Hydrant Relay

What Is Hydrant Relay?

A hydrant relay involves the coordinated operation of multiple fire apparatus, typically pumpers, to transport water from a remote hydrant to the fire scene. Each pumper in the relay enhances the pressure and flow of water, ensuring that adequate supply reaches the incident location, particularly in situations where the fireground is not directly accessible to hydrants. Relay setups often transport 1000+ GPM through 5-inch LDH over distances exceeding 3000 feet.

Why Hydrant Relay Matters on the Fireground

Hydrant relays are crucial for maintaining effective water supply during firefighting operations, especially in urban environments where hydrants may be spaced far apart. This method ensures that firefighters can effectively combat fires in a timely manner, even when faced with challenging terrain or extended distances.

Relevant NFPA Standards

• NFPA 1900: Standard for Aircraft Rescue and Firefighting Vehicles, Automotive Fire Apparatus, Wildland Fire Apparatus, and Automotive Ambulances
• NFPA 1010: Standard on Professional Qualifications for Firefighters

Field Procedures & Tactical Steps

1. Position primary source engine at the water supply point and lay large diameter hose (LDH).
2. Establish inline relay engines at calculated friction loss intervals (typically 800-1000 ft).
3. Maintain 20 PSI residual intake pressure on receiving pumpers during throttle adjustment.
4. Coordinate engine RPM and discharge pressure via dedicated water supply radio channel.

Common Context & Application

Relay pumping operations link multiple engine companies in series to move water over long distances when mains or hydrants are remote.

Frequently Asked Questions about Hydrant Relay