Information
-
Patent Grant
-
6443660
-
Patent Number
6,443,660
-
Date Filed
Monday, November 27, 200024 years ago
-
Date Issued
Tuesday, September 3, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Shackelford; Heather
- Lee; Jong-Suk
Agents
-
CPC
-
US Classifications
Field of Search
US
- 405 160
- 405 170
- 405 172
- 405 173
- 405 222
- 405 223
- 405 224
- 405 2241
- 405 226
- 405 227
- 114 44
- 114 50
- 114 51
- 114 54
- 114 244
- 114 248
- 114 254
- 254 269
- 254 362
- 254 323
- 254 264
-
International Classifications
-
Abstract
An apparatus for manipulating an object located proximate an underwater floor is disclosed, in a preferred embodiment comprising a foundation implantable in the underwater floor; a lifting frame extending between the foundation; and a multiplicity of slings mounted adjacent to each other and attached to the lifting frame such that each of the slings is suspended in a cradle-like configuration from the lifting frame. Each of the slings further comprises a top surface facing away from the underwater floor and a padding material mounted proximate the top surface of each sling. The foundation may further comprise suction piles. A monitoring system comprising instrumentation may also be used to aid in guiding the load transfer of the object from the floor to the lifting frame. A method of lifting is described comprising lowering and securing the foundation into the underwater floor proximate the object to be retrieved, positioning the lifting frame proximate the object to be retrieved, installation of containment material, securing lifting frame ends onto the foundation, securing each end of each sling onto the lifting frame as well as positioning each sling under the object to be retrieved, tensioning each sling, and then raising the object by raising the lifting frame.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to manipulating objects located proximate an underwater floor. By way of further particularity, the present invention relates to an apparatus and method of using the apparatus for salvage and recovery of fully or partially submerged objects. By way of further particularity, the present invention relates to an apparatus and method for recovering fully or partially submerged objects from an underwater floor such as a seabed, lake, river, or marsh, especially in operations having delicate or difficult archeological retrieval characteristics.
2. Description of the Related Art
There are numerous patents in the field of underwater salvage and recovery systems and methods. As summarized below, these patents neither teach nor suggest use of a support foundation implanted or otherwise imbedded in an underwater floor such as a seabed or having a lifting frame with a series of slings that are suspended from the lifting frame in a cradle-like configuration.
U.S. Pat. No. 4,658,745 issued to Beucher discloses a salvage apparatus that includes a drum container. The salvage apparatus
10
is taken by a diver from a surface craft to an object to be retrieved
12
from the ocean floor.
U.S. Pat. No. 5,820,109 issued to Jermyn, et al. discloses a salvage apparatus that includes a lift system
10
. The lift system
10
has a flotation unit
18
having connection means to provide appropriate points on a harness
20
to provide for attachment of tethers. Means for attaching to and lifting underwater salvage items are disclosed.
U.S. Pat. No. 4,319,372 issued to Tausig discloses a salvage apparatus for delivering a heavy cable from the ocean's surface to an extended depth for attachment to an object to be salvaged. The apparatus
10
includes a buoyancy float
12
formed of a syntactic foam. The buoyancy float
12
further has a central longitudinal aperture
18
extended from a rounded top of the buoyancy float
12
to a substantially flat bottom of the buoyancy float
12
.
U.S. Pat. No. 5,551,801 issued to Gallaher, et al. discloses a hyjack platform with compensated dynamic response. An offshore platform structure is disclosed for temporarily using a jack-up rig. Pile sleeves
20
support a truss assembly, e.g. surface tower
28
. See also U.S. Pat. No. 5,741,089 issued to Gallaher, et al. and U.S. Pat. No. 5,593,250 issued to Smith, et al., each of which also disclose hyjack platforms and methods of use.
U.S. Pat. No. 5,655,938 issued to Huguenun, et al. discloses a variable buoyancy float/ballast system having a float/ballast assembly
23
. A lower ballast portion
26
carries a fixed but adjustable ballast in modular increments. A floatation chamber
27
is attached to float/ballast assembly
23
. When chamber
27
is flooded, float/ballast assembly
23
sinks, and when filled with air, float/ballast assembly
23
rises. One or more mooring lines attach to float/ballast assembly
23
and to an object to be raised such as cage
20
.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a plan view of a representative configuration of the salvage system of the present invention.
FIG. 2
is a plan perspective view of a representative lifting frame.
FIG. 3
is a plan perspective view of a representative sling.
FIG. 4
is a plan perspective view of a representative lifting frame being lowered into place over a partially embedded object to be retrieved.
FIG. 5
is a plan perspective view of a representative sling being positioned under a partially embedded object to be retrieved.
FIG. 6
is a plan perspective view of a representative sling being attached to a representative lifting frame.
FIG. 7
is a plan perspective view showing buffer bags being inflated.
FIG. 8
is a plan perspective view showing a plurality of slings deployed under an object as the object is being lifted.
DETAILED DESCRIPTION
The present invention relates to an apparatus for use in recovering objects such as objects that might be fully or partially submerged in a body of water such as a seabed or marsh, especially in operations having delicate or difficult archeological retrieval characteristics and/or where objects are fully or partially embedded into a floor of the body of water.
Referring now to
FIG. 1
, the present invention's system comprises foundation
10
, lifting frame
20
, and rigging system
30
.
Foundation
10
may be constructed from any material appropriate for use underwater. It is understood that the underwater environment may be fresh water, salt water, brackish water, marshes, or any combination thereof and that each underwater environment may present differing turbulence or tidal features. As opposed to the prior art use of similar foundations to support a tensile load such as to anchor a floating oil platform, foundation
10
of the present invention supports a compressive load.
Foundation
10
supports lifting frame
20
and comprises bearing table
18
as well as outer wall
15
and top surface
16
defining cavity
17
that is at least partially implantable into floor
100
where floor
100
is a seabed, lake floor, river bed, or the like. Bearing table
18
may be adjustable such as to allow for variations in position of lifting frame
20
into position onto foundation
10
.
In the preferred embodiment, foundation
10
comprises a pair of suction piles
12
, similar to those used in oilfield operations as will be familiar to those of ordinary skill in offshore platform construction arts. Examples of similar suction piles may be seen in U.S. Pat. No. 4,432,671 issued to Westra et al. and U.S. Pat. No. 4,318,641 issued to Hogervorst. Outer wall
15
of suction pile
12
provides for skin friction load bearing and top surface
16
may bear directly on floor
100
. Suction piles
12
are positioned to a predetermined position on floor
100
proximate object
110
. In the preferred embodiment, suction piles
12
comprise welded A36 steel, but, by way of example and not limitation, can further comprise general purpose mild steel or any other material capable of supporting lifting frame
20
and its loads. The actual dimensions of suction piles
12
may vary depending on the actual or presumed characteristics of floor
100
including the depth of floor
100
, as will be familiar to those of ordinary skill in the underwater construction arts.
Alternatively, foundation
10
may be a sufficiently supportive floor
100
. Suction pile
12
is preferred when floor
100
is of unknown load bearing ability. However, if floor
100
is sufficiently firm, a “mud mat” such as a concrete mat (not shown in the figures) may be used to more or less conform to or lay flat on floor
100
to support the weight of lifting frame
20
and object
110
. Mud mats may comprise steel, concrete, wood, or any combination of materials that sinks and can provide sufficient support for lifting frame
20
and object
110
.
Alternatively, foundation
10
may be a sufficiently supportive floor
100
. Suction pile
12
is preferred when floor
100
is of unknown load bearing ability. However, if floor
100
is sufficiently firm, a “mud mat,” generally referred to by the numeral “
11
,” such as a concrete mat
11
may be used to more or less conform to or lay flat on floor
100
to support the weight of lifting frame
20
and object
110
. Mud mats
11
may comprise steel, concrete, wood, or any combination of materials that sinks and can provide sufficient support for lifting frame
20
and object
110
.
In the preferred embodiment, submersible hydraulic pump
51
has an approximately 4″ diameter inlet pipe mated to an approximately 4″ pipe stub welded in through top surface
16
of suction pile
12
. Alternatively, submersible hydraulic pump
51
may be electrically or pneumatically actuated, and alternatively may be located on a deck of vessel
120
, a platform , or another suitable structure such as a river bank, providing that pump
51
has sufficient power to create a differential pressure needed to drive suction pile
12
into floor
100
.
Lifting frame
20
is a structure to be supported by foundation
10
. Lifting frame
20
may be configured as a truss or any other appropriate structure, all of which will be readily understood by those of ordinary skill in the structural design arts. In a preferred embodiment, lifting frame
20
is a light weight truss whose length is at least equal to that of object
110
.
In the preferred embodiment, lifting frame
20
further comprises a first longitudinal member
21
and a second longitudinal member
22
where longitudinal members
21
,
22
are spaced apart a distance greater than or equal to the width of object
110
. However, lifting frame
20
may comprise a single longitudinal member such as longitudinal member
21
or have any predetermined shape capable of supporting object
110
during lifting, by way of example and not limitation such as a substantially rectangular shape.
Lifting frame
20
may be made of any material appropriate to withstand the fluid and chemical environment into which lifting frame
20
may be submerged. In a preferred embodiment for salt-water use, lifting frame
20
comprises a suitable grade of steel such as 500 grade steel which has greater material strength that the material used for suction piles
12
. In alternative embodiments, lifting frame
20
may comprise any material appropriate in light of factors relevant to object
110
and its environment, by way of example and not limitation including the weight and condition of object
110
, the distance between foundation
10
components, the number and location of rigging connections between object
110
and lifting frame
20
, and water current forces.
Once lowered into place, ends
21
a
,
22
a
,
21
b
, and
22
b
of lifting frame
20
are supported on foundation
10
and lifting frame
20
fixed in place such as by securing ends
21
a
,
22
a
,
21
b
, and
22
b
. Alternatively, securing ends
21
a
,
22
a
,
21
b
, and
22
b
may rest on foundation
10
, secured by the weight of lifting frame
20
onto foundation
10
. In a currently preferred embodiment, lifting frame
20
is supported by adjustable bearing table
18
to account for foundation misalignment of plumb, altitude, placement, and/or rotation, and is chained to foundation
10
to secure it to foundation
10
. Alternatively, lifting frame
20
may further comprise bolt holes located within or proximate to lifting frame
20
bearing seats (not shown in the figures) that land on foundation
10
on bearing table
18
. Preconfigured bolt holes may exist in bearing table
18
to receive one or more through bolts where the through bolts also pass through lifting frame
20
bolt holes. In an alternative embodiment, bolt holes may be drilled or otherwise created in mounting table
18
to receive through bolts. As will be apparent to those of ordinary skill in the construction arts, lifting frame
20
may also be secured to foundation
10
by chains, bolts, locking latches, pin-and-box, ball-and-socket, or any other appropriate connectors.
Sling securing ends, generally referred to by the numeral “
32
” in the figures and shown as sling securing ends
32
a
and
32
b
in
FIG. 1
, are disposed about lifting frame
20
. In a preferred embodiment, sling securing ends
32
connect padeyes
27
running the length of lifting frame
20
. In a currently preferred embodiment, padeyes
27
are secured to lifting frame
20
as by welding or other securing means, all of which will be understood by those of ordinary skill in the fabrication arts.
Rigging system
30
comprises at least one sling
34
secured to lifting frame
20
using sling ends
32
such as by attachment to padeyes
27
. In a currently preferred embodiment, sling
34
comprises a multiplicity of slings
34
mounted adjacent to each other where each of slings
34
has a first end
34
a
attached to first longitudinal member
21
at sling securing end
32
a
and a second end
34
b
attached to second longitudinal member
22
at sling securing end
32
b
, such that, once attached to lifting frame
20
, each of slings
34
is suspended in a cradle-like configuration from lifting frame
20
.
Referring now to
FIG. 2
, lifting frame
20
may be configured as a truss with a plurality of longitudinal members
21
,
22
, a plurality of support legs
25
, and a plurality of ribs
26
. If floor
100
is sufficiently supportive, foundation
10
maybe eliminated and lifting frame
20
secured directly onto floor
100
or other support structures such as mud mats such as by support legs
25
. In situations, length of support legs
25
may be adjustable such as to account for irregularities in floor
100
.
In alternative embodiments, one or more measurement gauges such as strain gauges, tension gauges, sonic, and/or linear variable displacement transducers or “LVDTs”
42
may also be present. In a presently preferred embodiment, LVDT
42
is a tubular further comprising rod
42
a
(not shown in the figures) movably mounted within LVDT
42
. Rod
42
a
may contact object
110
such as by gravity or other attaching means. The movement of rod
42
a
within LVDT
42
induces a current within a sensing loop such as by a disturbance in a magnetic field. Current may then be passed to monitoring equipment to sense the current. In an alternative embodiment, rod
42
a
may be calibrated and monitored visually.
Referring now to
FIG. 3
, each sling
34
further comprises top surface
35
facing away from floor
100
. Slings
34
may further comprise buffering and securing components, including by way of example and not limitation buffer bags
36
such as nylon buffer bags located proximate top surface
35
, tensioning hardware such as turnbuckles
32
and chains
37
, and monitoring instrumentation
41
(not shown in the figures) suitable to aid in guiding the load transfer of object
110
from floor
100
to lifting frame
20
. Buffer bag
36
provides a cushioning contact area that will conform to an surface geometry of object
110
.
In a preferred embodiment, slings
34
comprise nylon slings that range from around 8″ to around 18″, but the actual dimensions of slings
34
may vary depending on the actual object
110
to be retrieved. Slings
34
may further comprise hole pattern
31
for attaching buffer bags
36
. Bag fasteners
33
(not shown in the figures) may be used to attach buffer bags
36
to sling
34
by any appropriate means, such as rope, cord, monofilament lines, fasteners, hooks and loops, small lines, cable ties, and the like, or any combination thereof.
“Secondary” slings
34
may be used to minimize stress in object
110
and provide general flexibility in securing object
110
. Secondary slings
34
are distinguished from other slings
34
by usage. By way of example and not limitation, where object
110
has structural characteristics indicating points of weakness along object
110
, secondary slings
34
may be used as a precaution to reduce the stress induced in object
110
. Secondary slings
34
may be attached to lifting frame
20
such as at sling ends
34
a
,
34
b
or to other slings
34
. Thus, in situations where object
110
could have compromised or questionable structural integrity, and/or disarticulated or fractured features, secondary slings
34
may be used to provide additional, ancillary support as opposed to main lifting support of other slings
34
.
In the presently preferred embodiment, a single buffer bag
36
comprising a nylon mesh adapted to receive and retain a fluid therein is disposed proximate top surface
35
. Each buffer bag
36
may be independent of any other buffer bag
36
and each may be independently fillable with fluid. In an alternative embodiment, buffer bags
36
may further comprise injector ports adapted to receive and retain fluids. Further, the present invention can be satisfied with a single buffer bag
36
whether independent of or integrated into sling
34
, a plurality of buffer bags
36
whether independent of or integrated into sling
34
, or any combination thereof. In a currently envisioned alternative embodiment, buffer bags
36
may be preformed out of a material such as out of a neoprene material to a desired conforming shape before attaching buffer bags
36
to slings
34
.
A tensioning system for each sling
34
may be present as well, and may further comprise turnbuckles
32
, chains
37
, load cells
41
, and vertical measurement gauges (“LVDTs”)
42
(shown in FIG.
2
). In an alternative embodiment, the tensioning system may employee ratchet type tensioners, chain binders, and cable slings, as will be familiar to those in the construction arts. Load cells
41
and LVDTs
42
may be further connected by an appropriate signaling means such as a wire or optical pathway
39
to instrumentation such as data recording and display systems (not shown in the figures) located at vessel
120
or a surface such as a river bank. Pathway
39
may thus be used to relay information about tension in sling
34
and other monitored data to data recording and display systems such as by way of example and not limitation to general purpose computers, special purpose computers, digital readout devices, analog readout devices, or the like, or any combination thereof.
A tensioning system for each sling
34
may be present as well, and may further comprise turnbuckles
32
, chains
37
, load cells
41
, and vertical measurement gauges (“LVDTs”)
42
(shown in FIG.
2
). In an alternative embodiment, the tensioning system may employee ratchet type tensioners, chain binders, and cable slings, as will be familiar to those in the construction arts. Load cells
41
and LVDTs
42
may be further connected by an appropriate signaling means such as a wire or optical pathway
39
to instrumentation such as data recording and display systems
200
(
FIG. 1
) located at vessel
120
or a surface such as a river bank. Pathway
39
may thus be used to relay information about tension in sling
34
and other monitored data to data recording and display systems such as by way of example and not limitation to general purpose computers, special purpose computers, digital readout devices, analog readout devices, or the like, or any combination thereof.
Lifting frame
20
is then positioned into place onto foundation
10
proximate object
110
such as by lowering it from vessel
120
, and lifting frame ends
22
are then secured onto foundation
10
. In a preferred embodiment, lifting frame ends
22
are secured such as by chains secured through padeyes
27
that may be present in bearing table
18
. When secured onto foundation
10
, lifting frame
20
is positioned in a predetermined position proximate object
110
suitable for lifting object
110
in support structure.
In an alternative embodiment, foundation
10
may be preassembled with lifting frame
20
before lowering foundation
10
and lifting frame into the water.
Referring now to FIG.
5
and
FIG. 6
, once lifting frame
20
is secured onto foundation
10
, each sling
34
to be used during the salvage operation is attached to first longitudinal member
21
at sling securing end
32
a
and then draped or otherwise positioned under object
110
. Floor
100
material may be partially excavated from near and/or under object
110
to facilitate draping or otherwise positioning sling
34
under object
110
. Second end
34
b
of sling
34
is then retrieved from under object
110
and then attached to second longitudinal member
22
at sling securing end
32
b
, such that each of slings
34
is suspended in a cradle-like configuration from lifting frame
20
under object
110
. In a currently preferred embodiment, excavation can occur in a progressive manner, such that the load of object
110
is transferred incrementally. As each incremental tension step occurs, additional excavation may then take place.
Referring now to
FIG. 7
, if not already attached, buffer bags
36
are attached such as by lacing to each sling
34
using hole patterns
31
and bag fasteners
33
. Alternatively, buffer bags
36
may have already been placed onto sling
34
or sling
34
may be integral with buffer bags
36
. Buffer bags
36
are then injected with a predetermined fluid, by way of example and not limitation directly through an outer surface of buffer bag
36
or through an injector port. In the preferred embodiment, the fluid used is a two part industrial polyurethane foam commonly used in the insulation and refrigeration industry. One such foam is FROTH-PAK(TM), produced by Flexible Products, 1007 Industrial Park Drive, Marietta, Ga. 30062. It is anticipated that standard foam hoses and foam injection guns can be used to inject the fluid into buffer bags
36
, and that manual as well as mechanized or other pressurized means such as pressure tanks, compressors, and the like may be used. Further, although a single buffer bag
36
may be used, a plurality of buffer bags
36
may be used to better conform to the shape of object
110
.
If a foam is used as in the preferred embodiment, the foam may be inserted into buffer bag
36
by inserting a nozzle tip of the foam injection gun directly into buffer bags
36
and injecting foam until each buffer bag
36
conforms to object
110
or otherwise appears full to the person injecting the foam. In an alternative embodiment, buffer bag
36
further comprises one or more injector ports into which the nozzle tip may be inserted. The foam may then be allowed to harden.
Referring now to
FIG. 8
, once each sling
34
is positioned and buffer bags
36
filled, each sling
34
is tensioned to transfer the weight of object
110
to lifting frame
20
and foundation
10
. Numerous means of tensioning may be used as will be familiar to those of ordinary skill in the structural arts, including by way of example and not limitation use of turnbuckles
32
attached to one or more ends of sling
34
, or rachet type tensioners comprising straps secured on one side with hooks, passed under buffer bags
36
, and threaded into spools in a support bracket. The spools may be turned such as with a lever or other extension to tighten the straps against the load to hold it in place.
Slings
34
are tensioned using the tensioning system. Tension may be estimated initially or the tensioning system may be used to adjust the tension for each sling
34
. Once object
110
is secured, such as when all slings
34
are tensioned, lifting frame
20
is released from foundation
10
, if secured to foundation
20
, and lifting frame
20
is then lifted, along with object
110
. As object
110
is lifted, tensioning may be further adjusted, either manually, automatically, or a combination thereof. Once fully retrieved, lifting frame
20
may be secured onto a surface such as a ship or barge deck by using support legs
25
. Alternatively, lifting frame
20
may be positioned onto a cradle on a surface such as a ship or barge deck where the cradle is preconfigured to accept lifting frame
20
and object
110
suspended in slings
34
.
In a preferred embodiment, LVDTs
42
allow monitoring of bending of object
110
. Thus, during tensioning and/or lifting, if monitors determined that the bending is excessive, LVDTs
42
will indicate where the tensioning needs to be adjusted. Divers may be instructed on tension adjustments during the lifting from monitors such as by radio, direct linkage, or other means as are well known in the diving arts. In addition, tension adjustments may be made automatically through automated means using data gathered by a data recording and display system (not shown in the figures). It is understood that as used herein above, “monitors” may be human beings, automated systems, or any combination thereof.
Suction piles
12
may be retrieved after use by reversing the installation procedural steps.
In addition to using the apparatus and method of the present invention for salvage and retrieval operations, the present invention may also have use in other underwater endeavors. By way of example and not limitation, the current example can be used to manipulate pipeline equipment such as underwater tubulars, underwater telephony cables, valve assemblies, other underwater structures such as pumps or electro-mechanical machinery, and the like, or any combination thereof. Such usage may also include manipulation of underwater objects for installation, maintenance, and repair operations as well as salvage and/or removal. These are by way of example and illustration only as the scope of the invention is described by the claims herein.
It will be understood that various changes in the details, materials, and arrangements of the parts which have been described and illustrated above in order to explain the nature of this invention may be made by those skilled in the art without departing from the principle and scope of the invention as recited in the following claims.
Claims
- 1. A system for manipulating an object located underwater, comprising:a) a foundation implantable in an underwater floor; b) a lifting frame having a first end and a second end, each adapted for mounting on the foundation, the lifting frame further comprising a first longitudinal member and a second longitudinal member extending between the first and second ends, the longitudinal members being spaced apart a predetermined distance; c) a multiplicity of slings mounted adjacent to each other, each of the slings having a first end attachable to the first longitudinal member and further having a second end attachable to the second longitudinal member, such that, when attached to the first longitudinal member and second longitudinal member, each of the slings is suspended in a cradle-shaped configuration from the lifting frame, each of the slings further comprising a top surface facing away from the underwater floor; and d) a padding material mounted proximate the top surface of each sling.
- 2. The system of claim 1 wherein the lifting frame further comprises a plurality of support legs and support ribs.
- 3. The system of claim 1 wherein the spacing of a predetermined distance of the longitudinal members is at least equal to a width of the object sought to be manipulated.
- 4. The system of claim 1 wherein the padding material comprises at least one buffer bag adapted to receive a fluid.
- 5. The system of claim 4 wherein the fluid is an expansive foam.
- 6. The system of claim 1 wherein the foundation further comprises:a) a first suction pile implantable in the underwater floor, the first suction pile having an outer wall and a top surface defining an interior void that is at least partially implanted into the underwater floor; and b) a second suction pile implantable in the underwater floor, the second suction pile having an outer wall and a top surface defining an interior void that is at least partially implanted into the underwater floor, the second suction pile being positioned a predetermined distance from the first suction pile; wherein the lifting frame extends between the first and second suction piles, the lifting frame having a first end adapted for mounting on the first suction pile and further having a second end adapted for mounting on the second suction pile; and the predetermined distance between the first and second suction piles exceeds a length of the object sought to be recovered from the underwater floor.
- 7. The system of claim 6 further comprising a submersible hydraulic pump operatively connected to a hydraulic power unit through at least one fluid hose, the hydraulic pump further operatively connected to an inlet in at least one of the suction piles, whereby the hydraulic pump creates a differential pressure needed to drive the suction pile into the underwater floor.
- 8. The system of claim 6 wherein the first suction pile further comprises a bearing table disposed proximate the top surface of the first suction pile, and the second suction pile further comprises a bearing table disposed proximate the top surface of the second suction pile, wherein each of the bearing tables is adapted to receive either the first end or the second end of the lifting frame.
- 9. The system of claim 1 further comprising a tensioning system, the tensioning system comprising:a) a tension adjuster disposed between each sling and the lifting frame; b) a load cell operatively connected to a sling; c) a vertical measurement gauge operatively in communication with the object; d) a pathway; and e) a data recording and display system operatively connected to the pathway; f) wherein the pathway is further operatively connected to and conveys data between at least one of the load cell or the vertical measurement gauge to the data recording and display system.
- 10. A system for lifting an object disposed proximate an underwater floor, where the density of the underwater floor can support a compressive load, the system comprising:a) a lifting frame extending between a first foundation portion and a second foundation portion, the lifting frame having a first end adapted for mounting on the underwater floor and further having a second end adapted for mounting on the underwater floor, the lifting frame further comprising at least one object lifting support member; b) a multiplicity of slings mounted adjacent to each other, each of the slings further comprising: i) a first end attached to the object lifting support member; ii) a second end attached to the object lifting support member; iii) a top surface facing away from the underwater floor; and iv) a padding material mounted proximate the top surface of each sling. c) wherein i) each of the slings is suspended in a cradle-shaped configuration from the lifting frame and ii) the padding material is disposed intermediate the object and the sling.
- 11. The system of claim 10 wherein the object lifting support member further comprises a first longitudinal member and a second longitudinal member extending between the first and second ends, the longitudinal members being spaced apart a distance greater than or equal to the width of the object sought to be recovered.
- 12. The system of claim 10 further comprising at least one mud mat deployable on the underwater floor, the mud mat being capable of supporting the lifting frame during at least an initial lifting of the object.
- 13. A method of manipulating an object that is at least partially underwater with an apparatus comprising a lifting frame comprising a first longitudinal member, a second longitudinal member, and first and second lifting frame ends adapted for mounting on a foundation; and at least one sling adapted to receive padding material; the method comprising:a) positioning the lifting frame proximate an object to be retrieved from an underwater floor; b) securing one end of the at least one sling onto the first longitudinal member of the lifting frame; c) positioning the at least one sling under the object to be retrieved, the at least one sling further positioned adjacent to at least one other sling; d) retrieving a free end of the least one sling from under the object to be retrieved; e) securing the free end of the at least one sling onto the second longitudinal member of the lifting frame; f) disposing padding material intermediate the object and the at least one sling; g) conforming a predetermined amount of padding material to the object; h) tensioning the at least one sling; and i) raising the object by raising the lifting frame.
- 14. The method of claim 13 for a system further comprising a foundation, the method further comprising:a) positioning the foundation onto the underwater floor proximate the object to be retrieved before positioning the lifting frame proximate an object to be retrieved from the underwater floor; b) securing the foundation into the underwater floor before positioning the lifting frame proximate the object to be retrieved from the underwater floor; and c) securing the lifting frame to the foundation after positioning the lifting frame proximate the object to be retrieved from the underwater floor.
- 15. The method of claim 13 for a system further comprising a plurality of suction piles, each suction pile having a top surface and an outer wall defining an inner cavity, the method further comprising:a) lowering each of the suction piles to a predetermined position proximate the object to be retrieved; b) connecting a submersible hydraulic pump powered by hydraulic fluid pumped to it from a separate hydraulic power unit to a fluid supply hose and fluid return hose; c) connecting the fluid supply hose and the fluid return hose to a predetermined number of the suction piles; d) using the pump to remove the water from within the suction pile cavity, thereby creating a lower pressure inside the suction pile than outside the pile; e) using the greater pressure outside the suction pile to create a force on the top surface of the suction pile to push the suction pile into the floor; and f) pumping water from inside the suction pile into water surrounding the suction pile until the suction pile is embedded in the floor to a predetermined depth.
- 16. The method of claim 15 for suctions piles further comprising bearing tables mounted proximate the top surface of at least one suction pile and adapted to receive an end of the lifting frame, the method further comprising securing the end of the lifting frame into an adapter portion of the bearing table adapted for receiving the end of the lifting frame.
- 17. The method of claim 13 wherein the padding material comprises a first predetermined number of buffer bags adapted to receive fluid, the method further comprising injecting a predetermined fluid into a second predetermined number of the buffer bags until the fluid attains a predetermined volume.
- 18. The method of claim 17 wherein the fluid is a foam fluid that hardens, the method further comprising allowing the foam fluid to harden in the second predetermined number of buffer bags prior to tension each sling.
- 19. The method of claim 13 for an apparatus further comprising a tension monitoring system, the method further comprising:a) continually monitoring tension in at the least one sling; and b) adjusting the tension in the at least one sling prior to and/or during the raising of the object to achieve a desired tension.
- 20. The method of claim 13, further comprising:a) positioning at least one mud mat proximate the object to be retrieved; b) positioning the lifting frame proximate the object to be retrieved; and c) securing the lifting frame onto the mud mat.
US Referenced Citations (24)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2193776 |
Feb 1988 |
GB |