Which hose line size is most frequently used for interior fire attack?

The size that is most frequently used for interior fire attack is 1 ¾ inches. This hose line diameter strikes a balance between maneuverability, flow capacity, and the ability to deliver a sufficient volume of water to effectively suppress fires in residential and commercial structures.

Using a 1 ¾ inch hose allows firefighters to quickly advance the line into a structure while still providing enough water flow to combat various types of fires. The flow capabilities of this size also make it versatile for different fire conditions, accommodating the need for higher water volumes when facing more intense fires.

In contrast, larger hoses, such as 1 ¼ inches, are generally used for exterior operations or larger commercial fires, where larger volumes of water are required. Smaller hoses, like 1 inch or ½ inch diameters, while they may be used in specific situations, do not provide the necessary flow rates needed for effective interior fire attack. Therefore, the preference for 1 ¾ inches in interior firefighting reflects its practical advantages in real emergency scenarios.