TECHNICAL FIELD

[0001] The present invention relates to the storage and transport of water or other fire-fighting fluids and, more particularly to the storage and transport of water for the fighting of bush fires.

BACKGROUND

[0002] A perennial problem in Australia and other countries with forests in sub-tropical regions, is that of bush fires in the summer months when high temperatures, low humidity, lightning strikes and high winds can create conditions for devastating wild fires.

[0003] Fire fighting vehicles for operation in what is often rugged terrain, are required to negotiate difficult fire trails and are thus limited in size and hence water carrying capacity.

[0004] For example, a typical vehicle employed by the Rural Fire Service of the state of New South Wales in

Australia, is a dual cab, four wheel drive tanker truck equipped with hoses, pumps and ancillary gear, and limited to just 3000 to 40001itres of water of which usually lOOOliters is kept in reserve for emergency protection of the fire crew. The relatively small volume of water these vehicles can apply to a fire is quickly exhausted, and for replenishment, the vehicle may have to travel a

considerable distance to a source of water.

[0005] A general problem of transporting water (or other fluids) in tankers, and one that is exacerbated when negotiating rough an uneven terrain, is that of surge. Thus it requires considerable structural strength of the tank and hence a considerable weight penalty, in fire-fighting tanker trucks. [0006] It is known to use relatively lightweight bladders for storage of fluids such as that disclosed in US 8763843 B2. A bladder filled or partly filled with a fluid will assume an equilibrium form when at rest, but to transport such a bladder, requires substantial containment structures to counteract the momentum of surging fluid in the flexible bladder due to the motion of the transporting vehicle .

[0007] It is an object of the present invention to address or at least ameliorate some of the above

disadvantages or provide a useful alternative.

Notes

[0008] The term "comprising" (and grammatical variations thereof) is used in this specification in the inclusive sense of "having" or "including", and not in the exclusive sense of "consisting only of".

[0009] The above discussion of the prior art in the Background of the invention, is not an admission that any information discussed therein is citable prior art or part of the common general knowledge of persons skilled in the art in any country.

SUMMARY OF INVENTION

[00010] Accordingly, in a first broad form of the

invention, there is provided a fluid storage and transport system for use in fighting forest and other fires; the system including a rigid rectangular platform and a vessel secured to the platform; the vessel configured such that at maximum volume the vessel is in the form of a portion of a notional right cylinder comprising an upper arced element, a base element and end elements; end elements of the vessel forming segments in which the length of respective chords of the segments is equal to or less than the diameter of the notional right cylinder and wherein arcs of the

segments subtend an angle at their respective centres equal to or less than 180degrees.

[00011] Preferably, the base element of the vessel forms a planar surface extending between the chords of. the end elements; the base element secured to lie flush with an upper surface of the rigid platform.

[00012] Preferably, the vessel is formed of a flexible but inelastic material.

[00013] Preferably, the material of the vessel extending in an arc between the side edges of the vessel r is

provided with reinforcing ribs extending from one side edge to another at intervals along the side edges; the

reinforcing ribs forming arcs conforming to arcs defined by the segments of the end elements.

[00014] Preferably, when the vessel is filled to capacity with a fluid, the vessel assumes a substantially rigid body.

[00015] Preferably, the fluid is water.

[00016] Preferably, the end elements of the vessel are supported by end structures at either end of the rigid platform; the end elements forming substantially planar surfaces against the end structures when the vessel is filled to capacity with the fluid.

[00017] Preferably, the vessel is provided with at least a fluid inlet and a fluid overflow valve.

[00018] Preferably, the rigid platform is a load bed of a transport vehicle.

[00019] Preferably, the rigid platform conforms in dimensions and mounting structures to ISO defined

diraensions and mounting structures of an ISO Platform

Container . [00020] Preferably, the rigid platform is provided with wheels and towing structures for towing by a prime mover vehicle .

[00021] In another broad form of the invention, there is provided a method of providing sources of water for

fighting forest or other fires; the method including the steps of:

-mounting a vessel of flexible but inelastic material to a rigid platform to form a water storage assembly, -filling the vessel with a fire fighting fluid such

that the vessel forms a substantially rigid body, -placing one or more of the water storage assemblies at strategic locations, and

wherein the vessel comprises a portion of a notional right cylinder; end elements of the vessel formed as segments of a cross section of the notional right cylinder; the segments having a chord length which is equal to or less than the diameter of the notional right cylinder and wherein an angle subtended by an arc of the segments is equal to or less than 180degrees.

[00022] Preferably, the end elements of the vessel are maintained substantially planar by rigid end structures mounted to the rigid platform when the vessel is fully filled with water.

[00023] Preferably, the vessel for use is filled to maximum capacity with water so as to form a substantially rigid body.

[00024] Preferably, the rigid platform is provided with structures adapted for transporting the water storage assembly by transportation vehicles equipped with twist locks . BRIEF DESCRIPTION OF DRAWINGS

[00025] Embodiments of the present invention will now be described with reference to the accompanying drawings wherein :

[00026] Figure 1 is a perspective view of a preferred embodiment of a platform and vessel assembly of a water storage and transport system according to the invention,

[00027] Figure 2 is an end view of the platform and vessel assembly of Figure 1 illustrating geometric

constraints,

[00028] Figure 3 is a perspective view of a further preferred embodiment of the invention.

DESCRIPTION OF EMBODIMENTS

[00029] With reference to Figure 1, a fluid storage and transport system according to the invention, is adapted for use in the fighting of forest and other fires.

[00030] The system provides for a water, or other fire- fighting fluid, storage assembly 10 which includes a rigid rectangular platform 12 and a vessel 14 of a flexible, but inelastic material, secured to the platform along the perimeter of the base of the vessel. The vessel 14 is comprised of an arced upper element 16, opposing end elements 18 and a flat base element (obscured in Figure 1) which lies flush against the upper surface 20 of the platform 12. End elements 18 are maintained as planar surfaces when the vessel is filled with water by rigid end structures 22 (only one of which is shown for clarity) attached to the platform 12.

[00031] The invention provides for the curve of the upper element 16, when the vessel is filled with water, to conform to the arc of a circle. This provides for the area under the arc to be a maximum within a minimum perimeter as defined by the arc and the chord of the lower edge of the end element 18.

[00032] With reference to Figure 2, when the vessel 14 is fully filled with water and end elements 18 are constrained to form substantially planar surfaces, the vessel conforms to a portion of a notional right cylinder.

[00033] In this condition, the end elements 18 of the vessel form segments of cross sections of the notional right cylinder. It is a feature of the invention, that the length of respective chords 24 of the segments is equal to or less than the diameter 26 of the notional right

cylinder, and that the arc subtends an angle at the centre no greater than 180 degrees.

[00034] Preferably, as illustrated in Figure 2, the length of the chord 24 is equal to or less than the

diameter 26 of the notional right cylinder of which the vessel forms a portion, and extends substantially the full width of the supporting platform. As demonstrated by Dido's solution to the "isoperimeter problem" some two thousand years ago, with the chord length equal to the diameter, the area under the semicircular arc is a maximum and therefore the capacity of the vessel is a maximum. It follows that the subtended angle cp is equal to or less than 180degrees. For transporting vehicles with a reduced load carrying capacity, the chord length preferably remains the same, that is substantially the width of the platform, but the diameter 26 of the right cylinder may be larger than the chord length, thus reducing the area under the arc and hence the volume of the vessel.

[00035] The relationship between the chord length and the subtended angle of the arc of the end segments is critical to the invention since it is this relationship which ensures that the vessel 14, when fully filled, acts as a substantially rigid body. This rigidity allows for the transport of the vessel with no enclosing structures (other than the end structures 22) .

[00036] The vessel 14 is formed of a flexible but inelastic polymer material. The arc of the arced upper element 14, which conforms to a semi circle or at least to a circular arcuate form, is provided with isoperimetric strengthening ribs 30 spaced at intervals along the length of the vessel and which assist in defining the shape of the vessel. These may be inserted into sleeves provided in the flexible material in the manner of reefs provided in a sail of a sailing craft.

[00037] The vessel 14 is further provided with at least a fluid inlet/outlet spigot 32 and overflow valve 34. It is important that the vessel be filled to capacity to ensure the flexible upper element 14 assumes the arcuate surface of a section of a right cylinder. The vessel may be filled through an aperture (not shown) in the upper element 14 from an overhead source of water, or alternatively through the inlet/outlet spigot 32. Preferably, the overflow valve 34 should have an outlet opening at some level above that of the crown of the upper element 14 when fully filled.

[00038] In a preferred embodiment as shown in Figure 1, the rigid platform 12 is configured dimensionally to a standard ISO defined, 20foot Platform Container, and be provided with corner fittings 36 which allows for the storage assembly 10 to be transported on vehicles equipped with twist locks for the transport of shipping containers, as well as the loading and unloading from such vehicles by side lifters for example.

[00039] In another preferred embodiment shown in Figure 3, the storage assembly 10 may be provided with its own set of wheels 40 for towing behind a prime mover vehicle. [00040] Preferably also, the rigid platform 12 may be provided with levelling elements (not shown) to allow the platform to be stably supported on uneven terrain.

[00041] The use of a platform able to be transported in the manner of a shipping container would allow for an optimum chord length of approaching that of the width of the platform, that is approaching 2.5m.

In Use

[00042] The vessel 14 is completely filled with water (or other fire-fighting fluid) through the inlet/outlet spigot 32 from a pressurized source until water flows from the overflow valve 34. At this point both inlet/outlet spigot 32 and valve 34 are closed. The vessel and its volume of water now form a substantially rigid body on the rigid platform 12.

[00043] The storage assembly may now be transported either to proximate current fire fronts or be positioned strategically in areas of known high fire risk.

INDUSTRIAL APPLICABILITY

[00044] The water storage and transport system of the invention provides an economical system for the provision of highly mobile water sources for use in fire-fighting. The geometry of the filled vessel has the advantage of acting as a substantially solid body obviating the need for complex and expensive structures for restraining the vessel during transportation.