Ch13 Set 09: Master-Stream Devices

When are master-stream devices generally deployed?

When fire exceeds handline effectiveness or water must be applied where firefighters cannot safely work.

Why is master-stream placement important?

It must provide effective reach and penetration; repositioning is labor-intensive and interrupts operation.

What movement is possible while a master-stream device operates?

The nozzle can aim up, down, or sideways; shut down before relocating the device.

What entry angle does the outline recommend for a master stream into a structure?

An upward angle to deflect off ceilings or overhead objects and distribute smaller droplets over the fire.

How should master streams be positioned for broad coverage?

Choose locations covering the greatest building surface area and allowing aim into multiple openings.

How are master streams used for exposure protection?

Wet the surface facing the fire so water runs down it; use multiple devices or sweep one across a wide exposure.

What minimum master-stream operating flow does the operations section state?

350 gpm; master streams are described as more than 350 gpm.

What is a typical minimum conventional master-stream supply arrangement?

Two 2½-inch lines; a single line may serve temporarily while more are added.

How can a master stream receive additional water?

Add a third 2½-inch line or LDH; some devices accept a single 4-inch or larger supply line.

What structural danger can master-stream water create?

Water accumulating on floors or absorbed by contents adds weight and increases collapse risk.

How many firefighters generally deploy and operate a master-stream device?

At least two to deploy the device and supply lines, except apparatus-mounted deck guns.

Why should a firefighter normally remain at a flowing master-stream device?

To redirect the stream and prevent hose pressure moving the device.

When may personnel withdraw from a master-stream device?

When its position is hazardous, such as near a weakened wall or LPG tank.

What can the pump operator do if an anchored master-stream device begins moving?

Decrease pressure at the apparatus.

What are elevated master streams used for?

Upper-floor attack, supplying handlines, and protecting exposed structures.

What apparatus commonly provide elevated master streams?

Quints, aerial ladders, and aerial platforms.