Patent Application
20050058509
The present invention generally relates to breakwaters, piers, docks, wave breakers, wharfs, etc., hereinafter in the specification and claims referred to collectively as breakwaters, used for protecting coasts namely shore lines and harbors, and offshore elements e.g. marine watercrafts and structures. More specifically the invention is concerned with floating such elements, useful in a variety of embodiments and different purposes.
Maritime structures of the concerned type have many purposes. For example, they may be used to minimize wave damage and for erosion control of shores and structures (either at shoreline or at open waters). Furthermore, such structures may be used to form wharfs for ships to moor and for connecting with land. Other examples of use of such structures may be bounding of non-shore areas to define restricted areas, e.g. a swimming zone, maritime sports zone etc. Alternatively, such bounding may be used for bordering hazardous areas or areas of ecological danger (for example oil leaks, etc).
A wide variety of such breakwater structures have been proposed throughout the years of mankind exploring open waters. One type of such breakwater requires employment of massive seabed foundations which are time consuming in setting up, as well as expensive and requiring special equipment for deployment thereof. Floating, flexible such structures, collectively belong to another type, where substantially little time is required for setting up a breakwater or the like, whilst being relatively cheap and offering modularity and flexibility as far shape and features, e.g. aesthetics, water circulation, knock-down time, etc.
However, floating breakwater structures have some disadvantages setting as examples ineffectiveness in reducing height of slow waves, susceptibility to structural failure at extreme conditions, maintenance requirements, etc. One other significant draw back of some prior art floating breakwater structures is the problem of slack/taut of cables of such structures, e.g. owing to waves, tide, etc.
Several prior art publications disclose floating breakwaters, amongst which are the following U.S. Pat. Nos. 2,185,458, 3,792,589, 3,863,455, 3,969,901, 4,316,994, 4,693,631, 4,715,744, 5,429,452, 5,310,283, 5,702,203 and 6,408,780.
Another type of breakwaters is the so-called offshore floating breakwater, used for attenuating waves and reduce sea state wave conditions for safe marine vessel operation. A detailed study concerned with such breakwaters was disclosed in the article ‘Field and numerical comparisons of the RIBS floating breakwater’, by M. Briggs, W. Ye, Z. Demirbilek and J. Zhang. published in the Journal of Hydraulic Research, Vol. 40, 2002, No. 3.
It is an object of the present invention to provide a novel modular floating breakwater structure of the concerned type, requiring substantially little storage space, cheap in transportation costs and fitted for easy and rapid deployment into its operative state and has some substantive advantages regarding durability and management of dynamic forces developing under wave force.
The present invention calls for a modular breakwater suitable for attenuating waves in open waters and water ways. The breakwater comprises a plurality of rods assembled in a fixed parallel array for positioning in the water at a substantially vertical position at least partially submersed in water, whereby the assembly is flexible and is deformed into an arched/bowed structure.
According to the present invention there is provided a floating breakwater assembly comprising an array of elongate rods articulated to one another for extending at a substantial vertical position at least partially submersed in water, wherein said rods are made of a flexible material and where the array is elastically deformable into an arcuate shape by bending the array.
The breakwater assembly is flexibly deformable in different ways depending on its intended use. For example, the breakwater may be part of a port gateway, where the width of the opening is controllable. It may also be part of an off-shore moor, fixed at the open waters (e.g. suitable as a moor or for protection of constructions like a lighthouse etc.) or deployable from a ship for temporary and rapid assembly, e.g. while unloading cargo from a ship to barges, etc. Other examples are establishing a protected zone of attenuated waves suitable as a sport resort and the like, etc. In each case the span of the assembly, the size of the arch and its direction are determined according to the intended use.
The breakwater may be elastically deformed by pulling the ends thereof in a direction so as to form a bow. This may be carried out for example by pulling the ends directly towards one another, or puling them at a direction giving rise to a vector of force in that direction. Elastic deformation may be obtained by applying force at one or both ends of the array.
The breakwater is made of a plurality of rods, each of which may be constructed of several rod segments, said segments being substantially straight tubular elements made of flexible material allowing its elastic bending. The rod segments may be made of any suitable material, each imparting it with different mechanical properties like elasticity, strength, etc. and is typically manufactured by extrusion. For example, the rod segments may be manufactured of any of the following materials and their combinations: plastic, epoxy, polyester, etc., and may be reinforced by various fibers such as glass, charcoal, Kevlar®, etc.
In order to retain the array floating at a substantially vertical position, one or more upper rods of the array have buoyant properties, e.g. hollow rods filled with foamed polyurethane, etc., whilst rods below said buoying rods are hollow and are filled with water, to thereby stabilize the assembly and support it vertically.
The rods of the assembly are retained at an array such that they extend parallel to one another and about a substantially vertical plane. This is obtained by a rigid connecting element receiving the rods and supporting them at a fixed position. The connecting element is also suitable for applying force on portions of the array to obtain its desired elastic deformation.
According to one particular embodiment, ends of the array are anchored e.g. to an anchor laying or fixed to the sea bed, thus giving rise to generation some vector of force also at a vertical direction. According to a different embodiment of the invention, the array is attached to a buoy which in turn is anchored, thereby substantially reducing the vertical vector of force.
The breakwater is stabilized at an substantially upright floating position by a load of weight associated with a lower end thereof, e.g. suspended from the lower rod or integral therewith or insertable therein.
The breakwater according to some of its applications is fitted with mooring arrangements, such as suitable boat/ship anchoring facilities. According to a specfic arrangement, there is provided one or more mooring rods pivotally secured to the array and tiltable between a stow position and an operative position, wherein at said operative position either a stem or bow of a mooring boat is secured to a free end of a mooring rod and an other of the stem or bow of the mooring boat is secured to the array.
According to still an application of the present invention, a deck is mounted on the breakwater, for easy access along the breakwater and optionally for transfer facilities such as electricity, fresh water supply, sewage suction, communication cables, etc. The deck may be integrally formed with an upper rod of the array, or may be mounted thereon. The deck may be constructed of a plurality of segments attached to or mounted on the rods and may also have buoyant parameters to assist in establishing buoyancy and positioning of the array in the water.
Furthermore, it is possible for one or more rod segments of the array have different elasticity coefficients (dimensions, material, shape, etc. of a rod segment), to render the array different bending parameters.
In order to understand the invention and to see how it may be carried out in practice, some embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which:
15
With further attention directed also to
The rods are typically manufactured by an extrusion process and are made, for example of any combination of materials such as plastic, epoxy, polyester and may be reinforced by various fibers such as Kevlar®, glass or charcoal fibers, etc., as known in the art. The rods are flexible and are normally biased to return to their straight position.
Parallel relationship and the fixed position of the rods with respect to one another is obtained by end pieces 31 (one seen in
The breakwater 20 has a bowed shape owing to the force applied thereto in a radial/tandem direction wherein the end piece 31 is linked to a buoy 40 via link 42 and buoy 40 is in turn anchored via cable 44 to a concrete slab 46 lying on the sea bed. It is appreciated that the link 42 and cable 44 may be made of chains, cables, rods, etc. imparting various degrees of freedom. It is further appreciated that the positioning of the anchor, namely, slab 46 or other suitable anchor (e.g. natural rock, steel anchor, etc.) will result in obtaining different arcs of the breakwater.
The purpose of buoy 40 is to reduce vertical force vector acting in a downwards direction, to thereby stabilize the array 22 at a more-or-less fixed level, whereby a vertical degree of freedom is absorbed through the buoy 40. It is however appreciated that the end piece 31 may be directly connected to the anchor 46. It is further appreciated that the length of cable 44 may be changeable upon demand to change the shape of the breakwater, depending on magnitude and direction of waves. It is further appreciated that in case of a serious storm, one or both ends of the breakwater may be detached from the anchor to avoid damage and to better withstand the powerful waves.
The buoy 40 has at its lower end a mass 74 to maintain it at an upright position, as in
The deck 120 comprises a plurality of T-like deck elements 126 each comprising a substantially flat surface 128 extending above an uppermost rod 130 and a rod engaging portion 134 mounted on several consecutive rods, e.g. by sliding the elements 126 over the rods 130 as in the illustrated example, or by clamping or otherwise attaching thereto (not shown). Typically the deck elements 126 are made of lightweight material, e.g. injection molded plastic and may be filled with foamed material to increase the overall buoyancy of the water break. It is advantageous that a top surface 129 of the deck elements 126 be fitted with an anti-slip arrangement e.g. a roughened surface, a coating of anti-slip material etc.
The rod engagement portion 134 comprises several apertures 138 through which different cables and supply lines may extend, as mentioned hereinabove.
It is further appreciated that the deck elements may be of different size and may be, in accordance with an embodiment of the invention (not shown) be integral with an upper rod of the breakwater.
It is apparent from the embodiment of
It is further appreciated that an anchorage in accordance with such an embodiment is easily assembled and disassembled, requiring only little labor and being inexpensive.
In the embodiment of
The arrangement is such that the entrance into the anchorage 186 is protected by the breakwater 194 to thereby attenuate waves and protect boats moored within the anchorage 186. However, in accordance with the particular embodiment of
In accordance with a particular embodiment, the arrangement may be such that the breakwater 194 may be closed, partially opened or widely opened, at will by, pivoting the breakwater 194 about its pivot end 196, where it may displace between different positions.
This arrangement has several particular advantages. For example, the breakwater 216 may be stored aboard the ship 228 and may be erected at any desired position within a short period of time. Second, the position of the ship may continuously change, depending on the direction of wind (in the present example represented by arrow 230) whereby the breakwater 216 changes its position to maintain a concave position facing the wind.
This arrangement offers attenuating of waves at the surroundings of the ship 228, to facilitate unloading cargo from the ship to a barge 230. Such an arrangement may also be used to attenuate waves at the vicinity of ships carrying out different works at open waters, e.g. maintenance of underwater oil pipes, communication lines, etc.
In
Turning now to
In
Whilst some embodiments have been described and illustrated with reference to some drawings, the artisan will appreciate that many variations are possible which do not depart from the general scope of the invention, mutatis, mutandis.
