A platform, breakwater, or endless track includes an array of molded cells nterconnected by a system of elongate flexible members, such as wire ropes or lines. The molded cells are cast in molds located at overlapping portions of the cables. The molds may be flexible nylon bags having openings for receiving the cables through them and a fill port to receive material. The molds may be retained on cast cells or removed and reused. A buoyant material, such as expanding self-hardening foam is pumped from foam mixing and pumping equipment into the molds to cast the cells for floating on water, although negatively buoyant cells could be cast for some applications. The cells may be cast on site or elsewhere and then transported to the work site. The cables either can be secured or free running in the molded cells. Accordingly, flotation cells may be separated by lengths of cables to provide for venting the effects of underwater detonations and for dissipating surface wave energy, or flotation cells may be drawn together to provide a solid work platform or roadway. An endless-track mine clearing structure that is readily repairable may be constructed from the cells and cables. Sections of molded cells and cables can be interconnected to provide differently sized and shaped platforms for various applications.

BACKGROUND OF THE INVENTION 
This invention relates to structures for floating on water. In particular, 
this invention relates to rapidly deployable structures having flotation 
cells molded on systems of cables and methods of fabrication thereof. 
The current methods for providing working areas in swamps, marshes and 
shallow water leave much to be desired. Generally speaking, most of the 
methods call for building-up the proposed work site with large quantities 
of fill dirt, making elaborate manmade structures having pilings and 
elevated work platforms, or bringing in awkward barges that are difficult 
to maneuver. These methods consume considerable amounts of time and 
material and, usually, an inordinate amount of equipment must be brought 
in to build the platforms. Furthermore, the elaborate construction 
procedures and roads necessary to get to and from the work area can and do 
cause excessive ecological damage. 
When helicopter fields or air fields are needed in marshy or wet areas, the 
areas usually must be improved using huge volumes of fill dirt. Next, 
pierced steel planking is laid which requires considerable heavy equipment 
and a large sea-lift load. These requirements may severely limit the areas 
that are suitable for such military fields. In addition, the contemporary 
construction techniques are unduly time consuming and, consequently, could 
produce an unacceptable delay in the buildup of forces. 
A more acceptable, quickly deployed means for passing over dangerous 
shallow water areas is needed. Presently, crossing obstacle-laced and 
mined surf and beach zones relies on brute force methods, such as 
detonating explosive line charges, explosive nets, bombs and 
swimmer-deployed countermeasure charges. Large quantities of explosives 
and/or skilled manpower are used to clear mines from the avenue of advance 
of the fighting forces. The M-58 line charge is a typical explosive 
launched by an MK-22 rocket motor. Unfortunately, detonations of some line 
charges may cause only some mines to explode, so that large numbers of 
mines might be left in the path of the advance. In addition, detonations 
by line charges may not clear magnetic influence mines. Consequently, 
after line charges are detonated, the area must be closely checked for 
unexploded mines. 
In addition, a better way to cross rivers is needed. For years pontoon 
bridges or Bailey bridges have been used. These bridges require long times 
to emplace and large volumes of shipping space. Moreover, these bridges 
are not easily repaired, nor do they provide for easy expansion in case of 
rising water. 
Thus, in accordance with this inventive concept, a need has been recognized 
in the state of the art for rapidly deployed structures having molded 
cells and method of manufacture thereof. 
SUMMARY OF THE INVENTION 
The present invention is directed to providing a method for making 
structure that floats on water. Overlapping elongate flexible members 
produces overlapping portions for molding cells at the overlapping 
portions. Structure includes a plurality of elongate flexible members 
having overlapping portions and an array of molded cells each disposed at 
separate overlapping portions of the flexible members. 
An object is to provide structure having an array of molded cells mounted 
on a system of cables. 
Another object is to provide structure in which damaged molded cells may be 
repaired or replaced without disassembly of associated structure. 
Another object is to provide structure having cells molded from rigid or 
semi-rigid foam on cables. 
Still another object is to provide methods of making structure using 
preassembled cables and molds for cells that are cast at the work site. 
Another object is to provide portable structure of reduced weight. 
An object of the invention is to provide improved flotation structure for 
platforms or breakwaters. 
Another object is to provide flotation structures having arrays of molded 
flotation cells mounted on systems of cables. 
Another object is to provide structures that can be changed to adapt to 
different applications. 
Another object is to provide cells made from self-hardening foam, any rigid 
or semi-rigid polymeric material, concrete over air bags, or metal. 
Another object is to provide flotation structure in which damaged flotation 
cells may be repaired or replaced without disassembly of associated 
structure. 
Still another object is to provide methods of making flotation structures 
using preassembled cables and molds for flotation cells that are cast at 
the work site. 
Another object is to provide flotation structures having flotation cells 
made from self-hardening foam, any rigid or semi-rigid polymeric material, 
concrete over air bags or metal. 
Still another object is to provide flotation structures having few, if any, 
ferrous components to reduce the effects of rust and corrosion. 
Another object is to provide breakwater platforms having flotation cells 
separated from one another. 
Yet another object is to provide platform structures having flotation cells 
abutting one another to provide flat surfaces. 
Another object is to provide endless track of molded cells mounted on 
cables for clearing mines. 
These and other objects of the invention will become more readily apparent 
from the ensuing specification when taken in conjunction with the appended 
claims.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1 of the drawings, flotation platform 10 and its 
expedient method of fabrication provide for buoyant support of men, 
materials, and supplies to assure safe transit across otherwise hazardous 
areas, such an obstacle-laced and mined beach zones, for example. 
Flotation platform 10 is intended to float on water and is fabricated from 
system of cables 15 coupled to array of flotation cells 20. 
System of cables 15 includes a plurality of parallel longitudinally 
extending cables 16 that reach the entire length of platform 10 and first 
and second sets of parallel obliquely extending cables 17 and 18 that go 
from one side to the other of platform 10. First set of cables 17 
obliquely extends across longitudinal 16 cables in one direction from one 
side of platform 10 to the other side. Second set of cables 18 obliquely 
extends across longitudinal cables 16 and oblique cables 17 from one side 
to the other side of platform 10 in the opposite direction than cables 17. 
Thus, longitudinal cables 16 and first and second sets of oblique cables 
17 and 18 respectively have overlapping portions 16a, 17a, and 18a where 
they overlap each other. 
FIGS. 2 and 3 show that overlapping portions 16a, 17a, and 18a are located 
in the center of each flotation cell 20. Optionally, guide element 19 may 
be included in each flotation cell 20 to position cables 16, 17, and 18 so 
that overlapping portions 16a, 17a, and 18a are centered in each flotation 
cell 20, see FIG. 2. Guide element 19 may also grip or otherwise engage 
overlapping portions 16a, 17a, and 18a to secure the overlapping portions 
in each cell. Hence, guide element 19 helps assure separation between 
flotation cells 20 in platform 10. In addition, biasing spacer 20a also 
may be included between adjacent cells 20. Biasing spacer 20a may be 
resilient material, coiled spring, or similar biasing member that 
resiliently urges the separation of adjacent cells. Only two such biasing 
spacers are shown in FIG. 1 to avoid cluttering the drawings, it being 
understood that biasing spacers could be included between all the cells 
herein described. This separation may be a desirable feature to help avoid 
wear, to vent the force of possible underwater explosions that might 
otherwise damage platform 10, or to dissipate flotsam that may otherwise 
accumulate. 
Cables 16, 17, and 18 may be fabricated from many different elongate 
flexible members including natural fibers, manmade fibers, metal cables or 
nonmetal cables as the situation requires. Commercially available wire 
rope and other steel-based cables have sufficient strength and flexibility 
to perform satisfactorily; however, they are vulnerable to rust and other 
corrosive influences that may compromise their usefulness. Accordingly, 
since platform 10 is to be used in fresh or salt water, cables 16, 17, and 
18 may be constructed from any of many commercially available natural or 
synthetic fibers, such as nylon, for example. 
While the system of longitudinal and oblique cables has been described 
herein, it is to be understood that other cable assemblies might be used 
within the scope of this invention. For example, having the teachings of 
this invention in hand, one skilled in the art might make rectangular, 
square or other matrices of longitudinal and lateral cables and cells, and 
still be within the scope of this inventive concept. 
Flotation cells 20 are buoyant structures formed in molds 30. FIGS. 2 and 3 
show in greater detail flotation cell 20 made from buoyant material 25 
that fills mold 30. The molds may be rigid or flexible bag-like forms that 
may be removed and reused or may remain on the cast flotation cells to 
provide an additional measure of protection. In the drawings the flotation 
cells are hexagonally-shaped parallelepipeds. The flotation cells could 
have many different shapes, such as hexagonal, cylindrical or square 
parallelepipeds, etc. An endless-track structure, such as described below, 
may find tapered hexagonally-shaped cells more useful. The shape of the 
flotation cells is decided by the requirements of the job at hand. 
Therefore, it is to be understood that, having the teachings of this 
invention in hand, one skilled in the art to which this invention pertains 
could configure the cells in many different shapes, besides hexagonal, 
cylindrical or square parallelepipeds, etc., and still be within the scope 
of this invention. 
Molds 30 are fashioned in closed bag-like shapes from flexible material, 
although rigid molds could be made and used in accordance with this 
inventive concept. The flexible bag of each mold 30 has bottom, sides, and 
top defining a mold for a hexagonal parallelepiped-shaped cell. Mold 30 
has openings 31 to receive cables 16, 17, and 18 therethrough so that 
overlapping portions 16a, 17a, and 18a can be located in the center of the 
mold. Fitting 32 extends through the flexible material of each mold and 
receives buoyant material 25, such as self expanding and hardening foam, 
through hose 27 from mixing and pumping equipment 26, see FIG. 8. Fitting 
32 preferably is flush with the upper surface of mold 30 and has a one-way 
valve, not shown, to prevent foam from leaving mold 30 after it has been 
pumped into the mold. Guide element 19 may be positioned in each mold 30 
before the casting material is added. 
Bearing plates 16b, 17b, and 18b are mounted on some flotation cells 20 to 
secure distal ends of the cables to the perimeter of platform 10, see 
FIGS. 1 and 2. In FIG. 2 one end of one longitudinally extending cable 16 
is secured to bearing plate 16b. Plate 16b is mounted on the outer surface 
of mold 30 which contains flotation cell 20 that is located at one 
longitudinal end of floating platform 10. The opposite end of this 
longitudinal cable 16 is secured to a similar plate 16b on the outer 
surface of another flotation cell at the opposite end of platform 10. 
Similarly, the other longitudinal cables also are secured at their 
opposite ends to bearing plates in flotation cells at opposite ends of 
platform 10. In like manner, bearing plates 17b and 18b are attached to 
opposite ends of oblique cables 17 and 18, respectively. These plates are 
carried on opposite sides of lateral-most flotation cells 20 of platform 
10. All the bearing plates at opposite ends and opposite sides help 
provide structural integrity for the platform. 
Buoyant material 25 can be any of a number of self-hardening foams, any 
rigid or semi-rigid polymeric material, small hollow spheres or chip-sized 
pieces of material that float, or concrete over air bags or metal shells. 
Lightweight concrete might be made by replacing the stone aggregate with a 
lightweight aggregate. The bag-shaped molds might be partially filled with 
foam and then topped-off with concrete. 
However, for some applications of this invention, material 25 can be a 
material that is not buoyant. For example, as explained below, the 
invention might be used for land mine clearing and it may be desirable to 
have the cells negatively buoyant so as to exert greater pressure on the 
ground. 
For the purposes of setting forth salient features of this invention, 
however, buoyant material 25 is made from a self-expanding and 
self-hardening foam, such as rigid polyurethane foam. This foam is shipped 
and stored as a two-part liquid that can be handled and mixed using well 
known fluid mixing and pumping equipment 51, see FIG. 8. One of the 
characteristics of rigid polyurethane foam is that after mixing, it 
expands up to sixty times its original volume. These properties make this 
foam attractive for this invention since it takes less storage space and 
can be mixed and cast in bag-like molds 30 at the work site. 
Rigid polyurethane foam is well known in the art and is available from 
several commercial sources. For example, selections of a desirable 
polyurethane foam could be made from components marketed under the trade 
designations: NCF1811-91 by North Carolina Foam Industries of North 
Carolina, BKC 44307 by Kansas City Division of Allied Signal at Kansas 
City, PP475-20 by Premium Polymers Company, or Stathane 4802W, Stathane 
6603 MSH or Stathane 6502 MSH by Expanded Rubber and Plastics Company. 
These foams and other commercially available materials could be selected 
and applied. For example, the polyurethane NCF1811-911 comes in two parts. 
The two part materials are mixed, fed into mold 30, expand, foam, and then 
further expand before hardening into a rigid or semi-rigid form, in this 
case, hexagonally-shaped flotation cells 20. The wide variety of foams 
available have different rise times, tack-free time, curing times, and 
densities. Accordingly, having the teachings of this invention before him, 
a designer is free to select the foam needed for the job at hand. 
The technique of mixing the constituents of the foam is well established in 
the art. It involves a continuous process of mixing the two part viscous 
liquids in a static or motionless mixer. Typically, the viscosities of two 
representative foam components are in the range of from 320 centipoise to 
580 centipoise. A motionless mixer uses stationary-shaped diverters inside 
conduits, or pipes, which force the fluids to mix themselves through a 
progression of divisions and recombinations. This forms striations of ever 
decreasing thickness until the stream is uniform. Motionless mixers 
continuously interchange fluid materials between the walls and the center 
of the conduit, to enhance heat transfer and uniform residence times. The 
power consumed by motionless mixer 51 during mixing is provided by an 
interconnected pump which moves the fluids against the resistances of the 
diverters. 
Referring to FIG. 1, platform 10 may be used for offloading materials and 
supplies. Overlapping portions of cables 16, 17, and 18 are cast and 
secured within each of the buoyant cells as shown in FIGS. 2 and 3. This 
securing provides spaces between adjacent cells so that possible 
explosions and wave energy can be dissipated and flotsam can be washed 
away. Cleats or loops L may be provided on some cells to receive lifting, 
towing, or anchoring lines. 
FIGS. 4, and 5 show flotation platform 10A having modified flotation cells 
20'. The modifications in flotation cells 20' permit their slidable 
displacement on cables 16, 17, and 18 so that the cells can be pulled 
together as shown to create an uninterrupted flat surface or roadway. 
Noting FIG. 5, each flotation cell 20' has lateral sleeves 33 that extend 
from one side to the other through openings 31' of each mold 30'. Lateral 
sleeves 33 keep cables 16, 17, and 18 from being engaged by the casting 
material and are sized to slidably receive these cables and allow their 
free-running therethrough. Distal ends of flexible members 16, 17, and 18 
are secured to bearing plates 16c, 17c, and 18c that are molded or 
otherwise suitably attached to the outer surfaces of flotation members 
20'. These plates are located on the periphery of one side and one end of 
flotation platform 10A, see FIG. 4. 
After flotation cells 20' have been cast and flotation platform 10A is 
emplaced or located, tensile forces are exerted on cables 16, 17, and 18. 
The tensile forces pull on bearing plates 16c, 17c, and 18c to draw the 
hexogonally-shaped flotation cells 20' together to form a flat coextensive 
working surface. After the cells are drawn together, the opposite ends of 
flexible members 16, 17, and 18 are appropriately secured to hold the 
platform together. 
The hexagonally-shaped parallelepiped form of the cast flotation cells 
provides a solid interlocking structure when the cells are drawn together. 
This interlocked structure resists wave and surf action. The simple 
tensioning of the cables to tighten-up the cells of platform 10A can be 
done at or away from the work site depending on the situation. Cleats or 
loops L may be provided on some cells to receive lifting, towing, or 
anchoring lines. 
FIG. 6 shows breakwater structure 10B. Breakwater 10B is substantially 
identical to a portion of the spaced-apart system of cables and flotation 
cells of flotation platform 10 in FIG. 1. The buoyant material of each 
buoyant flotation cell 20 engages the overlapping portions of cables 16, 
17, and 18 to hold flotation cells 20 apart. However, only three rows of 
flotation cells 20 coupled in system of cables 15' are included in the 
exemplary breakwater 10B. This provides for dissipation of the energy of 
ambient surface waves. Any number of such rows and interconnected cables 
could be included as wanted. Breakwater 10B is anchored by appropriate 
means to the ocean floor according to conventional practice. For example, 
cleats or loops L may be provided on some cells to receive lifting, 
towing, or anchoring lines. A multitude of individual anchor lines or 
tethers might be added that each extend between individual weights or 
anchors and separate flotation cells. This creates a tethered float 
breakwater having enhanced energy dissipation. 
FIG. 7 is a side view of another embodiment of the invention shaped as an 
endless track 10C for breaching mined areas. Track 10C is made up of 
substantially the same constituents as flotation platform 10 and 
breakwater 10B. An array of flotation cells 20" is secured to overlapping 
portions of system of cables 15", which, like platform 10 and breakwater 
10B, can be made up of longitudinal cables, and two sets of obliquely 
crossing cables. Ends of the longitudinal cables of track 10C are secured 
together to form the endless track that is wrapped about at least one pair 
of rollers 40 journaled in framework 41. Framework 41 is connected to boom 
42 that extends from tracked vehicle 45, such as a tank. Operators in 
vehicle 45 selectively articulate boom 42 to place track 10C on areas to 
be cleared of mines. 
Track 10C is made up of a plurality of replaceable cells 20" which may or 
may not be selected from materials that float. It is a simple matter to 
repair or replace a cell if an exploding mine damages or destroys it. If a 
cell is damaged, merely apply some foam to the damaged area and allow the 
foam to cure; if a cell has been destroyed, add a replacement cell from 
inventory or replace a mold, fill it with foam and allow the cast cell to 
cure. Then, resume clearing the area. 
This embodiment of the invention is intended to provide a movable platform 
that can be pushed across mine or obstacle fields on land or in the water 
and survive underwater detonations in the scale expected to be found in 
the surf zone, less than ten feet water depth. Ferrous materials and/or 
electrical conductors connected to a power source may be included in the 
cells and cables, if desired, so that track 10C also is effective against 
magnetic influence mines. 
Referring to FIG. 8, bundle 10D of preassembled cables 15 and molds 30 is 
transported to a remote work site and unloaded. Previously, the cables and 
attached molds were either rolled or folded together in bundle 10D at a 
distant depot or staging area to reduce the assembly time and work force 
at the work site. FIG. 8 shows bundle 10D partially unfolded to expose a 
portion of molds 30 and the attached cables. Foam mixing and pumping 
equipment 26 has at least one feeder hose 27 connected to valved fitting 
32 on one of the exposed molds 30aa to form cell 20aa. Equipment 26 pumps 
the required amount of foam into each of the exposed molds 30 and then is 
turned off or disconnected from valved fittings 32. The one-way valve 
inside each valved fitting 32 closes each mold and holds the foam in the 
mold while it is given time to cure. This curing causes the foam to 
expand, fill, and harden in the full shape of the flotation cell that is 
defined by the mold, in this exemplary case, a hexagonally-shaped 
parallelepiped. After cells in the exposed portion of the molds have been 
cast, then other portions of the bundled molds and cables are unrolled or 
unfolded and cast. The process is repeated until all flotation cells are 
cast. The structure is completed at the work site and all that remains is 
to anchor it in place and, possibly, add decking to prevent excessive 
wear. 
FIG. 9A depicts a method of the invention which provides structure for 
floating on water. Overlapping 50 flexible members, such as cables, 
precedes molding 51 cells of buoyant material at the overlapping portions. 
Molding 51 includes providing 52 a mold at each of the overlapping 
portions and locating 53 overlapping portions in each mold. Next, placing 
54 buoyant material in each mold permits curing 55 of the buoyant material 
that includes expanding 56 and hardening 57 foam created from the buoyant 
material into buoyant cells shaped as hexagonally-shaped parallelepipeds. 
The method includes either engaging 58 sleeves that slidably receive the 
flexible members in the buoyant material in each mold or engaging 59 the 
overlapping portions of the flexible members by the buoyant material in 
each mold. Exerting 60 tensile forces on the flexible members that are 
slidably received in sleeves and pulling 61 the buoyant cells together 
provides a tightened-up structure that presents a flat upper surface. FIG. 
9B shows bundling 62 interconnected flexible members and molds and 
exposing 63 a portion of the bundled flexible members and molds and 
repeating 64 the steps of exposing, placing, and curing portions of the 
bundled flexible members and molds to assure deployment of the structure. 
Although the platform, breakwater and mine-clearing structures generally 
have been described as being fabricated from materials which produce cells 
which float, it is to be understood that readily repairable nonbuoyant 
cells could be molded from nonbuoyant materials where the need for a 
heavier structure is needed. This selection of well-known fabrication 
materials is within the purview of one skilled in the art having the 
teachings of this invention in hand. 
The invention hereindescribed casts the cells in molds made from fabric, 
for example, nylon, "bags" that are manufactured in the correct shape and 
size. A typical hexagonal bag might measure in the neighborhood of about 4 
ft.times.4 ft.times.4 ft. Thus, a cell of foam is self-healing since 
damaged cells could be left with their pieces in place in the "bag" of the 
mold and still fulfill their intended use. 
The invention hereindescribed and claimed has the "bags" (molds) 
preattached to cables that may be bundled in a roll. The roll is unrolled 
and each bag is attached to the mixing equipment and filled. As the foam 
expands, the cells take the final shape. Since individual cells can easily 
be picked up by one man, the cells and cables are lightweight and 
portable. Accordingly, this invention can easily be used in remote areas 
since the work area can be built up from adjoining foam cells. The 
required components may be brought in by helicopter and do not require any 
roads or other support structures to be built. After the job is complete, 
the system could be dismantled and hauled out by helicopter. 
Other applications have assembled sections that can be floated and joined 
with other sections to make the required shape and size, which could be 
floating airfields or breakwaters that extend for miles. The assembled 
sections can be pushed or towed into position using a landing craft air 
cushion vehicle or boat. Furthermore, the structure of this invention 
creates a firm base for the discharge of cargo and vehicles from landing 
craft air cushion vehicles. Locking rings, for example, could be attached 
to each section to simplify joining the sections. After the assembled 
sections are in position, they are anchored or secured to other sections. 
Any damaged cells could be repaired simply by adding foam to damaged 
cells, refilling molds with foam or replacing cells from inventory. The 
time required to emplace these systems could be as little as one tenth the 
time required using current approaches. 
Assembled sections pushed in front of invasion vessels, will detonate 
contact type mines and will travel over or around obstacles. If a mine is 
detonated, the separation of the cells might reduce sustained damage by 
venting the explosion. If a cell, or a section of cells, is damaged, it is 
easy to repair by putting the foam in the damaged areas. Any obstacles 
encountered can be completely covered by the sections to allow passage of 
men, vehicles, and equipment. 
It should be readily understood that many modifications and variations of 
the present invention are possible within the purview of the claimed 
invention. It is therefore to be understood that within the scope of the 
appended claims the invention may be practiced otherwise than as 
specifically described.