What is relay pumping?

• A. Using a single pump to move water directly to the nozzle.
• B. Using auxiliary power to pressurize the water within the hoses.
• C. Using successive pumps to move water from the source to the nozzle, maintaining pressure.
• D. Priming a pump by manually filling the suction.

Answer: (C)

Relay pumping is moving water from the source to the fire scene by using several pumps in sequence, with each engine boosting the pressure as water passes from one to the next. This approach overcomes big friction losses and elevation changes over long hose lays, so the final attack line arrives with enough pressure and flow to reach the nozzle. The first pump draws from the water source and discharges into the next pump, which then adds more pressure to push the water further, and so on until the nozzle is supplied. This is different from relying on a single pump for the entire distance, from using extra devices to pressurize hoses, or from simply priming a pump to start suction—those scenarios don’t describe multiple pumps working in tandem to maintain pressure along a supply chain.