Machinery for forest fire prevention

Maintenance work on forest areas, such as fire tracks, among others, is increasingly important in light of climate changes. These increase temperatures and reduce rainfall, exposing forest canopies to fire risk. A wide range of specialized machinery and equipment is the necessary support for prevention efforts

The climate change phenomenon appears to have a noteworthy influence on forest fires as well. This phenomenon can be most likely linked to the rise in average temperatures, the tropicalization of formerly temperate areas and the increase in many areas of extended periods of extreme heat with little rain.

Last summer alone, in Italy, with maximum temperatures touching as high as 45 °C in some areas, we, unfortunately, saw more than 20,000 hectares of land burn in Sardinia, with forests, olive groves and cultivated fields wholly reduced to ashes and nearly 1,500 people displaced. Sad to note then those things are not much better in the world either: in the same period, there have been exceptionally large and devastating fires in Siberia, Canada, California, Greece, Turkey, the Amazon, Australia, and several African countries. However, according to estimates provided by the WWF, in the United States alone, in the last 40 years, the number of fires has increased by 1000%. In short, planet Earth is burning, and this is confirmed by an eloquent image released by Nasa’s Fire Information for Resource Management System showing all the places on our planet that are currently affected by wildfires. (Photo: Nasa fires map)

A forest fire is still a severe phenomenon that can have natural or anthropogenic causes. In both cases, it is a spreading firefront that causes damage to vegetation and sometimes even human settlements. In the latter case, when the fire is close to houses, buildings, or public places, it is referred to as an "interface fire." In addition to severe damage to the environment and infrastructure, there is the risk of counting casualties due to the fire.

In Italy, and according to Article 2 of Law No. 353 of 2000, a "forest fire" is a fire that tends to spread over wooded, bushy, or arboreal areas, including any manufactured structures and infrastructure located within the same areas or over cultivated or uncultivated land and pastureland adjoining the areas. The same law entrusts the regions with the responsibility for forecasting, preventing and actively fighting forest fires, while the State is responsible for assisting in extinguishing activities using the State's aerial firefighting fleet.

Although all Italian regions are affected by forest fires, some are more severely hit than others. Basically, it is possible to say that the different climatic conditions of the peninsula facilitate the development of fires mainly in two seasons in the year. On the Alpine arc and at the higher altitudes of the Apennine areas, forest fires develop primarily in the winter and spring seasons. On the contrary, the central and southern regions having a Mediterranean climate are mainly affected by this disastrous phenomenon in the summer season, which is commonly hot and dry.

However, forest fires in Italy and around the world are a phenomenon that, although it cannot be eliminated, can nevertheless be somewhat curbed in its expansion. This can be done by resorting to the common firefighting means used to extinguish the firefront and, above all, to the appropriate prevention techniques. These are summarized in implementing a series of fire lines (or avenues or tracks), i.e., corridors carved within forests and natural areas that are artificially stripped of their natural vegetated cover.

These works aim to contain a possible fire within a delimited area, but it is also valuable for wildlife because it is, in fact, also a corridor through which they can quickly take cover from the advancing flame front. It is also helpful to rescue teams who can use this artificial corridor to extinguish the fire more efficiently and more quickly and also carry out subsequent maintenance, and vegetation restoration works in the areas affected by the fire. 

These works are usually carried out within the forested areas, throughout their length, width, and depth. They must be perpendicular to each other and must be maintained, keeping them clear of shrubs, dry grass, and flammable materials at least a couple of times a year. As a rule, to maximize their effectiveness, avenue systems are set up with the main ridge, perpendicular to the prevailing winds, which are joined by secondary avenues, dividing the forest into sectors, preferentially made on the displuves.

In the United States, thanks to the 'experience gained in California for several decades now, the creation of these firebreaks has become a well-established practice, so much so that they have been made mandatory by special laws, also to prevent fires at the borders of residential and industrial settlements, along roads, railroads, but also at the edges of cultivated fields. After harvesting crops, it is mandatory to leave swaths clear of flammable materials, and inspections (with associated penalties) by law enforcement agencies are quite frequent and timely, even with advanced technologies such as satellite photos.

Yet these works of naturalistic engineering are an Italian invention; in fact, the first firebreaks were constructed two centuries ago by the Grand Duke of Tuscany. For the firebreak to be suitable for permanently stopping any fire, it is necessary to eliminate the vegetation with considerable width lines. This width can vary, depending on the site's characteristics, between 100 and 200 m.

Unfortunately, very often, the creation of these firebreaks is opposed by environmentalists, who are opposed to the carrying out of any kind of manufactured intervention in wilderness areas, when in fact, it is now clear and proven that they are remarkably effective for the long-term preservation of larger forests and the wildlife living in them. This is why they are not so widespread in the world, and we often end up having to create fire lines by operating in a "state of emergency," that is, with the fire that has already broken out.

Well, it is self-evident that by operating in a preventive manner, it is possible to carry out the work more calmly and recover the resulting woody material to enhance it as construction timber or combustible material properly. Conversely, when operating in an emergency, it is necessary to achieve the highest possible productivity to create fire lines very quickly to contain the advance of the flame front. In addition, there are difficult operating conditions and hard-to-reach areas that the retrieval of the waste material would become uneconomical anyway. Therefore, in most cases, it is a matter of intervening with forestry mulchers, i.e., conducting a seemingly simple task, which can, however, suddenly turn into a job impossible to perform if the appropriate machinery is not available. Vegetation, sometimes very dense, often conceals unexpected obstacles such as stumps, boulders, or outcropping rock slabs. Therefore, it is vital to be equipped with machinery specifically manufactured to work in the harshest conditions to avoid nasty surprises.

Thus, it is a matter of employing robust forestry mulchers, which are machines characterized by a high and highly variable power demand over time according to the prevailing type of material to be crushed, the working depth, and the forward speed.

Many domestic manufacturers are offering valuable machinery operating in this particular sector which offer industry professionals a comprehensive and varied package of solutions. These include models with mechanical drive (for tractors from 100 to over 600 Hp), or hydraulic drive, which are in this case suitable for coupling with skid steer loaders, excavators, or special dedicated vehicles.

A highly robust structure characterizes them, and they usually exert considerable stress on the tractor to which they are attached. Furthermore, these heavy machines require significant power and operate at low speeds.

Forestry flail mowers are usually carried by the three-point hitch.

They derive their motion from the splined male of the PTO through the classic cardan shaft, which must be generously sized and equipped with overload protection devices. Forestry flail mowers are usually carried by the three-point hitch.

They derive their motion from the splined male of the PTO through the classic cardan shaft, which must be generously sized and equipped with overload protection devices.

Their main organ is a heavy rotor located transverse to the direction of travel that carries, mounted on them, the tools providing crushing.

These tools are made up of distinct types and sizes depending on the manufacturers and the kinds of hardness of the material they can reach to crush. In some rare cases, these tools may be hinged to the rotor, but in most cases (and for the heaviest applications), we are dealing with rigidly fixed tools.

In any case, the parts in contact with the material to be shredded are made of very wear-resistant materials. It is also common to use very high-grade wear-resistant steel to ensure high reliability.

Fixed "tooth" working organs are usually used for the heaviest uses.

They may have a flat or pointed profile, and in some cases, they even go as far as to use diamond end caps. In such cases, the machine can also operate on solid rock. However, it is necessary in this case to foresee a certain amount of wear and tear on the working parts, a decrease in forwarding speed and a conspicuous increase in energy requirements.

To complete the work of the working parts, a crushing chamber is provided, often represented by the sturdy casing above them, usually supplied with a coating of wear-resistant material.

This hood can, in some cases, be provided with hydraulic adjustment to be able to vary its distance from the working organs. In this way, it is then possible to change the average size of the material resulting from crushing accordingly.

To amplify the operational capabilities of these machines to the maximum, the safety for the operators, and also to enable them to operate very close to the flame front, special self-propelled tracked vehicles have also been designed, which can, in some cases, also be driven remotely by remote control.