Reconfigurable and navigable salinity barrier systems and devices

Abstract

Systems and devices which provide flexible, configurable salinity barriers and barrier systems which limit the mingling of freshwater with saltwater in areas where such waters interact such as channels, canals, rivers, and bays. The disclosed systems and devices also provide a navigable portion which allows sailing vessels to pass therethrough while still limiting the mingling of freshwater and saltwater.

Description

RECONFIGURABLE AND NAVIGABLE SALINITY BARRIER SYSTEMSAND DEVICESCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is related to and claims priority to US Provisional Patent Application No. 63 / 621,303 filed on January 16, 2024 which is incorporated herein by reference.FIELD

[0002] The claimed technology relates generally to structures used in navigable waters and more particularly to floating partition structures for use in canals or navigable rivers.BACKGROUND

[0003] Locations where fresh water and sea water meet present an issue with saline intrusion into freshwater bodies. In areas where freshwater outflow is sufficiently high sea water is held back from infiltrating up into a freshwater body such as a river or canal. If freshwater outflow is too low, such as during a drought, sea water can migrate into such freshwater bodies increasing their salinity and potentially having deleterious ecological impacts. Changes made to a landscape to improve waterways for navigation by vessels and / or to divert freshwater flow for other uses can exacerbate this problem. The construction of canals which connect sea water to freshwater bodies which had been previously isolated can introduce saline water infiltration into new ecosystems. Lake Gatun in Panama is one example of a freshwater body impacted by such saline infiltrationvia the Panama Canal. Not only does salination of such bodies of water impact the local flora and fauna but it also impacts the utility of such affected bodies as sources of drinking water for nearby populations. There is a need for a barrier which slows the exchange of sea and freshwater at such interfaces but does not prevent navigation by vessels through such interfaces.SUMMARY

[0004] In one aspect, a navigable saline barrier system is provided which includes a water-impermeable barrier disposed in a waterway and a volume compensation system, the water-impermeable barrier including a first non-navigable barrier, a second non- navigable barrier, and a navigable barrier having a floatation portion and an anchor portion; where the navigable barrier is disposed between the first and second non- navigable barriers and where the impermeable barrier is disposed between and prevents water from flowing between a saltwater portion and a freshwater portion of the waterway. Optionally, the floatation portion keeps the top of the navigable barrier at water level and the anchor portion keeps the bottom of the navigable barrier at the bottom of the waterway. In one example the navigable barrier is capable of adapting its shape to the hull of a ship allowing a ship to pass therethrough and the navigable barrier may return to its original shape after as ship has passed therethrough. The first non-navigable barrier and second non-navigable barrier may be anchored to opposite sides of the waterway. Optionally, the waterway is a canal disposed between a freshwater body and a saltwater body and bounded by concrete sidewalls. The first non-navigable barrier and second non- navigable barrier may be flexible and move in response to volumetric hydraulic pressure caused by tides or other forces. The navigable barrier may be made from a phase transforming cellular material which is optionally bistable and / or metastable.

[0005] In another aspect, a navigable saline barrier system having a water-impermeable barrier disposed in a waterway which separates a saltwater body from a freshwater body, the water-impermeable barrier including a first non-navigable barrier anchored to one side of the waterway, a second non-navigable barrier anchored to the opposite side of thewaterway, and a navigable barrier disposed between the first and second non-navi gable barriers and having a floatation portion and an anchor portion; a volume compensation system configured to maintain a freshwater level on one side of the water-impermeable barrier higher than the saltwater level on the other side of the barrier, where the navigable barrier is configured to adapt its shape to vessels passing therethrough. Optionally, the floatation portion keeps the top of the navigable barrier at water level and the anchor portion keeps the bottom of the navigable barrier at the bottom of the waterway. The navigable barrier may return to its original shape after as ship has passed therethrough. The first non-navigable barrier and second non-navigable barrier may be flexible and move in response to tidal hydraulic pressure. The navigable barrier may be made from a phase transforming cellular material. The navigable barrier may further comprise an internal structure made from a phase transforming cellular material covered by an elastomeric membrane. The navigable barrier may include a plurality of bars capable of expanding to accommodate the hull of a vessel and contracting to close behind said vessel. Optionally, the volume compensation system is a tidal lock disposed between the water-impermeable barrier and the saltwater body, or a pump operationally connected to a freshwater reservoir and configured to pump fresh water in and out of the freshwater side of the water-impermeable barrier. The system may further include a ramp which is draped over a portion of the navigable barrier to assist in opening the navigable barrier in response to a ship passing therethrough.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] FIG. l is a side view of a navigable barrier according to one example of the disclosed technology at high tide.

[0007] FIG. 2 is a side view of a navigable barrier in FIG. 1 at low tide.

[0008] FIG. 3 is a perspective view of a navigable barrier system according to one example of the disclosed technology.

[0009] FIG. 4 is a perspective view of a navigable barrier system according to another example of the disclosed technology.

[0010] FIG. 5 is a perspective view of a navigable barrier system according to still another example of the disclosed technology.

[0011] FIG. 6 is a partial cross sectional front view of a ship passing through a navigable barrier system according to one example of the disclosed technology.

[0012] FIG. 7a shows a force displacement curve for a bistable mechanism.

[0013] FIG. 7b shows a force displacement curve for a metastable mechanism.

[0014] FIG. 8 shows examples of ID PXCM under load.

[0015] FIG. 9 is a partial cross sectional front view of a ship passing through a navigable barrier system according to one example of the disclosed technology.

[0016] FIG. 10 shows examples of 2D PXCM geometries.

[0017] FIG. 11 shows how forces should be applied to transition a PXCM from one stable configuration to another stable configuration.

[0018] FIG. 12 shows an example of how bladders may be used in ID PXCM.

[0019] FIG. 13 shows examples of how bladders may be used in 2D PXCM.

[0020] FIG. 14 is a schematic of a configuration of a navigable barrier system according to one example of the disclosed technology.

[0021] FIG. 15 is a schematic of a configuration of a navigable barrier system according to another example of the disclosed technology.

[0022] FIG. 16 is a schematic of a configuration of a navigable barrier system according to still another example of the disclosed technology.

[0023] FIG. 17 is a schematic of a configuration of a navigable barrier system according to yet another example of the disclosed technology.

[0024] FIG. 18 is a schematic of a configuration of a navigable barrier system including a tidal lock according to one example of the disclosed technology.

[0025] FIG. 19 is a partial cross sectional side view of a ship traversing a navigable barrier system with a ramp according to one example of the disclosed technology.

[0026] FIG. 20 is a partial cross sectional perspective view of an example of a movable barrier which may be used with the disclosed technology.

[0027] FIG. 2 lis a partial cross sectional view of a ship traversing a navigable barrier system according to one example of the disclosed technology.

[0028] FIG. 22 is a partial cross sectional perspective view of an example of movable barriers which may be used with the disclosed technology.

[0029] FIG. 23 is a partial cross sectional side view of an example of a movable barrier which may be used with the disclosed technology.

[0030] FIG. 24 is a partial cross sectional side view of another example of a movable barrier which may be used with the disclosed technology.

[0031] FIG. 25 is a plan view of one example of a PXCM framework and covering which may be used with the disclosed technology.

[0032] FIG. 26 is a perspective view of another example of a PXCM framework and covering which may be used with the disclosed technology.DESCRIPTION

[0033] For the purposes of promoting an understanding of the principles of the claimed technology and presenting its currently understood best mode of operation, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the claimed technology is thereby intended, with such alterations and further modifications in the illustrated device and such further applications of the principles of the claimed technology as illustrated therein being contemplated as would normally occur to one skilled in the art to which the claimed technology relates.

[0034] The present disclosure describes systems and structures for preventing / reducing the infiltration of sea water into fresh water bodies such as where a river or canal contacts an ocean or other salt water body. Several of the examples contained herein are described with respect to the Panama Canal which includes Lake Gatum, but the systems and structures disclosed herein may be adapted to any location where salt and fresh water come into contact, particularly where navigation by vessels is present.

[0035] In one example, a floating and adaptable structure is disclosed capable of following tidal or other volumetric variations, employing internal mechanisms based on multi-stable cells to adjust geometry and minimize losses of fresh water. Being deformable and dynamically adjustable, the barrier mimics the cross-section of ship hulls, avoiding the risk of interference with propulsion and rudder systems, ensuring smooth operation without entanglements or obstructions. In another example, the disclosed barriers are configurable in any desired shape and typically include a floating upper portion and a closure lower portion. Such configurations are compatible with volumevariations and adaptable to tidal height variations during operations. Such configurations may also be adapted to promote a higher freshwater level. In some examples, one or more openings allow for the passage of marine fauna through the barrier.

[0036] A general example of the disclosed technology is shown in FIG. 1-2. In this particular example, a structure similar to a barrier or separator 100 that can isolate the waters on both sides of the barrier 100. This barrier 100 is designed to be placed in a navigable canal or river where sea water and fresh water meet. This type of barrier 100 has an upper portion 102 which can float, always adapting to variations in tidal height. Additionally, this barrier 100 in its entire depth 104 can crinkle or stretch vertically with the aim of following variations in tidal height. This device is designed to preserve the fresh water of a river or canal from the saltwater of the sea in cases where the flow of fresh water from the river or canal is not sufficient to prevent the entry of saltwater during high tide.

[0037] The disclosed saline barriers may also have the ability to modify their geometry to keep the level of fresh water slightly higher than that of saltwater. This may be achieved by altering the level of the enclosed area of fresh water, meaning that reducing the enclosed area increases the level such as at high tide (FIG. 4) whereas decreasing the level is achieved by increasing the freshwater area such as at low tide (FIG. 3). In this particular example, flexible, waterproof, non-navigable side barriers 106 are disposed with a navigable barrier 108 between them. The navigable barrier 108 includes meta- / bistable elements discussed in greater detail below. Both the flexible side barriers 106 and the navigable barrier 108 have elements that allow for compensation of level variations and maintain the seal during movement such as those discussed herein. Alternatively, thelateral restraints 110 can be fixed and the navigable barrier 112 allowed to move along the canal 114 depending on tidal conditions to increase or decrease the height of the freshwater to the sea water (FIG. 5). It is preferable for the level of fresh water to be slightly higher than that of saltwater. Although the barrier acts as a filter, in instances where the seal fails there is the potential for water leakage. Furthermore, even under equal pressure conditions, there is the phenomenon of diffusion that could contaminate fresh water. Therefore, maintaining a slightly higher level helps minimize these leaks and preserve the quality of fresh water in the area. Optionally, if the disclosed barrier systems are used in areas which include locks to raise and lower ships the existing lock pumping systems may also be used in combination with the disclosed tidal or volume compensation systems to maintain a desired freshwater level.

[0038] The barrier moves over a flat bottom, similar to a ski. The flat base on the bottom can be assembled with prefabricated plates, and the gap with the canal bottom can be fdled with concrete. Alternatively, the saline barrier may function similar to a window curtain, reaching down to the bottom of the water body. Using flexible and impermeable materials, this barrier could further minimizing the possibility of permeability. This additional approach could enhance the effectiveness of the barrier by preventing unwanted saltwater leakage and ensuring better protection for fresh water in the designated area. The design also allows for the construction and installation of the entire system with minimal disrupting to river traffic. The procedure involves assembling the navigable barrier arranged longitudinally along the canal using an auxiliary buoy. Then, the auxiliary buoy approaches the buoy on the opposite side, closing the navigable saline barrier system.

[0039] In the event of a barrier breakage due to an accident, having a second barrier as a redundancy prevents excessive salt water / freshwater interchange during repairs and / or replacement of the damaged barrier. Such a system also allows for one barrier to be taken out of service for maintenance / repairs without compromising the protection provided by the backup barrier. Optionally, a backup barrier could be kept nearby and / or in the water ready to deploy quickly in the event of an accident with the primary / deployed barrier.

[0040] The navigable saline barriers optionally include a portion that acts as a deformable gate, adopting the lower shape of the ship's hull as it navigates through, further reducing freshwater losses that occur in the gaps between the navigable barrier and a ship's hull. This barrier has an internal structure formed by a multitude of components capable of absorbing the required deformation to allow the passage of the ship and will be discussed in greater detail below. In addition to this internal structure, which functions as a reconfigurable skeleton, the barrier may also include a waterproof film or coating surrounding the reconfigurable internal structure. This allows the barrier to be reconfigurable, rigid (once the shape of the ship's hull is established), and waterproof.

[0041] The navigable saline barriers may also include internal mechanisms which allow it to maintain a fixed deformation (particularly when the cross-sectional area of a ship's hull is at its maximum) to avoid contact with the rear region of the hull intended for propulsion and direction. Another optional set of internal mechanisms facilitates the rapid closure of the barrier when the vessel finishes crossing, minimizing freshwater losses. The internal mechanisms to reinforce the shape of the barrier when the cross-sectional area of the ship's hull is at its maximum and the mechanism for rapid closure, returning toits original shape, can be controlled with hydraulic pressure circuits and / or control systems operated by cables, for example.

[0042] Turning now to the navigable barriers, generally the barriers disclosed herein allow passage and adapt to the shape of a ship passing therethrough using systems of structured, bistable materials. A small amount of freshwater spillage due to the positive slope / height of fresh water compared to saltwater sides is anticipated by the tide compensating systems previously described. The operation of the navigable barriers is automatic and allow for passage of ships therethrough without the need for direct intervention or monitoring.

[0043] The structural foundation of the navigable saline barriers disclosed herein is based on materials known as Phase Transforming Cellular Materials (PXCMs), or phasechanging structured materials, which act as reconfigurable materials. These materials include mechanical cells designed to operate in a bistable and elastic manner, similar to a wall light switch. The bistable nature of these cells allows the material to have multiple stable states, causing the barrier to change its shape, as illustrated in FIG. 6. This property allows the barrier 118 to assume multiple stable states, dynamically altering its shape to accommodate the passage of a vessel 116 through a canal 120. Unlike traditional materials, PXCMs enable the barrier to efficiently and automatically adapt to the cross- sectional area of a ship's hull, minimizing freshwater losses and ensuring an effective seal. Within the context of PXCM, bistable mechanisms refer to structural elements with two stable configurations. As shown in FIG 7a, in a bistable mechanism the Force vs. displacement curve in (solid curve) and energy vs. displacement (dashed curve) has two stable configurations when Force is zero. These configurations are characterized bydistinct energy minima, allowing the material to exist in either state until an external force triggers a transition. Metastable mechanisms, on the other hand, involve structures with a single stable state and an adjacent, higher-energy state that serves as a potential energy barrier. As shown in FIG. 7b, in a metastable mechanism the Force vs. displacement curve in (solid curve) and energy vs. displacement ( dashed curve) has only one stable configuration when Force is zero. The transition to the higher-energy state can occur under specific conditions, often initiated by external stimuli. The key distinction lies in the number of stable states: bistable mechanisms possess two stable configurations, while metastable mechanisms have one stable state with the potential for a temporary shift to a higher-energy state. The controlled manipulation of these mechanisms in PXCM enables tailored material behavior, offering applications in areas such as barrier design and shape adaptation, as described in our inventive salinity barrier concept.

[0044] In some examples the PXCM employed in the navigable saline barriers is a ID cellular material, primarily exhibiting phase-transforming behavior in the vertical direction only. Unlike 2D alternatives, phase transformations in a ID PXCM 124 occur exclusively under loads 122 in one direction (FIG. 8). This characteristic makes it especially suitable for the specific mechanical behavior found in some examples of the navigable saline barriers disclosed herein, where vertical adjustments are useful for maintaining a proper seal between a barrier 126 and a vessel’s hull 128 (FIG. 9). While the current focus is on the ID PXCM for the navigable saline barrier, it's noteworthy that 2D PXCMs, which exhibit phase transformations in two directions, can find applications in some scenarios. For instance, the 2D PXCMs could be advantageous for constructingbarriers with enhanced lateral adaptability, improving performance in areas where lateral movements are critical. The introduction of PXCMs represents a paradigm shift in material design, offering unparalleled adaptability and mechanical responsiveness for applications ranging from structural engineering to advanced barrier systems. FIG. 10 shows additional examples of 2D PXCMs and their different geometries.

[0045] The functionality of the Phase Transforming Cellular Materials (PXCMs), whether ID or 2D, uses their ability to undergo controlled bistable transformations. The challenge lies in actuating these individual bistable unit cells efficiently to enable the desired cascade effect for opening and closing a navigable saline barrier. Several actuation mechanisms can be employed to achieve this, each offering advantages and considerations. FIG. 11 shows an example of how the internal forces may be applied at the cell level to induce phase transformation. In other words, these internal forces (that can be actuated remotely using hydraulic, pneumatic, or mechanical means), allow the configurations changes from one stable configuration to another stable (or metastable) configuration. FIG. 12-13 show examples of how bladders may be used in ID and 2D PXCM. Bladders do not have to necessarily be present in every cell (FIG. 13) but rather mechanisms of instabilities and dynamics / inertia that can be used to trigger adjacent cells.

[0046] In some examples, strategically positioned bladders within key cells can inflate and deflate on demand as shown in FIG. 12-13. In operation, inflation and deflation of bladders induce small forces, effectively toggling the bistable unit cells between stable configurations. If the PXCM is bistable, the bladders may be placed in a way that a certain group of bladders will “close” the cell and the second group will “open”. In thisway, the switch from one state to another one may be triggered remotely by just selectively controlling the pressure of the individual bladders through small hoses. The PXCM does not have to be necessarily bistable. It can also be metastable. Being metastable allows for additional functionality such that there is no need to add additional bladders to switch back to the original configuration as the cells would automatically switch back to their original stable condition. Fluid-based actuation allows for precise control and minimal mechanical wear. In other examples, actuation through mechanical means, similar to a bicycle braking cable systems. These cables can be operated remotely via motors, mechanical gear systems, levers, and the like. A set of actuated cable systems may replicate the effects of hydraulic / pneumatic actuation without relying on fluid presence. Mechanical actuation eliminates the need for fluid systems, reducing potential maintenance complexities. In another example, smart materials, including shape memory alloy wires, shape memory alloy devices, piezoelectric elements, and the like may be used. These materials can undergo controlled shape changes in response to external stimuli, providing an alternative actuation method. Such materials offer diverse options for actuation without the need for elaborate external systems. Architected materials may also be used to analogously achieve shape memory alloy-like behavior. Mimicking the characteristics of shape memory alloys for controlled actuation of bistable unit cells utilizes principles inspired by shape memory alloys while providing additional flexibility in material design. Implementation may require careful material selection and validation. The choice of actuation mechanism depends on specific design considerations, balancing factors such as precision, maintenance requirements, and system robustness.

[0047] In one example a saline barrier system according to the present disclosure may include at least one impermeable navigable barrier portion which adapts its shape to the hull of the ship to allow navigation through it and preventing the mixing of waters on both sides of the barrier; a flotation system to keep the navigable barrier at the water level; at least one horizontal barrier section or wall that completes the enclosure of the freshwater body, for example, up to the canal's edge; and at least one vertical barrier section which completes the enclosure to the canal's bottom and can crinkle to adapt to tidal variations. In some examples, the systems may also include an active water level control system to maintain a freshwater level slightly higher than the saltwater level so as to insure minimal contamination due to small leaks.

[0048] Some example configurations of saline barrier systems according to the present disclosure are shown in FIG. 14-18. These examples are not exhaustive and other configurations using the technology disclosed herein are also contemplated. FIG. 14 shows a system having fixed longitudinal sidewalls 200 (similar to a lock), with a floating navigable barrier section 206 moving along rigid walls 204 and a flat bottom. The navigable section below has a crinklable barrier to close the gap at different tide heights as previously described. Volumetric control such as caused by tides may be achieved by allowing the floating navigable barrier section 206 to move 208 along the sidewalls 200 towards or away from the freshwater body 202 so as to maintain a slightly higher level of freshwater than saltwater at the navigable barrier section 206 as previously described. FIG. 15 shows an example system having flexible sidewalls 220 attached at one end to a fixed channel wall 218 and the other end connected to a navigable barrier 222. For volume control the entire assembly, including the navigablesection and flexible sections, moves along the canal, maintaining fixed points only on the canal walls, similar to systems previously discussed. FIG. 16 shows a system having fixed longitudinal sidewalls 212 attached to channel walls 210 with a fixed navigable barrier 214 in the navigation direction. Tide level compensation is assisted by freshwater from a reservoir 216 and / or an active pumping system. FIG. 17 shows an example system using a transverse fixed sidewall with variable volume saltwater pouches. In this example, the freshwater area is enclosed by parallel rigid side walls 224 to which fixed sidewall portions 226 are attached. The navigable barrier section 230, is disposed between the fixed sidewall portions. Volume compensation due to tides is achieved through variable volume pouches / bags 228 that are inflated or deflated by seawater according to the tide's height. The volume in the bag 228 raises or lowers the level of freshwater in such a way that the height between freshwater and saltwater tends to equalize on both sides of the barrier. An additional pumping system over the saltwater can slightly raise the level of freshwater above saltwater. These bags 228 can be in a shape and size similar to trawl fishing nets but with impermeable walls, although other configurations may also be used. FIG. 18 shows an example of a system such as those disclosed herein used in conjunction with a tidal lock. In this example, rigid side walls 236 attached to canal walls 232, together with the navigable barrier 238 as previously described, enclose a freshwater reservoir 242 with a fixed height, which could, for example, be the average between high tide and low tide. On the seaward side of the navigable barrier 238, through a single-lock system 234, another reservoir of saltwater 242 is formed at the same level as the freshwater one. In this way, the navigable saline barrier operates without volumetric variations, and the slight elevation of freshwaterrequired can be generated by discharges from the river supplying the system. The lock 234 that separates the artificial saltwater reservoir 242 from the sea area subject to tidal variations can be supplied by reservoirs / sumps 240 of saltwater placed on one or both sides of the canal. The lock 234 takes in or discharges from these reservoirs 240 to operate. During low tide, the sump is discharged, and during high tide, the high-level reservoir is filled. The size of the reservoirs may be dimensioned to meet the required traffic. A tidal lock may also be used for volume control purposes in conjunction with the other systems and configurations disclosed herein.

[0049] Different designs, materials, and mechanisms may be used to achieve the closure of a navigable barrier which adapts to the shape of the hull according to the present disclosure. In one example, a passive deformable elastic system includes a mesh of cells that deform elastically, yielding to the passage of the vessel and closing when it completes crossing. The elastic recovery of the cells can be intrinsic to the material or activated, for example, by hydraulic pressure. However, such a passive system may pose challenges with the bow bulb of most ships. Optionally the temporary placement of a traditional bow mask for barrier crossing may be used in such situations. To prevent accidents, a stern mask may also be used. Alternative solutions include placing a ramp underwater, which, when the ship approaches, exerts pressure thereby initiating the deformation of the barrier 248 in advance of the ship 246 (FIG 19).

[0050] In other examples bars or plates for horizontal, vertical, or radial closure movement may be used. In such examples bars or plates can operate with an active system based on hull shape sensors (ultrasound, laser, contact, and the like.) as the vessel approaches the barrier. Such mechanisms allow for the early opening of the barrier whenthe vessel is approaching, and closure occurs when it is detected to have completed the crossing. For horizontal bars, it is possible to activate them in advance automatically by the hull's force, using lateral drive ramps on both sides of each horizontal bar. The combination of mechanisms like scissors, cells for elastic energy accumulation, or bistable cells can aid in smooth opening and closing, avoiding issues with the bow bulb, propeller, and rudder. Each closure bar may include internal materials and mechanisms that provide significant contraction and expansion capacity and fast operation.

[0051] Flotation systems for use with the navigable barrier portions disclosed herein are configured to adapt to the operation of the navigable barrier. The floatation system’s primary function is to keep the unaffected / unmoved sections of the navigable barrier afloat during passage of a ship. In the case of a deformable cell barrier, the flotation system acts to resist the force required for cell deformation without sinking the barrier in the lateral zone of the hull. In the case of a barrier activated by plates or bars, a flotation system ensures flotation that accompanies the deformation of these elements. In all cases, the top of the barrier uses flotation to achieve effective separation of freshwater from saltwater and to place level sensors that detect variations between them and activate the corresponding compensatory systems. In the case of deformable cells, the flotation volume contains elastic deformable material that supports the same degree of deformation as the cells. For horizontal bars, each time a reduction in length occurs, the floating volume may be segmented and rotate in the navigation direction, maintaining its buoyancy and reducing the space occupied in the transverse direction that is compressing.

[0052] Vertical barrier sections or depth adjustment are disposed at the base of the barrier systems disclosed herein. Below the navigable barrier and / or below the flexible barrier,an impermeable barrier is used which can adapt to variations in tidal height. This can be achieved with a waterproof membrane that simply wrinkles when reducing the depth. Cross-section of barrier / side barrier of an impermeable barrier, which does not need to be navigable, serves to complete the enclosure of the freshwater volume and separate it from the saltwater volume. It can be rigid or flexible, movable or static, as desired, depending on the volume compensation system being used. In flexible and movable cases, it typically contains a waterproof membrane anchored at the bottom with weights sliding along the seabed. The bottom part may have the ability to wrinkle to compensate for tidal height. It may be secured at the top with a flotation system. On the sides, at one end, it typically has a buoy which is also connected to the navigable barrier, while the other end remains fixed to the coast or canal wall.

[0053] An active volume compensation system allows adjustments to tidal height variations. To adapt to tidal height variations, the volume of freshwater does not have the same dynamics as tides, requiring leveling the levels. This can be achieved through transfer systems with reservoirs and drains through active pumping or gravity, as explained previously. The freshwater mirror area can also be varied to alter the level, either with fixed walls acting as a piston or with flexible walls, similar to squeezing a plastic bottle; the movement of flexible walls can be activated with traction cables. Another possible way is through inflatable bags placed on a fixed wall, changing from a concave to convex position activated by tidal height, thus varying the freshwater level to balance it with saltwater.

[0054] An active control system to maintain a slightly higher freshwater level may also be included int eh disclosed systems. The volume compensation and freshwater andsaltwater level balance system can primarily work with tidal force, but if a higher level is necessary, it could be added by tensioning the cables of the flexible membrane drive, through pumping, or through the transfer of freshwater from a reservoir. Optionally, one or more places in the barrier, preferably the fixed portion of a barrier in such systems that used fixed portions, include one or more passages for marine fauna to pass therethrough. Where necessary or desired, one or more permanent openings can be introduced which are small enough area for the passage of fish or other aquatic creatures and a labyrinthine and tortuous flow shape to minimize freshwater leakage.

[0055] In one example of the disclosed saline barrier systems is shown a mechanism that accomplishes this function by compressing or expanding bars that move horizontally. The complete barrier is divided into two sets of bars, with bars on the right and left sides relative to the center when viewed from the front. This configuration allows adaptation to the depth of the ship's draft by opening or closing more or fewer pairs of horizontal bars (rows), allowing the copying of the cross-section shape by varying the opening of the bars based on depth. Within a certain range, it is also possible to adapt to a ship positioned offset from the center of the barrier. That is, a ship that advances through the barrier with its center not aligned with the barrier’s center. The way these horizontal bars expand or contract is based on an internal structure or skeleton capable of making that movement, and an impermeable membrane covering the structure, conferring the seal ability of the assembly to the passage of water from one body of water to another.

[0056] While there are many solutions for the internal structure, a simple and well- known alternative might be those used in extendable scissors or extendable wall clotheslines, where an actuator 250 at one end achieves the desired length of extension asshown in FIG. 20. In this example, the scissor system 252 is covered by an impermeable membrane 254. As the system expands, thereby reducing a transverse dimension (for example, the height), this effect can be compensated by placing longitudinal cables from the free end of a bar to the fixed end connected to the rigid wall of the barrier. These cables can be positioned at each corner of a rectangular plate at the free end. If these cables can maintain a desired tension, they can act as a displacement guide for the adjacent bars.

[0057] Given that the cross-section of cargo ships 256 is mostly a convex shape, with a wider upper part, the lower bars 260 will always act as a guide for the adjacent upper bar 258 (the lower, the narrower). This condition facilitates the sliding mechanisms as the upper bar 258 slides across the lower bar 260. The navigable saline barrier in this example may have a final rigid bar 262 at its bottom, below the maximum allowable draft, which provides structural support for the system by connecting the lateral rigid walls 264 at the base and serving as a support for the lowest retractable bar 266 as seen in FIG. 21-22.

[0058] To allow such a navigable salt barrier to be used by, for example, Neo-Panamax ships, the range of expansion and contraction of these bars is approximately 30 meters. To reasonably discretize the profile of the cross-section in depth (with a maximum draft of 15 meters), these bars can be approximately 1 meter in height each. In other settings, larger or smaller bars may be used to accommodate ships of other sizes. The navigable salt barrier must withstand a drag flow in the direction of navigation produced by the moving vessel, the differential pressure that drives density currents, and the convective flows that occur when the ship moves from one body of water to another. To resist theseforces in the axial direction, the NSB must have a reasonable slenderness ratio as seen inFIG. 22. For a height of 15 meters, approximately 4 meters are required in the axial direction in the lower bar, progressively reducing the width of each bar slightly as it goes up to improve the stability of the entire structure. In other examples, wider or narrower bars may be used as conditions require.

[0059] The flat end of each 1 -meter-high bar typically does not achieve a perfect fit with the ship's cross-sectional profile because this profile changes continuously. Additionally, for safety reasons, the navigable salt barrier preferably does not have direct contact with the hull of the moving ship. As a result, there will be water leakage from one body to another through the interstitial spaces around the ship's cross-sectional perimeter. The direction of these leakage currents will depend on the difference in height between the fresh water and salt water, the depth at which it occurs, the clearance, and the direction and speed of the ship's movement. Optionally, one alternative to reduce these leakage currents is to add a soft material 268, such as foam rubber, to the flat end of each bar 270 as shown in FIG. 23.

[0060] One limitation of an extensible scissor system which may limit the overall length of such systems (and thereby limit the width of ships they may accommodate) is that within a wide range of expansion a vertical actuator at the fixed end over the two arms of the scissors has a challenging time controlling the extension and experiences very different forces depending on the degree of expansion. If the scissors only had restorative force and the aforementioned cables only contracted the bar when wound, controlling the system would be improved. A simple spring system would have very high force when fully contracted and would be very lax when fully extended in such a configuration.

[0061] In another example, the scissors may be replaced by a series of bistable structures 272 in sequence as shown in FIG. 24, which can maintain the restorative force within a bounded range throughout the entire extension of the bar 274. Upon reaching the threshold force, one unit undergoes buckling, reducing the tension, and sequentially, without exceeding the same threshold force, all cells close. When the cable tension is reduced, the system begins to expand to restore its original length, but the restorative force decreases slightly and then increases again, keeping it within the same range as each cell expands sequentially.

[0062] In another example of the disclosed saline barrier systems is shown a mechanism that accomplishes this function by using an internal “skeleton” 276 made of a periodic cellular material (PXCM) that provides reconfigurability covered by a waterproof “skin” 278 that ensures the barrier 280 provides separation between saline and freshwater environments as seen in FIG. 25-26. The core structural element of a barrier according to these particular examples is a periodic cellular material (PXCM) that serves as the skeleton. PXCMs are composed of unit cells that can transition between two stable configurations, providing a bistable system. This bistability allows the barrier to adjust its shape by switching between different geometric configurations, accommodating external forces such as the impact of vessels or water pressure variations. The bistable nature is what gives the PXCM skeleton its reconfigurability while maintaining stability in either state.

[0063] One advantage of using PXCMs is their ability to undergo large deformations without permanently altering their structural integrity. These bistable unit cells can change between two configurations based on external stimuli (e.g., pressure ormechanical force), enabling the barrier to reshape itself to accommodate the contours of ship hulls or other structures passing through it. Additionally, the collective behavior of many bistable unit cells allows for macroscopic reconfigurability in the barrier. The cellular skeleton essentially mimics biological skeletons by providing a foundation upon which the entire structure can rely, yet remaining flexible enough to adjust to changing conditions. Just as the bones in an animal’s legs or wings provide both support and mobility, the PXCM skeleton ensures the barrier can adapt to environmental changes without losing its structural stability.

[0064] The second key component of a barrier according to these particular examples is the skin, which is designed to ensure impermeability while allowing flexibility and movement. In engineering terms, this could be envisioned as a flexible elastomeric bellow, similar to the joints used in articulated buses or trains, where the bellow allows for movement between connected sections while maintaining an enclosed, impermeable structure. The skin prevents the ingress of saline water while accommodating the dynamic movement of the skeleton. A particularly innovative approach to designing this skin involves using concepts from origami or kirigami, where folding techniques are applied to create highly flexible, expandable, and contractible surfaces. The use of origami-inspired designs allows the skin to stretch and compress as needed while remaining intact and impermeable, much like how the bellow of a bus can expand or contract depending on the movement of the vehicle.

[0065] In the context of the present barrier system examples, the origami-inspired skin wraps around the PXCM skeleton, adjusting its shape as the skeleton reconfigures. This ensures that no matter how the barrier reshapes itself to accommodate ship traffic orchanging water currents, the separation between saline and freshwater environments is always maintained. This flexible yet impermeable layer allows for maintaining the barrier’s functionality, as it prevents water from penetrating through the structure, even in extreme conditions.

[0066] The use of bistable PXCMs not only provides reconfigurability but can also accommodate large strains and deformations. The bistable units can transition from one configuration to another, allowing the barrier to deform significantly when necessary, such as when accommodating large ships passing through. At the same time, these unit cells snap back to their original configuration when the external force is removed, ensuring that the barrier maintains its structural integrity. Moreover, the geometry of these PXCMs can be optimized to handle different levels of strain depending on the specific requirements of the environment. For instance, in regions where the barrier must undergo large deformations due to frequent ship traffic or strong water currents, the unit cells can be designed to withstand higher strains. Conversely, in more stable regions, the cells can be optimized for minimal movement, providing maximum structural rigidity.

[0067] The geometry of PXCMs impacts their ability to accommodate strain and adapt to external forces. By optimizing the shape and design of these unit cells, engineers can enhance the performance of the barrier in various scenarios. For example, PXCMs with more intricate geometries may be able to undergo larger deformations, making them ideal for regions of the barrier exposed to higher mechanical stresses. Additionally, different bistable PXCM configurations can be designed to handle a wide range of deformation magnitudes, allowing the barrier to be tailored for different environments and conditions. Whether it’s the ability to reconfigure for passing ships or the need to resist strong watercurrents, PXCM geometries can be fine-tuned to provide the optimal balance between flexibility, reconfigurability, and structural integrity.

[0068] The materials for the skeleton in such systems could be any elastic material that is considered structural and can operate within the elastic regime. Metals like steel and aluminum, which are known for their high Young’s modulus and yield strength, are prime candidates for such applications. Steel offers excellent strength and stiffness, while aluminum provides a favorable strength-to-weight ratio, making it suitable for lightweight designs. Both are commonly used in harsh environments and can be treated to prevent corrosion, making them ideal for maritime applications. Alternatively, high- performance polymers such as polyamide (Nylon) and polyetheretherketone (PEEK) can be used, especially when weight reduction or corrosion resistance is a priority. These polymers exhibit excellent mechanical properties and are used in various industries due to their resistance to wear, fatigue, and environmental degradation. In cases where extreme mechanical performance is required, fiber-reinforced composites (e.g., carbon fiber- reinforced polymers, or CFRP) can be utilized. These materials provide a combination of high strength, stiffness, and low weight, and their anisotropic properties allow for tailored designs that can withstand specific load conditions while remaining lightweight.Composites also offer excellent corrosion resistance and longevity, particularly in marine environments. For PXCM-based materials, where the material is designed to remain in the elastic regime, it is essential that the skeleton material has a high Young’s modulus and yield strength to prevent plastic deformation. Metals like titanium or stainless steel could be excellent choices due to their durability, strength, and resistance to environmental degradation. Fiber-reinforced composites can also be considered for thisapplication, as they offer customizable stiffness properties and can be optimized for specific loading conditions while reducing overall weight.

[0069] The skin membrane that surrounds the skeleton preferably exhibit properties that support long-term performance in harsh environments. Elastomers are suitable for such applications, particularly those with high UV resistance, flexibility, and durability in marine and automotive environments. Common elastomers used in these types of applications include Ethylene Propylene Diene Monomer (EPDM), Silicone Rubber, Chloroprene (Neoprene), and Polyurethane Elastomers, although this is a non-exhaustive list of some of the suitable materials. The selection of elastomers preferably prioritizes resistance to UV radiation, saltwater corrosion, and mechanical wear, ensuring that the membrane remains flexible and impermeable under prolonged exposure to environmental stressors. Additionally, elastomers such as EPDM and neoprene have been used in the automotive and maritime industries for decades, showcasing their resilience and longterm reliability in extreme conditions. Since the skeleton can be enclosed within the elastomeric membrane, it may be possible to create a controlled or dry internal environment, which can significantly reduce concerns about corrosion and other environmental impacts on the skeleton material itself. This design ensures that both the skeleton and the elastomeric skin can work in unison to provide durability, flexibility, and structural integrity in the most challenging operational settings.

[0070] Fabrication of the PXCM and its associated elastomeric bellow membrane typically involves a combination of traditional manufacturing techniques, modem additive manufacturing methods, and potential automation for mass production. This section outlines various fabrication approaches based on the materials selected for thePXCM and elastomer membrane. In one example a PXCM (Skeleton) may be made of metal and several manufacturing techniques can be employed depending on the complexity of the design and the scale of production.

[0071] One traditional approach involves cutting metal sheets into strips, which can then be assembled into the desired PXCM structure using simple tools. Metal strips can be cut using waterjet cutting, laser cutting, or traditional shearing processes. Once cut, the strips can be bent or formed into the required shapes. The components can then be joined using riveting, bolting, or welding. This manual process is well-suited for prototyping and small-scale production. Riveting can be used to join cut metal strips in predefined configurations, offering strong mechanical joints. Welding / brazing provides another method to create a robust, continuous structure, although it requires more specialized equipment and skill.

[0072] For complex geometries and highly precise structures, additive manufacturing techniques, such as Selective Laser Melting (SLM) or Direct Metal Laser Sintering (DMLS), can be used to fabricate the PXCM skeleton. These methods allow for intricate designs that would be difficult or impossible to create using traditional techniques. Additive manufacturing also enables a high degree of customization, with the potential to adjust the stiffness, flexibility, and mechanical behavior of the structure based on its design. Powder bed fusion and Electron Beam Melting (EBM) are also viable options, particularly for metal alloys like titanium or stainless steel, which can offer high strength and corrosion resistance in marine environments.

[0073] As demand scales, the PXCM structure can be manufactured using automated fabrication lines. CNC machining, robotic laser cutting, and automated forming processescan streamline production and reduce costs. For mass production, the design could be optimized for stamping or die-cutting, which would allow rapid fabrication from metal sheets with minimal waste. By using a combination of manual and automated processes, PXCM structures can be tailored for specific applications, ensuring flexibility in both design and production scale.

[0074] The elastomeric membrane that encases the PXCM skeleton can be fabricated using well-established processes from the elastomer and rubber industries. These processes have been optimized over decades for durability, flexibility, and resistance to environmental stressors like UV radiation and saltwater. In one example, elastomeric materials such as EPDM, silicone, or neoprene can be fabricated into sheets or bellow structures using extrusion. The material is heated, forced through a die, and cooled into the desired shape. This method is particularly suitable for creating long, continuous bellow structures that need to flex without losing their integrity. For more complex shapes or customized bellow designs, injection molding can be used. Elastomer pellets are melted and injected into molds, where they cool and solidify into the desired geometry. This process is commonly used in automotive and maritime industries for parts that require precision and durability. Another option for fabricating elastomeric membranes is compression molding, where raw elastomer material is placed in a heated mold, compressed into shape, and then cured to create a strong, resilient membrane.

[0075] Optionally for increased durability, the elastomeric membrane can be reinforced with woven fabrics or mesh made from high-strength fibers like Poly(azanediyl-1,4- phenyleneazanediylterephthaloyl) (Kevlar ®) or Nylon. These reinforcements improve the tear resistance, tensile strength, and overall longevity of the membrane in demandingenvironments. The combination of elastomer and reinforcement is commonly used in industries where the membrane will be subjected to repetitive mechanical stress, such as in automotive air springs or maritime seals. The elastomeric membrane can be processed through vulcanization, a chemical process that increases the durability, elasticity, and weather resistance of the rubber. Vulcanized elastomers are ideal for harsh environments, offering superior performance under UV exposure, saltwater immersion, and mechanical wear. Vulcanization is standard practice in producing rubber components for the automotive, aerospace, and marine industries. Once the elastomeric membrane is fabricated, it must be joined to the PXCM skeleton. Various sealing techniques can be employed, such as adhesive bonding, heat sealing, or mechanical fasteners. Adhesive bonding is often used in elastomeric structures, where a strong yet flexible bond is required. In some cases, vulcanized joints may be used to create seamless, impermeable membranes that prevent leaks and maintain flexibility.

[0076] The navigable saline barrier systems and devices disclosed herein provide a means for proactively counteracting saltwater intrusion into navigable channels and freshwater rivers in general. These innovative systems provide a safeguard against saltwater contamination during high tide and mitigate the impact of drought conditions that can drastically diminish river flow at their outlets to the sea. Saltwater intrusion, when left unchecked, not only leads to the salinization of rivers or canals for extensive distances inland but also contributes to saltwater infdtration through aquifers. This pervasive issue, exemplified in the current challenges faced in the San Joaquin Valley in California, underscores the urgent need for comprehensive solutions. In the context of the Panama Canal, the dual challenges of drought and the substantial volume of water taintedwith salt during each ship's transit through the locks pose formidable obstacles, constraining the global maritime traffic that relies on the canal's passage. The navigable saline barrier systems and devices herein offer a transformative potential to alleviate these challenges. These systems have the potential to mitigate these problems not only in the mentioned sites but also in any other location with similar characteristics, not only preventing contamination with saltwater but also maintaining the navigability of the water body.

[0077] While the claimed technology has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character. It is understood that the embodiments have been shown and described in the foregoing specification in satisfaction of the best mode and enablement requirements. It is understood that one of ordinary skill in the art could readily make a nigh-infinite number of insubstantial changes and modifications to the above-described embodiments and that it would be impractical to attempt to describe all such embodiment variations in the present specification. Accordingly, it is understood that all changes and modifications that come within the spirit of the claimed technology are desired to be protected.

Claims

CLAIMSWhat is claimed is:

1. A navigable saline barrier system, comprising: a water-impermeable barrier disposed in a waterway, including: a first non-navigable barrier; a second non-navigable barrier; and a navigable barrier having a floatation portion and an anchor portion; a volume compensation system; wherein the navigable barrier is disposed between the first and second non- navigable barriers; wherein the impermeable barrier is disposed between and prevents water from flowing between a saltwater portion and a freshwater portion of the waterway.

2. The navigable saline barrier system of claim 1 wherein the floatation portion keeps the top of the navigable barrier at water level and the anchor portion keeps the bottom of the navigable barrier at the bottom of the waterway.

3. The navigable saline barrier system of claim 1 wherein the navigable barrier is capable of adapting its shape to the hull of a ship allowing a ship to pass therethrough.

4. The navigable saline barrier system of claim 3 wherein the navigable barrier returns to its original shape after as ship has passed therethrough.

5. The navigable saline barrier system of claim 1 wherein the first non- navigable barrier and second non-navigable barrier are anchored to opposite sides of the waterway.

6. The navigable saline barrier system of claim 5 wherein the waterway is a canal disposed between a freshwater body and a saltwater body and bounded by concrete sidewalls.

7. The navigable saline barrier system of claim 1 wherein the first non- navigable barrier and second non-navigable barrier are flexible and move in response to volumetric hydraulic pressure.

8. The navigable saline barrier system of claim 1 wherein the navigable barrier is made from a phase transforming cellular material.

9. The navigable saline barrier system of claim 8 wherein the navigable barrier is made from a bistable material.

10. The navigable saline barrier system of claim 8 wherein the navigable barrier is made from a metastable material.

11. A navigable saline barrier system, comprising:a water-impermeable barrier disposed in a waterway which separates a saltwater body from a freshwater body, including: a first non-navigable barrier anchored to one side of the waterway; a second non-navigable barrier anchored to the opposite side of the waterway; and a navigable barrier disposed between the first and second non-navigable barriers and having a floatation portion and an anchor portion; a volume compensation system configured to maintain a freshwater level on one side of the water-impermeable barrier higher than the saltwater level on the other side of the barrier; wherein the navigable barrier is configured to adapt its shape to vessels passing therethrough.

12. The navigable saline barrier system of claim 11 wherein the floatation portion keeps the top of the navigable barrier at water level and the anchor portion keeps the bottom of the navigable barrier at the bottom of the waterway.

13. The navigable saline barrier system of claim 11 wherein the navigable barrier returns to its original shape after as ship has passed therethrough.

14. The navigable saline barrier system of claim 11 wherein the first non- navigable barrier and second non-navigable barrier are flexible and move in response to volumetric hydraulic pressure.

15. The navigable saline barrier system of claim 11 wherein the navigable barrier is made from a phase transforming cellular material.

16. The navigable saline barrier system of claim 15 wherein the navigable barrier further comprises an internal structure made from a phase transforming cellular material covered by an elastomeric membrane.

17. The navigable saline barrier system of claim 11 wherein the navigable barrier includes a plurality of bars capable of expanding to accommodate the hull of a vessel and contracting to close behind said vessel.

18. The navigable saline barrier system of claim 11 wherein the volume compensation system is a tidal lock disposed between the water-impermeable barrier and the saltwater body.

19. The navigable saline barrier system of claim 11 wherein the volume compensation system is a pump operationally connected to a freshwater reservoir and configured to pump fresh water in and out of the freshwater side of the water- impermeable barrier.

20. The navigable saline barrier system of claim 11 further comprising a ramp which is draped over a portion of the navigable barrier.

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