Whitepaper: Timothy Herrick (Wildland Program Director, Maui (HI) Fire Department), Jack Smith (Chairman, R&D, Maui Fire Department), Gavin Fujioka (Deputy Fire Chief, Maui Fire Department)
This white paper presents findings from a series of live fire tests comparing combination fog nozzles (“Fog”) to combination blade nozzles (“Blade”) for fire suppression. Flow rates, ease of use, nozzle operator mobility, and overall fire suppression effectiveness were assessed using both video and thermal imaging. Results show that a Blade nozzle with 45 GPM flow offers superior maneuverability, ground saturation, and fire control compared to Fog nozzles, while also featuring simpler operational controls. Moreover, these Blade nozzles not only enhance fire suppression effectiveness but also broaden firefighting capabilities by delivering strong performance at lower GPM. The FirePro 300 Thermal Imaging Camera (TIC) was similarly evaluated, highlighting its role in identifying hidden hot spots and ensuring thorough fire containment. Collectively, these findings suggest that transitioning to a 45 GPM Blade nozzle can significantly improve firefighting efficiency and safety.
1. Introduction
Fire dynamics have changed drastically in the past two decades, contributing to an increase in large-scale, destructive “megafires” worldwide. To meet this evolving threat, fire suppression tools and methods must also advance. Among the most critical tools are nozzles, which directly influence water flow rate, stream reach, fire knockdown power, and ease of handling.
Recent innovations in nozzle design focus on optimizing flow characteristics, reducing firefighter fatigue, and enhancing the simplicity of pattern adjustments. Combination Blade nozzles (“Blade”) are designed for extended reach, strong penetration, and minimal wind deflection. Their patterns can be adjusted from a wide “blade” to a straight stream with a simple twist.
To assess these nozzles in realistic conditions, a series of live burn tests were conducted. Video of the tests is available at this link: https://vimeo.com/881255417. Test scenarios included:
- Grass Fire Tests
- Side-by-side: Combination Fog Nozzle (60 GPM) vs. Combination Blade (45 GPM).
- Side-by-side: Combination Blade (45 GPM) vs. Combination Blade (20 GPM).
- Pallet Fire Tests
- Side-by-side: Combination Fog Nozzle (60 GPM) vs. Combination Blade (45 GPM).
- Side-by-side: Combination Blade (45 GPM) vs. Combination Blade (20 GPM).
In addition, a FirePRO 300 TIC by SEEK Thermal was used for post-fire assessment of hot spots. This paper examines the methods, outcomes, and practical implications of these tests, offering insights for agencies seeking to adopt new nozzle technologies and leverage thermal imaging effectively.
2. Methodology
- Equipment and Setup
- Apparatus
NIMS Type 6 Brush Trucks “Minis” that hold between 300-500gal of water/Class A foam.
- Nozzles Tested
- Combination Fog Nozzle (Ultimatic)
- Combination Blade Nozzle – 45 GPM (HEN Blade-45)
- Combination Blade Nozzle – 20 GPM (HEN Blade-20)
- Hoses and Pressure
Each test was performed with 300 feet of 1.5-inch single-jacket hose. Nozzle pressure was standardized at 100 psi, with the bale (valve) fully open. - Flow Tests
Prior to live fire testing, each nozzle underwent a flow test at 100 psi:- Ultimatic: 66 GPM
- HEN Blade-45: 41 GPM
- HEN Blade-20: No reading (the flow meter’s 30–500 GPM range could not accurately measure lower flows)
- Test Fire Parameters
- Grass fires were ignited under controlled conditions to simulate typical wildland fire behavior.
- Pallet fires were used to represent structural, or Class A fuel loads, permitting observation of flame knockdown, smoke conditions, and cooling.
- Operating Personnel
The same experienced nozzle operator (Firefighter J. Souki) was used throughout the tests to minimize variability. Additional observers—members of the Wildland cadre and other fire service professionals—provided qualitative feedback.
2.2 Procedure for Each Test Burn
- Ignition and Stabilization
Each grass or pallet fire was ignited and allowed to develop sufficient flame height and spread to mimic realistic firefighting conditions. - Nozzle Engagement
The nozzle operator approached the fire and applied water consistent with wildland or structural tactics:- Grass fires: Rapid sweeping and short bursts for flame-front knockdown.
- Pallet fires: More concentrated streams at the base and seat of the fire.
- Observation and Documentation
Observers recorded:- Time to knock down flames
- Smoke conditions
- Water penetration (fuel saturation)
- Operator mobility
Video recordings captured side-by-side perspectives for direct comparison. Available at this link: https://vimeo.com/881255417
- Post-Fire Inspection
During mop-up, the FirePRO 300 TIC was used to detect hot spots around the burn perimeter. Observers and the Incident Commander (IC) used TIC data to confirm containment and extinguishment.
3. Results and Observations
3.1 Grass Fire Test Comparisons
3.1.1 Ultimatic vs. HEN Blade-45
- Mobility and Maneuverability
The HEN Blade-45’s flow (41 GPM vs. 66 GPM for the Ultimatic) did not hinder effectiveness. Its design and manageable reaction force allowed the nozzle operator to move more quickly across uneven terrain, reducing fatigue. - Knockdown Power and Saturation
Despite lower flow, the Blade-45 effectively extinguished flames and cooled the ground. Observers noted a distinctive “quenching” sound, likely from improved water penetration into light, flashy fuels. - Stream Reach and Pattern Adjustability
The Blade-45 requires a 1/4 turn to switch from solid to blade (fan) stream. The Ultimatic requires a 3/4 turn through multiple settings (flush, wide fog, straight stream). The Blade-45’s simplified mechanism led to faster transitions and minimized confusion in fast-moving wildland environments.
Following image shows comparison between Combination blade nozzle and Combination fog nozzle for grass fire:
3.1.2 HEN Blade-45 vs. HEN Blade-20
- Flow Rate
The Blade-20 is engineered for lower GPM, though its exact flow could not be verified due to measurement constraints. Visually, it produced a smaller stream, potentially aiding in water conservation but less suitable for large-scale firefighting. - Knockdown and Saturation
The Blade-45 offered stronger knockdown power and more thorough ground saturation. The Blade-20 may excel in smaller brush fires or mop-up, while the Blade-45 is more suitable for initial attack on larger wildland fires. - Ease of Use
Both Blade nozzles share a simple 1/4 turn adjustment. Performance differences primarily stemmed from flow volume and stream reach.
Overall, in grass fire scenarios, the Blade-45 provided faster flame knockdown and more effective ground coverage compared to the Ultimatic (fog nozzle) and the lower-flow Blade-20. The following image shows Combination fog nozzle vs Combination blade nozzle.
Figure 1: (A) Ultimatic in straight stream mode. (B) Ultimatic in fog mode. (C) HEN Blade-20 GPM nozzle. (D) HEN Blade-45 GPM nozzle. Field data showed that wide concentrated edge of Combination blade nozzle, flowing 41 GPM provided superior suppression as compared to Combination fog nozzle at 66 GPM. This increased fire suppression effectiveness and lower GPM extended the firefighting capabilities with HEN Blade-45.
3.2 Pallet Fire Test Comparisons
3.2.1 Ultimatic vs. HEN Blade-45
- Heat and Smoke Reduction
Observers noted that the Blade-45 suppressed smoke more rapidly. Its blade pattern efficiently coated and cooled the pallets, offering a strong initial knockdown. - Pattern Adjustments
The Blade-45’s 1/4 turn from solid to blade pattern allowed firefighters to quickly choose a focused solid stream or wider blade for smoke reduction. In contrast, the Ultimatic’s more extensive rotation slowed operator response.
3.2.2 HEN Blade-45 vs. HEN Blade-20
- Fire Size and Flow Requirements
When dealing with substantial fuel loads (e.g., pallet stacks), flow rate is paramount. The Blade-45’s 41 GPM proved more effective than the Blade-20’s lower flow. - Firefighter Feedback
While both nozzles share the 1/4 turn adjustment, the Blade-45’s higher knockdown power made it the go-to choice for larger Class A fires. The Blade-20 remained adequate for smaller incidents or secondary use.
Following figure shows test setup to compare Combination blade nozzle and combination fog nozzles.
Figure 2: Pallet fire suppression analysis. Left: Combination fog nozzle; Right: Combination blade nozzle.
4. Discussion
4.1 Operational Advantages
- Mobility and Speed
In wildland firefighting, rapid movement to chase a fire head is critical. The Blade-45’s balanced flow and reduced reaction force aided swift, low-fatigue operations. - Stream Effectiveness
Although the Ultimatic provided a higher flow rate, the Blade-45’s targeted application and simplified pattern adjustment proved more operationally effective. - Simplicity and Training
With only a 1/4 turn required to switch patterns, the Blade-45 reduces the risk of human error under stressful conditions. The Ultimatic’s 3/4 turn and multiple settings can confuse even experienced operators, costing valuable time. Simplified controls also reduce training requirements.
4.2 Real-World Validation: Mahinahina Fire
On November 4, 2023, the HEN Blade-45 was used at a wildland fire in Mahinahina. Several firefighters, new to the nozzle, praised its knockdown power and ease of use. A single pass along the fire line successfully controlled the flames and cooled the ground. This incident corroborates test findings, solidifying the Blade-45’s status as an ideal option for wildland initial attack.
5. Thermal Imaging Enhancements
5.1 Use of the FirePRO 300 TIC
Throughout mop-up operations, the FirePRO 300 TIC by SEEK Thermal helped firefighters identify hidden hot spots undetectable by sight alone. Targeted water applications ensured complete extinguishment, leading the Incident Commander to declare the fire fully contained with greater confidence.
Key features of the FirePRO 300 TIC include:
- High-Resolution Imaging: Identifies subtle temperature differentials.
- Lightweight Design: Facilitates easy transport and shared usage.
- Enhanced Situational Awareness: Pinpoints high-risk areas, conserving water and manpower.
5.2 Feedback from the Field
Five firefighters used the TIC during mop-up at Mahinahina. All reported improved efficiency, reduced rekindle risk, and increased safety by minimizing unnecessary manual inspections. Such feedback underscores the growing importance of thermal imaging in both wildland and structural firefighting.
6. Conclusion and Recommendations
6.1 Summary of Findings
Based on controlled test burns and the real-world Mahinahina incident, the HEN Blade-45 nozzle emerged as a powerful tool for wildland and structural firefighting, particularly when compared to the Ultimatic (Fog) nozzle and the HEN Blade-20:
- Simplified Operation
Only a 1/4 turn adjusts between solid stream and blade (fan), reducing complexity and error. - Reduced Fatigue
The Blade-45’s lower flow rate than the Ultimatic (41 GPM vs. 66 GPM) still achieves strong fire suppression while reducing nozzle reaction and operator fatigue. - Effective Fire Suppression
Despite lower GPM, the Blade-45 consistently delivered impressive knockdown power, superior ground saturation, and rapid smoke reduction.
By contrast, the Blade-20—though similarly designed—is limited in capacity for large-scale incidents. It may still be valuable for smaller fires, mop-up, or scenarios where water conservation is critical.
Using these combination blade nozzles not only increases fire suppression effectiveness but also expands firefighting capabilities by operating effectively at lower GPM.
6.2 Implementation Considerations
- Transition Strategy
Fire agencies seeking to update their nozzle inventory should conduct field trials of the Blade-45 under local conditions to confirm suitability. - Training
While the Blade-45 is straightforward, initial orientation on its two core patterns ensures optimal usage. - Maintenance
Like all nozzles, routine checks (including cleaning, lubrication, and flow tests) are necessary to maintain peak performance.
6.3 Role of Thermal Imaging Cameras
The FirePRO 300 TIC’s success in spotting hidden hot spots emphasizes the modern firefighting strategy of integrating thermal imaging. Frontline use of TICs can:
- Boost Situational Awareness
Particularly valuable for mop-up in wildland incidents or in concealed structural voids. - Reduce Rekindles
Targeted application of water on hot spots minimizes the likelihood of fire resurgence. - Increase Command Confidence
Clear visual confirmation of extinguishment allows Incident Commanders to declare an “all-clear” with greater certainty.
As TICs become more accessible and user-friendly, adopting them for both structural and wildland firefighting is increasingly advisable.
7. Future Research and Testing
Further studies could include:
- Long-Distance Wildland Scenarios
Assess performance in large-scale or extended firefighting operations to monitor impact on firefighter fatigue and water consumption. - Comparative Analysis with Other Nozzle Types
Evaluating additional modern nozzles would provide broader context and validate the Blade-45’s standing in the marketplace. - Thermal Imaging in Complex Terrain
Exploring TIC effectiveness in heavy forest, steep slopes, and other challenging environments would help define operational limits and best practices.
In conclusion, the live fire tests and real-world performance during the Mahinahina incident indicate that Combination Blade nozzles—particularly the Blade-45—offer a balanced mix of performance, simplicity, and cost savings. Using these combination blade nozzles not only increases fire suppression effectiveness but also expands firefighting capabilities by operating effectively at lower GPM. When paired with advanced thermal imaging tools like the FirePRO 300 TIC, they can significantly enhance firefighting safety, efficiency, and confidence in extinguishment.
