Four Factors for Stretching the Initial Attack Hoseline

One of the most important, if not the most important aspect of structural firefighting is getting a sufficient amount of water for an attack on the seat of the fire. The initial arriving engine company must select the correct attack line for this...


FIRE LOAD – This is by far the most important consideration during the initial size-up. What is the smoke telling you? Are there signs of pending flashover or backdraft? What about the fuel load within the building? There used to be a time where most residential fires could be contained with the use of 1½-inch or 1¾-inch handlines, but now with the “”starter castles” that we see today, that is not the case. Today’s residential dwellings are almost three times the square footage of the legacy dwellings that preceded them (photo 3). More space equates to more fuel within the compartment, which results in a higher Heat Release Rate (HRR) within the building. Furthermore, today’s fuels are significantly higher in producing heat energy, as more contain hydrocarbon-based fuels rather than natural fiber fuels. The result is a rate of heat release that has exponentially risen in residential dwellings, requiring more water and faster delivery times to achieve extinguishment. For offensive attacks on the fire within the structure, many use the National Fire Academy Formula for needed fire flow (Length x Width/3 x % involvement) to determine needed gallons per minute (GPM) application from attack lines. Without this data, many interior operations come up short in BTU absorption, requiring transitions from offensive attacks to defensive operations.

 

Suppression Support

Stretching a back-up handline is critical to the overall success of the operation, but they can only support the suppression effort when they are placed into operation (photo 4). Most times, the back-up lines stay on the hose bed, and when they are needed, critical time lost trying to play catch-up usually results in a change of operational modes (defensive). Opinions vary on what characteristics officers list for back-up suppression lines; most will say that back-up lines should be of equal diameter and length as the initial attack line. But consider this: why would the back-up line have to be placed into operation? Three answers come to mind;

1. The initial line cannot get into position, for whatever reason, allowing the fire to increase exponentially (photo 5)

2. The IC’s initial calculation for BTU absorption will not provide adequate knockdown of the fire

3. The stretch to the seat of the fire came up short; pre-connects are truly convenient, but they are not always the best option.

These three scenarios can lead to disastrous results; therefore, I would recommend that back-up lines be at least one size larger in diameter, and at least one length longer in reach. This provides a higher GPM flow to compensate for an inaccurate flow calculation, and can cover the floor above to check for extension in the event the initial attack line has a good handle on the fire.

 

Conclusion

Initial arriving companies will set the tone for successful operations on the fireground. Pre-planning your response area will aid in determining needed fire flow well before the emergency. Armed with this information, crews can place the right line into operation, providing for a safer, more efficient emergency scene, as well as limiting property damage and loss to the people we are sworn to protect.

Until next time, stay focused and stay safe.

 

See Mike Live! Lt. Michael Daley will be presenting “Basement Fires” and “Strategies and Tactics for Fires in Attics and Cocklofts” at Firehouse Expo in Baltimore, July 23 - 27.

MICHAEL P. DALEY is a lieutenant and training officer with the Monroe Township, NJ, Fire District No. 3, and is an instructor with the Middlesex County Fire Academy, where he is responsible for rescue training curriculum development. Mike has an extensive background in fire service operations and holds degrees in business management and public safety administration. Mike serves as a rescue officer with the New Jersey Urban Search and Rescue Task Force 1 and is a managing member for Fire Service Performance Concepts, a consultant group that provides assistance and support to fire departments with their training programs and course development. You can reach Michael by e-mail at:FSEducator@aol.com.