US3732841A - Explosively embedded anchor - Google Patents

Abstract

The disclosed invention is an explosively embedded anchor assembly for use in all types of ocean bottom and in all water depths. The anchor assembly has a shaped charge explosive for producing a hole in a rock ocean floor, a projectile anchor for embedding in all ocean floors, and a pro-jectile gun for explosively embedding the anchor. The assembly is provided with bottom-contact detonating means which permits automatic firing of the shaped charge and the anchor, and with a buoyant reaction vessel affixed to the projectile gun to permit automatic recovery of the gun.

Description

United States Patent 1 Mayo 51 May 15, 1973 [S4] EXPLOSIVELY EMBEDDED ANCHOR [75] Inventor: Henry C. Mayo Fairfax,Va.

[73] Assignees The United States of America as represented by the Secretary of the Army [22] Filed: Mar. 26, 1971 [211 App]. No.: 128,299

[52] US. Cl. ..1 14/206 A, 52/155 [51] Int. Cl. ..B63b 21/28 [58] Field of Search ..114/206 R, 206 A,

[56] References Cited UNITED STATES PATENTS 3,207,115 9/1965 Anderson ..l l4/206 A 3,154,042 10/1964 Thomason et al. ..114/206 A 3,078,931 2/1963 Moore ..1 14/106 A X Primary Examiner-Milton Buchler Assistant Examiner-Galen L. Barefoot Attorney-Harry M. Saragovitz, Edward J. Kelly,

Herbert Berl & Glenn S. Ovrevik [57] ABSTRACT The disclosed invention is an explosively embedded anchor assembly for use in all types of ocean bottom and in all water depths. The anchor assembly has a shaped charge explosive for producing a hole in a rock ocean floor, a projectile anchor for embedding in all ocean floors, and a pro-jectile gun for explosively embedding the anchor. The assembly is provided with bottom-contact detonating means which permits automatic firing of the shaped charge and the anchor, and with a buoyant reaction vessel affixed to the projectile gun to permit automatic recovery of the gun.

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1 EXPLOSIVELY EMBEDDED ANCHOR GOVERNMENT USE The invention described herein may be manufactured, used and licensed by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefore.

THE INVENTOR The inventor is Henry C. Mayo, 8007 Hamilton Lane, Alexandria, Virginia, 22308 (Fairfax County), a citizen of the United States of America.

BACKGROUND OF THE INVENTION This invention relates to explosively embedded anchors universally suited for use in all types of ocean bottom materials, sediments and compositions. Further, it relates to explosively embedded anchors which are designed for installation in shallow waters near a shoreline or deep waters at exposed offshore locations.

Heretofore, means for anchoring or mooring ships,.

barges, work platforms, instrumentation platforms, and other vessels and structures to the ocean bottom have not been entirely satisfactory. The installation of conventional type anchorages using common fluke type anchors or piles and chain is expensive and time consuming. In addition, the common fluke type anchor is heavy and will not resist applied loads in more than one direction.

Present explosive embedment anchors in use have not been satisfactory because they do not provide holding capacity over a sufficiently wide range of bottom sediments. Prior art includes many designs, but these take different configurations commensurate with the expected bottom conditions. Holding power is very slight when the particular configuration is installed in an inappropriate bottom, eg a rock embedment anchor installed in a mud bottom.

Also, present explosive embedment anchors, in use, have not been fully satisfactory because they do not provide an automatic means of recovery of the reaction assembly and gun after embedment. Prior art includes designs in which the reaction assembly and gun are recovered by a lowering line or are left in place near the embedded projectile. The design in which the gun is recovered with the lowering line has the disadvantage of being unsuitable for use in deep water because during recovery the lowering line becomes fouled and tangled by the riser cable attached to the anchor. The design in which the reaction assembly and gun are left in place has the disadvantage of being unsatisfactory for long term usage because the in place components aggravate corrosion and wear of the riser cable. Furthermore, the reaction assembly and gun cannot be re-used.

Prior art in explosive embedment anchors has not resolved the problem of anchor emplacement in very deep water where little or no bottom or sub-bottom information is available and the anchor must be adaptable to a variety of bottom conditions.

SUMMARY OF THE INVENTION The present invention provides an explosively embedded anchor which solves the problem of single directional holding power of common fluke type anchors and circumvents the disadvantages of prior art explosive embedment anchors in deep water and varying ocean bottom compositions. This explosively embedded anchor lends itself to utilization for anchoring under-water structures and instruments, mooring floating platforms and vessels, and salvaging disabled vessels or equipment.

Briefly, the invention consists of (l) a bottom contact probe for initial detonation of the explosive, (2) a shaped charge for producing a large tapered hole in rock ocean bottoms, (3) a projectile anchor having: a center member; a tapered groved spike protruding from its lower end for insertion into the tapered hold formed by the shaped charge when a rock bottom is encountered; a pair of flukes hinged at their lower ends to the center member with keying flaps hinged to the upper edge of each fluke for penetration into a nonrock ocean bottom, (4) riser cable, (5) a projectile gun for explosively embedding the projectile, and (6) a reaction vessel having sufficient buoyancy to float itself and the projectile gun after firing. Ancillary parts include a short recovery cable attached to the gun, a small recovery buoy, a sliding eye at the upper end of the recovery buoy, a stopper and floats attached to the riser cable, a faking board for the lower portion of the riser cable, a recovery ring attached to the reaction vessel, and a fuze for detonation of the explosive charge.

The assembly is lowered to the ocean bottom and the probe, upon touching the bottom, detonates the shaped charge and also detonates the charge in the gun to drive the anchor projectile into the bottom. The reaction vessel and gun float to the surface for recovery, guided by the riser cable. In rock bottom, when an upward pull is exerted on the riser cable, the grooved spike engages the wall of the tapered hole made by the shaped charge. In a hard bottom, such as coral, deeper penetration of the anchor projectile occurs and the pulling force causes the hinged keying flaps to engage the wall of the crater made by the anchor projectile, In softer bottoms, the pulling force also causes the keying flaps to pivot outward; but on additional pulling, the action of the soil pressure against the flaps causes the flukes to open pivotally. When fully open, the flukes provide maximum resistance to pullout in very soft ocean bottoms.

It is therefore a principal object of this invention to provide an economical and rapid means of providing secure anchorages and moorings in all ocean floors, including those composed of consolidated rock or coral, hard but not consolidated sediments, and soft sediments.

It is another object of this invention to provide an explosively embedded anchor for use in the varying water depths encountered in oceans and like bodies of water, including shallow and deep water depths.

It is a further object of this invention to provide an explosively embedded anchor having a reaction vessel and a gun barrel recoverable by means of flotation.

It is an additional object of this invention to provide an explosively embedded anchor which is designed for universal use but at the same time is light weight and readily stowed.

The above and still further objects, features and advantages of the present invention willbecome apparent upon consideration of the following detailed description of one specific embodiment thereof, especially when taken in connection with the accompanying drawing, wherein:

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings in detail and particularly to FIG. 1 thereof, there is shown an explosively embedded anchor assembly comprised of a projectile anchor designated generally by reference character 1, a spherical reaction vessel 2, a projectile gun 4, a shaped charge 7, a firing probe 8, and a riser cable 15. The reaction vessel 2 is fastened to the gun 4 by the clamp 13. Recovery rings 18 are fitted to the outer surface of the reaction vessel 2. The reaction vessel 2 functions to reduce recoil of the gun 4 by means of its mass and by providing large resistance to quick motion through the water. The" reaction vessel 2 also functions as a flotation device to permit recovery of the gun 4 after firing. The gun 4, is standard equipment.

The projectile anchor is comprised of a central supporting shaft 14, a pair of identical flukes 3, a tapered grooved spike 6, a main hinge 29 at the lower portion of the flukes, and keying flaps 16. Each fluke 3 is a flat plate connected to the supporting shaft 14 by the main hinge 29 and by linkage members 11 and 12. The linkage members 12 are pivotally connected to the flukes 3 by hinges 26. The linkage members 11 are pivotally connected to the shaft 14 by hinge 27 and are pivotally connected to linkage members 12 by hinges 28. The linkage members 11 and 12 serve to limit the opening of the flukes 3 to ninety degrees with respect to the axis of shaft 14. Each keying flap 16 is pivotally attached to the fluke 3 by hinge 25 and is attached to reaction vesse] 2 by shear means, not shown. Rotation of the keying flaps l6 outward is controlled by stops 30 and 31. Rotation of the flaps 16 inward toward the shaft 14 is prevented by stops, not shown. Piston 10 is attached to the upper-end of the shaft 14 and is inserted into the gun A housing is provided to protect the shaped charge 7 from sea water and pressure. The probe 8 actuates the fuze 9 upon bottom contact. The fuze 9 is electrically connected, not shown, to detonating means, not shown, in the shaped charge 7 and the gun 4. The riser cable 15 extends from hinges 27 and is faked on a faking board 17. The faking board is attached to reaction vessel 2 by shear means, not shown.

The riser cable 15 further extends upward to attached floats 19, attached stop 24, and sliding eye 23. The sliding eye 23 may be fitted with rollers, not shown, or other means to facilitate sliding. The floats support the section of the riser cable 15 between the faking board 17 and the stop 24 to prevent damage to the cable 15 by recoil of the gun 4 and reaction vessel 2. The stop 24 is securely affixed to the riser cable above the floats 19 and functions to restrain the sliding eye 23 from sliding any further down on the riser cable 15. The sliding eye 23 also serves with the recovering buoy 21, the eye 22, and the recovery cable 20 to suspend the explosively embedded anchor assembly prior to firing. After firing, the buoyance of the recovery buoy 21 and reaction vessel 2, function to float the gun 4 upward toward the water surface, as shown in FIG. 2. The sliding eye 23 then functions to restrain the gun 4 and reaction vessel 2 from drifting away with the ocean currents.

OPERATION OF THE ILLUSTRATED EMBODIMENT OF THIS INVENTION The explosively embedded anchor of this invention is installed by lowering the assembly from a work vessel or barge in a vertical orientation as shown in FIG. 1 by means of the riser cable 15 until the probe 8 contacts the ocean floor. The shaped charge 7 is then detonated by the fuze 9 and electrical conductors, not shown. After detonation of the shaped charge 7, a short time delay is automatically effected in the fuze 9 to permit dissipation of explosive gases and ocean bottom debris from the hole produced in the ocean floor. After the time delay, the fuze 9 also detonates the charge, not shown, in the gun 4 to propel the piston 10 from the gun 4 and embed the spike 6 into the hole made by the shaped charge 7 in the ocean floor. When a consolidated rock ocean floor is encountered, the flukes 3 and keying flaps 16 do not penetrate the ocean floor, as shown in FIG. 3. The grooves of the spike 6 wedge into the hole and provide substantial holding power when an upward pull is applied to riser cable 15.

After firing, the piston 10 separates from the gun 4, and reaction vessel 2 and the gun 4 are sent upward for a short distance by recoil. Then the buoyancy of the reaction vessel 2 and recovery buoy 21 lift the gun 4 to the water surface for recovery. The sliding eye 23 attached to the recovery buoy 21 slides along the riser cable 15 during the ascent of the gun 4. After recovery of the'gun 4, the upper portion of the riser cable is fastened to a buoy, not shown, or structure to form a secure anchorage.

When an ocean floor of material softer than consolidated rock, e.g. coral, sand or mud is encountered, the flukes 3 and keying flaps 16 penetrate through the hole made by the shaped charge and the entire projectile anchor is embedded into the ocean floor. In a coral or similar ocean bottom, an upward pull on the riser cable 15 forces the keying flaps 16 to rotate downward and wedge into the walls of the crater formed by the penetrating projectile. Further upward pull is strongly resisted by the wedged keying flaps 16 and a secure anchorage is provided. In a sand, clay, mud or similar unconsolidated ocean bottom, initial upward pull on the riser cable 15 causes rotation and wedging of the keying flaps 16 in a manner similar to that described for a coral bottom. However, upon further upward pulling on the riser cable 15, the shaft 14 travels upward for a short distance forcing "the flukes 3 to rotate outward to the full open position. Action of the bottom sediments against the fully exposed area of the flukes 3 furnishes holding power for the anchor and provides a secure anchorage.

So it is seen that an explosively embedded anchor has been devised which is universally suited for use in all types of ocean bottom materials, sediments and compositions, and water depths. In addition, a means for automatic recovery of the reaction vessel and gun has been provided. The improvement in anchorages that is accomplished thereby fulfills a long recognized need.

While one specific embodiment of the invention has been described and illustrated, it will be clear that variations of the details of construction will occur to persons skilled in the art without departing from the scope of the invention as defined in the appended claims.

What is claimed is:

1. An explosively embedded anchor assembly comprising:

a projectile gun;

a projectile anchor assembly adapted to be embedded into hard or soft ocean bottoms by said gun, said assembly having an elongated central supporting member, an elongated and grooved spike attached to and axially extending from the lower end of said central supporting member, a first even number plurality of flukes each attached by hinge means to said central supporting member at a first selected point thereon, collapsible linkage connecting a second selected point on each of said flukes to said central supporting member at a second selected point thereon, and a second even number plurality of keying means, said second plurality being at least as great as said first plurality, and means for hinging an equal number of keying means to each fluke in said first plurality thereof; a waterproof shaped charge housing of substantially cylindrical configuration and adapted to contain said grooved spike with the axis of said housing and said central supporting member in axial alignment;

a shaped charge explosive disposed within said shaped charge housing and spaced from said grooved spike at the opposite end of said housing, said explosive being capable of producing a hole in rock ocean bottom;

contact firing means attached thereto and suspended below said shaped charge housing and adapted to fire said shaped charge, said contact firing means including time delay means adapted to fire said projectile gun and to embed said anchor assembly at a predetermined time interval subsequent to contact with the ocean bottom;

a buoyant spherical reaction vessel affixed to said projectile gun and adapted for counteracting recoil and for automatically recovering said projectile gun;

a riser cable means attached to said supporting member of said anchor assembly by pivotal means, a portion of said riser cable being faked on a faking board;

a recovery buoy;

buoy cable means attached to said recovery buoy and to said riser cable, said buoy cable means including sliding means for travelling along said riser cable;

a plurality of floats affixed to said riser cable at a location spaced from the point of attachment to said anchor assembly;

stop means affixed to said riser cable at a selected point thereon intermediate said plurality of floats and said sliding means of said buoy cable means, said stop means adapted to prevent movement of said sliding means in the direction of said plurality, of floats beyond said selected point on said riser cable.

2. An explosively embedded anchor assembly as defined in claim 1 wherein a single pair of flukes is attached by hinge means to said central supporting member at said first selected point thereon, said flukes in said pair being diametrically disposed about and pivotedly mounted to said central supporting member in the vicinity of said grooved spike end attachment thereto whereby each of said flukes is movable from a folded position substantially parallel to the axis of said central support member to an open position substantially perpendicular to the axis of said central support member, said collapsible linkage being adapted to limit the opening of said flukes to substantially each of said flukes having two keying flaps hinged to the outer end thereof;

said means for hinging said keying including restraining means adapted to limit the rotation of said flap whereby a wedging action isprovided by contact of the restrained keying flaps with the wall of the crater formed by entry of said anchor into the ocean bottom when said anchor is first embedded and subsequently entrenched by upward pull on said riser cable.

Claims (2)

1. An explosively embedded anchor assembly comprising: a projectile gun; a projectile anchor assembly adapted to be embedded into hard or soft ocean bottoms by said gun, said assembly having an elongated central supporting member, an elongated and grooved spike attached to and axially extending from the lower end of said central supporting member, a first even number plurality of flukes each attached by hinge means to said central supporting member at a first selected point thereon, collapsible linkage connecting a second selected point on each of said flukes to said central supporting member at a second selected point thereon, and a second even number plurality of keying means, said second plurality being at least as great as said first plurality, and means for hinging an equal number of keying means to each fluke in said first plurality thereof; a waterproof shaped charge housing of substantially cylindrical configuration and adapted to contain said grooved spike with the axis of said housing and said central supporting member in axial alignment; a shaped charge explosive disposed within said shaped charge housing and spaced from said grooved spike at the opposite end of said housing, said explosiVe being capable of producing a hole in rock ocean bottom; contact firing means attached thereto and suspended below said shaped charge housing and adapted to fire said shaped charge, said contact firing means including time delay means adapted to fire said projectile gun and to embed said anchor assembly at a predetermined time interval subsequent to contact with the ocean bottom; a buoyant spherical reaction vessel affixed to said projectile gun and adapted for counteracting recoil and for automatically recovering said projectile gun; a riser cable means attached to said supporting member of said anchor assembly by pivotal means, a portion of said riser cable being faked on a faking board; a recovery buoy; buoy cable means attached to said recovery buoy and to said riser cable, said buoy cable means including sliding means for travelling along said riser cable; a plurality of floats affixed to said riser cable at a location spaced from the point of attachment to said anchor assembly; stop means affixed to said riser cable at a selected point thereon intermediate said plurality of floats and said sliding means of said buoy cable means, said stop means adapted to prevent movement of said sliding means in the direction of said plurality of floats beyond said selected point on said riser cable.

2. An explosively embedded anchor assembly as defined in claim 1 wherein a single pair of flukes is attached by hinge means to said central supporting member at said first selected point thereon, said flukes in said pair being diametrically disposed about and pivotedly mounted to said central supporting member in the vicinity of said grooved spike end attachment thereto whereby each of said flukes is movable from a folded position substantially parallel to the axis of said central support member to an open position substantially perpendicular to the axis of said central support member, said collapsible linkage being adapted to limit the opening of said flukes to substantially 90*; each of said flukes having two keying flaps hinged to the outer end thereof; said means for hinging said keying including restraining means adapted to limit the rotation of said flap whereby a wedging action is provided by contact of the restrained keying flaps with the wall of the crater formed by entry of said anchor into the ocean bottom when said anchor is first embedded and subsequently entrenched by upward pull on said riser cable.

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