What is a master stream device that is permanently mounted on a vehicle and piped called?

A deck gun is a type of master stream device that is permanently mounted on a fire apparatus, such as a fire engine or ladder truck, and is piped into the vehicle's water system. This allows for a consistent and high-volume stream of water to be deployed rapidly directly from the vehicle, providing firefighters with the ability to extinguish fires effectively from a fixed position.

Deck guns can be operated remotely, allowing for precise aiming and control of the water stream, which is especially beneficial in firefighting scenarios where mobility may be restricted or where a higher elevation is required to reach the fire. Their design typically includes a swivel function to direct the flow of water efficiently across a wide area, making them a vital tool in combating large-scale fires.

While a monitor also refers to a device that directs water, the term is more commonly associated with portable units. Playpipes are typically handheld devices used by firefighters to create a master stream but are not permanently mounted. A Fire Department Connection (FDC) pertains to the system that allows external water sources to connect to a building’s standpipe or sprinkler system, rather than being a water delivery device itself.