Operating a fire truck pump is one of the most critical tasks for a firefighter during an emergency. Proper use of the pump ensures a continuous and reliable water supply to extinguish fires effectively. Whether you’re a trainee firefighter or just curious about fire service operations, understanding how to pump a fire truck involves learning about its components, the setup process, and step-by-step operational procedures. In this article, we’ll walk you through the essential steps and considerations involved in pumping a fire truck safely and effectively.
Understanding the Fire Pump System
Before operating the pump, it’s important to understand the basic components of a fire truck’s pump system. Most modern fire trucks are equipped with a centrifugal pump, which uses centrifugal force to move water under pressure.
Key Components:
Pump Panel: The control center for operating the pump. It includes gauges, valves, throttles, and switches.
Intake Valves: Where water is drawn into the pump, either from a hydrant, tank, or draft source.
Discharge Valves: Control water flow to various hose lines.
Primer Pump: Helps evacuate air from the pump and suction hose to allow water to flow during drafting.
Tank-to-Pump Valve: Connects the onboard water tank to the pump.
Understanding these components is vital before initiating pump operations.
Preparing the Fire Truck for Pump Operation
Proper preparation helps prevent equipment damage and ensures the safety of firefighters.
1. Position the Apparatus
Position the truck close to the water source (hydrant, pond, or portable tank) and on stable ground. Ensure the parking brake is engaged and the wheels are chocked to prevent rolling.
2. Engage the Pump
Modern fire trucks use a Power Take-Off (PTO) system or a transmission-mounted pump. Engaging the pump involves shifting the truck into pump gear.
Steps to Engage the Pump:
Shift the transmission to neutral.
Activate the pump switch in the cab.
Wait for the indicator to confirm the pump is engaged.
Shift the transmission to drive (if applicable, some trucks require this for PTO engagement).
Always refer to the truck’s operating manual, as procedures can vary by manufacturer.
Priming the Pump (For Drafting Operations)
When pulling water from a static source (e.g., pond or portable tank), priming is essential to remove air and create vacuum pressure.
Priming Procedure:
Ensure the hard suction hose is tightly connected to the intake and submerged in the water source.
Close the tank-to-pump valve to prevent air leaks.
Open the suction-side valve.
Activate the primer pump. It may be electric or manual.
Watch for a steady rise in pump pressure (usually around 30 seconds or less).
Once water is flowing steadily, turn off the primer.
Never run the primer for more than 45 seconds continuously to avoid damage.
Supplying Water to the Pump
Water can be supplied from 3 main sources:
1. Onboard Tank
Open the tank-to-pump valve.
Water flows immediately into the pump, useful for a rapid initial attack.
Monitor tank level closely and switch to an external source before it runs dry.
2. Hydrant Supply
Connect a supply hose to the intake valve.
Ensure the hydrant is fully opened.
Bleed air from the hose before opening the intake valve.
3. Drafting (Static Source)
Use a hard suction hose and primer as discussed.
Requires more attention to air leaks and strainer positioning.
Operating the Pump Panel
Once the water source is secure, use the pump panel to regulate pressure and flow to the hose lines.
Key Operations:
1. Throttle Control
Increases or decreases engine RPM to control pump pressure.
Start with idle speed and gradually raise to achieve the desired pressure (typically 100–150 psi, depending on the situation).
2. Discharge Valves
Open specific valves to send water to designated attack lines.
Control each line independently to match operational needs.
If the pump is running but not discharging water, activate the pump cooler to prevent overheating.
5. Tank Fill and Recirculation
Use the tank fill valve to return water to the tank and maintain circulation when hoses aren’t flowing water.
Prevents pump overheating and stagnation.
Maintaining Pump Pressure and Flow
A successful pump operation involves constant monitoring and adjustment.
Best Practices:
Communicate with the nozzle operators for flow rate needs.
Avoid sudden throttle changes to prevent pressure surges.
Monitor for kinks, blockages, or hose bursts.
Switch water sources smoothly—don’t let the pump run dry.
Pumping Multiple Lines:
Use pressure governors or relief valves to manage variable loads.
Balance pressures across multiple discharges.
Prioritize supply to critical attack lines during water shortages.
Shutting Down the Pump
Proper shutdown is as important as startup to avoid damage and ensure safety.
Shutdown Steps:
Gradually reduce the throttle to idle.
Close discharge valves slowly.
If drafting, open the tank-to-pump valve to allow residual water to circulate.
Disengage the pump and place the transmission in neutral.
Drain water from the pump if freezing conditions are expected.
Troubleshooting Common Issues
Loss of Prime:
Reprime the pump and check all connections for air leaks.
Cavitation:
Occurs when intake pressure drops too low.
Reduce discharge pressure or throttle down.
Overheating:
Activate the pump cooler or tank fill to recirculate water.
Air in the Lines:
Bleed air from discharge valves and recheck suction hose connections.
Final Thoughts
Pumping a fire truck is both a science and an art that demands training, practice, and attentiveness. Each incident is unique, and pump operators must adapt to changing circumstances on the fly. Mastering the fundamentals of pump operation not only ensures efficient firefighting but also protects valuable equipment and lives. Whether you’re working with a hydrant, onboard tank, or drafting source, the keys to success are preparation, control, communication, and safety.
