Synthetic seaweed

United States Patent [19]

Garrett

[n] Patent Number: 4,478,533 [45] Date of Patent: * Oct. 23, 1984

[54] SYNTHETIC SEAWEED

[76] Inventor: William L. Garrett, 100 Dickinson La., Wilmington, Del. 19807

[ * ] Notice: The portion of the term of this patent subsequent to Sep. 9, 1997 has been disclaimed.

[21] Appl. No.: 420,310

[22] Filed: Sep. 20, 1982

Related U.S. Application Data

[63] Continuation-in-part of Ser. No. 178,856, Aug. 18, 1980, Pat. No. 4,374,629, which is a continuation-inpart of Ser. No. 6,567, Jan. 26,1979, Pat. No. 4,221,500.

[51] Int. C1.3 E02B 3/04

[52] U.S. CI 405/24; 405/211

[58] Field of Search 405/21, 23, 24, 25,

405/27, 28, 32, 211; 428/17

[56] References Cited

U.S. PATENT DOCUMENTS

3,299,640 1/1967 Nielsen 405/24

3,426,473 2/1969 Cardarelli et al 405/211 X

3,540,415 11/1970 Bromley 405/24 X

3,559,407 2/1971 Schuur 405/24

3,590,585 7/1971 De Winter 405/24

3,638,430 2/1972 Smith 405/66

3,726,096 4/1973 Bahre 405/24

3,784,357 1/1974 Muraoka 405/211 X

FOREIGN PATENT DOCUMENTS

377004 6/1923 Fed. Rep. of Germany 405/27

2252009 6/1975 France 405/27

7710671 4/1979 Netherlands 405/25

Primary Examiner—David H. Corbin
Attorney, Agent, or Firm—Richard M. Beck

[57] ABSTRACT

Synthetic seaweed for use in inhibiting coastal erosion comprises an elongate anchor with strips of flexible non-woven material connected to the anchor. The strips may be buoyant with or without tabs of closed cell, low density foam affixed to the free end portions thereof to enhance the buoyancy of the strips whereby they maintain a generally upright position under water. Also, the strips are treated to inhibit or prevent marine growth from forming on the surface of the strips. Such treatment may include an antifouling agent or a smooth film, applied to the strips as a laminate or extruded directly onto the strips, for example. In use, the anchor rests upon the bottom of the sea and the submerged flexible strips of non-woven material extend upwardly therefrom. The strips sway in the ocean water thereby reducing currents in the surrounding water which permits accretion of suspended sand and promotes sedimentation of solid particles.

20 Claims, 8 Drawing Figures

SYNTHETIC SEAWEED

CROSS REFERENCE TO RELATED
APPLICATIONS

The present application is a continuation-in-part of application Ser. No. 178,856 filed Aug. 18, 1980, now U.S. Pat. No. 4,374,629 which in turn is a continuationin-part of application Ser. No. 6,567 filed Jan. 26, 1979, now U.S. Pat. No. 4,221,500, granted Sept.9, 1980. The disclosures of both applications are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to synthetic seaweed and more particularly to such seaweed treated to inhibit or prevent marine growth from forming thereon for use in building an underwater reef whose purpose is to inhibit coastal erosion and for use as a haven for marine life.

Prior to the present invention, artificial seaweed constructions have been proposed for dealing with coastal erosion problems. For example, U.S. Pat. No. 3,299,640, granted Jan. 24, 1967, describes a seaweed type structure for influencing the sub-marine migration of material. This structure consists of a screen formed by a large series of filamentary plastic strands secured at one end to an anchoring device placed at the bottom of the sea. The strands are buoyant and therefore assume and retain an upright position thereby reducing currents in the surrounding water while promoting the deposition of sand and other solid materials entrained by the water. Also shown in the above patent is a group of individual spaced apart buoyant tapes secured to a rope-like anchor. In each instance the function of these constructions is to combat coastal erosion.

U.S. Pat. Nos. 3,559,407 and 3,590,585, granted Feb. 2, 1971 and July 6, 1971, respectively, also disclose artificial seaweed wherein assemblages of filamentary strands of foamed, stretched polyolefin are used for influencing the migration of material at the bottom of bodies of water, as in combatting coastal erosion. Entanglement of the filamentary strands is troublesome during manufacture, installation and use, and U.S. Pat. No. 3,590,585 discusses several approaches to prevent such entanglement.

Obviously, it is important that once any artificial seaweed construction is installed, such construction functions to perform its intended purpose. In the case of artificial seaweed installed under water for the purpose of promoting sedimentation of solid particles, it is essential that the seaweed be sufficiently strong to withstand the ocean forces and also particularly designed so that the seaweed remains free of entanglement. It is equally important the seaweed maintain a generally upright position under water, and also that it be substantially free of marine growth which might otherwise weigh it down.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a unique form of synthetic seaweed having 65 high strength which is easy to make and effective to use for underwater installation in promoting marine life and/or inhibiting coastal erosion.

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Still another object of the present invention is to provide artificial seaweed which may be used under water without becoming fouled with marine growth.

In accordance with the present invention, synthetic seaweed for use in inhibiting coastal erosion comprises an elongate anchor with a plurality of flexible strips secured thereto. The anchor serves to hold the synthetic seaweed at the bottom of the sea and the flexible strips assume and retain an upright position in the water. These flexible strips function to effectively reduce ocean currents in the surrounding water which promotes sedimentation and permits accretion of suspended sand and also serves as a haven for marine life. In essence, the synthetic seaweed functions to promote a buildup of the ocean bottom in the same manner as sea vegetation.

At least some of the strips have tabs of closed cell, low density foam affixed to at least the free end portions thereof to enhance the buoyancy. Also, the outside surfaces of the strips have an antifouling inhibitor thereon to inhibit or prevent marine growth from forming on these surfaces. The antifouling inhibitor may comprise a liquid or slurry including tributylin fluoride or cuprous oxide for example, applied to the strips and allowed to dry to form a coating. Alternatively, such antifouling inhibitor may comprise a smooth film applied to the outside of the strips by extruding or laminating processes, for example.

The strips may be perforated whereby resistance of the strips to underwater currents is reduced. Preferably the percent open area of the perforations is approximately twenty-five to fifty percent.

It is preferred that the width of the strips be substantially the same and within the range of one-quarter inch to six inches wide. The most preferred width of each strip is within the range of two inches to three inches.

It is also preferred that the length of the strips be substantially the same and within the range of two feet to fifteen feet. The most preferred length of each strip is four feet to eight feet.

The preferred weight of the material comprising the strips is within the range of one-half to twelve ounces per square yard, the most preferred weight being three to six ounces per square yard. Preferably the material is non-woven.

BRIEF DESCRIPTION OF THE DRAWING

Novel features and advantages of the present invention in addition to those noted above will become apparent to those persons skilled in the art from a reading of the following detailed description in with the accompanying drawings wherein:

FIG. 1 is a diagrammatic view illustrating synthetic seaweed in actual use according to the present invention;

FIG. 2 is a side elevational view of the synthetic seaweed shown in FIG. 1 with the middle portion thereof broken away;

FIG. 3 is a sectional view taken along line 3—3 of FIG. 2;

FIG. 4A is a side elevational view of an alternate form of synthetic seaweed, according to the present invention, with the righthand portion broken away;

FIG. 4B is a side elevational view similar to FIG. 4A illustrating still another form of synthetic seaweed, according to the present invention, with the lefthand portion thereof broken away;