US 3309876 A
Description (OCR text may contain errors)
March 2, 1967 J. M. POTTER 3,3@9375 EROSION PREVENTION APPARATUS 5 Sheets-Sheet l Filed Feb. 13, 1964 ATTORNEYS March 2, 196'? J. M. POTTER EROSION PREVENTION APPARATUS 3 Sheets-Sheet 2 Filed Feb. 13, 1964 ATTORNEYS March 21, 1967 .1. M. POTTER 3,399,876
EEEEEEEEEEEEEEEEEEEEEEEE US BY ATTORNEYS United States Patent 3,309,876 ERGSION PREVENTION APPARATUS John M. Potter, 2224 Paris St., Virginia Beach, Va. 23454 Filed Feb. 13, 1964, Ser. No. 344,591 4 Claims. (Cl. 61-3) This application is directed to improvements in the prevention of erosion particularly along beaches where water lmotion causes recession of the beach line.
Many attempts to prevent beach erosion have been and are being used. Jetties and bulkheads are used in various attitudes with respect to the beach line. These, however, are not too eilicient in preventing erosion of the beach line in stormy weather.
It is an object of the invention to provide a barrier positioned out from the beach and extending up from the beach iloor below the mean water level so yas to cause a slowing down of the undertow and backwash in order that the existing beach will not be carried out and at the same time sand and particles carried in by the incoming waves and water motion -will be deposited on the beach to create an even wider shore line.
Another object of the invention is to provide an apparatus and method to prevent beach erosion and to build up the beach, such apparatus being positioned below the surface of the water and out from the shore line to permit small boat navigation and no obstruction of the views seaward or landward.
A further object of the invention is to provide apparatus that may .be relatively easily implanted od shore and beneath the mean water level which through its own weight will remain in place and which may be lifted and relocated as necessary.
Still further objects and the entire scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specic examples are given by way of illustration only and, while indicating preferred embodiments of the invention, are not given by way of limitation, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
This development is to be used on a sea coast Where an erosion condition occurs such as sand and earth leaving the mainland and being carried out to sea by stormy conditions of the sea water movement. High winds which create high seas in turn create an undertow or backwash of water which takes the sand and earth out to sea.
The apparatus to prevent this erosion may be triangularshaped in cross section and of framework with suitable bailles to build up a back pressure on the undertow and backwash between the shore line of the beach and its location where it may be installed. This apparatus yand its proper placement will eliminate the undertow and backwash from taking the material from the seashore and forcing it out to sea.
The apparatus according to this invention is designed to be installed in relatively deep water out in the ocean from the shore line. The design of this apparatus will allow water and particles of material to pass through and over it. By installing the apparatus oil shore in depths of to 20 feet of water and beneath the water level, an appreciable amount, it will allow rough seas and breakers to pass over the top of it in stormy conditions without damaging it or washing it up onto the shore. By permitting the rough seas and breakers to pass over it, particles of sand and material carried in are deposited on the shore line of the beach. At the same time the baille framework has created an impediment to the movement of the undertow and backwash which allows the ex- Patented Mar. 21, 1967 isting material to stay on the beach. The incoming material that is deposited creates a wider shore line. The design may be varied to meet the needs of the depths and distances of water from shore line and the occurring erosion conditions that take place at various Seacoast locations.
The apparatus is cc-nstructed of extra heavy steel angles, channels and shapes which will withstand water pressures under running sea conditions. Since it is installed in relatively deep water it will allow open navigation of small craft thereover. A particular desirable feature of the apparatus is that by its being beneath the surface ot the water, a clear unobstructed view is provided from shore -or from sea. It will not be a liability to the beach `or shore line and will not restrict free use of the water area as for bathing, boating and fishing.
The apparatus may be assembled on shore, transported -and placed by suitable marine handling equipment. It will anchor itself and may be positioned in spaced positioned as to its units or abutted together and secured together end to end if necessary. On its framework that may be of various lengths, baille plates of about one foot width are installed spaced from one to three feet apart or more depending on its location and use. Each unit is of generally triangular cross section and may have a twenty foot crosswise spread at its bottom between its leg members and a four to six foot spread at the top between its leg members. The leg members extend at about a 45 degree angle to the horizontal.
For a more complete understanding of a form that the barrier units may take and their installation and use, reference is had to the drawings in which;
FIG. 1 is a top plan view of a section of seashore with shore line having barrier units installed in spaced endwise relationship with their lower ends imbedded in the seashore bottom;
FIG. 2 is an end view of a unit along line 2-2 of FIG. l on an enlarged scale;
FIG. 3 is a top plan view of the barrier unit shown in FIG. 2;
FIG. 4 is a perspective view of one of the barrier units on a scale between that used in FIGS. 1 and 3; and
FIG. 5 is a top plan view of the shoreline and beach similar to that of FIG. l but with the barrier units disposed end to end conforming to the `general outline of the shoreline being protected.
Throughout the description like reference numbers refer to similar parts.
A section of beach at a seashore is indicated at lil in FIG. 1 having a shoreline 11, a bottom sloping downward to seaward at 12 in FIG. 2 with a depth of Water of about l5 feet, mean low water, as an illustration.
A barrier unit is generally indicated at 14 and is fabricated of extra heavy steel members here shown welded together but they could equally as well be riveted or bolted together. The units here shown are about twentyfive feet long and are fabricated with three spaced apart generally triangular in cross section frames 1S having legs 16-16 about l2 feet long positioned at their lower ends about 20 feet apart and at their upper ends about 4 to 6 feet apart. The legs 16 may be of angle or channel pieces. Suitably vertically spaced apart cross pieces 17, lower cross piece, 18, an intermediate cross piece, and l, a top cross piece are welded to the legs at each end of the cross pieces. A vertical central channel or angle member 20 is affixed to the cross members intermediate their lengths. Three of these generally triangular in shape frames 15, two ends and one center, are used in fabricating a unit 14. These three frame members 15 have welded or otherwise ailixed thereto as by riveting or bolting, longitudinal spaced apart baille members 21. Each baille member 21 may be an elongated ilat plate of about l2 inches Width and of about l inch thick and of the length of the barrier unit such as 25 feet. These baffle members 21 may be channel members with their llat web or bight portion of the U-shaped in cross section channel welded to the legs if a more rigid structure is required. These baille members 21 of about l2 inches width are spaced apart about 2 feet and each unit, as shown, utilizes four baille plates on each side.
The generally triangular frames 1S may be said to be generally isoceles trapezoids a, b, c, d, with the leg portions 16a depending from the leg portions ab and dc which are the non-parallel sides.
In placing a unit 14 in place out from the shore line, it will be noted that the lower ends of the legs 16 imbed themselves about five feet vertically down into the ocean bottom and for the unit shown that is placed in about l5 feet of water, the top thereof will be about 5 feet below the surface of the water.
In the illustration shown in FIG. l the units 14 are shown spaced apart less than a length thereof and generally parallel to their adjacent abreast portion of shore line out in deep water, thus, the undertow water move ment will move out in a direction generally normal to the particular unit in its location.
In FIG. 5 another arrangement of the units 14 is utilized. Here the six units illustrated as installed for the beach section 25 are positioned in generally abutting end to end attitude so as to follow the general contour of the seashore line 26. In order to carry this out, units 14a, 14b and 14C have their ends not quite fully abutting. In this case suitable spacer members 27, 2S and 29 such as pieces of pipe may be positioned between the ends at their non-abutting portions. These spacer members are held in position by suitable through bolt members generally indicated at 30 passing therethrough. The legs 16 are provided with suitable apertures to receive the bolts r elongated fasteners 3l). Like fasteners 30 are used at the directly abutting end portions to secure the ends of the units directly together,
As pointed out above, the barrier members 14 and the spaces bet-Ween the spaced apart baflle members 21 will permit the incoming wave motion to pass over and through the barrier. As the undertow and backwash follows, its movement is slowed up as it tends to go out to sea and the stirred up sand and any carried in sand drops to the bottom of the beach in place without being carried out to sea. Thus, the beach is held in place and even the carried .in sand and earth is deposited on the beach to build the same up due to this arrested undertow or backwash caused by the properly designed and placed barrier apparatus.
The action of the inclined surfaces of the ballles 21 as shown in FIGS. 2 and 4 to the undertow backwash moving as indicated by the arrow in FIG. 2 below the surface, tends to slow up this undertow water movement and lets the undertow go out relatively slowly. This back pressure action created in slowing the undertow outflow permits the sand that has been carried in and stirred up to precipitate and drop to the seashore bottom spaced well shorewise of the barrier apparatus. The cleared water of the precipitated sand moves back to sea along the bottom and Ithrough the effective vertical heights of the framework and in the spaces between the elongated batlles 21 of the barrier apparatus 14.
As desired, the barrier units 14 may be arranged in spaced endwise relationship as shown in FIG. l or in connected abutting position as illustrated in FIG. or as a combination of each such arrangement.
The bailles members 21 are illustrated as being arranged each in a common substantially horizontal plane, however, if greater resistance to undertow flow and back pressure to this llow is needed, these baille members 21 may be staggered with respect to each other in their receptive common horizontal planes.
This apparatus and method serves a long felt need to help solve the problem of beach erosion.
What is claimed is:
1. An erosion prevention system `for preventing seashore beach erosion comprising a plurality of elongated frameworks positioned out from the beach submerged below the mean low -water level without obstruction to navigation of surface craft thereover and in a position generally endwise adjacent each other to follow the general contour of the `beach line, each elongated framework having a plurality of spaced apart transverse generally triangular `frames with two legs of each frame diverging downwardly and interconnected with a base cross piece immediately adjacent the ocean bottom, at least some of said legs of the frames extending divergently downwardly Ibeyond the cross pieces into the ocean bottom to anchor said elongated framework thereto, each framework having a plurality of spaced apa-rt elongated baille members connecting the legs of said two legs of each of said spaced apart rframes defining shoreward and seaward faces of the framework and the baille members having upwardly extending planar surfaces with their axes extending generally horizontally and arranged in a common plane on the shoreward -face and on the seaward face and the two faces upwardly convergent at .attitudes with respect to the general Vertical height of each framework so as to retard the motion of the water, the lowerrnost baille members being immediately adjacent the cross piece and the ocean bottom and the topmost baille members being positioned on the legs of said frames below the mean `low water without obstruction to navigation of sunface craft, the other batlle members being spaced apart therebetween, and from each other a distance greater than the upwardly width of each planar surface, whereby incoming wave motion of the sea passes over and through the frameworks and between the baffles and is slowed down as it rushes up the ocean bottom and `floor of the beach and has its undertow motion and backwash rate of flow arrested so .that the sand carried in and the sand stirred up is deposited on the beach area spaced well shoreward in from said frameworks.
2. An e-rosion prevention system according to claim 1 wherein said frameworks are connected together end to end.
3. An erosion prevention system according to claim 1 wherein the frameworks are connected together with space-r members positioned between the frameworks to conform them to the general contour of the beach.
4. An erosion prevention system according to claim f1 wherein each of said transverse 1frames has a top cross piece to define with said two legs and said base cross piece a generally shaped isoceles trapezoid with each of the frames parallel cross pieces extending horizontally and its nonparallel two legs protruding below the ybase cross piece into and anchoring the framework to the ocean bottom.
References Cited by the Examiner UNITED STATES PATENTS 421,631 2/1890 Sutherland 61--4 762,727 6/ 1904 Landen'be-rger 6f14 1,858,976 5/1932 Thornley 61-3 `1,870,154 8/1932 Wehr 61-4 2,068,537 1/1937 Dorn 61-3 2,191,924 2/ 1940 Humphrey 61-4 FOREIGN PATENTS 760,731 12/1933 France.
EAiRL J. 'WIT'MEIL Prmaly Examiner.