Back in the 1980’s I had a deputy chief named Stewart Rose who used to talk about this in his strategy and tactics classes. He would say something to the effect that if we attacked the fire properly by taking the heat out of it, we shouldn’t need our structural firefighting ensemble to go in. In fact, we should be able to fight the fire buck naked.
It is a silly term but at the time, I didn’t understand what Rose was trying to convey. (I thought it was a joke.) He wasn’t advocating eliminating the need for structural firefighting personal proactive equipment (PPE); he was using a satirical mind picture to say that our PPE were not proximity suits – they were insurance policies and our last line of defense against a catastrophic thermal assault. Modern PPE has made us braver but not necessarily safer. The fire is still dangerous. With all the lightweight building construction and fire behavior involving modern synthetic fuels, we’re not as safe as we think. The number of structure fires in the U.S. has gone down while the number of line of duty deaths (LODDs) remains about the same. So why do we feel the need to mingle with the fire in order to put it out? That’s what Chief Rose was trying to say. Over the years, I finally
got it, but I’ve never forgotten the term “naked firefighting”.
The resistance to wearing Self-Contained Breathing Apparatus (SCBA) is now a thing of the past. Modern PPE and the cultural acceptance of SCBA have allowed us to become more aggressive in our tactics for interior firefighting. The strategy of attacking a fire from the uninvolved side towards the involved side is an accepted common practice and in many cases, is still the proper initial strategy to implement. It is important to get the nozzle between the fire and the victims. However, Rose understood the importance and safety advantages of transitional (defensive to offensive) and indirect fire attack. A fire doesn’t get worse when you put water on it; only when you don’t. While many people laughed and ridiculed him, he remained undeterred and stayed on message all these years. It took the recent Underwriter’s Laboratory (UL) and National Institute of Standards and Technology (NIST) experiments and test results on modern fire behavior and water application to scientifically validate what he and others have been saying for years.
Deputy Chief Vincent Dunn, FDNY (ret.) used to say “There’s nothing new under the sun in firefighting. There’s only new tools and methods to attack the same old problem.” Nobody knew that better than Jim “Jaws” O’Donnell. Back in 1963, O’Donnell was a fireman in Chicago, Illinois assigned to Truck 3. Back in ’63, there were no SCBAs so you really did have to be a smoke-eater. After a career of responding to fires, crawling down smoke-filled hallways, and enduring the heat, he kept thinking, “There’s gotta be a better way to do this.”
Together with his son, Kevin, now a 3rd generation firefighter for the O’Donnell’s, they came up with a prototype fog nozzle that was mounted on a tripod to spray water out from the interior of the fire room to hydraulically ventilate it quickly and effectively. Jaws knew he wanted a hands-free unit, but this version took too long to set up, position, and stabilize. Plus, it still required a firefighter to be inside the unventilated fire room.
They decided to try the fog nozzle at the end of a pipe that could be inserted into the fire room from the outside. The local muffler shop were the only guys who could bend aluminum pipe into a tight 90°angle, but the aluminum kept collapsing; so they had to fill the pipe with sand before bending the aluminum tube. The first attempts were a series of 90° wands with disappointing results.
Switching to steel made the pipe too heavy so they went back to heavy duty aluminum, but this time they had the pipe bent into an “S”. Having the fog nozzle positioned further in through the window, but still aiming outside, confirmed that the “S” design was the right way to go.
They tested and manufactured 45 (ventilation only) nozzles but in 1992, Jaws became ill with respiratory complications and their project stalled. All those years of fighting fires and eating smoke in the streets of Chicago finally took its toll and Jim “Jaws” O’Donnell died of lung cancer on June 12, 2002. His idea and the nozzles hung in the garage for another 10 years.
Lieutenant Kevin O’Donnell, now with the Hoffman Estates, Illinois Fire Department decided it was time to finish what his dad started. After two more years of peer input and studying the results from the UL and NIST tests, Kevin re-worked the nozzle and HydroVent™ was created.
HydroVent™
The concept is simple. HydroVent™ is a simultaneous hydraulic ventilation and fire suppression tool that is meant to be put directly into the fire room from the outside and left unmanned for the duration of the fire. The adjustable fog nozzle faces out from the window of the fire room for hydraulic ventilation and the interior nozzle, a series of straight streams, aims up and bounces off the ceiling to cool the interior temperatures of the fire room. Adding the interior straight steam nozzle is the most significant change from Jaws’ original design. Both of these simultaneous water applications make the interior IDLH (Immediately Dangerous to Life or Health) atmosphere more tenable for firefighters and victims by cooling the smoke and fire gases, preventing them from flashing over, while venting the interior heat and smoke to the outside atmosphere. There is no other nozzle on the market that does this!
The HydroVent™ nozzle is two sections of 46-inch pipe that connect together. It comes with a pistol-grip shut-off that connects to any 1 ¾” hose line. Once connected, the 7 ½ foot pipe takes a 90° bend into the objective and horseshoes back out. The 3”x 6” window sill holder is a mini iron rake that supports the weight of the tool and keeps it from sliding. In the middle of the horseshoe bend is a 2-inch spike for breaking out windows. Next to the window breaker is the straight stream nozzle tip with 4 smooth discharge holes. The horseshoe straightens out and ends with the adjustable fog tip. The nozzle reactions are directed back towards the horseshoe and down towards the window sill. The length and weight of the pipe rests against the exterior of the building. Simply placing the HydroVent™ and opening up the nozzle secures the tool in place for hands-free operation. All the connections are standard 1 ½ inch treads. With the shut off, the unit weighs 20 pounds. It also comes with a piercing nozzle that can attach at mid-pipe for attic fires and enclosed spaces.
The length was designed to make it easy to place into any 1st or 2nd floor window – our bread and butter fires. But you can place it higher from any ground extension or aerial ladder. Come to think of it, cutting a sufficient sized hole in the gabled end of a house to hang the HydroVent™ should allow you to horizontally ventilate an attic space
or cock loft by narrowing the fog pattern while introducing a sprinkler system into
the space.
It could also be used at highrise fires from the floor below the fire if the window was already vented. There should be enough reach that you could attack a fire from an adjacent balcony of a highrise unit. A highrise hose pack is available to carry the entire assembly with heavy duty padded handles and a wide, sturdy shoulder strap. An intake coupling adapter can be custom machined to accommodate any international thread.
Once in place, the fog stream hydraulically vents thousands of cubic feet of smoke and gasses per minute. This helps control and re-direct the flow path of the fire out through the window of the fire room, which is exactly where you want it to go – away from advancing firefighting teams. At the same time, water is being sprayed back into the fire room “softening the target” or “hitting hard from the yard”. Again, no other nozzle does this.
The minimum nozzle pressure is 60 psi, but higher pressures deliver more gallons per minute and increase the efficiency and speed of smoke removal with better results. The interior suppression nozzle flows 95 gpm. Once the fire is knocked down, it can manually be twisted shut while keeping the 95 gpm fog nozzle open for continual ventilation. (The HydroVent™ needs to be shut off at the pistol grip bale before you can close the suppression nozzle.) This prevents additional needless interior water damage.
The NIPSTA Tests
I attended the test burns at the Northeastern Illinois Public Safety Training Academy (NIPSTA) where Jill B. Ramaker is the Executive Director. We used two large shipping containers connected in the shape of an “L”. The smaller container was the burn room with a window for ventilation and two man doors. There was another door at the end of the 40-foot container. Firefighters could make entry to the fire room straight through the “front door” or “down the long hallway”. The fire load was four sheets of 7/16” OSB, four wooded pallets, and a full size sofa. Thermal couples were set in the fire room at 3 ft. and 6ft. to record interior temperatures. Thermal imaging cameras (TICs) and GoPro cameras recorded interior and exterior smoke and fire conditions.
We allowed the fires to really get going before all the doors were closed. Smoke filled both containers before the ventilation window was opened. Fire lapped out and up the container. (This is what first-in units often see on arrival.) The first two man doors were opened until a bi-directional vent path developed. This happens when the fire and the entry door are on the same floor. Smoke production overwhelms the vent window and looks for another path of least resistance. A bi-directional vent path is when fresh air rushes in at the bottom of the door and thick black smoke vents out at the top of the same door. It creates a little tunnel that firefighters typically crawl through to search for victims and the seat of the fire. Visibility is usually good and temperatures are around 100°F. This is why we say “stay low”. A dangerous situation occurs when a bi-directional vent path converts to a uni-directional vent path. This is caused by a wind-driven fire or a below-grade fire, like a basement. Once a basement door or window is opened, you have a low air intake. When the entry door is opened, you create a high exhaust point. The entry door is charged with pressurized smoke from top to bottom and becomes a chimney. This is where firefighters get trapped, injured, and killed. When the smoke flashes and gases ignite, that tunnel becomes a blowtorch. Firefighters cannot outrun a uni-directional vent path once it lights off. Previous tests show that the HydroVent™ venturi pattern can reverse wind speeds between 10 and 15 mph, preventing uni-directional vent paths from occurring within this range.
The fire room temperature at 6 feet was 1303°F. The 8-foot ceiling was probably around 1500°F. – well within flashover range. Using the TIC, you could see significant rollover occurring into the 40-ft container hallway. The temperature in the hallway was about 80°F. at the floor and 500°F. at the ceiling. Once the HydroVent™ nozzle was placed into the vent window of the fire room, temperatures immediately started to drop and the rollover and smoke issuing out of the man door started to reverse itself. At 15 seconds, the fire room temperature dropped to 1061°F. At 20 seconds, the smoke venting from the window turned to white steam. At 30 seconds, the temperature was 845°. At 45 seconds, 719°. At one minute, the fire room temperature dropped to 647° – about half! And smoke conditions had dramatically cleared. At 72 seconds, the temperature dropped to 590°. That’s incredible! Additional tests yielded similar results.
What impressed me at the NIPSTA fires – the HydroVent™ hose line was the only line laid. There were no back up lines. At the house fires test, back up lines were in place but never operated because the HydroVent™ controlled all the room fires. This nozzle is a transitional attack appliance – from defensive to offensive. HydroVent™ doesn’t completely extinguish the fire. Attack crews still need to go in and finish the job, but think what this tool can do for volunteer fire departments or any department with limited resources? One firefighter can arrive with an engine, lay out the line, charge it, and insert the HydroVent™ into a window without even entering an IDLH!
I was also amazed at how quickly the 40-foot container was cleared of smoke. The negative pressure created by the HydroVent™ in the fire room prevented the smoke from re-entering the hallway. It was like a curtain was placed at the man door! There’s no way my crew could have ventilated this structure as fast as HydroVent™ did. How many times have you seen crews having trouble starting a ventilation fan? This appliance starts to horizontally ventilate as soon as the nozzle is opened.
It is the simultaneous water applications and ventilation which makes it different from simply putting water quickly on the fire from the outside – the current recommendation from NIST and UL. This nozzle is truly revolutionary and could change the way we do fire attack in the future. It’s still fast water and first water. It directs the flow path away from firefighters and kills the flashover – making the interior safer, and increasing the survivability / rescue profile of the victims. In addition, you’re also limiting the exposure time and smoke concentrations for your firefighters. The connections between smoke absorption and cancer are well-known, so HydroVent™ is also an investment in the health, wellness, and longevity of your most valuable resource – firefighters.
I believe this nozzle will save firefighter and civilian lives. Anyone who scoffs at this new technology isn’t serious about firefighter safety. I’ve seen it for myself. And I guess – in theory – you could put the HydroVent™ into a window buck naked.
For more information, go to www.hydrovent.us
About the Author
Raul A. Angulo retired from the Seattle (WA) Fire Dept. with over 37 years of honorable service and is Captain Emeritus of Ladder Co. 6. He is an international author and instructor and serves as a member of the editorial advisory board for Fire Apparatus and Emergency Equipment magazine. He has been teaching at FDIC International since 1996 and currently presents the popular workshop, Drills You’re Not Going to Find in the Books.
