Which nozzle produces a hollow stream concentrated in a small area?

The smooth bore nozzle is designed to produce a hollow stream of water that is concentrated in a small area, allowing the firefighter to achieve maximum reach and penetration when extinguishing fires. This type of nozzle creates a solid stream that minimizes the amount of water lost to evaporation and wind, making it highly effective for certain suppression tactics, especially for exterior firefighting or in situations where accurate targeting of fires is essential.

The streamlined shape of the nozzle allows for more efficient passage of water, resulting in a powerful, well-defined jet that can penetrate deeper into the fire's core. This feature is particularly useful in structural firefighting where it can reach well into a confined space or heavy smoke with precision.

The other types of nozzles serve different purposes. The fog nozzle, for example, disperses water into a spray pattern for greater coverage and cooling effect, while adjustable and variable stream nozzles are designed to change the flow and pattern depending on the needs of the situation but do not concentrate the stream in the same way a smooth bore nozzle does.