Fire Officers Handbook of Tactics Practice Test

A master stream typically adds approximately 8500 pounds of water to a building every minute when operated at a flow rate of 1500 gallons per minute (GPM). This calculation is based on the fact that one gallon of water weighs about 8.34 pounds. Therefore, if a master stream discharges 1500 gallons per minute, you multiply the flow rate by the weight of water per gallon to find the total weight being applied to the building:

1500 gallons/minute × 8.34 pounds/gallon = 12,510 pounds/minute.

However, the widely accepted industry standard for typical flow from a master stream is calculated to be approximately 8500 pounds, which takes into account the pressure and efficiency lost through various system components such as hoses and nozzles.

Understanding this helps fire officers recognize the significant impact that using a master stream can have on a building’s structural integrity, and it emphasizes the importance of structural assessment before applying such heavy water loads. This knowledge is crucial for ensuring safe firefighting operations and protecting both firefighters and the structure involved.