WO2003063966A1

WO2003063966A1 - Firefighting

Info

Publication number: WO2003063966A1
Application number: PCT/AU2003/000096
Authority: WO
Inventors: Lindsay Charles Chinnery
Original assignee: Lindsay Charles Chinnery
Priority date: 2002-01-30
Filing date: 2003-01-29
Publication date: 2003-08-07
Also published as: AUPS019202A0

Abstract

A method of retarding fire comprising, packaging a fire retarding substance in a frangible package (25), and dropping the frangible package (25) from a flying aircraft onto the fire whereby to cause the frangible package (25) to rupture and release the fire retarding substance.

Description

FIREFIGHTING

Field of the Invention

This invention relates to fighting fires. It particularly relates to fighting bushfires using aircraft to drop fire retardant material on to the fires.

Background of the Invention

i the summer months, forest areas in Australia and other parts of the world are at significant risk from bushfires when temperatures are high and combustible materials such as tree foliage and grasses become dry.

Such bushfires can grow rapidly and burn uncontrollably over wide fronts. They represent a major danger to human and animal life as well as property. Generally, large numbers of firefighters on the ground deal with such fires using a combination of techniques. These may include attacking the fire directly with water and other fire retardants and creating firebreaks to interrupt the passage of such fires. These techniques are often augmented by aircraft in the form of helicopters and/or fixed wing aircraft which dump amounts of water or other fire retardants onto the fires.

Where the fires are in relatively inaccessible locations, the use of aircraft to assist with firefighting is particularly advantageous. However, because fires are generally associated with strong winds, it has been found that a substantial proportion of the water which is dropped from aircraft can be blown away by these winds and evaporation from high temperatures with the result that the effectiveness of this technique is reduced.

Thus, there is a need for an approach for combating fires involving the use of aircraft which reduces or obviates the likelihood of water or other fire retardant materials being dispersed by winds and high temperatures when they are dropped from the aircraft. Disclosure of the Invention

In one aspect the invention provides a method of retarding fire comprising, packaging a fire retarding substance in a frangible package, and dropping the frangible package from a flying aircraft onto the fire whereby to cause the frangible package to rupture and release the fire retarding substance.

Reference to retarding fire in this specification includes reference to retarding or extinguishing fire.

Similarly, reference to a fire retarding substance includes reference to any substance which retards or extinguishes fire. Examples of fire retarding substances which may be used in the practice of the invention include water, water loaded with fire retardants, solid fire retardants, materials which may create a fire retardant foam, and combinations of these.

In order to facilitate handling, it is preferred that there be more than one frangible package rather than a single large frangible package. For example, bags holding about 100 to 200kg of water may be used. The bags may be shaped so that they can be readily stacked on a pallet suitable for loading on an aircraft.

The bags comprising frangible packages may be formed of any flexible material which can hold the fire retardant material. In the case of liquids, the bags should preferably be liquid proof and should be sealed so as to avoid leakage.

The walls of the bag may comprise a plastic film. The plastic film may be any commonly available plastic film which is suitable for holding water. For example, PNC polyethylene, polypropylene, nylon or other material may be used.

The plastic film may be heat sealable to facilitate forming the film into bags and subsequently sealing the bags after they have been filled. Alternatively or additionally, the bags may include a spigot sealed by a bung. Thus the bags may be filled with water or other fire retardant through the spigot after which the bung is friction fitted or screwed onto the spigot to seal the spigot.

Suitably, the bags are shaped so that they may be stacked together readily in a manner which allows them to nest. In this way it is possible to ensure the volume they occupy is kept within reasonable limits. Given the restricted amount of space in an aircraft keeping volume low can be important. Examples of suitable bag shapes include drum or cylindrical shaped bags. The bags may be shaped so that they can readily be rolled or slid or otherwise fed or pushed out of the cargo bay of an aircraft.

The bags may include reinforcing materials in their walls to prevent accidental breaking of the bags prior to being released. The material of the bags may itself include a fire retardant. The material of the bags may be biodegradable.

An outer layer of netting may be used to strengthen the bags against accidental breakage.

The bags may be stored on an opened topped pallet or tray provided with sides for retaining the bags on the tray. One of the tray sides may be a side which may be dropped down to allow the bags to be rolled or pushed off the tray out of the rear cargo bay of an aircraft.

Alternatively the bags may be stored in an elongate mobile container which can be rolled into the cargo bay of an aircraft. In another alternative the bags may be suspended from a helicopter in netting. The netting may include releasable closure means for dropping the bags at a selected area with great accuracy.

h one particular embodiment, in order to improve the rolling characteristics of the bags for rolling out of the rear cargo bay of an aircraft, the bays may be formed as spherical packages. A preferred embodiment of the invention will now be described with reference to the accompanying example.

Example

A number of pallets with drop down sides may be stored in a hanger of an airport. The pallets are all loaded with a number of cylindrical bags which are each arranged on the pallet so that they may be readily rolled off the pallet when one of the drop down sides of the pallet is lowered.

During fire controlling operations, the pallets may be loaded through the cargo door of a fixed wing aircraft such as Caribou or Hercules using conventional loading equipment for such pallets commonly available at airports. Because the pallets and bags are pre-prepared, the time for loading an aircraft ready for take off can be made very short, eg. less than 40 minutes.

After loading, the aircraft may fly directly over a fire at which time the drop down end of the pallet is opened and the rear cargo door of the aircraft also opened. The aircraft angles upwards so that the bags roll off the pallets and out the rear door directly down onto the fire.

Because the bags do not tear until they hit the ground or objects such as trees near the ground, the water or other fire retardant material in the bags will not be dispersed to any great extent by the strong winds usually accompanying fires. Thus the area of application of the fire retardant material can be much more narrowly targeted.

This method is most suitable for fighting fires as soon as they start eg. by lightening strikes in very inaccessible areas. When these fires are not extinguished in a very short time they become uncontrollable as they soon take on a very wide front, burning large areas of forest and creating widespread pollution at ground level and upper atmosphere eg. ozone level. A good example of pollution was provided by the Sydney fires of 2002 which were a major concern in relation to pollution in the lower and upper atmospheres. These fires were followed by those covering a substantial portion of the Eastern side of Australia in January 2003.

This method would be most suitable for fighting these fires very soon after starting long before they cause major damage to forestry, farm and residential property.

The cost to the country is horrendous using the present method of waiting for the fire to come to the firefighters which is the last line of defence before reaching property.

This system will allow the firefighting to be taken to the fire front sometimes close to property though in many cases many kilometres from property and therefore a long time before the last line of defence is reached.

The number of planes in the air at any one time will depend on the size of the fire, its ^• course, threat to property and distance from an airport to the fire front. A large amount of firefighting liquid using this method could be applied to the fire front without endangering any firefighters on the ground.

This method of fighting the fires has been developed to save lives especially the men and women who put themselves in life threatening situations. It should also limit loss to property, forestry, costly insurances and financial burden to the community and country.

Other embodiments of the invention will now be described with reference to the accompanying drawings.

Brief Description of the Drawings

Figure 1 shows a mobile container assembly for performing the invention; Figure 2 shows a rear module forming part of the mobile container assembly;

Figure 3 shows an intermediate module forming part of the mobile container assembly;

Figure 4 shows a front module forming part of the mobile container assembly; Figure 5 shows a construction for filling the mobile container assembly;

Figure 6 shows rear loading of the mobile container assembly on a fixed wing aircraft;

Figure 7 shows release of fire retardant packages from the rear of the aircraft; and Figure 8 shows an alternative approach using a helicopter.

Detailed Description of the Drawings

The various elements identified by numerals in the drawings are listed in the following integer list.

Integer List

1 Mobile container assembly

3 Rear module

5 Intermediate module

7 Front module

9 Tubular portion

11 Flange

13 Bolt

15 Wheels

17 Closed end

19 Dover

21 Hinge

23 Latch

25 Fire retardant packages

27 Elevated platform 29 Netting

31 Releasable catch

Referring to Figures 1 to 4, the mobile container assembly generally designated 1 and shown in Figure 1 is one approach to rapidly load fixed wing aircraft with fire retardant materials for bombing fires. It will be appreciated that a store of a number of these mobile container assemblies which have been pre-filled may be held at airports in locations where there is the greatest likelihood of fire outbreaks within the surrounding region.

The mobile container assembly 1 comprises a number of modules. The modules themselves may be constructed in any fashion known in the art. Bearing in mind that they will be loaded on aircraft, it is preferred that their weight be kept as low as possible to allow maximum carrying capacity of the fire retardant packages. In one preferred method of construction of such modules, it is anticipated that they may readily be made by conventional rotational moulding techniques for plastic materials. The plastic material may suitably be polyethylene.

The modules making up the mobile container assembly comprise a rear module 3, one or more intermediate modules 5 (the number chosen being dependent on the length of container which can fit within an aircraft cargo bay), and a front module 7.

Each of the modules has a tubular portion 9 within which the fire retardant packages 25 may be stored.

The ends of the modules include a flange 11. The purpose of the flange is to allow easy connection between abutting modules using bolts 13. The flanges also can provide a strong securement point for the wheels 15 which are required to assist rolling of the mobile container assembly into the cargo bay of an aircraft.

The rear module 3 has a closed end 17 and is open at its opposite end whereas the intermediate module 5 is open at both of its ends. The front module 7 is open at one end and has a closed end 17 which is closed by the cover 19.

The cover includes a hinge 21 to allow it to swing upwardly for loading of the container assembly and also for discharge of the fire retardant packages 25 when required.

A latch 23 provided at the bottom of the cover secures the cover in the closed position until such time as the fire retardant packages need to be released.

As is shown in Figure 5, the fire retardant packages may be loaded into the mobile container assembly by tilting it between the ground and an elevated platform 27 and filling the assembly through the open front module.

The filled mobile container assembly may be loaded onto an aircraft via the rear cargo bay as is shown in Figure 6.

Thus, when the aircraft is in flight, it is a simple matter to release the fire retardant packages over a selected area by tilting the nose of the aircraft upwards, and opening the cargo bay door and the cover 19 to allow the packages to roll out under gravity. The rate at which the packages may be rolled out will be dependent on the degree of tilt of the aircraft. Thus the pilot of the aircraft has a significant degree of control over the extent of the area to be covered by the falling fire retardant packages as this will be a function of the aircraft ground speed, the height of the aircraft and the rate of delivery of the packages which in turn depends on the aircraft tilt angle.

Referring to Figure 8, an alternative form of delivery of fire retardant packages using a helicopter is shown. Netting 29 holding one or a number of fire retardant packages 25 is suspended by the helicopter above a fire. The packages may be caused to drop by releasing^" a releasable catch 31 holding one side of the netting. The netting remains attached by the suspension cable to the helicopter at one end whilst the other side of the netting drops allowing the packages to fall out onto the fire. This approach is particularly suitable for chemical fires or fires at oil refineries as the fire retardant can be specifically formulated to deal with the type of fire concerned. Thus for example foam fire retardant may be used for an oil fire. It may be delivered as a single large package eg. 1,000 to 10,000 litres or as several large packages.

It is to be understood that the word comprising as used throughout the specification is to be interpreted in its inclusive form ie. use of the word comprising does not exclude the addition of other elements.

It is to be understood that various modifications of and/or additions to the invention can be made without departing from the basic nature of the invention. These modifications and/or additions are therefore considered to fall within the scope of the invention.

Claims

1. A method of retarding fire comprising, packaging a fire retarding substance in a frangible package, and dropping the frangible package from a flying aircraft onto the fire whereby to cause the frangible package to rupture and release the fire retarding substance.

2. A method according to claim 1 wherein the fire retarding substance comprises any one of water, water loaded with fire retardants, solid fire retardants, materials which may create a fire retardant foam, and combinations of these.

3. A method according to any one of the preceding claims wherein the fire retarding substance is packaged in a plurality of flexible bags.

4. A method according to claim 3 wherein the flexible bags comprise PNC, polyethylene, polypropylene or nylon film.

5. A method according to claim 3 wherein the plurality of flexible bags containing fire retarding substances are housed in an outer container carried by the aircraft, and the flexible bags are dropped from the outer container onto the fire.

6. A method according to claim 5 wherein the outer container comprises an elongate rigid outer container with an outlet and an outlet closure, the rigid outer container being located in a cargo bay of a fixed wing aircraft with a rear cargo bay door, and the flexible bags containing fire retarding substance are dropped by opening the rear cargo bay door and outlet closure and tilting the aircraft so that the nose of the aircraft tilts upward.

7. A method according to claim 5 wherein the aircraft comprises a helicopter and the outer container comprises a net suspended from underneath the helicopter, the net including releasable closure means for keeping the flexible bags in the net and for allowing the flexible bags containing fire retarding substance to drop from the net when the closure means are released.

8. An assembly for carrying out the method of claim 1 comprising, an outer container, a plurality of flexible packages containing fire retarding substance housed in the outer container, and closure means for keeping the flexible packages in the outer container until such time as the closure means are released whereby to allow the flexible packages to drop under gravity from the outer container.

9. An assembly according to claim 8 wherein the outer container comprises a plurality of rigid modules connected together serially.

10. An assembly according to claim 9 wherein the rigid modules each include a hollow tubular portion and wheels.

11. An assembly according to claim 9 or claim 10 wherein opposite ends of the hollow tubular portions are each provided with a flange and the rigid modules are connected together by securing flanges on abutting modules together.

12. An assembly according to claim 8 where the outer container comprises netting.