U.S. patent application number 12/828631 was filed with the patent office on 2011-01-06 for temporary floating breakwater and causeway with simulated beach and kelp.
This patent application is currently assigned to WARWICK MILLS, INC.. Invention is credited to Charles A. Howland.
Application Number | 20110002739 12/828631 |
Document ID | / |
Family ID | 43412754 |
Filed Date | 2011-01-06 |
United States Patent
Application |
20110002739 |
Kind Code |
A1 |
Howland; Charles A. |
January 6, 2011 |
TEMPORARY FLOATING BREAKWATER AND CAUSEWAY WITH SIMULATED BEACH AND
KELP
Abstract
A durable, quickly deployable temporary floating breakwater
(FBW) can protect areas in austere locations. A plurality of
inflatable modules is encapsulated within a common cover, which
holds the modules together and in some embodiments supports a
causeway thereupon. A separate floating causeway can be included.
Embodiments include a semi-permeable "sloping beach" section which
causes waves to break before reaching the FBW. A bed of
wave-energy-absorbing synthetic kelp can be attached to the sloping
beach. The beach and/or kelp can include low-surface-energy fibers
and films, such as olefins and polypropylenes, to remove oil from
the water in case of an oil spill or accident. In embodiments, the
FBW can be temporarily sunk to avoid extremely high seas, ice,
and/or other surface hazards. The FBW is lightweight, can be
quickly and compactly stowed, and in some embodiments can be
transported and deployed from the deck of an LCU 1610.
Inventors: |
Howland; Charles A.;
(Temple, NH) |
Correspondence
Address: |
Vern Maine & Associates
547 AMHERST STREET, 3RD FLOOR
NASHUA
NH
03063-4000
US
|
Assignee: |
WARWICK MILLS, INC.
New Ipswich
NH
|
Family ID: |
43412754 |
Appl. No.: |
12/828631 |
Filed: |
July 1, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61222230 |
Jul 1, 2009 |
|
|
|
Current U.S.
Class: |
405/26 ;
114/230.2; 114/293; 14/27 |
Current CPC
Class: |
E01D 15/24 20130101;
B63B 35/44 20130101; Y02A 10/11 20180101; E02B 3/062 20130101; E01D
15/14 20130101; B63B 22/02 20130101; B63B 21/50 20130101; Y02A
10/15 20180101 |
Class at
Publication: |
405/26 ; 14/27;
114/230.2; 114/293 |
International
Class: |
E02B 3/06 20060101
E02B003/06; E01D 15/14 20060101 E01D015/14; B63B 21/00 20060101
B63B021/00; B63B 21/50 20060101 B63B021/50 |
Claims
1. A temporary floating breakwater comprising: a plurality of
inflatable modules; and an encapsulating fabric cover configured
for surrounding the inflatable modules when they are inflated, and
thereby maintaining the inflatable modules in close proximity to
one another; the floating breakwater when deployed being of
sufficient size and having suitable characteristics for protecting
shorelines and watercraft from waves having heights of more than 10
feet.
2. The temporary floating breakwater of claim 1, further comprising
a semi-permeable sloping beach section which is extendable from the
encapsulating fabric cover so as to cause approaching waves to
break before reaching the encapsulating fabric cover.
3. The temporary floating breakwater of claim 2, wherein the
sloping beach section includes at least one of low surface energy
fibers and films such as olefins and polypropylenes configured to
remove oil from both surface and water columns and the surface zone
in the event of an oil spill or accident.
4. The temporary floating breakwater of claim 2, further comprising
a bed of simulated floating kelp material attached to the sloping
beach and configured for absorbing energy from waves approaching
the encapsulating fabric cover.
5. The temporary floating breakwater of claim 4, wherein the bed of
simulated floating kelp material includes at least one of low
surface energy fibers and films such as olefins and polypropylenes
configured to remove oil from both surface and water columns and
the surface zone in the event of an oil spill or accident.
6. The temporary floating breakwater of claim 1, further comprising
a rigid top deck of textile cells integral with the encapsulating
cover and supportable by the plurality of inflatable modules so as
to serve as a causeway.
7. The temporary floating breakwater of claim 1, wherein the
plurality of inflatable modules can be deflated so as to
temporarily sink the floating breakwater and thereby avoid damage
due to surface hazards.
8. The temporary floating breakwater of claim 1, wherein each
inflatable module includes a plurality of air-enclosing flotation
bladders.
9. The temporary floating breakwater of claim 1, wherein the
inflatable floating modules are configured for filling with
urethane foam.
10. The temporary floating breakwater of claim 1, wherein the
inflatable modules are one of square and rectangular in cross
section.
11. The temporary floating breakwater of claim 1, further
comprising a floating causeway formed by a plurality of floating
modules and a causeway top surface supported thereby.
12. The temporary floating breakwater of claim 1, further
comprising mooring points suitable for attachment of mooring lines
thereto.
13. The temporary floating breakwater of claim 12, wherein the
mooring points are each able to sustain 25 k lbf applied by a
mooring line.
14. The temporary floating breakwater of claim 12, wherein the
mooring points include abrasion-resistant sacrificial nylon
layers.
15. The temporary floating breakwater of claim 12, further
comprising a plurality of mooring lines and a plurality of anchors
configured for stabilizing a location of the floating breakwater
when deployed on a body of water.
16. The temporary floating breakwater of claim 15, wherein the
plurality of anchors includes at least one vacuum pile anchoring
system.
17. A temporary floating breakwater system, comprising: a plurality
of inflatable floating breakwater support modules; an encapsulating
fabric cover configured for surrounding the inflatable floating
breakwater support modules when they are inflated, and thereby
maintaining the inflatable floating breakwater modules in close
proximity to one another; a floating causeway formed by a plurality
of floating causeway modules and a causeway top surface which is
supportable thereby; and a plurality of mooring lines and anchors
configured for stabilizing a location of the floating breakwater
and floating causeway when the floating breakwater and floating
causeway are deployed on a body of water; the floating breakwater
system when deployed being of sufficient size and having suitable
characteristics for protecting shorelines and watercraft from waves
having heights of more than 10 feet.
18. The temporary floating breakwater system of claim 17, wherein
the floating breakwater system is configured for packaging in a
plurality of containers suitable for simultaneous transport on the
deck of vessel having a size and general characteristics comparable
to an LCU 1610 class vessel.
19. The temporary floating breakwater of claim 18, wherein the
temporary floating breakwater system is configured for deployment
from the deck of the vessel with the assistance of a utility
vessel.
Description
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/222,230, filed Jul. 1, 2009, which is herein
incorporated by reference in its entirety for all purposes.
FIELD OF THE INVENTION
[0002] The invention relates to marine deployable apparatus, and
more particularly to temporary floating breakwaters.
BACKGROUND OF THE INVENTION
[0003] Permanent breakwater structures are offshore concrete or
earthen revetments designed to provide coastal defense and mitigate
shoreline erosion by absorbing and dissipating sea state intensity
and surf conditions. They are often used to extend and enhance
protection to harbors and seaports, and may also provide a
secondary function as a causeway or travel corridor for land
vehicles or foot traffic. The mass, logistics, and labor required
to construct a conventional breakwater makes them impractical for
remote areas. Temporary, floating breakwater designs have shown
some successes. However, such structures typically are intended to
attenuate waves with heights not exceeding 4 feet. Practical
applications of these temporary structures demand much greater
effectiveness in open ocean environments where wave heights up to
12 feet are common during storm conditions. To effectively
attenuate sea state conditions of this magnitude, temporary
floating structures according to previously disclosed designs would
need to be massive, requiring the transport of large volumes of
physical structures, mooring lines and anchors to the site being
sheltered. This approach is simply not feasible when the quick
establishment of a protected area is required.
Mooring Forces
[0004] The US Navy manual for mooring equipment (Mooring Design
Physical & Empirical Data Vessel & Ship Characteristics,
Mooring Lines & Chain Buoys, Anchors & Riser Type Mooring
Systems DESIGN MANUAL 26.6 APRIL 1986, herein incorporated by
reference) sets out the basic considerations for keeping a Floating
Breakwater (FBW) in place. Any floating structure is dependent on
its mooring system to maintain position. A FBW by design is moored
to a lee shore, which is an undesirable configuration for a
floating object. Under storm conditions, if mooring lines chafe or
anchors drag, there is no space or time to respond. A floating
breakwater that is driven into the surf zone and pounded between
the bottom and breakers will be a total loss.
[0005] In general, the design of a robust mooring system is the
most important single issue in the design of a breakwater. For a
FBW system, mooring loads are generated not just from wave action,
but also from wind and current. According to published studies on
floating breakwaters and realistic sea state requirements, a rough
order of magnitude estimate is that each 25 feet of FBW exposure
will require 20,000 lbs of mooring capacity. According to navy
ratings for anchors, the mooring capacity of an anchor is
approximately 15 times the anchor mass. Further design
considerations indicate an anchor specification of 2 tons per 25 ft
of breakwater length. Coast Guard data for buoy moorings suggest
that these values may not be conservative.
Floating Breakwater Configurations:
[0006] Each shoreline has a unique set of conditions for wind wave
and current action, and Floating Breakwater Systems can be designed
and configured to address various combinations. The most basic
configuration of a FBW concept is shown in FIG. 1. The unit 100 is
moored parallel to the shore 102 and facing the prevailing wind and
wave direction 104. This configuration has been well studied, and
provides 60-80% reduction of wave energy in flume testing (see
MOORING FORCES AND MOTION RESPONSES OF PONTOON-TYPE FLOATING
BREAKWATERS, S. A. Sannasiraj, V. Sundar and R. Sundaravadivelu,
Ocean Engineering Centre, Indian Institute of Technology, Madras
600 036, India, Received 1 May 1996, herein incorporated by
reference).
[0007] This arrangement has the greatest shore system length, and
provides the most direct solution for the most important set of
shore wind and wave conditions. This configuration permits
sheltered vessels 106 to operate up-wind and down-wind, and to moor
with either bow or stern facing into the weather. In addition, any
along-shore current 108 does not add significantly to the mooring
load, as the projection of the FBW of FIG. 1 is favorable in the
along-shore direction. In contrast, the configuration of FIG. 4 has
twice the system length and will be subject to very large mooring
forces if there is significant along-shore current. However the
Army RIBs configuration reflects a large proportion of the wave
energy and therefore reduces its mooring load.
[0008] An important consideration in the design of the present
invention is illustrated in FIG. 2, where the shoreline and the
wind-wave direction are at 45 degrees. This configuration shows the
difficulty of satisfying all the current and wind preferences in a
non-orthogonal situation of wind, shore, and current. In the design
shown, the FBW is in a good alignment to the weather--it will
reflect some of the wave energy and absorb the rest to keep the
wave action in the anchorage low. However the wind action on the
moored ships is far from optimal.
[0009] The configuration of FIG. 3 provides for a partial solution
in which the wind and anchorage directions are aligned, and some
reflection and absorption of wave actions results from the angle of
the FBW. However, the current adds to the mooring loads on the FBW.
It should be pointed out that the configurations of FIGS. 2 and 3
have the advantage of permitting the use of a decked FBW to double
as a causeway for vehicle transport directly to shore. The
potential elimination of a separate causeway requirement may
compensate for the other drawbacks of these non-orthogonal case.
The configuration of FIG. 1 has the most flexibility and the best
logistics.
[0010] What is needed, therefore, is an apparatus and method for
providing a portable, re-usable, floating breakwater that can be
deployed in various configurations as needed, and can withstand
realistic sea conditions with waves up to 12 feet in height.
SUMMARY OF THE INVENTION
[0011] A reusable, temporary Floating Breakwater (FBW) is claimed
that includes a plurality of inflated modules enclosed by an
encapsulating cover so as to join the inflated modules together,
thereby providing redundant buoyancy and in some embodiments also
providing support thereupon for a causeway without need of a rigid
beam. Various embodiments also include a semi-permeable "sloping
beach" section that causes waves to break before reaching the FBW.
Some of these embodiments also include a bed of
wave-energy-absorbing material that approximates the natural
wave-absorbing activity of kelp. And in some embodiments, the kelp
and/or synthetic beach include low surface energy fibers and/or
films such as olefins and polypropylenes to remove oil from both
surface and water columns and the surface zone in the event of an
oil spill or accident.
[0012] In certain embodiments, the claimed FBW can be temporarily
sunk when necessary so as to avoid damage due to hazards such as
extremely high seas and/or ice.
Component Level Design of the Floating Breakwater
[0013] Embodiments of the present invention use low-mass inflatable
materials. In some embodiments, the base material is a
urethane-coated Vectran.TM. woven with a tensile strength of 2500
lbf/inch.
[0014] One general aspect of the present invention is a temporary
floating breakwater which includes a plurality of inflatable
modules and an encapsulating fabric cover configured for
surrounding the inflatable modules when they are inflated, and
thereby maintaining the inflatable modules in close proximity to
one another. The floating breakwater when deployed is of sufficient
size and has suitable characteristics for protecting shorelines and
watercraft from waves having heights of more than 10 feet.
[0015] Some embodiments further include a semi-permeable sloping
beach section which is extendable from the encapsulating fabric
cover so as to cause approaching waves to break before reaching the
encapsulating fabric cover. In some of these embodiments the
sloping beach section includes at least one of low surface energy
fibers and films such as olefins and polypropylenes configured to
remove oil from both surface and water columns and the surface zone
in the event of an oil spill or accident. Other of these
embodiments further include a bed of simulated floating kelp
material attached to the sloping beach and configured for absorbing
energy from waves approaching the encapsulating fabric cover. And
in some of these embodiments the bed of simulated floating kelp
material includes at least one of low surface energy fibers and
films such as olefins and polypropylenes configured to remove oil
from both surface and water columns and the surface zone in the
event of an oil spill or accident.
[0016] Various embodiments further include a rigid top deck of
textile cells integral with the encapsulating cover and supportable
by the plurality of inflatable modules so as to serve as a
causeway. In some embodiments the plurality of inflatable modules
can be deflated so as to temporarily sink the floating breakwater
and thereby avoid damage due to surface hazards. And in certain
embodiments each inflatable module includes a plurality of
air-enclosing flotation bladders.
[0017] In some embodiments the inflatable floating modules are
configured for filling with urethane foam. In certain embodiments
the inflatable modules are one of square and rectangular in cross
section. And various embodiments further include a floating
causeway formed by a plurality of floating modules and a causeway
top surface supported thereby.
[0018] Certain embodiments further include mooring points suitable
for attachment of mooring lines thereto. In some of these
embodiments the mooring points are each able to sustain 25 k lbf
applied by a mooring line. In other of these embodiments the
mooring points include abrasion-resistant sacrificial nylon layers.
And still other of these embodiments further include a plurality of
mooring lines and a plurality of anchors configured for stabilizing
a location of the floating breakwater when deployed on a body of
water. In some of these embodiments the plurality of anchors
includes at least one vacuum pile anchoring system.
[0019] Another general aspect of the present invention is a
temporary floating breakwater system which includes a plurality of
inflatable floating breakwater support modules, an encapsulating
fabric cover configured for surrounding the inflatable floating
breakwater support modules when they are inflated, and thereby
maintaining the inflatable floating breakwater modules in close
proximity to one another, a floating causeway formed by a plurality
of floating causeway modules and a causeway top surface which is
supportable thereby, and a plurality of mooring lines and anchors
configured for stabilizing a location of the floating breakwater
and floating causeway when the floating breakwater and floating
causeway are deployed on a body of water. The floating breakwater
system when deployed is of sufficient size and has suitable
characteristics for protecting shorelines and watercraft from waves
having heights of more than 10 feet.
[0020] In various embodiments the floating breakwater system is
configured for packaging in a plurality of containers suitable for
simultaneous transport on the deck of vessel having a size and
general characteristics comparable to an LCU 1610 class vessel. And
in some of these embodiments the temporary floating breakwater
system is configured for deployment from the deck of the vessel
with the assistance of a utility vessel.
[0021] The features and advantages described herein are not
all-inclusive and, in particular, many additional features and
advantages will be apparent to one of ordinary skill in the art in
view of the drawings, specification, and claims. Moreover, it
should be noted that the language used in the specification has
been principally selected for readability and instructional
purposes, and not to limit the scope of the inventive subject
matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a simplified top view illustrating a typical
configuration of a FBW where the direction of the prevailing waves
and wind is perpendicular to the shore;
[0023] FIG. 2 is a simplified top view illustrating a typical
configuration of a FBW where the direction of the prevailing waves
and wind is oblique to the shore;
[0024] FIG. 3 is a simplified top view illustrating a typical
configuration of a FBW where the direction of the prevailing waves
and wind is parallel to the shore;
[0025] FIG. 4 is a simplified top view illustrating an alternate
configuration of a FBW where the direction of the prevailing waves
and wind is perpendicular to the shore;
[0026] FIG. 5 is a cross-sectional view of a preferred embodiment
of the present invention which includes a sloping beach section
with artificial kelp;
[0027] FIG. 6 is a simplified top view of a layout of a preferred
embodiment including a 300 foot breakwater and a 600 foot
causeway;
[0028] FIG. 7 is a simplified, close-up top, front, and side view
of an embodiment with a causeway supported by separated round
floats;
[0029] FIG. 8 is a simplified, close-up top, front, and side view
of an embodiment supported by adjacent round floats having a
causeway supported by top deck beams;
[0030] FIG. 9A is a simplified, close-up top and side view of an
embodiment supported by adjacent round floats having a causeway
which does not require top deck beams;
[0031] FIG. 9B is a close-up cross-sectional view of the floats of
FIG. 9A;
[0032] FIG. 10 is a simplified top view illustrating transportation
of a preferred embodiment on an LCU vessel;
[0033] FIG. 11 is a simplified top view illustrating the first step
in deployment of the embodiment of FIG. 10 from the LCU vessel;
[0034] FIG. 12 is a simplified top view illustrating the second
step in deployment of the embodiment of FIG. 10 from the LCU
vessel;
[0035] FIG. 13 is a simplified top view illustrating the third step
in deployment of the embodiment of FIG. 10 from the LCU vessel;
[0036] FIG. 14 is a simplified top view illustrating the fourth
step in deployment of the embodiment of FIG. 10 from the LCU
vessel; and
[0037] FIG. 15 is a simplified top view illustrating the fifth step
in deployment of the embodiment of FIG. 10 from the LCU vessel;
DETAILED DESCRIPTION
Main Tube and FBW Floats
[0038] FIG. 5 is a cross sectional view of an embodiment of the
present invention in which an inflatable floating breakwater
("FBW") 500 is deployed at 300 feet. The total packed volume of the
inflatable portion of this 300' system as shown in the cross
section of FIG. 5 can be packed in a single 20' ISO container. The
elimination of mechanical joints between inflated sections is a
major feature of this approach, since hinges with solid pivot
points are large, heavy, and prone to failure from wave action on a
FBW. The embodiment of FIG. 5 also provides redundant flotation
chambers 502 by enclosing a plurality of standard 10.times.25 ft
floats 502 within a continuous cover layer 504. The cover layer 504
protects the inflated floats 502 and forms a textile flex point in
the structure. This arrangement permits buckling of the assembly
under extreme loads without damage. By staggering the float
elements 502 in a second tube assembly 504 (i.e. the continuous
cover layer), this double-tube system provides for a stable
platform for service, and operation as a causeway if required.
Antifouling coatings can be applied to the topcoat of the
embodiment of FIG. 5, if required for example to prevent large
accumulations of marine growth.
[0039] In preferred embodiments, the FBW floats of the present
invention include at least one internal bladder for air holding. In
some embodiments, each 25 foot float section is fitted with
redundant bladders that permit the FBW 500 to be repaired while
deployed. In various embodiments, the use of heavy Urethane
extruded topcoat layers as part of a two-layer system limits the
risk of pack ice damage. Mounting for wear panels can be included
at the water line if the system is at risk from large ice
flows.
[0040] For embodiments that include only inflated elements in the
main floats 502 and the upper deck 506, the FWB 500 of the present
invention can be sunk if necessary in extreme weather. Both very
large ice flows and extreme Sea State 7 conditions would suggest
that the safest place for the FBW 500 would be on the bottom.
Inflation hoses supported on shore-anchored lines may permit
re-floating of the system without divers.
FBW Mooring
[0041] In preferred embodiments, mooring points 508 are separated
at 25 foot intervals, and can support a minimum of 25K lbf as the
estimated mooring load per 25 foot section when subjected to a 12
foot wave. In preferred embodiments, a design factor of 5 is
applied for this type of structure. This requires a load connection
to the FBW assembly 500 that is capable of spreading a mooring
point load into a 4-5 foot section of FBW cover material 504. As in
sail making practice, this is accomplished with doublers and
webbing, which are all heat-seal bonded to the base materials. The
loads can be addressed with these methods and materials. However,
chafing that results from excessive FBW motion in higher sea states
510 is a concern. The first step to address this chafe issue is to
limit motion by the pre-tensioning of the mooring lines 512. The
second step in various embodiments is the use of synthetic beach
514 and kelp 516 assemblies as stabilizers to reduce motion.
Finally in some embodiments the mooring connections include
low-friction sliders, combined with abrasion-resistant sacrificial
nylon layers.
[0042] As can be seen from the full layout of the embodiment of
FIG. 6, the moorings 512 for the breakwater 500, the causeway 600
and the ships 106 can all be separate, thereby providing good
redundancy in the design. As wave and wind storm loads increase,
larger vessels (3000 ton) 106 will need to move off shore and get
clear. This will free up these large moorings for use as a safety
on the FBW 500 and causeway 600. Lighterage and small craft will
have to stay behind the protection of the FBW 500 and will also
need added mooring capacity to prevent dragging.
[0043] Reduction of Mooring loads on the FBW 500 will make the
system more reliable, lower cost, improve the mean time between
repairs ("MTBR"), and system availability. The literature includes
the use of a low angle of incidence FBW such as the RIBs system
(see FIG. 4). Based on the problems associated with along-shore
currents 108 and the very large system length of the RIBs design,
embodiments of the present invention include a FBW 500 that is
moored parallel to the wave line 104. Wave reflection in this
configuration is limited.
Beach and Kelp Assemblies
[0044] Preferred embodiments of the present invention include a
mesh skirt that forms a simulated beach 514 in front of the FBW
assembly 500. In some preferred embodiments the beach 504 is
between 30 and 40 ft long, and extends at a slope from the main
tubes 502. The slope angle is controlled by mooring lines 512 and
out-hauls 602 on the beach seaward edge. A Bascom analysis of wave
energy distribution puts the majority of the energy at a depth
equal to 2/9'ths of the wave length. Realistic sea state design
criteria therefore puts the wave length at approximately 90-100 ft.
This results in a synthetic beach design depth of approximately 20
ft. The temporary synthetic beach 514 is intended to limit wave
height. However, this approach can tend to force the waves to
break. While wave breaking is a very effective energy reduction
technique, it can have adverse affects on the FBW 500 main
structure.
[0045] In some embodiments, wave breaking is mitigated by the
addition of an artificial kelp bed 516 made of polypropylene
textile strips with inherent buoyancy. The strips are long with
respect to their mounted depth (see FLOW AND FLEXIBILITY, THE ROLES
OF SIZE AND SHAPE IN DETERMINING WAVE FORCES ON THE BULL KELP
NEREOCYSTIS LUETKEANA MARK W. DENNY,*, BRIAN P. GAYLORD1 AND EDWIN
A. COWEN2, Hopkins Marine Station of Stanford University,
Department of Biological Sciences, Pacific Grove, Calif. 93950, USA
and 2Civil Engineering Department, Stanford University, Pacific
Grove, Calif. 93950, USA Accepted October 1997, herein incorporated
by reference) (see also Effect of the kelp Laminaria hyperborea
upon sand dune erosion and water particle velocities, Stig Magnar
Lovas and Alf Torum, Department of Coastal and Ocean Engineering,
Civil and Environmental Engineering, SINTEF Fisheries and
Aquaculture, Klobuveien 153, N-7465 Trondheim, Norway, herein
incorporated by reference).
[0046] The artificial kelp 516 is designed to reduce wave height in
the run up the synthetic beach 514 and reduce the violence of the
breaking wave. There are a number of design tools which the beach
514 and kelp 516 assemblies offer. By making the synthetic beach
514 from open mesh material and adjusting its deployed slope, wave
behavior can be further controlled. In addition, the use of the
kelp 516 permits additional adjustment of the incoming wave height.
And in some embodiments, the kelp and/or synthetic beach include
low surface energy fibers and/or films such as olefins and
polypropylenes to remove oil from both surface and water columns
and the surface zone in the event of an oil spill or accident
Top Deck Assembly
[0047] Various embodiments include a rigid top deck 506 of textile
cells. This deck assembly 506 is integral with the outer cover 504
of the main tubes 502. The top deck cells 506 can be simply
inflated and/or can be foam filled. Embodiments that use only
inflation are very simple to retrieve, and these embodiments can be
sunk and refloated for storm and ice protection. However,
embodiments in which the top deck cells are filled with urethane
provide greater durability. In some of these embodiments, the
textiles are coated with urethane. Foam materials soften textile
urethane coatings and form a high strength bond to the textile.
This 2-part foam is simple to mix and inject into a manifold panel
assembly. These foam-cell textile assemblies are very tough, and
need only a thin hard surface skin to permit vehicle transport.
Ground Tackle and Mooring Lines
[0048] The ground tackle required for the claimed FBW system is not
low in mass. The total soft goods mass is between 1/3 and 1/2 of
the expected anchor mass required for the system. In the event that
a deployment in coral is required, the use of low mass cordage
would not be acceptable, and chain would be required, adding
significant additional mass to the mooring budget.
[0049] The design of self-embedding anchors is not a new area of
engineering. For the breakwater alone, the expected requirement is
25-30 long tons of anchor capacity. Novel anchor systems such as
jetted or screw type anchors may be able to reduce the required
anchor mass. Some embodiments employ vacuum pile anchoring systems
for high strength lightweight mooring. Existing Side Load Warping
Tug (SLWT) units and other equipment have winch and A-frame gear
which may provide a capability to rapidly set such non-traditional
anchors.
Causeway
[0050] An M1A tank 700 at 61 long tons has been used as the
criteria for causeway flotation and structural design. This load
can be supported by embodiments of the present invention having a 5
foot minimum freeboard, and some embodiments include up to 8.5 ft
of freeboard with alternative float designs to improve
compatibility with INLS units. The top deck and floats of the
causeway 600 represents a trade space for selection of various
embodiments.
[0051] In FIGS. 6-7, embodiments are illustrated with a common
10'.times.25' round float 702 shown at 20 foot centers. These
embodiments minimize the number of floats 702 but maximize demands
on the structural performance of the top deck. As illustrated in
FIG. 8, the common round floats 702 can be moved together to
provide greater support and stability, at the expense of requiring
more floats 702. The same tradeoffs for inflation and foam filling
systems apply in this case as for the breakwater.
[0052] With reference to FIGS. 9A and 9B, other embodiments include
floats with a square or rectangular form. The square design
provides full support to the upper deck and allows a simple belt
design for the Deck layer without any inflated beams. Even though
the M1A 700 has a high mass, the contact pressures for the treads
are approximately 12 psi. Of the M1A 700, the full vehicle area
distributed load is as low as 3 psi. These are modest design loads
for the Causeway hard surface and can be supported with a single
thin hard surface panel that bears directly on square main
floats.
Logistics
[0053] As illustrated in FIG. 10, in preferred embodiments an LCU
1610 class vessel 1000 can be used as the primary transport and
deployment vessel. For example, forward on the LCU deck, a 40' ISO
container 1002 can be used to contain the breakwater cover 514 and
beach kelp 516 assemblies. The breakwater main float tubes 502,
which are in a 20' ISO container 1004, can be transported in a
second position on the deck of the LCU 1000, and the causeway
floats 702 and top deck 600 can be contained in a 30' ISO and
transported in a third position 1006 on the LCU deck.
[0054] A large fairlead assembly 1008 on the bow of the LCU 1000
can feed the soft goods components 1002, 1004, 1006. Beside the
soft goods containers 1002, 1004, 1006 the mooring system
components 1010 are also on the LCU deck. Three ship anchors 1012
and their rods can be loaded as deck cargo on a RORO rail assembly
1014. The 24 anchors and mooring lines for the breakwater can be
transported in two 40' ISO containers 1016 with integrated RORO
rails 1018 that run straight through. Container layout on the LCU
deck can thereby be designed to permit full deployment of the
claimed invention without re-positioning of container units. The
LCU 1000 is large enough to deliver the system containers. In
addition, a second vessel such as a LCM-8 or MPF 1020 utility boat
is required in support of a deployment mission to manage the static
ends during deployment and to support the inflation process.
Deployment
[0055] Deployment of preferred embodiments includes 5 primary
steps. With reference to FIG. 11, first the ship 1000 and causeway
anchors 1012 and mooring lines 512 are set from the roll-off rails
on the LCU 1000. As illustrated in FIG. 12, the seaward breakwater
anchors 1016 and the cover/beach/kelp assembly 516 are then set
along the outer mooring line with the aid of the second vessel
1020. The second vessel 1020 also provides the inflation air to
float the system. The baseline process has the tube floats 502, 702
drawn through a messenger tube in the forward container 1002. This
permits packing of the cover 504 and the main floats 502 in
separate containers positioned in line on the deck. The seaward
anchors 1012 are placed as the FBW 500 is deployed.
[0056] As illustrated in FIG. 13, step 3 is backhaul of the
breakwater to leeward.
[0057] Step 4, as shown in FIG. 14, consists of setting the leeside
moorings for the FBW 500 from the LCU 1000, using the utility boat
1020 to ferry the mooring lines 512 to personnel on the breakwater
top deck 600. Step 5, as shown in FIG. 15, is deployment of the
causeway unit from the third soft goods container 1006 on the LCU
deck. The utility boat 1020 will draw out the uninflated units and
inflate the system as it proceeds to shore.
[0058] The foregoing description of the embodiments of the
invention has been presented for the purposes of illustration and
description. It is not intended to be exhaustive or to limit the
invention to the precise form disclosed. Many modifications and
variations are possible in light of this disclosure. It is intended
that the scope of the invention include, but not be limited by this
detailed description, nor limited by the claims appended
hereto.
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