes a region of adhesive 1064 extending preferably along its entire length in the region that comes into contact with the interior faces 1029a and 1029b .09866 77Each of the three lower tubes 1015D, 1015E and 1015F includes a region of adhesive 1065 extending preferably along its entire length in the region that comes into contact with the interior faces 1029a and 1029b .

[0245] As an alternative to the direct connection between the adjacent tubes , and interior faces 1029a, 1029b, a strip or strips of material may extend between these elements and be adhered to adjacent ones of the elements by adhesive in a similar manner to that shown in Figure 57D or Figure 57E .

[0246] A beam sleeve, similar to that shown at 1066 in Figure 57B, may be fixed around the tubes 1015A-15E in order to hold the tubes together ( in addition to the adhesive 1060 ) .

[0247] The slide 1031 may be of significant length, such as 47 metres, and it will be appreciated by those skilled in the art that a slide of such a length requires a significant rigidity in order to avoid sagging .

[0248] Another type of slide is shown in Figs . 70 to 86.

[0249] Figure 70 shows a ship or other vessel 2001 that has an escape system 2003 provided on board and which is shown in a deployed state .

[0250] The escape system 2003 includes a slide 2005 that provides one or more passages from an entry platform 2007 on the ship 2001 to one or more exits 2009. The entry platform 2007 includes one or more entrances 2011 to the slide 2005. The entry platform 2007 may comprise graphene . The slide 2005 may be inflatable .

[0251] When it is desired to evacuate the ship 2001, passengers enter the slide 2005 via the entrance or entrances 2011 and travel down the slide 2005 until they reach the exit or exits 2009 at or near the sea level, and from where they can board one or more life rafts (or other type of crafts ) 2013.09866 78

[0252] Crafts 2013 may be inflatable . The crafts 13 may be of the type disclosed W02017 / 140890 filed on 17 February 2017 (our ref : 07076 ) or may be one of the crafts described herein .

[0253] The escape system may comprise a floating sea platform 2015 that is generally T-shaped and defines two recesses for accommodating the life rafts 2013 during boarding of the evacuated passengers . The sea platform 2015 may be inflatable . The sea platform 2015 may be formed of one or more sheets of material comprising graphene .

[0254] The slide 2005 , life rafts 2003 and sea platform 2015 may be stored in a deflated state in storage unit 2017 fixed to the ship 2001. The escape system 2003 advantageously occupies a small area on the ship 2001, so freeing up space for passenger accommodation and windows . The storage unit 2017 is closed by doors 2019 in order to control the environment in which the deflated escape system is stored. The storage unit 2017 and / or doors 2019 may comprise graphene .

[0255] When it is desired to deploy the escape system 2003, it is inflated by a supply of compressed gas on the ship 2001. The doors 2019 are opened and the slide 2005 , life rafts 2013 and sea platform 2015 are lowered to the surface of the sea .

[0256] The slide 2005 extends generally vertically. The slide extends generally parallel to the side of the ship 2001.

[0257] Figure 71 shows one embodiment of the slide 2005 in more detail . In this embodiment the slide 2005 comprises two slide assemblies 2021a and 2021b . Each of the slide assemblies 2021a and 2021b provides two helical paths 2023a and 2023b, each having a plurality of helix turns (a helix turn being a 360° turn of the path) . One of the slide assemblies 2021a will now be described in detail . The other of the slide assemblies 2021b is of the same configuration.09866 79

[0258] The slide assembly 2021a is of generally cylindrical or tubular form, and has an exit end 2025 attached to the sea platform 2015 and an entry end 2027 attached to the entry platform 2007. The slide assembly 2021a includes a substantially cylindrical outer wall 2029 and substantially cylindrical inner wall 2031. The outer wall 2029 and inner wall 2031 are formed from elastically deformable sheet material that may include graphene . The inner wall 2031 defines a central substantially cylindrical space 2033 along which the central axes of the helical paths 2023a and 2023b extend .

[0259] Between the outer wall 2029 and the inner wall 2031 an annular space is defined that accommodates the helical paths 2023a and 2023b . The helical paths 2023a and 2023b are connected (or fixed) to the outer wall 2029 and inner wall 2031. This enables the pitch of the helix turns to vary without imparting a twisting movement on the slide . The helical paths 2023a and 2023b may be formed by a sheet of material that includes graphene .

[0260] The helical paths 2023a and 2023b may have a double helix configuration. The helical paths 2023a and 2023b are interlaced. Each of the helical paths 2023a and 2023b turn in the same sense ( clockwise / anticlockwise ) about the cylindrical space 2033.

[0261] The entrance 2037a to the helical path 2023a is spaced on the entry platform 2007 from the entrance 2037b to the helical path 2023b, thereby allowing passengers to enter each of the helical paths 2023a and 2023b simultaneously.

[0262] The helical path 2023a has an exit 2039a directly into a first of the lifeboats 2013 , and the other helical path 2023b has an exit 2039b directly into the same life raft 2013.09866 80

[0263] Although two helical paths 2023a and 2023b are described, it should be appreciated that one, three or more helical paths may be provided.

[0264] The pitch or distance between adjacent helix turns of the helical paths 2023a and 2023b will vary as the distance between the entry platform 2007 and the surface of the water ( freeboard) changes, and also due to the effect of evacuee passengers travelling along the helical paths 2023a and 2023b and distorting the slide due to their weight . This movement can be referred to as concertinaing of the slide assembly 2021. The main deck height (where the entry platform 2007 is mounted) from waterline may be, e . g . , 16 metres . The sea conditions may be such that this distance may vary vertically + / - 6 metres .

[0265] Various different arrangements for controlling the spacing between the helix turns will now be described .

[0266] Figures 72 and 73 show alternative arrangements in which a series of spaced apart annular plates 2041 are provided that are fixed to the outer wall 2029. The annular plates 2041 each include a plurality of circumferentially distributed apertures or eyes (four are shown in the examples ) through which a corresponding plurality of wires or lines 2043 are slidably mounted, in order to maintain the cylindrical shape of the slide while allowing the length to vary. The wires / lines 2043 are fixed at the top of the slide 2005 and run through eyes in each annular plate 2041 and have a weight 2047 below the water surface to keep them taut . The annular plates 2041 may comprise graphene .

[0267] Opposite facing surfaces of the adjacent annular plates 2041 have fixed thereto opposite ends of a plurality of elastically deformable members 2045 . In the embodiments these elastically deformable member are elastic cords or ropes . The uppermost annular plate 2041 is fixed to the entry platform 2007. The weight 2047 may comprise a heavy ballast weight to09866 81prevent the elasticity of the members 2045 lifting the sea platform 2015 from the water .

[0268] The elastically deformable members 2045 may be configured in a linear or diagonal truss bungee arrangement, as shown in figures 72 and 73 , respectively. In Figure 72 the elastically deformable members 2045 extend parallel to one another and to the central axis of the helical paths 2023a and 2023b . In figure 73 the elastically deformable members 2045 extend obliquely to the central axis of the helical paths 2023a and 2023b in two different directions, the elastically deformable members 2045 crossing one another between the annular plates 2041.

[0269] The elastically deformable members 2045 are held in tension in normal sea conditions by weight 2047 .

[0270] Because the elastically deformable members 2045 have substantially identical elasticity, this tends to maintain a constant pitch along the helical paths 2023a and 2023b, so that the space 2049 between adjacent helix turns remains equal as the slide is longitudinally extended and contacted due to movement of the ship 2001 in the water .

[0271] An alternative approach to controlling the pitch of the helical paths 2023a and 2023b is shown in figures 74A, B and C . In this arrangement spaced annular plates 2041 , like those described with reference to figures 72 and 73 are again provided . For the sake of clarity figures 74A, B and C do not show the helical paths , other than schematically in figure 74C .

[0272] A series of pulleys 2051 and lines 2053 are provided that are attached to the annular plates 2041 to maintain the annular plates 2041 equidistant . The lines 2053 are all attached to the weight 2047. Each of the lines 2053 is of the same length and is attached to one of the plates 2041. Each line passes around one or more pulleys 2051 before being attached to a plate09866 822041 in order to control the longitudinal position of that plate 2041. As in figure 72 and figure 73 , a weight 2047 is provided in order to keep the lines 2053 in tension.

[0273] Figures 75A, B and C show a further alternative arrangement for maintaining an equal pitch between the helix turns of the helical paths 2023a and 2023b . In this arrangement spaced annular plates 2041 , like those described with reference to figures 72 and 73 are again provided . For the sake of clarity figures 75A, B and C do not show the helical paths, other than schematically in figure 75C .

[0274] In this embodiment one or more constant tension winches 2055 are provided with multiple drum diameter sections, around each of which a respective line 2057 is wound, the distal end of each of the lines 2057 being attached to a respective one of the annular plates 2041. The platform mount 2047 is weighted in this embodiment in order to keep the lines 2053 in tension . This arrangement requires a source of power for the winch 2055 and a feedback system. The arrangement of figures 75A, B and C may be combined with the arrangement of figures 74A, B and C .

[0275] Figures 76, 77A, 77B, 78A and 78B show an arrangement for maintaining a minimum pitch or spacing between adjacent helix turns of the helical paths 2023a and 2023b . In this embodiment, as in figures 72 , 73 , 74 and 75 wires / lines 2043 are provided. However, in this arrangement, rather than annular plates 2041, a series of hollow cylinders or tubes 2059 are provided to which the wires / lines 2043 are slidably coupled. The cylinders 2059 may be coupled to each other by elastically deformable members 2045 (not shown) as in Figures 72 or 73.

[0276] According to this embodiment, when the distance ( freeboard) between the entry platform 2007 and the surface of the sea reduces significantly, and the elastically deformable members 2045 are no longer held in tension, and so the tendency of the elastically deformable members 2045 to maintain the equal09866 83pitch is no longer effective, the cylinders 2059 will prevent the pitch reducing below a minimum value by adjacent cylinders 2059 sliding along the wires / lines 2043 until they abut (as shown in Figures 78A and 78B) , whereafter no further reduction in pitch in the region of the cylinders 2059 is possible .

[0277] The cylinders 2059 may be inflatable . They may each be a unitary inflatable structure, or may comprise a series of connected inflatable linear tubes or tubular rings which may allow for easier integration with other parts of the slide . The cylinders 2059 may be formed of drop stitch (or drop thread) material, having a form as shown in Figure 59. In such drop stitch a material, thousands of (e . g . nylon) threads connect the opposite faces to keep the panels in the desired shape when inflated and to provide rigidity. The treads may comprise graphene . By having the cylinders 2059 inflatable, this allows for the slide to be stored in a compact deflated state . The cylinders 2059 when deflated do not prevent the pitch reducing below the minimum value mentioned above - thereby facilitating compact storage . The outer material of the cylinders 2059 may comprise one or more sheets of material that includes graphene .

[0278] Figure 79 shows an alternative arrangement of slide 2005 to that of figure 71, in which a single slide assembly 2021 is provided.

[0279] The slide assembly 2021 provides two helical paths 2023a and 2023b, each having a plurality of helix turns .

[0280] The slide assembly 2021 is of generally cylindrical form, and has an exit end 2025 attached to the sea platform 2015 and an entry end 2027 attached to the entry platform 2007 . The slide assembly 2021 includes a substantially cylindrical outer wall 2029 and substantially cylindrical inner wall 2031. The outer wall 20229 and inner wall 2031 are formed from elastically deformable sheet material . The inner wall 2031 defines a central09866 84substantially cylindrical space 2033 along which the central axes of the helical paths 2023a and 2023b extend .

[0281] Between the outer wall 2029 and the inner wall 2031 an annular space is defined that accommodates the helical paths 20223a and02 23b . The helical paths 2023a and 2023b are preferably fixed to the outer wall 2029 and inner wall 2031. The helical paths 2023a and 2023b may have a double helix configuration. The helical paths 2023a and 2023b are interlaced. Each of the helical paths 2023a and 2023b turn in the same sense about the cylindrical space 2033.

[0282] In contrast to figure 71, where each helical path 2023a and 2023b provides a single track along which an evacuating passenger can slide, the figure 79 arrangement provides each of the helical paths 2023a and 2023b with twin tracks 2061a and 2061b arranged side by side . A dividing wall may be provided between the tracks 2061a and 2061b . The dividing wall may be formed of drop stitch material of the type shown in figure 59.

[0283] At each entrance 2037a and 2037b the two tracks 2061a and 2061b are available, so two passengers can enter each of the helical paths 2023a and 2023b simultaneously. The entrance 2037a to the helical path 2023a is spaced on the entry platform 2007 from the entrance 2037b to the helical path 2023b, thereby allowing passengers to enter each of the helical paths 2023a and 2023b (each having two tracks ) simultaneously.

[0284] The helical path 2023a has an exit 39a directly into a first of the life rafts 2013, and the other helical path 2023b has an exit 2039b directly into a second of the life rafts 2013.

[0285] Although each of the helical paths 2023a and 2023b is described with twin tracks 2061a and 2061b arranged side by side, it should be understood that tree or more tracks (arranged side by side, or otherwise ) may be provided.09866 85

[0286] Although two helical paths 2023a and 2023b are described, it should be understood that one, three or more helical paths (each with one, two, three or more tracks ) may be provided .

[0287] According to the figure 79 embodiment, although only a single slide assembly 2021 is provided, the evacuation rate is generally the same as the slide of figure 71 due to the twin tracks 2061a and 2061b . The twin tracks 2061a and 2061b may be formed by one or more sheets of material that includes graphene .

[0288] Figure 80 shows a further arrangement of the slide 2005 , which includes a slide assembly 2021 of the same general configuration as in figure 79, having two helical paths 2023a and 2023b, each with twin tracks 2061a and 2061b . The helical paths extend from the entry platform 2007 but not all the way to the sea platform 2015 . Instead, a linear (non-helical) slide assembly 2063 extends from the lowermost helix turn of each other helical paths 2023a and 2023b to the upper surface of the sea platform 2015 . In this embodiment the slide assembly 2021 having the helical paths 2023a and 2023b may have a fixed vertical length (rather than concertinaing in the manner of the previously described embodiments ) . Variations in distance between the entry platform 2007 and the surface of the sea are accommodated by variations in the angle of inclination of the linear slide assembly 2063 to the upper surface of the sea platform 2015 . The linear slide assembly 2063 may comprise graphene .

[0289] In any of the embodiments it is advantageous for the slide 2005 to be attached to the ship 2001, not only where it connects to the entry platform 2007 , but also at one or more positions closer to the surface of the sea .

[0290] Figure 80 shows one example of a bowsing line fixture point 2065 that is fixed to the hull of the ship 2001 and to which the slide 2005 is attached by a bowsing line (not shown) .09866 86The bowsing line fixture point 2065 in shown more clearly on Figure 81, and comprises a plurality of reinforced high pressure inflatable tubes 2067 . The tubes 2067 may be mounted to the hull of the ship 2001 by the storage unit 2017 or entry platform 2007. The tubes 2067 may provide a bowsing line fixing location close to the waterline that the storage unit 2017 or entry platform 2007 - e . g . 10 meters closer to the waterline that the storage unit 2017 or entry platform 2007. Advantageously, the inflatable tubes 2067 may be deflated when not in use . The tubes may be formed of drop stitch material of the type shown in figure 59. The inflatable tubes 2067 may have an outer material that comprises at least one sheet of material that includes graphene . The drop stitches may extend between surfaces of the outer material .

[0291] A plurality of retractable or removable bowsing line fixture points 2065 may be mounted spaced apart to the vessel 2001 and for attachment to corresponding attachment parts spaced along the slide 2005 between an entrance 2011 to the slide at the vessel 2001 and the water .

[0292] The bowsing line fixture points 2065 may be configured to be magnetically coupled to the structure .

[0293] The bowsing line fixture points 2065 may comprise a plurality of sections moveable between a deployed configuration and a retracted configuration. The bowsing line attachment part sections may be configured foldable or mounted for telescopic relative movement .

[0294] The bowsing line fixture points 2065 may be configured to be coupled to the vessel 2001 by suction .

[0295] One or more bowsing line fixture points 65 may be used with any embodiment of the invention, including those shown in Figures 71 to 76 and 77 to 79.09866 87

[0296] Figures 82A and 82B show a slide 1005 of the type of the figure 76 embodiment, where two side-by-side parallel slide assemblies 2021A and 2021B are provided and extend between the entry platform 2007 and the sea platform 2015 .

[0297] In any of the embodiments the helical paths 2023A and 2023B may each be formed of a continuous helical member (as shown in figures 71 to 82 ) that extends from the entry platform 2007 to the sea platform 2015 . The continuous members may be inflatable . The continuous members may be formed of drop stitch material of the type shown in figure 59. The continuous members may include graphene .

[0298] As an alternative to continuous members , the helical paths 2023a and 2023b may be formed of a series of discrete parts .

[0299] Figures 16A, B and C show an arrangement of the helical paths 2023A and 2023B, where the paths are formed by a plurality of partially overlapping slide sections 2083A and 2083B . Each section 2083A and 2083B has an upper surface having an exposed portion 2085 and overlapped portion 2087 that is overlapped by the section immediately above . The exposed portions 2085 are arranged to define a helical path and are the surfaces along which evacuating passengers slide . The sections 2083A and 2083B may be tapered from the overlapped portion 2087 to the distal end of the exposed portion 2085 to provide an inclined surface along which the evacuating passengers slide . The gap between the sections 2083A and 2083B may vary in some embodiments as the distance between the entry platform 7 and the surface of the sea varies .

[0300] The sections 2083A and 2083B may be inflatable, and may be formed of drop stich material of the type shown in Figure 58 . However, it should be understood that the sections 2083A and 2083B (and any other parts shown in Figures 83A, B and C) may09866 88be non-inf latable - e . g . they may be solid or hollow and rigid or flexible . The sections 2083A and 2083B may include graphene .

[0301] In any of the embodiments dividing walls 2089 may be provided between the helical paths 2023A and 2023B, between the helical path 2023A and the outer wall 2029, and between the helical path 23B and the inner wall 31. The dividing walls 89 may be formed of a series of cylindrical sections . The sections may be inflatable, and may be formed of drop stich material of the type shown in figure 59.

[0302] In any of the embodiments , as shown in figures 84A and 84B, a plurality of transverse horizontal supports 2099 may be provided underneath the helical paths 3023A and 32023B, and which are attached at opposite ends to the outer wall 3029 and the inner wall 2031, respectively. The supports 2099 may be inflatable . The supports may be formed of drop stitch material of the type shown in figure 39. The supports 2099 may include graphene .

[0303] The helical paths 2023A and 2023B may alternatively, or additionally, be suspended by supports 2091 from above, as shown in figures 85A and 85B . The supports 91 are attached at opposite ends to the outer wall 2029 and the inner wall 2031. The supports 2091 are attached to the helical paths 1023a and 1023b by cables 2093.

[0304] Figure 86 shows in detail an example configuration of the sea platform 2015 . The sea platform 2015 may be inflatable . The sea platform 2015 may be formed from drop stitch material of the type shown in figure 59. The sea platform 2015 may include one or more sheets of material that comprises graphene .

[0305] The edges of the central bar 2100 of the sea platform 2015 (that extends from the top bar 2011 of the sea platform 15 ) include vertical walls 2102 that extend above the flat upper09866 89surface of the platform 2015 along all or part of the central bar 2100.

[0306] Additionally, or alternatively, longitudinal stiffening beams 2104 may be provided along the central bar 100. The longitudinal stiffening beams 2104 may comprise graphene .

[0307] Embodiments have been described with one slide assembly, with two slide assemblies, and with one or two tracks for each helical slide . It should be understood that more than two slide assemblies and / or more than two tracks may be provided . Aspects of the different embodiments may be mixed with one another - e . g . so that a single slide assembly is provided with a single helical path having one or two tracks .

[0308] Although the invention has been described with reference to embodiments that relate to particular devices, it should be appreciated that the principles could be applied any other type of device . The device may be a lifesaving appliance such as a submarine escape suit, lifej acket, or single or multiple seater liferaft . The device may have another application that is not lifesaving . The device may be any lifesaving appliance as defined The International Life-Saving Appliance (LSA) Code . The device may be safety and / or survival equipment in general .

[0309] The invention is also applicable to rescue appliance (or parts thereof ) that are not inflatable . For example, the roof 328 in Fig . 11 is not inflatable but may be formed of a sheet of flexible material that includes graphene .

Claims

09866 90CLAIMS1 . A rescue appliance having at least one sheet of flexible material that includes graphene .2 . The rescue appliance of claim 1, wherein the graphene included in the sheet of flexible material comprises the graphene nano platelets .The rescue appliance of claim 1 or 2 , wherein the sheet of material further includes a flexible polymer .4 . The rescue appliance of claim 1 , 2 or 3, wherein the sheet of material includes polyurethane, PU .5 . The rescue appliance of any one of claims 1 to 4 , wherein the sheet of material includes thermoplastic polyurethane, TPU.

6. The rescue appliance of any one of claims 1 to 5 , wherein the sheet of material includes between 1 and 10% graphene by weight, preferably 1.5% graphene by weight .7 . The rescue appliance of any one of claims 1 to 6, wherein the sheet of material has a thickness of between 100 and 150pm.8 . The rescue appliance of any one of claims 1 to 7 , wherein the sheet of material is fluid impermeable .

9. The rescue appliance of any one of claims 1 to 8 , wherein the sheet of material is moisture-vapour permeable .

10. The rescue appliance of any one of claims 1 to 9, wherein the sheet of material is formed from fibres , threads or yarn that contains graphene .

11. The rescue appliance of claim 10 , wherein the fibres , threads or yarn are woven together to form the sheet of material .09866 9112 . The rescue appliance of any one of claims 1 to 11, including first and second sheets of material, one of which comprises said at least one sheet of flexible material that includes graphene .

13. The rescue appliance of claim 12 , wherein the first sheet of material is arranged to support the second sheet of flexible material .14 . The rescue appliance of claim 12 or 13 , wherein the second sheet of flexible material has a lower modulus of elasticity than the first sheet of material .15 . The rescue appliance of claim 12 , 13 or 14 , wherein the second sheet of flexible material is bonded to the first sheet of material .

16. The rescue appliance of claim 12 , 13 or 14 , wherein the second sheet material is separate from the first sheet of material .17 . The rescue appliance of any one of claims 12 to 16, wherein the second sheet of material flexible material forms at least part of an inflatable bladder .18 . The rescue appliance of claim 17 when dependent on claim 15 or 16, wherein first sheet of material is configured to limit the expansion of the inflatable bladder .

19. The rescue appliance of any one of claims 12 to 18 , wherein the first and / or second sheet of flexible material includes graphene .

20. The rescue appliance of any one of claims 1 to 19, wherein the sheet of flexible material that includes graphene forms at least part of an inflatable device having a drop stitch structure .09866 9221 . The rescue appliance of any one of claims 1 to 28 , wherein the sheet of flexible material that includes graphene is connected to another sheet of material by an in shear and / or in peel connection .22 . The rescue appliance of any one of claims 1 to 21 , wherein the rescue appliance is inflatable .

23. The rescue appliance of any one of claims 1 to 22 , wherein the rescue appliance is an inflatable survival craft .24 . The rescue appliance of claim 23 , wherein the inflatable survival craft is a liferaft, single seat liferaft, multiple seat liferaft, lifeboat or marine escape system, MES .25 . The rescue appliance of any one of claims 1 to 24 , including a floor, and an inflatable structure having an inner layer and an outer layer, wherein the inner layer is separable from the outer layer, and wherein the floor is connected to the inflatable structure .

26. The rescue appliance of claim 25 , wherein the inflatable structure comprises a buoyancy tube at the periphery of the liferaft .27 . The rescue appliance of any one of claims 23 to 26, including an inflatable chamber having an inner layer laminated to an outer layer, wherein the arrangement is such that the inner and outer layers partially de-laminate when the chamber is inflated .28 . The rescue appliance of any one of claims 1 to 24 , including inflatable members, the survival craft comprising a hull formed from the inflatable members and an inflatable wall formed from the inflatable members for mounting a rigid pod to the hull .09866 9329. The rescue appliance of claim 28 , wherein at least one of the inflatable members is formed from a drop thread material .

30. The rescue appliance of claim 28 or 29, wherein the inflatable wall facilitates the application of motive power from a propulsion source to the hull to move the hull in water .

31. The rescue appliance of claim 28 , 29 or 30, wherein the hull includes a floor extending between the gunwales , wherein the floor is formed by a plurality of modular inflatable chambers in a cross laid arrangement and / or with multiple layers .32 . The rescue appliance of claim 31 , wherein the floor supports the inflatable wall .

33. The rescue appliance of any one of claims 1 to 22 , wherein the rescue appliance is an escape slide or escape chute .34 . The rescue appliance of claim 33, for evacuating people from a first structure to a second structure, and having a slide, comprising : at least three longitudinal beams, including two lateral lower beams and an upper beam, spaced apart transversally over their length and substantially parallel to each other in the inflated state, each beam comprising at least one inflatable longitudinal tube; and a plurality of inflatable lateral panels connected to said upper beam and to said lateral lower beams; wherein the inflatable lateral panels comprise drop stitch material .35 . The rescue appliance of claim 34 , wherein the inflatable longitudinal tube comprises a braid tube .

36. The rescue appliance of claim 33, comprising a slide for facilitating evacuation from a structure to water, wherein the slide comprises at least one helical path, wherein the slide comprises spacing means for controlling the pitch09866 94between helix turns of the or each of the helical inflatable paths ; wherein the spacing means is operable to set a minimum distance between two adj acent helix turns of the or each of the helical inflatable paths; and wherein the spacing means comprises a plurality of hollow cylinders attached to the slide, the gap between adjacent ones of the hollow cylinders varying with the pitch between the helix turns, and the abutment of adjacent hollow cylinders preventing the distance between two adj acent helix turns falling below said minimum distance .37 . The rescue appliance of claim 36, wherein the or each helical inflatable path is configured to extend generally vertically between the structure and the water .

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