WO2011035362A1

WO2011035362A1 - Floating module for water storage evaporation control

Info

Publication number: WO2011035362A1
Application number: PCT/AU2010/000778
Authority: WO
Inventors: Alistair Cedric Marris; Ian Woodfield; Christopher James Murray
Original assignee: Aqua Guardian Group Ltd
Priority date: 2009-06-23
Filing date: 2010-06-23
Publication date: 2011-03-31

Abstract

A module forming part of a floating modular cover for a body of water, including an upper shell, a lower shell, a chamber defined by the upper and lower shells, a water ingress opening in the lower shell to allow ingress of water into the chamber for ballast, an air opening in the upper shell to allow air to flow into and out of the chamber, and a plurality of discrete flotation cells for ensuring flotation of the module, wherein the upper shell and lower shell, when the module is in an assembled state, act to house each flotation cell in a predetermined position within the chamber.

Description

FLOATING MODULE FOR WATER STORAGE EVAPORATION

CONTROL

Field of the Invention

The present invention relates to a floating modular cover for reducing water loss due to evaporation particularly in large water storages. Background to the Invention

In regions of high evaporation and seasonal rainfall, water loss from large open storages due to evaporation is high and difficult to control.

Evaporation control in relatively small areas of a few hectares or less is usually achieved with a cover over the total surface which is anchored at the edges. However, such covers are typically only used to reduce water loss from evaporation in limited areas due to their inherent dynamic inflexibility on the water surface, the need to be affixed to the perimeter of the water storage and the need to be held down during high winds.

International Patent Application No. WO 98/12392 discloses a modular cover for large areas consisting of a flat polygonal floating body where the faces of the floating body have partly submerged vertical walls with lateral edges. The device has an arched cover with a hole in the top cover for air exchange. Although the wall depth is large under wave and local high surface wind conditions, the covers can be blown off the water surface and overturned.

International Patent Application No. WO 2006/010204 discloses a floating modular cover for a body of water consisting of a series of modules. Each module is formed from an upper shell and a lower shell which are sealed together to form a central chamber and one or more peripheral flotation cells. One or more openings are provided in the lower shell to allow the ingress of water into the chamber for ballast. One or more openings are also provided in the upper shell to allow air inflow into and out of the chamber depending upon the water level within the chamber. The provision of a closed chamber ensures that water within the chamber functions as ballast preventing the module from being easily blown around or overturned. This difference provides a significant advantage over the arrangement disclosed in International Patent Application WO 98/12392.

The size of the modules are chosen to provide a large surface cover. The periphery of each module has a polygonal shape, the number of sides being determined by a desired application to allow the packing of the modules on the water surface. For example, the modules may have a hexagonal or octagonal shape. When placed to float on a body of water, the modules will tend to accumulate in an area dictated by the prevailing winds. The area of coverage will depend upon the number of modules used on the body of water. The shape of the individual modules and the movement between them will conserve water storage by limiting evaporation of the water without interfering with the aqua culture because sufficient area will be exposed to allow oxygenation of the water.

However, it has been found that the modules forming the floating modular cover disclosed in International Patent Application No. WO 2006/010204 are subject to stress and cracking in use, were difficult to hermetically seal, which may lead to the sinking of modules and shortened life of the modular covers forming the cover. Furthermore, the manufacture and assembly of the modules has been found to be complex, expensive and time consuming.

It would be desirable to provide a module for use in a floating modular cover for a body of water which is less expensive, less complex and quicker to manufacture and/or assemble than the modules disclosed in International Patent Application No. WO 2006/010204.

It would also be desirable to provide a module for use in a floating modular cover for a body of water which ameliorates or overcomes one or more disadvantages of inconveniences of known modules for use in such floating modular covers.

The above discussion of background art is included to explain the context of the present invention. It is not to be taken as an admission that any of the documents or other material referred to was published, known or part of the common general knowledge at the priority date of any one of the claims of this specification. Brief Description of the Invention

With this in mind, one aspect of the present invention provides a module forming part of a floating modular cover for a body of water, including:

an upper shell,

a lower shell,

a chamber defined by the upper and lower shells,

a water ingress opening in the lower shell to allow ingress of water into the chamber for ballast,

an air opening in the upper shell to allow air to flow into and out of the chamber, and

a plurality of discrete flotation cells for ensuring flotation of the module, wherein the upper shell and lower shell, when the module is in an assembled state, act to house each flotation cell in a predetermined position within the chamber.

A module forming part of a floating modular cover for a body of water having these features enables the manufacture of the flotation cells separately from the upper and lower shells, thereby eliminating the need to form the flotation cells as an integral component of a hermetically sealed shell. This reduces the complexity of manufacturing and assembling the module.

Sealing the flotation cells within an outer encasing formed from the upper and lower shells protects the flotation cells. This improves the operational life of the module and reduces the likelihood of failure. Further, by housing the flotation cells within the upper and lower shells, the problem of debris and dirt being caught around the flotation cells in the arrangement described in International Patent Application No. WO 2006/010204 may be avoided. This also avoids the growth of vegetation on the upper shell in this area.

Preferably, at least one of the shells includes a plurality of recessed portions for receiving the flotation cells.

Each shell preferably includes a plurality of recessed portions for receiving the flotation cells, each recessed portion in one of the shells opposing a corresponding recessed portion in the other shell when the module is in an assembled state.

When the module is in an assembled state, opposing recessed portions preferably define compartments for retaining the flotation cells. Perimeters of the upper and lower shells may have polygonal shapes and the cell recesses are adjacent to vertices of the polygonal shapes.

In one or more embodiments of the invention, the shell further includes a plurality of first ribs extending from each recessed portion towards the centre of the shell.

Each shell further may also or alternatively include a plurality of second ribs extending from a location mid-way between each vertex of a respective polygonal shape towards the centre of the shell.

Conveniently, each shell may further include a series of first spacer portions projecting outwardly from the shell so that, when the shell is stacked with other shells, the first spacer portions act to space the shell from an adjacent shell in the stack.

These first spacer portions may be located so that, at a desired angular offset of the shell from an adjacent shell in the stack, the first spacer portions of adjacent shells in the stack are not superposed.

Preferably, the first spacer portions of each shell are angularly separated by integer multiples of the desired angular offset.

In one or more embodiments, the first spacer portions of each shell at even multiples of the desired angular offset may be located at a first radial distance from the centre of the shell.

The first spacer portions of each shell at odd multiples of the desired angular offset may be located at a second radial distance from the centre of the shell, the second radial distance being different to the first radial distance.

Each shell may further include a series of second spacer portions projecting outwardly from the shell so that, when the shell is stacked with other shells, the first spacer portions act to space the shell from an adjacent shell in the stack, the second spacer portions being located at angular positions between adjacent first spacer portions.

These second spacer portions may be located so that, at the desired angular offset of the shell from an adjacent shell in the stack, the second spacer portions of adjacent shells in the stack are not superposed.

The second spacer portions of each shell may be angularly separated by integer multiples of the desired angular offset. In one or more embodiments, the second spacer portions of each shell at even multiples of the desired angular offset may be located at the second radial distance from the centre of the shell.

The second spacer portions of each shell at odd multiples of the desired angular offset may be located at the first radial distance from the centre of the shell.

The first and second spacer portions conveniently project from a first side of each shell.

Each shell may further includes a series of third spacer portions projecting outwardly from the other side of each shell so that, when the shell is stacked with other shells, the third spacer portions act to space the shell from an adjacent shell in the stack.

These third spacer portions of each shell may be angularly separated by integer multiples of the desired angular offset.

In one or more embodiments, the third spacer portions of each shell are located at angular positions mid-way between adjacent spacer portions projecting from the first side of the shell.

Conveniently, the third spacer portions are located along one of the first ribs.

Each shell may also include a shell locating portion at the centre of each shell, the shell locating portion having a male shape on one side of the shell and a female shape on the opposing side of the shell to enable the concentric location of the shell on an adjacent shell.

The air/water ingress opening is preferably formed through the shell locating portion.

The shell locating portion may include an annular disc surrounding the air/water ingress opening.

Another aspect of the invention provides a floating modular cover for a body of water, the cover consisting of a plurality of individual modules as described here above.

Yet another aspect of the invention provides a shell forming part of a module as described here above.

A further aspect of the invention provides a method of making a module forming part of a floating modular cover, including the steps of: forming a plurality of discrete flotation cells for ensuring flotation of the module,

forming an upper shell having an air opening to allow air to flow into and out of a chamber in the module,

forming a lower shell having a water ingress opening to allow ingress of water into the chamber for ballast,

locating the flotation cells between the upper shell and lower shell, and joining the upper shell and lower shell together to thereby retain the flotation cells in predetermined positions between the shells.

Preferably, at least one of the shells includes a plurality of recessed portions for receiving the flotation cells and the step of locating the flotation cells includes locating the flotation cells in the recessed portions.

Each shell may include a plurality of recessed portions for receiving the flotation cells, each recessed portion in one of the shells opposing a recessed portion in the other shell when the module is in an assembled state, and the step of locating the flotation cells includes locating the flotation cells in opposing recessed portions.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings. It is to be understood that the particularity of the drawings does not supersede the generality of the preceding description of the invention.

Brief Description of the Drawings

Figure 1 is an isometric view of a module forming part of a floating modular cover for a body of water;

Figure 2 is an isometric view of part of the module of Figure 1 ;

Figure 3 is a sectional view of the module of Figure 1 ;

Figure 4 is an isometric view of the module of Figure 1 ;

Figures 5 to 7 are sectional views of a stack of shells used to form modules such as that shown in Figure 1 ;

Figure 8 is a top view of the centre of a shell used to form the module of Figure 1 ;

Figure 9 is a bottom view of the centre of a shell used to form the module of Figure 1 ; Figure 10 is a sectional view of the centres of a stack of shells of the sort used to form the modules shown in Figure 1 ;

Figure 1 1 is an isometric view of a floating modular cover including a number of modules of the type depicted in Figure 1 ;

Figure 12 is a flowchart of a method of making a module forming part of a floating modular cover.

Detailed Description

Referring to Figures 1 to 3, there is shown a module 10 forming part of a floating modular cover for a body of water, such as a dam, reservoir, pond or golf course water hazard. The module 10 includes an upper shell 12 and a lower shell 14. When in an assembled state as depicted in Figures 1 and 3, the upper shell 12 and lower shell 14 define a chamber 16 there between. The lower shell 14 includes a water ingress opening 18 to allow ingress of water into the chamber 16 for ballast when the module is located on a body of water. Similarly, the upper shell 12 includes an air opening 20, to allow air and/or water to flow into and out of the chamber 16 depending upon the water level within the chamber.

The upper and lower shells are depicted as having a hexagonal circumferential shape, although it will be appreciated that in other embodiments one or both shells may have another polygonal or non-polygonal circumferential shape. It will also be appreciated that the module can be inverted in water so that the upper and lower shells are inversed. In this case, the water ingress openings become the air openings and vice versa.

As seen in Figure 2, the module 10 also includes a plurality of discrete flotation cells for ensuring flotation of the module. Four such flotation cells 22 are depicted in this figure. The upper shell 12 and lower shell 14, when the module is in an assembled state, act to house each flotation cell in a predetermined position within the chamber 16. To this end, the upper shell 12 and lower shell 14 each include a series of recessed portions for receiving a flotation cells. Recessed portions 30 and 32 are shown in Figure 2 without the presence of a flotation cell for the sake of clarity.

Conveniently, the recessed portions are adjacent to vertices of the hexagonally-shaped shells 12 and 14. Each recessed portion in one of the shells opposes a corresponding recessed portion in the other shell when the module 10 is in an assembled state. As can be best seen in Figure 3, opposing recessed portions thus define a compartment for retaining a flotation cell.

It will be appreciated that in other embodiments the recessed portions may be omitted, or there may be cell recesses in one shell only.

In order to optimise their structural strength, each flotation cell 22-32 has a substantially spherical shape. Of course, other shaped flotation cells/ cell recesses are also possible.

As can be seen in Figure 1 , each shell 12 and 14 of the module 10 includes a series of first ribs 40 to 50 extending from each recessed portion towards the centre of the respective shell. In addition, each shell further includes a series of second ribs 52 to 62 extending from a location midway between each vertex of the hexagonally shaped shell towards the centre of that shell. The first ribs 40 to 50 and the second ribs 52 to 62 act to provide structural rigidity to the module 10.

As best appreciated from Figure 4, each of the shells 10 and 12 may include a series of first spacer portions 70 to 80 projecting outwardly from the shell. In the case of the shell 12 seen in Figure 4, the first spacer portions 70 to 80 project upwardly, whereas the (unseen) first spacer portions of the opposing shell 14 will project downwardly. The first spacer portions act so that when the shell 12 is stacked with other identical shells, for example for transportation to a site at which the modules will be assembled, the first spacer portions 70 to 80 act to space the shell from an adjacent shell in the stack. In that regard, the first spacer portions 70 to 80 are located so that, at a desired angular offset of the shell from an adjacent shell in the stack, the first spacer portions of adjacent shells in the stack are not superposed, as will now be explained.

As can be seen from Figure 4, every first spacer portion 70, 74 and 78 are separated from each other by 120^Q around the centre 82 of the shell 12. Each of these first spacer portions 70, 74 and 78 are located at a first radial distance di from the centre 82 of the shell.

The other first spacer portions 72, 76 and 80 are also separated from each other by 120^Q around the centre 82 of the shell 12, and are located at an angular position midway between adjacent pairs of the first spacer portions 70, 74 and 78, but at a second radial distance d₂ from the centre 82 of the shell 12. The first and second radial distances di and d₂ are different from each other, so that when an identical shell to that shown in Figure 4 is stacked on top of the shell 12 having firstly been provided with a 60^Q angular offset to the orientation shown in Figure 4, none of the first spacer portions 70 to 80 on the shell 12 will be superposed with any of the spacer portions on the stacked shell.

Accordingly, the first spacer portions 70 to 80 of the shell 12 are angularly separated by integer multiples of a desired angular offset which is to be applied to each shell as it is stacked on top of an adjacent shell.

The first spacer portions of each shell at even multiples of the desired angular offset (in the example shown in Figure 4, first spacer portions 70, 74 and 78) are located at the first radial distance from the centre of the shell. However, the first spacer portions of each shell at odd multiples of the desired angular offset (that is, first spacer portions 72, 76 and 80 in Figure 4) are located at a second radial distance from the centre of the shell. The second radial distance being different to the first radial distance.

It can also be seen from Figure 4 that the shell 12 includes a series of second spacer portions 84 to 94 which also project outwardly from the shell 12 and act to space the shell 12 from an adjacent shell stacked on top thereof. It can be seen that the second spacer portions 84 to 94 are located at angular positions between adjacent first spacer portions 70 to 80. As was the case with the first spacer portions 70 to 80, the second spacer portions 84 to 94 are angularly separated by integer multiples of a desired angular offset applied to a shell which is to be stacked onto the shell 12. It can be seen that the second spacer portions of the shell 12 at even multiples of the desired angular offset to be applied to a shell stacked onto the shell 12 (that it, second spacer portions 86, 90 and 94) are located, in this example, at the second radial distance d₂ from centre 82 of the shell 12. It can also be seen that the second spacer portions of the shell 12 at odd multiples from the desired angular offset (that is, second spacer portions 84, 88 and 92) are located at the first radial distance di from the centre 82 of the shell 12.

The manner in which the first and second spacer portions of adjacent shells in a stack are not superposed can be further appreciated from Figure 5, which shows a stack of eight shells of the type depicted in Figures 1 to 3. Figure 5 shows stacked shells 100 to 1 14. In the stack of shells 100 to 1 14 shown in Figure 5, these shells all have an identical configuration and shape to that shown in Figures 1 to 3, and each shell has a desired angular offset (that is, rotation of the shell in a horizontal plane about an axis passing through the centre of the shell) of 60^Q applied to the shell prior to stacking.

The shells 100, 104, 108 and 1 12 are shown as having first spacer portions respectively referenced 1 16, 1 14, 120 and 122. Similarly, the shells 102, 106, 1 10 and 1 14 include first spacer portions respectively referenced 124, 126, 128 and 130. The first spacer portions 1 16 to 122 are located at a second radial distance d₂ from the centre of the shell, whereas the first spacer portions 124 to 130 are located at the first radial distance di from the centre of the shell. It can be seen from Figure 5 that each of the first spacer portions 1 16 to 130 is not superposed with a first spacer portion of an adjacent shell in the stack and that each of the spacer portions supports and provides separation from adjacent shells in the stack.

Each of the shells may further include a series of third spacer portions projecting outwardly from the opposing side of the shell to that from which the first and second spacer portions project. Once again, these third spacer portions act so that when the shell is stacked with other shells, the first spacer portions space the shell from an adjacent shell in the stack. An exemplary embodiment is shown in Figures 6 and 6A (which is an expanded view of the left most portion of Figure 6), in which it can be seen that a third spacer portion 140, which is located along one of the ribs 142 extending from each recessed portion towards the centre of a shell 144 engages with an adjacent shell 146 in a stack of shells so as to provide spacing therebetween.

Figure 7 provides a more detailed view of a number third spacer portions 150 to 156 which respectively project outwardly from a side of shells 158 to 164 (in this case the side of the shell that is located on the interior of the module when so formed) to provide spacing between the shells 158 to 164 when stacked.

In this exemplary embodiment, the third spacer portions of each shell are angularly separated by integer multiples of the desired angular offset applied to each shell prior to stacking on top of over shells in the stack. Preferably, the third spacer portions of each shell are located at angular positions midway between adjacent spacer portions projecting from the other side of the shell to which the third spacer portions project.

Each shell includes a shell locating portion best seen in Figures 8 to 10. The shell locating portion 180 shown in Figures 8 and 9 is located in this embodiment at the centre of each shell. The shell locating portion has a male shape on one side of the shell (which can be seen in Figure 8) and a female shape on the opposite side of the shell (which can be seen in Figure 9) to enable the concentric location of the shell on an adjacent shell in a stack. Figure 10 depicts the shell locating portions of a stack of five shells 190 to 198. It can be seen that the air/water ingress opening of each shell is conveniently formed through the shell locating portion of each shell. The shell locating portion of each shell includes an annular disc surrounding the air/water ingress opening.

Referring once again to the single shell locating portion 180 depicted in Figures 8 and 9, can be seen that a series of strengthening ribs are located on the side of the shell locating portion 180 having a female shape, so as to strengthen the annual disc surrounding the air/water ingress opening 200 of that disc. The ribs also act to space adjacent shells in a stack, as can be seen from the superposed ribs 202 to 210 shown in Figure 10.

Once assembled, a series of individual modules, such as the modules

220 to 228 shown in Figure 10 are placed on the surface of a body of water and together form a floating modular cover 230 to reduce water loss due to evaporation from that body of water.

A method of making a module 10 is depicted in Figure 12. At step 240, a plurality of discrete flotation cells are formed. The flotation cells are formed by blow moulding or injection moulding and ideally should be sealed to create a hollow water-tight unit. In other embodiments though, the hollow space within the flotation cell could be filled with foam or like buoyant material. Alternatively, the flotation cell could be manufactured so that it was solid throughout and formed from a naturally buoyant material. However, these variations are likely to increase the cost and complexity of manufacture.

At steps 242 and 244, the upper and lower shells 12 and 14 are formed. The upper and lower shells 12 and 14 are preferably formed from polymer or other plastics material by injection moulding or thermoforming, although any other convenient material, manufacturing process or technique may be adopted.

The flotation cells are housed between the upper shell and lower shell at step 246. In this case, opposite portions of each flotation cell are received within a recessed portion in the top shell and a recessed portion in the bottom shell respectively. The upper shell 12 and lower shell 14 are joined together at step 248 to thereby retain the flotation cells in predetermined positions between the shells. The shells may be joined by ultrasonic welding, clips or the application of heat stakes. Various other plastic assembly technologies will be known by persons of ordinary skill in the relevant field of technology.

The upper and lower shells 12 and 14 in the above described module are identical. Conveniently, this requires only one shell form to be manufactured. Pairs of identical shells are then able to be assembled by placing a first shell in a jig or similar support, locating one end of each flotation cell in a cell recess in the first shell, lowering the second shell onto the first shell so that the other end of each flotation cell is received in a cell recess on the second shell, and joining the shells together.

The ease with which the module 10 is able to be assembled facilitates the assembly of the module on site at the location in which the floating modular cover is intended to be used. Rather than being required to assemble each module at a central manufacturing location, and then transport the assembled modules to a desired location for use, the unassembled shells are able to be stacked and transported to a particular site, together with a supply of flotation cells.

Assembly of the modules can take place quickly and conveniently next to the body of water upon which the floating modular cover is intended to be placed. A relatively inexpensive and easy to operate ultrasonic welding, staple, clip or heat staking piece of equipment is the only piece of apparatus required.

While the present invention has been described in conjunction with a limited number of embodiments, it will be apparent to those skilled in the art that many alternatives, modifications and variations are possible in light of the foregoing description. The present invention is intended to embrace all such alternatives, modifications and variations as may fall within the spirit and scope of the invention as disclosed.

The present application may be used as a basis for priority in respect of one or more future applications, and the claims of any such future application may be directed to any one feature or combination of features that are described in the present application. Any such future application may include one or more of the following claims, which are given by way of example and are non-limiting with regard to what may be claimed in any future application.

Claims

CLAIMS:

1 . A module forming part of a floating modular cover for a body of water, including:

an upper shell,

a lower shell,

a chamber defined by the upper and lower shells,

2. A module according to claim 1 , wherein at least one of the shells includes a plurality of recessed portions for receiving the flotation cells.

3. A module according to claim 1 , wherein each shell includes a plurality of recessed portions for receiving the flotation cells, each recessed portion in one of the shells opposing a corresponding recessed portion in the other shell when the module is in an assembled state.

4. A module according to claim 3, wherein, when the module is in an assembled state, opposing recessed portions define compartments for retaining the flotation cells.

5. A module according to any one of claims 2 to 4, wherein perimeters of the upper and lower shells have polygonal shapes and the cell recesses are adjacent to vertices of the polygonal shapes.

6. A module according to claim 5, wherein each shell further includes a plurality of first ribs extending from each recessed portion towards the centre of the shell.

7. A module according to claim 6, wherein each shell further includes a plurality of second ribs extending from a location mid-way between each vertex of a respective polygonal shape towards the centre of the shell.

8. A module according to any one of the preceding claims, wherein each shell further includes:

a series of first spacer portions projecting outwardly from the shell so that, when the shell is stacked with other shells, the first spacer portions act to space the shell from an adjacent shell in the stack.

9. A module according to claim 8, wherein the first spacer portions are located so that, at a desired angular offset of the shell from an adjacent shell in the stack, the first spacer portions of adjacent shells in the stack are not superposed.

10. A module according to claim 9, wherein the first spacer portions of each shell are angularly separated by integer multiples of the desired angular offset.

1 1 . A module according to claim 10, wherein the first spacer portions of each shell at even multiples of the desired angular offset are located at a first radial distance from the centre of the shell.

12. A module according to either one of claim 10 or 1 1 , wherein the first spacer portions of each shell at odd multiples of the desired angular offset are located at a second radial distance from the centre of the shell, the second radial distance being different to the first radial distance.

13. A module according to any one of claims 8 to 12, wherein each shell further includes:

a series of second spacer portions projecting outwardly from the shell so that, when the shell is stacked with other shells, the first spacer portions act to space the shell from an adjacent shell in the stack, the second spacer portion being located at angular positions between adjacent first spacer portions.

14. A module according to claim 13, wherein the second spacer portions are located so that, at the desired angular offset of the shell from an adjacent shell in the stack, the second spacer portions of adjacent shells in the stack are not superposed.

15. A module according to claim 14, wherein the second spacer portions of each shell are angularly separated by integer multiples of the desired angular offset.

16. A module according to claim 15, wherein the second spacer portions of each shell at even multiples of the desired angular offset are located at the second radial distance from the centre of the shell.

17. A module according to either one of claim 15 or 16, wherein the second spacer portions of each shell at odd multiples of the desired angular offset are located at the first radial distance from the centre of the shell.

18. A module according to any one of claims 8 to 17, wherein the spacer portions project from a first side of each shell.

19. A module according to any one of claims 8 to 18, wherein each shell further includes:

a series of third spacer portions projecting outwardly from the other side of each shell so that, when the shell is stacked with other shells, the third spacer portions act to space the shell from an adjacent shell in the stack.

20. A module according to claim 19, wherein the third spacer portions of each shell are angularly separated by integer multiples of the desired angular offset.

21 . A module according to claim 20, wherein the third spacer portions of each shell are located at angular positions mid-way between adjacent spacer portions projecting from the first side of the shell.

22. A module according to any one of claims 19 to 21 , when dependent upon claim 6, wherein the third spacer portions are located along one of the first ribs.

23. A module according to any one of the preceding claims, wherein each shell includes a shell locating portion at the centre of each shell, the shell locating portion having a male shape on one side of the shell and a female shape on the opposing side of the shell to enable the concentric location of the shell on an adjacent shell.

24. A module according to claim 23, wherein the air/water ingress opening in formed through the shell locating portion.

25. A module according to either one of claims 23 or 24, wherein the shell locating portion includes an annular disc surrounding the air/water ingress opening.

26. A floating modular cover for a body of water, the cover consisting of a plurality of individual modules according to any one of the preceding claims.

27. A shell forming part of a module according to any one of claims 1 to 26.

28. A method of making a module forming part of a floating modular cover, including the steps of:

forming a plurality of discrete flotation cells for ensuring flotation of the module, forming an upper shell having an air opening to allow air to flow into and out of a chamber in the module,

29. A method according to claim 28, wherein at least one of the shells includes a plurality of recessed portions for receiving the flotation cells and the step of locating the flotation cells includes locating the flotation cells in the recessed portions.

30. A method according to claim 28, wherein each shell includes a plurality of recessed portions for receiving the flotation cells, each recessed portion in one of the shells opposing a recessed portion in the other shell when the module is in an assembled state, and the step of locating the flotation cells includes locating the flotation cells in opposing recessed portions.

31 . A module forming part of a floating modular cover substantially as hereinbefore described with reference to the drawings.

32. A floating modular cover substantially as hereinbefore described with reference to the drawings.

33. A shell forming part of a module substantially as hereinbefore described with reference to the drawings.

34. A method of making a module forming part of a floating modular substantially as hereinbefore described with reference to the drawings.