Background of the Invention The inventor is aware of a method of fighting fires in tree plantations wherein a tractor pulls a trailer with a water tank on it spraying water between the rows of trees.

Numerous difficulties have been experienced using this method.

Firstly, due to the paths between the rows of trees not always being of uniform width, tractors with trailers often get wedged between the trees and cannot be moved without considerable effort. Also, if a driver attempts to reverse the tractor's direction of motion, for example to avoid an oncoming fire, the trailer invariably"jack-knifes", again leaving the tractor with the trailer wedged between the trees.

Secondly, the tractor or trailer often becomes stuck on objects such as termite hills, rocks or tree stumps in the paths between the trees due to these objects engaging with the underside of the tractor or trailer. Due to the lack of manoeuvrability of the tractor and trailer, the assembly can again only be freed using considerable effort.

The above difficulties make fighting fires in tree plantations an expensive effort as many tractors and trailers are lost to the fire due to their drivers abandoning them when they get stuck or wedged between trees. This also endangers the lives of the drivers as well as rendering the method an unreliable way of fighting fires.

The inventor therefore believes that a need exists for an apparatus and a method for fighting fires in tree plantations which will not endanger human lives, which will be effective and which will not cause the loss of tractors or trailers.

It is to be understood that the word"pipe"as used in this specification is not limited to a hollow elongate member, nor to a specific diameter or cross-sectional profile.

Summary of the Invention Thus, according to a first aspect of the invention, there is provided a frame which is mountable on a vehicle and which extends beyond the perimeter of said vehicle over a predominant portion of the perimeter.

The frame may be manufactured from piping, beams, sheets, and the like. The frame may be made of any suitable material such as steel or a polymer, having fire retardant or fire inhibiting properties.

The piping may be hollow and of any suitable diameter and is typically of 100mm diameter.

The frame may be configured to be mountable onto a tractor. Equally, the frame may be configured to be mountable onto a trailer, or onto a combination of a tractor and trailer.

The frame may have an upper region describing a perimeter which exceeds that of the perimeter of the vehicle.

The perimeter of the frame may be such that it is substantially oval in plan view.

The frame may include a bow-like section consisting of one or more pipes which may be either straight or bent so as to resemble a bow of a boat. The bow-like section may extend from the upper region of said frame to a lower region of said frame. The bow-like section may be located at the front end and/or the rear end of the frame.

The frame may include a guide means located on the lower region of the frame.

The guide means may be in the form of a guide bar attached to the frame in such a way that it includes the lowest point of the frame and represents the minimum clearance from the surface over which the vehicle may travel.

In a different embodiment the guide bar may be attached to the vehicle independently of the frame.

The guide bar reduces the risk of ensnaring the underside of the vehicle on termite hills, tree stumps, rocks and the like.

The frame may additionally include a guard means which protects the underside of the vehicle onto which said frame is mounted from impact damage and/or becoming ensnared with any objects protruding from the ground and which are in said vehicle's direction of travel.

The guard means may be manufactured from any suitable impact resistant material such as metal or polymer. Typically, the guard means is in the form of a plate, a grid or a mesh.

The upper and lower regions of the frame may be connected by a plurality of pipes which are configured to fit around the vehicle onto which said frame will be mounted so as to form a grid-like barrier around the sides of said vehicle. In one embodiment, plates or sections of plate may be attached to the frame to provide an impact and/or heat resistant barrier for the vehicle.

The frame may consist of a pipe forming an egg-shaped circumference which extends beyond the circumference of vehicle.

The dimensions of the circumference of the frame may be such that it may be mounted onto a trailer which may be configured to carry on it a tank of liquid. The tank is preferably a water tank for fire fighting purposes, but may alternatively be a tank for a liquid herbicide, pesticide, fertilizer or the like for crop spraying.

The tractor may tow the trailer with its frame.

The tractor and the tank on the trailer may be combined so as to form a unit.

In a particularly useful embodiment the frame is configured such that no or few angular portions, capable of becoming ensnared on obstacles, protrude beyond the perimeter of the frame.

In another form of the invention, the panel work of the body of the vehicle may be made similarly to that of the frame i. e. it becomes the integral part of the vehicle and serves the same purpose as the frame to inhibit the vehicle becoming ensnared.

According to a second aspect of the invention, there is provided a vehicle having a frame substantially as described above.

According to a third aspect of the invention, there is provided a method of fighting fires which includes: -driving a water-ferrying vehicle along a path between rows of trees in a plantation or forest; and -deflecting the vehicle off any obstacles along the edges of the path so as to ensure that the vehicle remains substantially on the path formed between the rows of trees.

The obstacles along the edges of the path may be the trees of the rows between which the path extends, in which case, the vehicle is deflected back onto the path.

The method may be performed using an unmanned vehicle.

Detailed Description of the Invention The invention will now be described by way of a non-timiting example with reference to the accompanying drawings, wherein:- Figure 1 shows a side view of one embodiment of the invention wherein the frame is mounted onto both a tractor and a trailer; and Figure 2 shows a top view of one embodiment of the invention as shown in figure 1 wherein the frame is mounted onto both a tractor and a trailer passing between two rows of trees.

In the drawings, reference numeral 10 generally indicates a frame in accordance with the invention.

The frame 10 is mounted onto a tractor 12 and onto a trailer 14 which are connected to each other by means of a tow-bar type arrangement 13.

The trailer 14 carries a tank 15 filled with water.

It is clear from the drawings, that the frame 10 extends beyond the perimeter of the tractor 12 and the trailer 14 over a predominant portion of the perimeter.

The frame 10 is manufactured from piping 16 of any suitable material such as steel or a polymer. The piping 16 may be hollow and of any suitable diameter, although it is typically 100 mm in diameter.

As shown in the drawings, the circumference of the frame 10 is such that it is substantially oval in plan view in the case of the tractor 12 and egg-shaped in plan view in the case of the trailer 14.

The frame 10 includes sections 18.1 and 18.2 consisting of one or more pipes 16 which are bent so as to resemble a bow of a boat which extends from the upper region 20 of the frame 10 to a lower region 22 of the frame 10.

The frame 10 includes a guide bar 24 located on the lower region 22 of the frame 10.

The guide bar 24 is attached to the frame 10 in such a way that its lower region includes the lowest point of the chassis of the tractor 12 and trailer 14.

The guide bar 24 reduces the risk of the underside of the tractor 12 or trailer 14 becoming ensnared on termite hills, tree stumps, rocks and the like which lie in the path of the tractor.

Similarly, the frame 10 also includes a guard means in the form of a plate 26 along the extent of its lower region 22, which protects the underside of the tractor from becoming ensnared with any objects protruding above the ground and which may be in the way of the tractor. The guard plate 26 may be manufactured from any suitable material such as a metal or polymer.

The upper and lower regions 20 and 22 of the frame 10 are connected by a plurality of pipes 16 which are configured to fit around the tractor 12 so as to form a barrier around the sides of the tractor 12.

In accordance with the invention, a fire in a tree plantation may be fought by driving the tractor 12 towing the trailer 14 with the water tank 15 along a path 27 formed between two rows of trees 28.

If the tractor 12 veers of the path 27, then the frame 10 (shown in Figure 1) acts as a deflector, with the arcuate leading edges 11 being to the trees 28, and upon collision, deflecting the tractor 12 back onto the path 27.

The method may be performed using an unmanned tractor 12 as shown in figure 1 or by using a manned tractor 12 (not shown). In such a case, the tractor 12 is left in gear and drives along, being deflected back onto the path 27 whenever it would have veered of the path. This permits the use of a tractor and trailer combination to be used in fire fighting with a reduced risk of injury to staff and loss of equipment.

The tractor and trailer may additionally be used in orchards, vineyards and the like to spray crops with liquid pesticides, herbicides and/or fertilisers. The oval or egg- shaped configuration of the frames surrounding the tractor and trailer are advantageous in that if the tractor or trailer hits any vegetation, for example, branches of fruit trees, then the branches will be deflected from the frames and will be less likely to break.

It is to be understood that the frame described above is not limited to the specific embodiment described and that it is not limited to being mountable onto tractors and trailers only.