In which type(s) of operations are master stream devices used?

Master stream devices are typically utilized in defensive operations but can also be used in offensive situations. These devices, which include aerial streams or large-diameter hoses, are designed for delivering large volumes of water, making them highly effective for controlling and extinguishing large fires that may be beyond the capacity of handlines.

In defensive operations, the goal is often to protect exposures and prevent the fire from spreading, especially when it is too dangerous to enter the structure. The ability to project a significant amount of water from a distance helps protect firefighters and other structures in the vicinity.

In offensive operations, master streams may be employed when firefighters need to rapidly gain control of a significant fire, particularly in denser smoke or within a mixed occupancy where visibility and access are limited. However, their use in offensive maneuvers is not as common, as firefighters typically rely on smaller handlines for more direct attack strategies inside the building.

Therefore, the key reason for choosing the response focusing on typically defensive but occasionally offensive use is that it accurately reflects the operational intent behind when master streams are most effectively deployed.