March-April 2012
An Ill Wind: Smoke Control Research – Part 1
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Reprinted
from With New York Firefighters Magazine (WNYF)*
By Gerald Tracy, George Healy
and John P. Ceriello The FDNY, since it was established in 1865, has been battling fire with courage and grace. The service we provide today has become exceedingly diverse with challenge far afield from firefighting. We offer service and assistance in emergency health care, hazardous materials release that is a threat to life, technical rescue and the list goes on. First and foremost we are still a FIRE department that is exceptionally experienced in waging war against fire to save and protect life and property when fire burns uncontrolled. We have encountered an untold number of difficult fires in those years, because of the volume of fire on arrival, the fuels present adding to intensity of fire, condition of the structure, and on occasion complications of establishing a water supply, gaining access, placing hose lines in position to achieve success and weather conditions. Weather has always been an adversary in the extremes of winter and summer because of oppressive humidity and heat or the bitter cold firefighters must endure. When we experience a change in weather there is a change in barometric pressures either high, which is the influx movement of warm air temperatures or low the influx of cold air temperatures. The speed or change of these pressures would equate to a mild change (slow) in temperature, an accelerated change accompanied with a change in weather and/or windy conditions or an abrupt change that is often accompanied with a foul weather storm. Usually a drop in barometric pressure and its speed will dictate the influence of wind and weather conditions and change. We are called upon to fight fires in all of these conditions. Wind can and has been a factor for some of the most difficult fires this department has encountered with devastating results. Wind has the propensity to accelerate fire into great proportions. Deputy Assistant Chief John Norman’s article in WNYF 1/20071 described the difficulty encountering fires in high rise multiple dwellings during high wind conditions and offered alternatives in strategy of attack. The focus of the article was extreme wind-driven fires that are physically impossible to extinguish using our standard fire attack practices. He noted that the conditions are not fully understood at this time. That is the reason for this article on “Ill Wind.” As Chief Norman claimed, we have experienced severe fires in these type buildings periodically since the 1970’s. One of our most difficult wind-driven fires was one in which involved the apartment owned by the jazz great Lionel Hampton in January of 1997 across from Lincoln Center. The winds were gusting at 35 miles per hour direct into the fire apartment and the apartment door had been left in the open position. Chief Tracy was the captain of Tower Ladder 35 at that time and had embarked upon the exploration of alternative strategies to extinguish these extreme wind-driven fires. Tower Ladder 35 was the first due Truck at this most difficult fire. After that fire, Chief Tracy had arranged to perform water-flow tests in a high-rise under construction in the district of Ladder 35. The flow test was set up to gather data in four modules of study. The first test was to measure the duration of time to charge a dry standpipe to the 27th floor. The riser control valve above 27th was closed and the standpipe was bled of air from the outlet valve on 27th floor. The standpipe was charged in one minute and forty seconds. The second module of the test was to measure the flows and loss of water from hand lines when additional lines begin to operate and are supplied from the same standpipe riser. You can expect that when a second or third hand-line opens up those hand-lines that are engaged will experience a 20-25% loss in flow. It is imperative that before additional hand-lines begin operations, ALL units on the fire ground and the IC is notified because there will be a significant loss of water that has a profound effect on the efficiency in their attack and safety. The third module of the test was to measure the flows from a Master Stream Appliance, the Akron New Yorker (Apollo) and a method to secure the device from any back pressure movement on a high rise floor. This test was successful and measured flows greater than 700 gpm with the supply of two 2½-inch hand-lines. The standpipe outlet pressures were 80 psi and the pressures at the appliance was 40 psi. The last module of the test comprised to register the gpm from a device referred to as the Navy Fog Applicator. It is 10 feet in length with a 90° bend near the tip with a nozzle that produces a water mist. (Impinging fog) See Figure 1.
A flow of 155 gpm of water mist was achieved after modifying the orifices of the nozzle to a greater diameter. The back pressure experienced was insignificant for the fact that the tip produced a water mist and not a straight stream. It was conceived that this nozzle could be deployed from a window directly below the fire apartment when the wind conditions were a factor negating a direct attack on the fire floor. These conditions have been experienced when the door to the fire apartment has been left open and windows in the fire apartment have failed due to the heat of the fire. The hallway leading to the fire apartment would be subject to tremendous heat, negating that approach without injury or worse. This method of deployment from the floor below would allow the wind which would preclude a direct frontal attack on the fire floor to carry the water mist through the fire apartment and reduce the intensity of the fire or bring it under control from a safe vantage point. At that time the results of the test were shared with the administration of the FDNY, but test of the Navy Fog Applicator was considered theoretical research and not proven fact. A determination was made that professional science and engineering would be required to prove and validate theory into fact and to educate any diverse opinions within the department. Chief Tracy developed a relationship with an engineer of the National Institute of Standards and Technology and solicited his assistance to conduct research into alternative methods of attack (approach) to fires burning in high rise structures when wind could or would be a factor. That engineer is Daniel Madrzykowski P.E. a fire protection engineer with the Fire Research Division of NIST. It has taken the patience of almost ten years for this research to become a reality with the acquisition a vacant high rise structure in Toledo, Ohio in June of 2006 and funding from Homeland Security that afforded NIST the opportunity to launch this research. In those ten years the
challenge and problems the FDNY and the fire service as
a whole has experienced at high rise fires in both
commercial and residential structures had been discussed
and noted. As a matter of fact NIST had investigated
facts and data from the Vandalia Street fire and
completed a computer modeling of the event but was
reluctant to publish the results because the study
revealed temperatures in the hallway outside the fire
apartment to be so extreme NIST had questioned the
accuracy of the results.
The problems and challenge have been characterized into
following categories of research.
Develop an understanding of the dynamics of
interior pressure differentials, stack effect
(interior air movement) verse fire behavior in a
fire compartment/area in high rise buildings. This
information would provide our department a
comprehensive approach and disciplines to
incorporate into our firefighting procedures to
increase our safety and efficiency at high rise
fires. This will ultimately provide increased life
safety for civilians who occupy these type
structures.
Our department experienced two
difficult wind-driven fires in the winter of 2006. On
January 26th, 2006 a fire located at 40-20 Beach Channel
Drive in the Rockaway Peninsula occurred in the same
building that claimed the life of Firefighter James
Williams of Ladder 121 January 5, 1996. He became
trapped in a dead-end hallway after attempting to escape
from the fire apartment while conducting a search when a
window failed creating conditions that became extreme in
a matter of seconds.
This fire in 2006 was similar in that units where in a position with a hose-line and search team and soon after entering the fire apartment a window failed and conditions change dramatically causing more than a dozen firefighters to exit the floor to save their lives. Numerous firefighters incurred injuries. Again a firefighter became trapped again in a dead end hallway. The OVM of Ladder 121 having gained access to the adjoining apartment (an area of refuge) heard the firefighter’s plea for help entered the hallway in extreme conditions and led the firefighter to safety. These firefighters then remained in this adjoining apartment for almost 60 minutes until an alternate strategy could be set up to extinguish the fire and allow their removal. Had this young firefighter incurred critical injury he would not have received medical attention until this tactic was complete. Within a few weeks, on February 26th , 2006, the FDNY would experience another wind-driven fire at 20 Moshulu Parkway, Tracy Towers in the Bronx. The circumstances similar while units were positioning an attack line and search was being conducted a window failed and firefighters were injured in their escape. This fire auto exposed and involved the apartment on the floor above complicating operations. The fire blanket was deployed but due to the fire intensity and its inability to reduce the wind conditions a flanking maneuver was launched and simultaneous attack on the floor above proved successful, but not without the courageous effort of all those firefighter on scene. Our Chief of Department Salvatore Cassano requested Deputy Assistant John Norman to form a High Rise Committee4 to accelerate our research on wind-driven fire events. Each participant of the committee was given a specific project of research. Chief Tracy contacted Dan Madrzykowski of NIST and it was coincidental in that the Toledo Ohio Fire Department at that time was seeking research on Positive Pressure Ventilation (PPV) in large area structures to assist in search and extinguishment because of minimal staffing of their truck companies. Dan advised Deputy Chief John “Skip” Coleman of Toledo that the FDNY was also interested in this type of research but our focus was with high-rise structures. It so happened that a high-rise structure located in downtown Toledo was vacant, and Chief Coleman arranged authorization with the owner to conduct baseline research in the building without fire or damage. In June of 2006 we formed a collaborative partnership of research with the Toledo FD, Chicago FD, Ottawa Fire Services and NIST. We contacted the Ottawa Fire Services for the fact that a Safety Officer Peter McBride had been involved in a prior study with the National Research Council of Canada (NRC) that lasted five years in a ten story burn lab to record the effects and efficiency of PPV during high rise fires. Ottawa extended an invitation back in November of 2001 to then Deputy Chief John Coloe and Chief Tracy to join a team of individuals from fire departments throughout the US and Canada to review the data. This research provided a baseline of computer data for NIST that added to the foundation of data we were now integrating to taller buildings and our research for live fire scenarios. The FDNY has enjoyed a long standing relationship with the Chicago FD. Chief Tracy contacted CFD Commissioner Raymond Orozco and he agreed to join this endeavor of research. Lessons Learned from Toledo Our structure in Toledo was a 30 story fireproof office building, built of fire protected steel columns and beams supporting Q-deck cement floors, housing a center core with five banks of elevators including a freight elevator. The building was designed with two enclosed stairwells serving the upper floors with one terminating a roof level and the other terminating in a machinery room on the top floor. Two separate stairwells gave access to the basement, one was enclosed and the other was an open access stair from a lobby area. The basement included an electric service panel room, service rooms for domestic water, fire pumps and gas, storage and business spaces. The foot print of the building measured approximately 200 X 100. See figure # 2.
NIST prepared the structure with instruments connected via cable harnesses to computers that would record the ongoing data during the actual tests to validate the most effective equipment, placement and methods to achieve pressurization of the stairwell(s) to eliminate or reduce the infiltration of contaminates (smoke & heat) into the stairwells. NIST also placed meters and instruments to record the wind and weather exterior of the building. The interior instruments measured pressure differentials for the height of the structure, CO readings, and air movement. This preparation took five engineers from NIST one week to complete for the commencement of our research. The reason to record and monitor CO readings was that we were utilizing portable gas powered fans to produce the positive pressures in the stairwells and the exhaust from the fans would also be introduced into the stairwells. We needed to confirm if we reached concentrations of CO that would be considered harmful or the limits stipulated by NIOSH standards. In the next week NIST conducted more than 160 different test scenarios, using fans of various size, design, and capacity to move air in cubic feet per minute (cfm). They were placed at a variety of locations exterior and interior of the building. They were also placed at various distances to doors leading to the stairwells, placement in lobby areas and floors areas of the building. Upon conclusion of the study we did in fact validate that pressures could be achieved in the stairwells of a 30 story building that would keep the stairwells clear of contaminates from a fire with the attack stair door open. The test did not factor a fire that would be experienced with window failure and a wind blowing into the building. We also included in the study the effectiveness to remove smoke from the below grade areas of the building by pressurizing the basement at the top of the enclosed stair leading to the basement directing the smoke up and out the access stair at the other end of the building into the lobby and then directing the smoke out of the building through an exterior entrance door by pressurizing the lobby. It was also determined that the CO produced by the fans was less than those concentrations which NIOSH considers a ceiling limit. As a matter of fact even with the placement of multiple fans pressurizing the stairwell and structure the levels of CO did not exceed 100 ppm. A post critique was held with NIST, Toledo, Chicago and FDNY and it was agreed that the research needed to progress to a study with live fire and window failure type conditions. The representatives from the FDNY that were present for this research were BC Tracy Bn49, BC Healy Bn51 and Lieutenant Ceriello of Squad 252. The full report of this study can be accessed on the NIST web site and or follow this link. http://www.fire.nist.gov/bfrlpubs/NIST_IR_7412.pdf Lessons Learned from Chicago The Chicago FD in October of 2006 with the support from their commissioner Raymond Orozco and Mayor Daley acquired a 16 story fireproof multiple dwelling that was planned for demolition to proceed with this research. See Figure # 3.
The preparation for this structure entailed 11 members from NIST and a contingent of Chicago personnel including their recruit class two weeks to complete. The preparation required more than the placement of meters, thermocouples, video and thermal cameras, and computers but also construction and modifications of the structure providing hallways leading to the proposed fire apartments. The structure was originally built with exterior open halls leading to the apartments. They had to be enclosed on those floors (15, 10 and 3) where apartments were staged with ordinary fuels and furnishings for the live burn research. It was essential that these floors depict the conditions in the hallway outside a fire apartment with the door open to the fire. NIST conducted the equivalent of 18 All Hands Fires (10-75’s) in the next week. NIST recorded the heat (temperature) release rates from ceiling to floor in the fire apartments, hallway and attack stairwell from ignition to flashover for each fire and then the change in pressure, air movement and temperatures with the introduction of stairwell pressurization. The use of a fan to pressurize the attack stairwell during our live fire tests were effective in not only clearing the stairwell but also moving the smoke and heat back into the fire apartment. Each and every live burn exercise was also captured and recorded on actual and thermo video. On the second to last day of live fire research NIST incorporated a test scenario replicating Wind Driven Fire conditions. The CFD has a large mobile ventilation unit that is capable of producing a wind of 150 mph. They use this appliance to pressurize and move smoke from large structures and underground rails systems in the city. It was set up outside (3rd floor) of our burn building and calibrated to when turned on would produce a 22-mph wind into the proposed fire apartment. The fire apartment was furnished with typical fuels of furniture in the bedroom and living room only. The fire was ignited in the bedroom that had window to the exterior. When the bedroom reached flash over the 22-mph wind was introduced and the fire became a horizontal tornado that raced through the apartment in a matter of seconds and out into the hallway. All of these events were captured on video and thermal cameras. Not only were flames visible in the hallway, the thermal camera recorded a rise in temperature from approximately 73° F to temperatures near 2000° F floor to ceiling in under one minute! This test duplicated the Vandalia Street event. Now NIST has been able to validate their computer model of this fire. A preliminary report can be accessed following this link: http://www.nist.gov/public_affairs/techbeat/tb2006_1122.htm#firetest The representatives from the FDNY that were present for this research were AC Galvin Chief of Training, BC Tracy Bn49, BC Healy Bn51 and Lieutenant Ceriello of Squad 252. Expanding Partnerships The FDNY has reached out to a neighbor at Metro Tech, Polytechnic University to join in our research. At our initial meeting with PU it was agreed that the engineers from NIST would still be involved to perform the live fire test and measurements and that the FDNY would pursue the acquisition of a structure(s) here in the NYC area. Irene Sullivan from our Office of Intergovernmental Affairs applied for and was successful in achieving a grant from the US Fire Administration awarded to PU the fund the project. Moving on to Governors Island With the assistance of Manhattan Borough Commander Michael Weinlein the FDNY has been given authorization from the Governors Island Preservation and Education Corporation (GIPEC) to continue our live fire research in buildings that are planned for demolition on the island. The continued research once commenced will take approximately one year to gather the data needed to review. Again the research to be conducted on GI will be to validate methods of extinguishment, control and approach to high rise fires when wind is a factor. The modules of test will increase our understanding of the dynamics of wind exterior of the structure and fire behavior interior of the structure including the path fire, heat and smoke will move from the fire area, hallways, and stair shafts. Upon the conclusion of this research and after the recorded data is reviewed by Polytechnic University and NIST, we believe the FDNY can incorporate increased safety and efficiency in our high rise operations. References:
*To subscribe to WNYF Magazine click here: https://www.fdnyfoundation.org/subscribe ] |
Who Stole Our Trade? – T.J. Welch
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Peaked Roof Operations and the Pressure Nonsense – Ted Corporandy
Stay True to Yourself – George Burk