Smoking may cause fires accidentally when they are not disposed off properly such as the improper disposal of cigarette butts. Embers that fall off a cigarette call a dropped light is also a probable cause. The fuel source must be dry and powdery in order for the easy ignition of the fuel. For such fires to occur, the moisture content of the fuel needs to be below 25%.
Sunlight may be refracted by certain shiny or transparent materials such as glass or metal. The converging of such rays may cause intense heat on fuel. The concave surface of such a metal can cause the light rays to converge but this cause of fire is highly unlikely due to its short focal length.
Machinery and Vehicles
Heat may be produced from vehicles either by providing easily combustible fuel or an ignition source such as overheated pars, burning carbon, fuel leaks, vapors and spills and friction. A more detailed elaboration will be made in the section on Motor vehicle fires. The most common causes of such fires will be to provide ignition temperatures, such as sparks, in its operation when operated near to combustible vegetation. Railroads can also contribute to the fire potential by exhaust carbon, hot brake metal or overheated wheel bearings called the hotbox.
Trees may accidentally come into contact with power lines, this would cause the portion of the tree to ignite. The burning portions may the fall to the ground subsequently igniting the dry vegetation or any other fuel on the ground. Another probable cause would be the conductors coming into contact with each other in the presence of a powerful windstorm, this would cause a hot metal globule to be created which ignites fuel on the ground when it drips.
Other than power lines, transformers may have short circuits and malfunction, resulting overheated or molten metal falling. Underground cables might also have been damaged by digging operations or heavy equipment thus resulting in a fire. The role of animals must not be forgotten as well as animals may have come into contact with equipment and caused it the short out and catch fire, falling into nearby fuel.