BY RICHARD J. MUSICANT
Firefighting in high-rise build-ings presents numerous challenges to firefighters. Access and water supply in many cases can be extremely limited, and firefighting operations often require more personnel than usual. Additionally, high winds can create the “blowtorch effect,” which can intensify and extend the fire, making conditions untenable for firefighters, reducing their ability to control and knock it down, resulting in increased property damage.
 Fire on the second floor is escaping from a window; there is no wind blowing it back into the room. [Photos by Ned Barber, Park Ridge (NJ) Fire Department Photo Unit.]
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The blowtorch effect is one of the most dangerous aspects of high-rise fires. This dangerous condition occurs when a heavy fire load is intensified by high winds blowing through an opening on the fire floor, pushing the intense heat, gases, and fire into the primary access route (usually a hallway), creating a potential deathtrap for an advancing interior team. In many cases, concrete walls contain the heat and intensify the effect. Blowtorches can develop with little or no warning and have been responsible for at least four firefighter deaths and numerous injuries in New York.
COMBATING THE BLOWTORCH EFFECT
Fire Department of New York (FDNY) Battalion Chief John Norman, who has experience in high-rise firefighting, found the most effective way to fight the blowtorch effect was to choke it off from the outside. From lower floors, an indirect attack by hoseline or master stream would be effective, but above the 10th floor, this is not a viable option. Norman came up with two methods for dealing with this.
 Because of fan pressure at the front window, there are no flames at that window, and smoke is venting from a side window. |
The first method involves using the Rockwood Navy fog applicator from the floor below the fire. The problem with this method is that deploying additional handlines to the floor below is time-consuming and requires more personnel. Also, with a heavy fire load, the Navy fog applicators don’t provide enough gallons per minute (gpm) to effectively cool the fire and reduce the blowtorch effect. This method also puts the attack team in a superheated steam condition.
Realizing the difficulties with the first option, Norman, along with FDNY’s Assistant Chief Joseph Callan, then FDNY chief of training, sought a more effective way to fight fires in a challenging and dangerous environment. They came up with the idea for a high-rise fire curtain. Such a curtain would be deployed in front of a window on the fire floor, blocking high winds, reducing the blowtorch effect, and enabling a hose team to advance to the seat of the fire. Callan authorized Norman to contact Industrial Energy Products, Inc. (IEP) of New Jersey to develop this product. The result was the Hot-Stop 1500T M High Rise Building Fire Curtain.
DEVELOPING A FIRE CURTAIN
IEP specializes in high-temperature and fire-resistant insulation materials for the energy industry. Various IEP fabrics were considered for the curtain, some with lower temperature resistance but excellent durability and some with very high temperature resistance but with limited durability. Hot-Stop 1500T M fabric was selected for its balance of temperature resistance and durability. It was designed originally for welding blankets and for wrapping insulation pads in power plants. Hot-Stop 1500T M is a treated fiberglass fabric that withstands 1,8007F for 30 minutes before its fibers begin to melt, providing ample working time for fire crews.
 The Hot-StopT 1500 M High Rise Building Fire Curtain is ready for deployment from two windows above the fire floor. |
The Hot-Stop curtain is available in nine- and 11-foot widths and 10-, 11-, and 12-foot lengths. Custom sizes have been supplied on request. The curtain includes high-strength strap handles made of woven aramid tape with excellent abrasion resistance and tensile strength. The handles are sewn into the vertical hems and reinforced with rivets. Lengths of heavy-duty chain are individually sewn into separate pockets along the bottom hem to ensure that the curtain will unfurl and make a positive contact with the building. A modified curtain has been developed that can be deployed using a ladder for low-rise buildings and exposure protection.
At 35 pounds, the curtain is fairly lightweight and portable. It can be carried by one firefighter and deployed by two to three members, depending on window placement. The deployment team must access the rooms above the fire floor on both sides of the fire room. One team member places the curtain on the sill of the window directly above the fire and tosses handles to members in windows to his left and right. Gripping the handles tightly, firefighters push the curtain out the window. The weights in the bottom and the handles on top allow the curtain to unfurl and fall into place over the fire floor window below. The deployment team can adjust the curtain’s position by increasing or taking up slack on the curtain handles as needed. A spotter on the ground can relay positioning in-structions to the de-ployment team. Once in place, the curtain’s long handles can be tied off to a secure object. Additional handles extending from the bottom of the curtain can be used by firefighters on the floor below the fire to also assist in positioning. The results, as demonstrated in tests, were almost instantaneous.
The Hot-Stop 1500T M High Rise Building Curtain recently completed a rigorous testing phase with excellent results, proving it can be an effective tool in fighting deadly high-rise fires. A test conducted at the Rockland County (NY) Fire Training Center in Pomona involved deployment of the curtain in a live-burn training situation.
 Steam escapes from the window, indicating knockdown is completed. |
The purpose of the test was to demonstrate the curtain’s effectiveness in keeping winds from entering a fire compartment and to develop standard operating guidelines (SOGs) for using the curtain. The results of the first test were even better than anticipated, considering that none of the firefighters involved had ever deployed the curtain under live-burn conditions, according to Tom Connolly, Jr., president of IEP and a third-generation firefighter.
LIVE BURN TESTING
At the Rockland County Fire Training Center, we conducted tests at a three-story concrete structure with a hallway on the second floor that simulates a hallway in a typical high-rise building. All doors between the fire room and the stairs at the opposite end of the hall were sealed off with 5/16-inch particleboard coated with an intumescent coating (supplied by IEP) to create a corridor stretching from the fire room to the stairs. The fire room contained materials similar to the typical fire load of an apartment. Some hay was used to assist in ignition, but no accelerants were used. Two large 20,000-cfm fans positioned outside the window atop a tower ladder simulated high winds.
Thermal imaging, low-light video, and regular video cameras inside and outside the building recorded the demonstration, and video and thermal images were recorded from a variety of angles during the numerous deployments. Voice communications were also re-corded in conjunction with the videos to properly document conditions and note the times of deployment and knockdown.
 The deployment team lowers the fire curtain to vent the room once the fire is out. |
Firefighters from Park Ridge and Ridge-field, New Jersey, participated in the testing, which employed two interior teams. In the original scenario, the four-member interior hose team would be stationed just below the top step of the stairway. Once the fire was in the free-burning stage, the fans would be turned on, simulating high winds. The hose team would attempt to advance to the fire and, when conditions were severe enough, call for the two-member curtain deployment team (stationed on the ground) to go to the third floor to deploy the curtain. Additionally, camera operators, safety officers, and backup teams would be present inside and outside of the building. The conditions were monitored from the ignition of the fire through the incipient stage and into the free-burning stage.
 A low-rise curtain is deployed on a ladder. |
At the first demonstration, the hose team radioed Command that conditions were too severe for advance and called for the curtain deployment team, which accessed the third floor by the building’s fire escape. As in many first-time demonstrations, the first curtain deployment did not go completely as planned but nonetheless provided a valuable lesson that helped develop deployment SOGs. The curtain became fouled during the initial demonstration, and one of the straps became entangled in a vertical window member, preventing proper deployment. The force of the resulting blowtorch pushed the heat and smoke through the stairwell and even down the stairs to the first floor, pushing the hose team down the stairs and out of the building. The heat was so intense that it melted the facepiece on one firefighter’s helmet. Thermal imaging clearly shows the blowtorch’s superheated gases and fire being pushed down the hall with great force. The thermal imaging camera operator recorded temperatures higher than 1,0007F.
 The low-rise curtain in place. |
The curtain problem was corrected, and the curtain was eventually positioned properly. The hose team went back inside and knocked down the fire. The scenario was modified, with the curtain deployment team stationed at the windows of the floor above before the beginning of each demonstration.
The next several deployments were more successful. In each instance, the curtain deployed smoothly and fell into place with only minor adjustments needed. The deployment team adjusted the curtain’s position by pulling on the handles as needed. The wind pushed the curtain against the building, creating an effective seal. A spotter on the ground outside aided the deployment team in positioning the curtain properly. With the intense heat and fire rising from the floor below, it was potentially dangerous for members of the deployment team to expose any body parts during initial positioning. Even with high winds pushing the fire back into the structure, a lull in the wind or other changes in conditions could create hazards for the curtain deployment team. In each subsequent evolution, until the curtain was properly in place, the hose team could not move out of the stairwell and onto the fire floor.
In subsequent successful curtain deployments, the thermal image shows a rapid drop in temperature as soon as the curtain covers the window. The fire darkens instantly after each deployment. With the curtain in place, the interior hose team could advance on the fire room in less than a minute each time. In each case, curtain deployment knocked down the fire in a matter of moments. The curtain literally choked the fire almost to the point of complete knockdown. The hose team knocked down and overhauled the fire with a single hoseline. At another fire curtain demonstration at the FDNY Randall’s Island Training Academy, a firefighter exclaimed, “It’s like someone turned off the switch!”
LESSONS LEARNED
Below are some lessons learned from the testing, including SOGs.
SOGs
The deployment team should wear full PPE and SCBA. Heat and fire may be momentarily deflected upward as the curtain falls into place, depending on conditions. Deployment team members should wear full PPE and SCBA when deploying the curtain and should keep their entire bodies inside the windows. It’s also important for the team to maintain a firm grip on the handles to avoid losing the curtain.
Deploy the curtain over vented windows before committing a hose team to the fire floor. When a window vents prior to hose team deployment, the exit route (in this case, a stairwell) can become the travel route for the exhaust required to cause a blowtorch.
Deploy the curtain over the window before it self-vents. For interior hose team safety, the curtain should be deployed over an intact window to prevent it from self-venting and causing a blowtorch. If deployed on initial response, the hose team will be protected from the time it exits the stairway to the time it makes the fire.
Deployment Team Tools
Forcible entry. The deployment team should carry forcible entry tools, since the curtain is deployed from the floor above the fire and the team may have to force entry to the rooms above. On entry, doors should be closed.
Pike poles. If there is a great distance between the two windows on the floor above, a pike pole can be useful in retrieving the curtain handle and tying it off.
Portable radios. Communicating with a spotter on the ground outside the building expedites proper curtain positioning. The spotter instructs the deployment team in which way to adjust the curtain for maximum effectiveness.
The high-rise building fire curtain is an extremely effective tool for preventing and combating the blowtorch effect in high-rise fires and can be deployed rapidly with minimal personnel. The curtain reduces the risk to firefighters operating on the fire floor, allowing them to advance on and quickly and effectively knock down the fire. With limited air to feed the fire, extinguishment requires less water and fewer personnel. Rapid knockdown also reduces potential structural damage.
RICHARD J. MUSICANT is a third-generation emergency services volunteer, a firefighter, and a 15-year veteran of the Park Ridge (NJ) Volunteer Fire Department. He is a New Jersey state-certified fire instructor and fire inspector.
