What are observable indicators that a fire stream has been properly applied?

When assessing the effectiveness of a fire stream, observable indicators are crucial for determining whether the fire suppression efforts are successful. In this context, flames retreating is a clear and significant indicator that the fire stream has been properly applied. This observation suggests that the fire is being controlled or extinguished, as the heat and combustion process is being disrupted by the application of water or fire suppressant.

When flames begin to retreat, it indicates that the cooling effect of the water is working to lower the temperature of the fire, thereby suppressing it. It reflects an immediate response to the application of the fire stream, demonstrating proper technique and positioning of the hose, as well as an effective choice of method in engaging the fire.

In contrast, other options such as increased fire intensity or hose kinking do not provide positive or valid indicators of effective firefighting actions. Increased fire intensity would suggest that the fire is worsening, thus showing that the stream is not properly applied or effective. Steam production could be an indicator of effective cooling but may not directly relate to the immediate success of suppressing the flames as visibly as flames retreating. Hose kinking would point to a problem with the operation of the firefighting equipment, impeding effective water flow. Hence, the observation of