Floating Lift Systems and Methods for Launching and Recovering Structures in a Marine Environment

The present application claims the benefit of U.S. Provisional Patent Application No. 63/642,463 (pending), filed on May 3, 2024, and entitled “LIFT SYSTEMS AND METHODS FOR LAUNCHING AND RECOVERING STRUCTURES IN A MARINE ENVIRONMENT”, the entirety of which is incorporated herein by reference.

The present disclosure relates to floating systems and methods for launching and recovering structures in a marine environment.

The offshore wind farm market faces challenges in optimizing supply chain to ensure timely project execution, cost-effectiveness, and minimal environmental impact. For example, the assembly, deployment, ongoing maintenance, and replacement of components of an offshore wind farm suffer from supply chain issues, including the availability and proximity of equipment capable of lifting offshore wind farm components. While some technologies exist for the launch of floating wind foundations, existing technologies are not capable of a rate of launch and recovery of floating wind foundations that is sufficient to achieve a timely transition to offshore wind generation in view of global climate concerns.

Shiplifts are used to deploy ships. Such lifts do not exceed 35 meters in span, as they are designed to handle vessels that are much longer than they are wide. Also, shiplifts include a platform supported on plate girders, which are suitable for use at spans only up to about 40 meters, and only under moderate loading conditions. These limitations render existing shiplifts incapable of launching and recovering fully assembled floating wind foundations.

The ability to streamline the assembly, deployment, maintenance, and replacement of offshore wind farm components is an important element in the transition of the global energy supply from land-based fossil fuels to offshore wind generation. There is need for technologies capable of launch and recovery of floating wind foundations or other large and heavy marine structures.

Embodiments of the present disclosure include a system for launch and recovery of marine equipment. The system includes a floating dock. The floating dock includes a plurality of floating modules coupled together. Cavities of the floating modules include buoyant concrete. A plurality of hoists are coupled with the floating dock. The system includes a lift platform. The plurality of hoists are coupled with the lift platform and configured to raise and lower the lift platform relative to the floating dock.

Embodiments of the present disclosure include a method of launching and recovering marine equipment. The method includes providing a floating dock. The floating dock includes a plurality of floating modules coupled together. Cavities of the floating modules include buoyant concrete. The method includes providing a lift platform coupled with the floating dock. The method includes deploying marine equipment into water by positioning the marine equipment on the lift platform and lowering the lift platform, relative to the floating dock, into the water; retrieving marine equipment from water by lowering the lift platform, relative to the floating dock, into the water, positioning the marine equipment on the lift platform, and raising the lift platform, relative to the floating dock, out of the water; or combinations thereof.

Embodiments of the present disclosure include a system for launch and recovery of marine equipment. The system include a quayside dock and a floating dock moored adjacent the quayside dock. The floating dock includes a plurality of floating modules coupled together with cavities of the floating modules containing buoyant concrete. A plurality of hoists are coupled with the floating dock. The system includes a lift platform. The plurality of hoists are coupled with the lift platform and configured to raise and lower the lift platform relative to the floating dock.

Systems and methods according to present disclosure will now be described more fully with reference to the accompanying drawings, which illustrate various exemplary embodiments. Concepts according to the present disclosure may, however, be embodied in many different forms and should not be construed as being limited by the illustrated embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough as well as complete and will fully convey the scope of the various concepts to those skilled in the art and the best and preferred modes of practice.

Certain aspects of the present disclosure include floating systems and methods for launching and recovering vessels and structures in a marine environment. In some embodiments, the systems and methods are configured for launch and recovery of relatively large and heavy marine vessels and equipment, such as offshore wind turbines, foundations thereof, and components thereof. In one particular embodiment, the systems and methods are configured for launch and recovery of foundations (also referred to as “floating wind foundations”) for offshore wind turbines. The floating wind foundations can be semisubmersible floating wind foundations or tension leg platform (TLP) floating wind foundations. While the embodiments shown in the Figures of the present disclosure illustrate the systems and methods used to launch and recover floating wind foundations for offshore wind turbines, the systems and methods disclosed herein are not limited to this particular application and may be used for launch and recovery of other marine vessels and equipment. For example, the systems and methods may be configured for launch and recovery of commercial and military ships, submarines, yachts, or other relatively large and heavy marine vessels and equipment.

The present disclosure includes floating hubs that can be moored at a site, in proximity to a wind farm, for use during the installation, maintenance, and decommissioning of wind farm equipment, including for use as a dry dock for storage of components used for construction and maintenance of wind farms. Exemplary operations of embodiments of a floating hub in the maintenance of a wind farm are illustrated with reference to.

depicts an exemplary floating system for assembly, launch, recovery, and maintenance of wind turbines, including floating wind foundations for offshore wind turbines. Systemis in the form of a floating hub that includes a dock. The dockcan be a floating dock that is moored at the site. The sitecan be in proximity to a wind farm, such that the systemis positioned to provide for the ongoing launch and recovery functions related to the installation, maintenance, and decommissioning of the wind farm. The dockalso functions as a dry dock for storage of components and tools related to the assembly and maintenance of the components of the wind farm. For example, the dockincludes assembly area. The assembly areafunctions, at least in part, as a staging area for floating wind foundation componentsthat are used in the assembly and/or maintenance of floating wind foundations and other components of wind turbines. The componentscan be assembled together on the dock(e.g., at assembly area) to construct a floating wind foundation, as shown in, or to construct a fully assembled wind turbine. In some embodiments, the dockis sufficient in size to simultaneously assemble multiple floating wind foundations. While not shown, tower, nacelle and/or blade installation onto the floating wind foundationcan also be performed on the dockprior to deployment of the floating wind foundation.

The dockincludes two lift platforms. The systems disclosed herein are not limited to including two lift platforms, and may include only one lift platform or more than two lift platforms. The lift platformsare used for the launch of wind turbine components (or fully assembled wind turbines), as well as for the recovery of wind turbine components (or fully assembled wind turbines), such as for repair, maintenance, or decommissioning.

illustrate the transport of an assembled floating wind foundationon the dock. After assembly, the floating wind foundationis transported on the dockfrom the assembly areato one of the lift platforms. The floating wind foundationis transferred on the dockvia bogiesmoving on railsandon the dock. The lift platformsare positioned adjacent the dockwithin a space defined, at least partially, by the dock. The lift platformsinclude railsandthat align with the railsandon the dock, such that the bogiestransport the floating wind foundationonto the lift platform.

The lift platformsare supported by a plurality of girders. The dockincludes a plurality of chain jackspositioned along both sides of each lift platform. The chain jacksare coupled with the lift platformand configured to raise and lower the lift platformrelative to the dock. While chain jacks are illustrated, the systems disclosed herein are not limited to chain jacks and may include other lifts or lifting systems capable of raising and lowering the lift platforms. In, the lift platformis shown in a raised position relative to the dock.

After placement of the floating wind foundationon the lift platform, the bogiesare disconnected from the floating wind foundationand moved from the lift platformback onto the dock. To deploy the floating wind foundation, the lift platformis lowered, using the chain jacks, from the raised position shown into a lowered position as shown in. In, the lift platformis not visible as it is positioned below a level of the water. With the floating wind foundationin the water, tug boatsare tethered to the floating wind foundationvia lines. The tug boatstow the floating wind foundationfrom the dockto the desired location, wind farm, as shown in. At the wind farmthe remaining components (e.g., a tower, nacelleand/or blades) are assembled onto the floating wind foundationto form a wind turbine. In other embodiments, the tower, nacelleand/or bladedare already assembled onto the floating wind foundationat the dockand are towed to the wind farm. The steps of assembly, transport, and installation of a wind turbine, described in references to, can be repeated to provide the wind farm with the desired number of wind turbines. Furthermore, the assembly, transport, and installation of a wind turbine is not limited to the particular steps or order of steps as shown in. One skilled in the art would understand that some steps may be eliminated, added, or combined, and that the order of the steps may be modified.

With the wind farm installed, as illustrated in, the systemcan remain in place for ongoing maintenance of the wind farm, as well as for decommissioning of the wind farm. That is, the dockcan remain moored at the sitein proximity to the wind farm. The dockcan function as both a dry dock storing components for repair of the wind turbines, as well as a work site for repair and maintenance operations to be performed. With reference to, when a wind turbineof the wind farmrequires maintenance, repair, or decommissioning, tug boatscan be tethered to the wind turbinevia linesfor towing of the wind turbineback to the dockfor the maintenance, repair, or decommissioning. Whileshows a fully assembled wind turbinebeing towed back to the dock, in other embodiments, less than an entirety of the wind turbinemay be in need of maintenance, repair, or decommissioning, such that only those components (e.g., the blades) requiring maintenance, repair, or decommissioning are towed back to the dock.

The tug boatstransport the wind turbinefrom the wind farmand into the spaceof the dockwhere the lift platformis positioned. In, the lift platform is not visible in the spaceas it is positioned below a level of the water. The wind turbineis positioned above the lift platform. With the wind turbinepositioned above the lift platform, the lift platformis raised by the chain jacksfrom the lowered position shown into the raised position shown in. The wind turbinecan then be moved on the rails of the lift platformand dockto the assembly areaor another area on the dockfor repair, maintenance, and/or disassembly (e.g., in the case of decommissioning). After repair or maintenance is performed, the wind turbinecan be transported back to the wind farm for installation in the same or similar manner as described with reference to. If the wind turbineis decommissioned, then a replacement wind turbine can be transported to the wind farmfor installation.

The lift platforms disclosed herein are configured for lifting and lowering of floating wind foundations and fully assembled wind turbines. The lift platforms have spans that are sufficiently sized to fit floating wind foundations and fully assembled wind turbines, and the platforms are sufficiently supported by girders capable of supporting the weight of floating wind foundations and fully assembled wind turbines. The lift platforms and components thereof are shown and described in more detail with reference to.

depicts lift platforminstalled on dockwith a plurality of chain jacksarranged along the lateral side edges of the lift platform, andis a detail view of a portion of. In, the top platform of the lift platformis not shown, revealing the underling plurality of girdersthat support the top platform.

Each chain jackincludes a jack(e.g., a cylinder jack) coupled with a chainand a support structureto support the components of the chain jackon the dock. The chainis coupled with the jackand with the lift platform, and is engaged on a chainwheel. When actuated, the jacklets out the chainto lower the lift platformor hauls in the chainto lift the lift platform. The actuation of the plurality of chain jacks, to raise or lower the lift platform, can be controlled by a hydraulic power uniton the dock. The plurality of the chain jackscan be operated synchronously. In some embodiments, the operation of the chain jacksto raise and lower the lift platformis the same or substantially the same as the operation of the chain jacks to raise and lower the shiplift platforms as is described in U.S. patent application Ser. No. 15/817,876 (the '876 application), the entirety of which is incorporated herein by reference. The lift platformsand chain jacksdisclosed herein are capable of raising and lowering floating wind foundations and wind turbines for wet tow, dry dock, repair, maintenance, and/or replacement, such as to extend the life of the floating wind foundation and associated wind turbines.

is a top view of the dockwith the lift platformand a plurality of chain jacks.show the lift platformin the raised position above the level of water. The chainsof each chain jackare coupled with the lift platform. In the embodiment shown in, each chainis coupled with a chain plate, and each chain plateis coupled (e.g., bolted) with a platform plate. The platform platemay be coupled with the lift platformor be an integral part of the lift platform. With the chainscoupled with the lift platform, the chain jackscan be actuated to raise and lower the lift platformrelative to the level of the water.

The lift platformhas a width spanand a length spanthat is of sufficient size to accommodate floating wind foundations and wind turbines. In some embodiments, the top surface of the lift platformhas a square-shaped top surface to accommodate floating wind foundations for wind turbines that have triangular cross-sections. The top surface of the lift platforms disclosed herein are not limited to having square-shaped top surfaces. In some embodiments, the width spanranges from 60 meters to 120 meters, or from 70 meters to 105 meters, or any range or discrete value therebetween. In some embodiments, the length spanranges from 60 meters to 120 meters, or from 70 meters to 105 meters, or any range or discrete value therebetween. The width spanmay be equal to, greater than, or less than the length span. The width spanand length span are at least 60 meters, or at least 70 meters.

is a cross-sectional view showing the lift platformin the raised position with a top of the lift platformpositioned above the level of the water.is a cross-sectional view of the lift platformidentical to, but showing the lift platformin the lowered position with a top of the lift platform positioned below the level of the water.

is a top view of the lift platform, andare cross-sectional views of the lift platform.show the lift platformin the lowered position, below the level of the water. Lift platformincludes top platform(also referred to as upper deck) supported by a plurality of girders. The top platformis configured to receive floating wind foundations and fully assembled wind turbines. The girdersare positioned beneath the top platform.

depicts the support structure of the lift platformin isolation from the dock and chain jacks.is a top view of the support structure of, andare front and side views of. The lift platformincludes a plurality of girders. Each girderincludes a lower chord (truss)and top chord (truss). Extending between and connecting the lower chordand top chordare a plurality of members that form a web, including inner vertical web truss, inner diagonal web trusses, outer diagonal web trusses, and outer diagonal bracing. The support structure of the lift platformalso includes lower chord bracing, top chord bracing, inner truss diagonal bracing, cap plats, knuckle clevis(serving as the platform plate), and runwayand runway girder. The girders disclosed herein are not limited to the particular shape and configuration shown in the drawings. The girderscan be in the form of box truss girders capable of spanning the width span and supporting the load of a floating wind foundation, with or without the remaining components of the wind turbine attached thereto. The girdersare made of a material capable of supporting the load of the floating wind foundations and wind turbines at such width spans. For example, and without limitation, the girderscan be made of steel. In some embodiments, the components of the support structure of the lift platformare coupled together such that the support structure of the lift platformforms a unitary structure capable of supporting the lift platformand any load thereon.

In some embodiments, one or more buoyancy tanks are incorporated into the lift platform. With reference toan embodiment of the lift platform including a buoyancy tank is shown. Lift platformis identical to the one shown inwith the exception that a buoyancy tankis incorporated into the lift platform. The buoyancy tank(e.g., floatation tank) in attached to or otherwise incorporated into the support structure of the lift platform. The buoyancy tankcan be configured to provide the lift platformwith a negative buoyancy or positive buoyancy. By providing the lift platformwith a negative buoyancy, the depth of the truss structure of the lift platformcan reduced; thereby, reducing the excavation depth that is required for installation of the lift platformat the site. This reduction in excavation can reduce the cost of installing the lift platformby saving dredging and excavation costs. The incorporation of the buoyancy tankcan, in some embodiments, improve the efficiency of the lift system by from 17% to 20%, for example. In some embodiments, as shown in, the buoyancy tankis positioned along a center axis (i.e., along a center of the span) of the lift platform. With the buoyancy tankpositioned along the center axis of the lift platform, the buoyancy tankoffsets dead load of the lift platformand reduces the depth the truss (girders) required to support any payload on the span of the lift platform. While shown as including a single buoyancy tank, the lift platforms disclosed herein can include more than one buoyancy tank. While the buoyancy tank is shown along the central axis of the lift platform, in other embodiments, the lift platform includes buoyancy tanks posited at other locations on the lift platform.

In some embodiments one or more portions of the floating lift platforms, floating docks, and/or floating hubs disclosed herein include, at least partially, a buoyant, floatable material that floats in water. For example, and without limitation, one or more portions of the systems disclosed herein may be composed, at least partially, of a buoyant material (e.g., a buoyant concrete) in accordance with the material and floating structures disclosed in U.S. Pat. No. 11,932,359 ('359 patent), the entirety of which is hereby incorporated herein by reference and made a part of the present disclosure. In some embodiments, the systems disclosed herein include floating modules joined to form floating structures as described in the '359 patent. The system can include a floating structure having multiple floating modules assembled together and joined by a material cast in a hollow between the floating modules, the hollow having a thickness configured to ensure a mechanical continuity between the floating modules. In some embodiments, the systems disclosed herein include one or more floating modules or floating structures as shown in any ofof the '359 patent. As the floating modules and structures, and the assembly thereof, of the '359 patent are described in detail in the '359 patent, the present disclosure will only briefly describe such structures and the assembly thereof.

The systems disclosed herein can include a floating structure in accordance with the '359 patent that includes at least one first floating module and at least one second floating module. Each floating module of the floating structure includes a plurality of walls extending between a first longitudinal end and a second longitudinal end. Each floating module includes a first partition and a second partition connecting each wall of the plurality of walls, defining with the plurality of walls an internal volume of the respective floating module. Each floating module includes at least one extension emerging from an external face of a respective wall of the plurality of walls. The at least one extension extends longitudinally in projection from the first longitudinal end or from the second longitudinal end. The at least one extension and the respective wall from which the at least one extension emerges is materially integral. A sealing device is located between the at least one first floating module and the at least one second floating module. The sealing device is inserted between the at least one extension of the at least one first floating module and the at least one extension of the at least one second floating module. A hollow bounded by a first cavity of the at least one first floating module and by a second cavity of the at least one second floating module is filled with concrete.

In some embodiments of the floating structure in accordance with the '359 patent at least one of the first floating module and the second floating module includes an edge of one of the first longitudinal end and the second longitudinal end of a first wall of the plurality of walls and the at least one extension extending from the first wall. The edge at least partly bounds one of the first cavity and the second cavity.

In some embodiments of the floating structure in accordance with the '359 patent, a thickness of the first cavity or the second cavity is equal to or greater than a thickness of the first wall from which the at least one extension emerges.

In some embodiments of the floating structure in accordance with the '359 patent, at least one of the first floating module and the second floating module includes an external face of a first wall of the plurality of walls and an internal face of the at least one extension extending from the first wall. The external and internal faces lie in the same plane.

In some embodiments of the floating structure in accordance with the '359 patent, at least one of the first floating module and the second floating module includes a first extension situated on each of at least two lateral walls of the plurality of walls of the respective floating module and on a bottom wall of the plurality of walls of the respective floating module.

In some embodiments of the floating structure in accordance with the '359 patent, at least one of the first floating module and the second floating module includes a first wall of the plurality of walls comprising a first extension of the at least one extension of the first wall situated in a region of the first longitudinal end and a second extension situated in a region of the second longitudinal end.

In some embodiments of the floating structure in accordance with the '359 patent, at least one of the first floating module and the second floating module includes the plurality of walls, the first partition, the second partition and the at least one extension formed of an integral material, with the material being concrete.

In some embodiments of the floating structure in accordance with the '359 patent, a metal reinforcement extends inside at least one wall of the plurality of walls and emerges into at least one of the first cavity and the second cavity.

In some embodiments of the floating structure in accordance with the '359 patent, a prestressing sheath extends inside one wall of the plurality of walls and emerges into at least one of the first cavity and the second cavity.

In some embodiments of the floating structure in accordance with the '359 patent, a continuity between a metal reinforcement of the at least one first floating module and a metal reinforcement of the at least one of the second floating module, and/or a continuity between a prestressing sheath of the at least one first floating module and a prestressing sheath of the at least one second floating module is located in the hollow.

In some embodiments of the floating structure in accordance with the '359 patent, a thickness of a first wall of the plurality of walls of the at least one first floating module is equal to a thickness of a second wall of the plurality of walls of the at least one second floating module. The thickness of the first wall of the at least one first floating module and the thickness of the second wall of the at least one second floating module being equal to a thickness of the hollow.

In some embodiments of the floating structure in accordance with the '359 patent are assembled by a method that includes a step of alignment of the at least one first floating module relative to the at least one second floating module, a step of removably coupling the at least one first floating module to the at least one second floating module, and a step of casting the concrete in the hollow. The method can include a step of emptying a space bounded by the first and second partitions, by the at least one extension of the at least one first floating module and by the at least one extension of the at least one second floating module. The method can include a step of providing a mechanical connection between a metal reinforcement of the at least one first floating module and a metal reinforcement of the at least one second floating module. The method can include, after casting the concrete, a step of installation of at least one prestressing cable laid in a prestressing sheath of the at least one first floating module and in a prestressing sheath of the at least one second floating module, and a step of application of a traction force to the prestressing cable.

One skilled in the art would readily understand the floating modular structures disclosed herein as such structures are shown and described in detail in reference toof the '359 patent which has been incorporated herein in its entirety and made a part of the present disclosure. As used herein, the terms “floating structure” and “floating module” have the same meaning as used in the '359 patent.

In some embodiments, the systems disclosed herein include a composite of materials, including buoyant concrete and steel. For example, in one embodiment the lift platforms (e.g., shiplift platforms) include steel and the floating docks include buoyant concrete caissons. es, generally that is the base case. In some embodiments, a base of the floating dock is concrete and a top surface of the floating dock is steel, with the lift platform being steel.

In embodiments the floating docks with lift platforms of the present disclosure can function as floating hubs for use in deploying, maintaining, and decommissioning wind farms. With reference to, a floating hubis deployed at a site away from shore. Floating hubincludes floating dock. The floating dockhas railsfor facilitating the movement of wind turbine components-thereon. The wind turbinescan be at least partially assembled on the floating dockfrom the wind turbine components-. The floating dockincludes one or more lift platformswith lifting equipment(e.g., rotary chain jacks), allowing for deployment of the assembled wind turbinesinto the water by lowering the lift platformusing the lifting equipment. In some embodiments, the floating hubis at least partially made of a floating structure, including floating modules, in accordance with the '359 patent. For example, the floating dockand/or the lift platformcan be made of a floating structure, including floating modules, in accordance with the '359 patent. In some embodiments, the floating dockincludes a control and power house (not shown) configured for controlling and powering the operations of the lift platform, such as controlling the flow of power and/or hydraulic fluid to the lifting equipment. The top surface of the floating dockcan include space for assembly and storing vessels (e.g., wind turbines). The floating dockcan be moored at the site, such as via mooring lines and anchors (not shown). In the embodiment of, the floating dockincludes four lift platforms, only one of which is visible in the view. The floating hubs may include more or less than four lift platforms.

depicts two floating hubsanddocked at a quayside dock. Each floating hubandincludes a floating dock, railsthat mate with railson the quayside dock, a lift platform, and lifting equipment. A wind turbineis positioned on each lift platform. The floating hubsandare positioned and docked at the quayside dockfor deployment or retrieval of the wind turbines, with the lift platformspositioned opposite the quayside dock.

depicts two floating hubsand. Floating hubis docked at a quayside dock. Floating hubis approaching (or leaving) the quayside dock. Each floating hubandincludes a floating dock, railsconfigured to mate with railson the quayside dock, a lift platform, and lifting equipment. A wind turbineis positioned on each lift platform. In contrast to the embodiment of, when docked at the quayside dockthe lift platformsare positioned adjacent the quayside dock. The lift platformof floating hubis docked at the quayside dockin a raised position above the hull of the floating dock. The lift platformof the floating hubis in a lowered position below the hull of the floating dock.

Thus, the floating hubs disclosed herein are capable of being floated (e.g., towed) to and from the shore at quayside. The floating hubs can be tied-off to the quayside docks when at shore such that loads (e.g., wind turbines) can be transferred onto and off of the lift platform. The lift platforms are raised and lowered using the lifting equipment, such as chain jacks, hoists, winches, and/or other lifting systems. The ability to lift the lift platforms at and above the deck level of the floating docks allows the lift platforms to be maneuvered up or down depending on tide, such as to align with the height of a quayside dock for transferring vessels or other loads on and off the lift platform and dry land. The raising and lowering of the lift platforms can be performed manually by an operator or automatically, such as by using sensors and automated motion controls that detect tide level relative to platform level.

While the floating hubs are described in reference to receiving, transporting, deploying, and retrieving wind turbines, the floating hubs are not limited to this particular application, and may be used to handle other equipment and vessels. For example, the floating hubs can be used to decommission an oil rig by transporting components to shore. Also, the floating hubs can be used to transport large modules for greenfield plants, such as hydrogen or natural gas.

In some embodiments the lift platforms are secured to the floating dock. For example, during towing of the systems disclosed herein it may be desirable to secure the lift platforms to the floating dock. Also, during rough water conditions, such as during a storm (e.g., hurricane or typhoon), it may be desirable to secure the lift platforms to the floating dock. In one embodiment, the lift platforms are secured to the floating docks via pinning the lift platforms to the floating docks (e.g., a concrete base of the floating dock). With reference to, a floating hubis depicted. Floating hubincludes floating dockmade of buoyant concrete caissons. The buoyant concrete caissons can be the same or similar to the floating structures, including floating modules, of the '359 patent. Floating hubincludes lift platform. Lift platformcan be a steel lift platform. Thus, floating hubincludes a composite of materials, including concrete and steel. The lift platformcan be secured (e.g., locked) to the floating dockwith the lift platformin the raised position. For example, removable pinscan be pinned to both the lift platformand the floating dock, thus securing the lift platformto the floating dock. Pinning, locking, or otherwise securing the lift platformto the floating dockstiffens the floating hubby reducing relative movement between the lift platformand floating dock. Securing the lift platformto the floating dockcan increase the strength of the floating hub. By including both steel and concrete, the floating hubhas the advantages of both materials, such when towing in adverse environmental conditions. Also, the amount of concrete used can be optimized, lowering the overall cost of the floating hub. The floating dockincludes a main bodyand arms, with the lift platformpositioned between the arms. With the steel lift platformsecured to the concrete floating dock, vertical and horizontal relative deflections between armsof the floating dockare reduced, increasing ability to operate in high wave conditions.

is a side view illustrating one embodiment of pinning the lift platform to the floating dock. Floating hubincludes floating dockand lift platform. Lift platformis shown in both the raised and lowered (in broken line) positions. The lift platformis moved between lowered and raised positions vial lift systems(e.g., rotary chain jacks) and chains. In the raised position, the lift platformis pinned to the support frame of the lift systemvia a lock pin. The lock pinextends through the pin receiver.shows a portion of the support frameof the lift system, showing the lock pinin a disengaged position and the lock pinin an engaged position. The pin receiverslides into the locking slotfor receipt of the pin. With the pin receiverin the locking slot, the locking pinsandcan be actuated (e.g., hydraulically) to engage through the pin receiverand locking slotto lock the lift platform to the floating dock.

In some embodiments, the floating hubs can include one or more structural arms or gates that extend between the arms of the floating dock. With reference to, floating hubincludes floating dockwith main bodyand dock arms, defining a generally U-shaped floating dock. Coupled between the dock armsis are structural arms. The structural armscan be in the form of gates, for example. When closed, as shown in, the structural arms extend between the dock armsat the open end of the floating dockwhere vessels enter onto and exit off of the lift platform. The generally U-shaped structure of the floating dockwith the dock armscan, in some environments (e.g., rough waters, storms), be insufficiently stiff. The structural armsprovide a structural connection between the dock armsopposite main dock bodywhich can reduce deflection in the dock armsboth during environmental events and during the lifting of the lift platformto lift a vessel. The structural armscan swing or otherwise open (as showing in) and close (as shown in) to allow vessels onto and off of the lift platform. In some embodiments, instead of two structural arms extending from each dock arm, the floating dock can include one structural arm that extends from one dock arm to the other. When in the closed position, the structural arms can be locked to each other and/or to the dock arms and, thereby, secured in place.