We have all seen it on the fireground: a fire requiring more than one pumper to extinguish. There are several methods firefighters use to supply these pumpers. The use of multiple supply lines is one method; this is almost a must when each pumper is moving large amounts of water. But what about the fires that for whatever reason require more than one pumper, but the flows are kept reasonably low? Sure, each pumper could bring in it’s own supply line, but is this the most efficient way to operate? More hose will be needed and depending on where the hydrants are located, and this could require a large amount of hose.
The best way to share water between pumpers on the fireground is with a dual pump operation. With dual pumping, one hydrant, especially a strong one, can be used to supply two or more pumpers. In this operation water is shared between the pumpers by connecting a supply line from the unused intake of the pumper connected to the supply line from the hydrant to the intake of the next pumper. Because of the design of the centrifugal pump, any water not used by the first pump will be passed through the impeller and directed out the opposite intake under hydrant pressure. It is this same hydrant pressure that will than move the water through the supply line between the pumpers, thus allowing the water to be shared.
Paul Shapiro is Director of Fire Flow Technology. He is a nationally recognized instructor on large flow water delivery. He is also a retired engineer from the City of Las Vegas (NV) Fire Department. Paul has authored numerous articles for fire trade magazines. He has been in the fire service since 1981 and is author of the popular book Layin’ the Big Lines and produced the first in a series of videos on large flow water delivery. Paul can be reached at 702-293-5150 or Layinline @aol.com to answer any questions.