FIRE RESISTANT BARRIER
Technical field
This invention relates to a fire resistant barrier and to the use of such barrier for protection of property against fires. The invention has been developed primarily for use in protecting property against bush and forest fires and the invention will be described hereinafter in such context. However, it will be understood that the invention does have broader application, for example in protecting one property from a fire at an adjacent property.
Property that might typically be protected in use of the barrier may include various types of vehicles, residential dwellings and other buildings.
Background art
Bushfires represent a risk to life, property and the environment in rural and urban areas.
The destructive elements of bushfire attacks can be categorised in five forms: wind, smoke, burning debris, radiant heat and flame. Any given strategy to provide bushfire protection relies on minimising the impact of one or more of these elements.
Construction standards have been devised in many countries to minimise the risk of fire damage. In Australia the Construction Standard AS 3959 - 1999 sets out the requirements for construction of buildings in designated bushfire prone areas. Similarly, the United States Standard NFPA 299 provides criteria for fire safe development in areas that may be threatened by wildfire. In Australia AS 3959 incorporates both construction
requirements for various elements of the building and a methodology for determining when those construction requirements should apply.
Both AS 3959 and the United States NFPAQ 299 identify requirements for creating a defensible space around the building through landscaping and vegetation control, and ensuring that there is roadway access for emergency responders and evacuation.
Conforming to these building standards is important in minimising the risks associated with bushfire, but there is evidence that more protective mechanisms are required to prevent property damage.
Barrier systems have been proposed that utilise fire resistant blankets to substantially cover buildings. United States Patents 6125941, 5829200, 5608992, 4858395, 9766958 and 3715843 disclose various arrangements which, whilst not forming part of the common general knowledge in the field of interest, propose the deployment of continuous or discontinuous fire resistant or fire retardant blankets.
The disclosed prior art arrangements propose the employment of permanent and semipermanent fixing methods and they provide variously for protection from wind, smoke, burning debris, radiant heat and flame. However, these arrangements, as disclosed, likely require an unacceptable amount of time for installing, deployment and/or anchoring in position.
Disclosure of the invention
A first aspect of the invention may be defined broadly as providing a fire barrier arrangement which comprises:
a) a flexible blanket that is formed from a fire resistant material and which is sized in use to substantially cover property to be protected from an external fire, and b) at least one restraining device for anchoring the blanket wherein the restraining device is arranged to receive a ballast material for weighting the device when required to perform the anchoring function.
Depending upon its specific application and intended site of use, the covering provided by the flexible blanket and the restraining device (s) may be designed to maintain its integrity when exposed to the destructive forces of high velocity winds associated with a bushfire. The fire barrier arrangement may also be designed to limit access of smoke, burning debris, radiant heat and flame to the property to be protected.
The restraining device can also facilitate anchoring on uneven, rocky or sandy surfaces where more conventional methods of fixation such as by use of solid bars, pegs or stakes would not be as convenient.
In a second aspect, the invention may also be defined as providing a method of deploying the fire barrier arrangement comprising the steps of: a) directing at least one rope connected to the blanket over the top of the property to be protected from an external fire, b) employing the rope to draw the flexible blanket over the property in a manner substantially to cover the property, c) engaging the or each restraining device with the flexible blanket in a manner to retain the flexible
blanket in the position substantially covering the property, and d) either before or after step c) , charging the or each restraining device with a ballast material.
Preferred features of the invention
The or each restraining device is preferably provided in the form of a collapsible receptacle. This provides for easier transportation and facilitates positioning of the restraining devices in difficult terrain due to their ability to adapt to various surface topographies.
In an alternate arrangement, the or each restraining device may be provided in the form of one or more rigid receptacles. The rigid receptacles provide the ability to shape the receptacles to decrease the likelihood of rolling on a sloped surface.
The or each restraining device may be provided integrally with the blanket. This may provide for reduced - deployment time. Alternatively, the or each restraining device may be provided separately from the blanket and be arranged to be charged separately with the ballast material .
As a further alternative, some or all of the restraining devices may be interconnected to allow ballast material to flow between individual restraining devices. Such interlinking may decrease the deployment time of the system by allowing multiple restraining devices to be charged simultaneously via one or many charge points. The ballast material is preferably a fluidisable material. This fluidisable material can include both particulates and liquids. Particulates include sand, dirt or rocks.
One immediately possible liquid for ballast is water.
The blanket is preferably formed in a desired size and shape from a single piece of fire resistant material, but it may take the form of several conjoined panel (led) portions. The material from which the blanket is formed is preferably a fire resistant textile. In or other preferable embodiment the blanket is formed from a fire resistant fabric comprising interwoven yarns of heat- resistant material. In a further possible embodiment, the heat-resistant material is a synthetic fibre.
Embodiments of the invention can incorporate ropes for attachment to the fire resistant barrier for deployment of the barrier.
The invention will be more fully understood from the following description of a preferred embodiment of a fire barrier arrangement for the protection of property. The description is provided with reference to the accompanying drawings.
Brief description of drawings An embodiment of the present invention will now be described by way of example only, with reference to the accompanying drawings, in which:
Figure 1 shows a perspective view of a fire barrier arrangement positioned (deployed) over a residential dwelling,
Figure 2 shows a plan view of the fire barrier arrangement positioned over the residential dwelling,
Figure 3 shows a perspective view of the fire barrier arrangement deployed over the residential dwelling and illustrates two different charging point devices for restraining devices of the barrier arrangement,
Figure 4 illustrates an initial stage in the deployment of a flexible blanket of the barrier arrangement,
Figures 5 and 6 illustrate successive further stages in the deployment of the flexible blanket,
Figure 7 shows a perspective view of blanket clasp device,
Figure 8 shows a perspective view of two interconnected anchoring devices, and Figure 9 shows a perspective view of a fire barrier arrangement positioned (deployed) over an automobile.
Modes for carrying out the invention
As illustrated, the fire barrier arrangement 10 comprises a flexible blanket 11 which is formed from a fireproof fabric. Restraining devices 12, located in use in cavities 13, are formed by hemming the marginal edge of the flexible blanket 11. The restraining devices 12 are inserted into the cavities 13 via slits 14.
The restraining devices 12 can be in the form of either flexible or rigid receptacles. In this particular embodiment the restraining devices are flexible. Eyelets 15 are positioned at the perimeter of the blanket 11 for the attachment of ropes.
Each restraining device 12 has a domestic hose fitting 16 and a fire brigade hose fitting 17 positioned adjacent to the end of the restraining devices and projecting towards the exterior of the fire barrier arrangement .
These fittings (or further fittings in other embodiments) can also be used to interconnect restraining devices as illustrated in Figure 8 where two restraining devices 40 are interconnected by a hose 41, with the hose
41 connecting to fittings 42 integrated into each of the restraining devices 40.
The blanket 11 is formed from a fire resistant textile which is formed from interwoven yarns of heat- resistant material . In particular embodiments this yarn may be fire resistant polypropylene.
Figure 2 shows the position of the residential dwelling 18 in relationship to the fire barrier arrangement and Figure 3 shows a flap 18 which is provided to detachably cover the slits 14.
Figures 4 to 6 illustrate successive stages of deploying the blanket of the fire barrier arrangement. A rope 19, attached to a projectile 20, is directed over the residential dwelling 18 using a catapult or other such projecting device. One or more ropes 19, that have been positioned over the top of the residential dwelling 18, are attached to the eyelets 15 and are employed to pull the flexible blanket 11 into position over the residential property 18. The fire barrier arrangement 10 is shown in Figure 6 in the deployed position over the residential property 18.
The restraining devices 12 are located in the cavities 13 and a domestic hose 23 is attached to the domestic hose fitting 16 to fill the restraining devices 12 with ballast water. Alternative ballast materials include sand, dirt and other particulate or liquids. It is preferable that the ballast material is non-flammable.
To facilitate formation of the loops a clasp device
21 as shown in figure 7 may be employed. This comprises four spring-loaded wedges 22 which are located within a casing 23, and the wedges are in use retracted by actuation of a pushbutton 24.
As an alternative to hemming the marginal edge of the fire blanket to provide the cavities for accommodating the restraining devices, loops 50 as shown in Figure 9 may be provided at the near the edges of the blanket through which the restraining devices may be fastened or threaded. Alternatively, the loops 50 can be positioned at various locations around the blanket 51 to enable the restraining devices 52 to be positioned at the margins of the property to be protected. In this embodiment an automobile 53 is shown, with extraneous portions of the blanket 51 remaining unrestrained.