HIGH RISE MANUAL 91-110.pdf

SETTING THE PRESSURE • When the nozzle team opens the line and flows it in the stairwell, the control firefighter sets the pressure on the line by slowly closing the gate valve until the desired pressure is reached on the in-line gauge: o 150’ (50’ of 2 ½” and 100’ of 2”) with 1 1/16” SB requires 90...

SETTING THE PRESSURE • When the nozzle team opens the line and flows it in the stairwell, the control firefighter sets the pressure on the line by slowly closing the gate valve until the desired pressure is reached on the in-line gauge: o 150’ (50’ of 2 ½” and 100’ of 2”) with 1 1/16” SB requires 90 PSI while flowing • If an additional section of hose is added making the hose length 200’: o 200’ (100’ of 2 ½” and 100’ of 2”) with 1 1/16” SB requires 95 PSI while flowing o 200’ (50’ of 2 ½” and 150’ of 2”) with 1 1/16” SB requires 105 PSI while flowing • Crews should consider the following if additional hose is needed for the stretch: o The extra 50’ section of 2 ½” requires an additional 5 PSI for friction loss, but it may limit mobility o The extra 50’ section of 2” requires an additional 15 PSI for friction loss, but it is more mobile The photos here help to illustrate the importance of setting pressure while flowing water. The pressure on the left is with the standpipe outlet and the gate valve open and the line fully charged while not flowing. (Static) The gauge shows approximately 150 PSI. The photo on the right shows the pressure with the line open and flowing prior to adjusting the gate valve. (Residual) The gauge shows approximately 90 PSI. Click here to view Vector Solutions video on Setting the Pressure/Urfa PRV Adjustment TROUBLESHOOTING Firefighters can take the following steps if unable to reach the target flowing pressures: • Inform the Fire Attack Group Supervisor of the situation • How much pressure is lacking? Is a PRD or adjustable PRV present? o The supervisor will radio down to the I/C and the FDC engines and request them to start pumping o This may require communication back and forth until the desired pressure is achieved. In a perfect world, this will solve the problem • If it does not, the Fire Attack Group Supervisor will make the call to either advance the line as is, or call for additional lines to be stretched from a different stairwell and riser o A 2” line under pumped is still a powerful weapon • Placing a choker tip on the nozzle can make a huge difference o Instead of the 1 1/16” tip, use a 1” or a 15/16” tip o Flow will be less, but reach and back pressure will improve Second Edition 01/11/22 83 THE HOSE ADVANCE “More lives are saved from a properly sized and placed handline than any other tactic.” Lt. Andy Fredericks (FDNY, LODD on 9/11) • Clear the Attack Stairwell one last time of civilians, then chock the door open • Open the nozzle fully: o Let the reach of the stream and the GPM do their job o 240 GPM is hard to quantify, but four gallons per second is easy to imagine o This is not 1 ¾”; it does not need to be whipped violently • Let the power of the stream remove the ceiling tiles • Sweep the floor to move falling debris out of the way ADVANCING • Communicate with the team while the nozzle is fully open o Tell the back-up firefighter how far you want to move forward • Using distances makes it easier for the team behind you to move hose: o Five feet or ten feet are common distances to use; relay that distance to every member on the line o Move slowly and controlled. Stay in balance and only move as far as the distance you asked for • The goal with the 2” hose is to keep the nozzle fully open and flowing during the advance o If crews become fatigued or if conditions allow, they can gate the bale down halfway. This reduces nozzle reaction and helps firefighters advance forward • Once at the next position, let the back-up know you are going to fully open the nozzle • Doing so allows them to transition from a moving position to a bracing position to handle the nozzle reaction WHILE THE NOZZLE IS FLOWING IN A STATIC POSITION • The hose team is gathering hose for the next move • Each member will identify areas that hose can be pre-loaded • Each member will communicate needs to the team and work together to pre-load their areas WHILE THE NOZZLE IS MOVING FORWARD • Each team member is advancing hose up to the next team member, and that team member is doing the same • Every person behind the nozzle team is working to advance hose during the movement phase or is pre-loading hose during the static phase • At no time is there a rest phase! CONTINUE MOVING AND PRE-LOADING UNTIL • The fire is out • The hose supply is exhausted • The team gets relieved by replacement crews Click here to view Mt Carmel High Rise Training—Moving and Flowing Second Edition 01/11/22 84 2 ½” HOSE LINE OPTIONS OVERVIEW There will be times when the hybrid hose package of 100’ of 2” hose and 50’ of 2 ½” hose will not have enough knock down power for every fire that firefighters may face. Examples could include a fully involved commercial style high-rise with an open floor plan, a residential high-rise fire that has overtaken the common hallway, or possibly a wind driven fire. Every engine company coming in on the initial assignment will be bringing their high-rise equipment to the resource floor. This will provide three complete high-rise packs and standpipe bags upstairs during the initial stages of the incident. In the event that such a fire is encountered, firefighters will need to have a plan to deliver more than the 240 GPM that the current high rise hose package delivers. In such cases, it is recommended that crews join the three (50’) sections of 2 ½” hose together and create an attack line consisting of 2 ½” hose. The tips shown below will then be used with the 2 ½” nozzle. The increase in hose diameter will help reduce friction loss, and the larger tip sizes will provide the higher GPM necessary for these types of fires. ELKHART ST-185-AIFD “INDY STACK” TIPS • Indy Stack Tips—1 1/8” (266 GPM at 50 PSI NP) and 1 ¼” tip (328 GPM at 50 PSI NP) • Carrying these Indy Stack tips in the standpipe bag gives firefighters the option of using either tip with a 2 ½” nozzle and the 2 ½” hose mentioned above 1 1/8” Tip 150’ 50 PSI 266 25 PSI 98 LBS Standpipe Discharge Pressure 75 PSI 200’ 50 PSI 266 30 PSI 98 LBS 80 PSI Hose Length Nozzle Pressure GPM Friction Loss Nozzle Reaction 1 ¼” Tip 150’ 50 PSI 328 35 PSI 121 LBS Standpipe Discharge Pressure 85 PSI 200’ 50 PSI 328 45 PSI 121 LBS 95 PSI Hose Length Nozzle Pressure Second Edition 01/11/22 GPM Friction Loss Nozzle Reaction 85 MQA/RAM Using multiple sections of 2 ½” hose also opens up the possibility of using an MQA or RAM. Each of these devices is capable of delivering up to 500 GPM; they are ideal for commercial fires with an open floor plan or untenable residential hallways that are beyond hand-line control. Remove any stream straighteners on the MQA or RAM during high rise operations. Stream straighteners can become clogged with standpipe debris. The tables below show the appropriate standpipe discharge pressures for the MQA and the RAM, at distances of 150’ and 200’ with 2 ½” hose. MQA Tip Size 1” 1-1/8” 1-1/4” 1-3/8” 1-1/2” Nozzle Pressure 80 80 80 80 55 GPM 266 336 415 502 496 Friction Loss in 100’ 15 25 38 55 55 Standpipe Discharge Pressure 150’ 100 115 135 165 165 Standpipe Discharge Pressure 200’ 110 130 155 190 190 RAM Tip Size 1-3/8” Nozzle Friction Standpipe Discharge Standpipe Discharge GPM Pressure Loss in 100’ Pressure 150’ Pressure 200’ 80 505 55 165 190 *Appliance will have roughly 9.5 PSI of friction loss at 500 GPM Even if the standpipe does not have enough pressure available to pump the MQA/RAM at the desired pressures shown in the charts above, an under pumped MQA/RAM is still a powerful weapon that is still worth using as long as there is a usable stream. This type of operation is not going to happen often, but when it does firefighters need a plan to bring the bigger line into service. Having extra tips in the standpipe kit and joining the 2 ½” hose together will provide the weapon needed to fight such a fire. Another factor to consider on larger, more involved fires like these is the potential need to add a second hose line onto the same standpipe. See the link below for more information. Click here to view Brass Tacks and Hard Facts video on Adding a Second Line off the same Standpipe, starring Lt. Robertson Second Edition 01/11/22 86 THE FIRE FLOOR AND FLOORS ABOVE THE FIRE FLOOR • Life safety is still the primary goal; the fire floor is no exception • During hose advancement and extinguishment, the members of the hose team will also be searching the fire area for victims • Ladder company members can move off the line and search • If victims are found, remove them to the CCP two floors below. The line may need to remain in one position until firefighters return from making the rescue THE FLOORS ABOVE • The floor above and areas beyond will be searched by the USE Group • The USE Group is composed of the first rescue and second ladder • Ladder officer is the USE Group supervisor • The USE Group travels using the evacuation stairwell • Although SOP 02-03-04.04 states a specific order in which the USE Group will perform their search, a real high-rise incident will be a little more fluid. For instance, the Fire Attack Group should be checking the Attack Stairwell as they recon for entry onto the fire floor. Doing so frees up the USE Group to check the Evacuation Stairwell as they move to the floor above the fire. Once the floor above the fire is cleared, the USE Group will check the top floor, elevators, and other remaining areas • When victims are located, remove them to the CCP two floors below the fire. If a protect in place strategy is in effect, be guided by the I/C’s directions • The USE Group Supervisor will inform the IC of the conditions encountered • Once an All Clear is given for areas above the fire floor, the USE Group can be reassigned to other functions There are many other groups that have not been discussed in detail. These groups are important groups in the High-Rise operational plan, but they are not immediately staffed by the first alarm companies or the working fire assignment. As the incident progresses, the I/C will add these groups in as needed. They will be formed from later arriving multiple alarm companies. Refer to the Division SOPs for details. Some of these other groups include the following: • Resource Group • Stairwell Support Group • Medical Branch • Rehab Group • Ventilation Group • Staging Area Manager This concludes the operational sections of this manual. This book can never encompass all the fire scenarios you might encounter in your career; the intent is to improve the base knowledge of CFD firefighters and provide a framework in which to operate. The next section of this manual will cover Stack Effect, stairwell design, and many other building features that can impact operations and hose deployment in high-rise buildings. Second Edition 01/11/22 87 PAGE LEFT BLANK FOR DOUBLE SIDED PRINTING Second Edition 01/11/22 88 CONSIDERATIONS WHEN OPERATING IN HIGH-RISE BUILDINGS HIGH-RISE OPERATIONS MANUAL SECTION TOPICS The Stack Effect by Curtis S.D. Massey Stairwell Designs Standpipe Systems Fire Control Room Backup Generators Elevator Control Room Fire Pump Room SECTION OBJECTIVES Describe stack effect and its considerations in high-rise fires Understand and describe what a multi zone system is Define return, scissor, and access stairwells State the purpose of jockey pumps Understand the capabilities of a Full Control Annunciator Panel Identify cases in which turning off the fire pump would be beneficial State the uses of a built-in public address system Successfully identify Class 1, 2, or 3 standpipe systems Describe the steps necessary to utilize Fire Department handsets Understand the basic types of elevators and their control room locations State what back-up generators may power inside a building State the basic considerations for dealing with elevator car fires Second Edition 01/11/22 89 THE STACK EFFECT By Curtis S.D. Massey A fire department is dispatched to a reported structure fire in a 52-story high-rise office building. It is a weekday, 4:30 P.M. The building is fully occupied. Upon arrival, first-due units report heavy fire intermittently showing out three windows on the exposure 1 side (front/north) and immediately start pulling their equipment off the rigs to begin a difficult firefight. It is early January in this northern city and the temperature is 26 degrees, with a slight northerly breeze blowing toward the building frontage. Crews trudge up to the front entrance and experience some difficulty in opening the swinging entrance doors. Believing that the problem lies with the breeze blowing against his back, the firstdue engine captain asks two men on the second engine to prop open the swinging doors and collapse the revolving doors to expedite getting equipment and manpower into the building. This is done in very short order. As the crews enter the building, they feel a strong wind rushing past them into the lobby, almost like being in a wind tunnel, but again, figure it is just the slight breeze gaining velocity as it squeezes through the doorways along with the firefighters. Tenants who have already reached the lobby are either milling around or are leaving the building. Crews check the fire panel for confirmation of the alarm floor as they listen to the security guards and chief engineer excitedly bark out what they have seen or received in information from tenants. They are told that an entire tenant space of about 2,000 square feet on the 38th floor is on fire in the un-sprinklered 1960s-era steel frame skyscraper, along with a report that several people are missing and presumed to be trapped. They are advised that the lone freight elevator is down for repairs. From their position, the crews no longer feel the wind entering the building. After gaining access to floor plans, stair master keys, and fireman service keys to the elevators, the engine, ladder, and rescue units head over to the elevator banks to ascend to the staging floor, two floors below the fire floor. They step into two cabs as wind whistles around them in the shaft ways. They insert their keys, put the cars into phase-two service, and push the designated floor and door close buttons to begin their rise into the burning office tower. The doors on both cabs close about three-quarters of the way as the whistling intensifies, then stop and go no farther. The crews try to push the doors the rest of the way closed, but to no avail -- they remain partially open. Frustrated, both crews exit their respective cars with their keys and attempt to commandeer cars across the elevator lobby in the same bank. They experience the same situation. Time passes and stress mounts with every second they remain in the lobby while the blaze races out of control above them with occupants trapped. The decision is made to then go for the stairs and initiate a long, grueling hike up to the fire, knowing that precious time will be wasted. Second Edition 01/11/22 90 After 25 minutes of intense climbing, they reach the fire floor, sweating profusely in gear that does not let their bodies breathe. One exhausted crew begins stretching the first attack line from the standpipe on the 37th floor in the now-designated "attack stair" (the north stair, closest to the fire), while the search crew deploys out onto the fire floor from the opposite stair in a concerted effort to find the missing tenants. Other occupants continue to stream down from the upper floors, trying to stay out of the firefighters' way while still keeping their momentum going in an attempt to flee the light to moderate smoke now entering the attack stairwell as the door is propped open on the 38th floor for the deployment of a 2½-inch hand line. The engine captain radios the command chief in the lobby that the north stair is becoming smoky. The battalion chief at the fire command station realizes that the wind entering the windows blown out from the fire on the windward side of the building must be increasing the Venturi effect of the smoke working its way into the stairs. He pauses for a moment to try and decide if it might be best for his attack crew to hold off the assault on the fire until all tenants coming down from the upper floors have passed them, or try to ventilate the stair by opening the lobby stairwell door and the door leading to the roof at the top of the north stairs. The building's pre-fire plan stair diagram has shown the north stair terminates at roof level. The chief decides to vent the stairwell and continue the fire attack. After the lobby stair door is propped open and two firefighters from the fire floor make it to the roof to open the stair door there, the rush of air up into the attack (north) stair intensifies. Meanwhile, the engine company on the fire floor is advancing the initial hand line out of the attack stair onto the floor. A severe wind-tunnel effect then takes place and conditions rapidly become untenable in the attack stair above the fire floor as heavy black smoke now enters the stairwell and rises towards the tower's upper floors. The attack team is experiencing extreme difficulty making any headway against the fire roaring at them, even with the large hand line flowing well over 200 gpm. Within minutes, the dispatcher relays numerous reports from people calling on their cell phones that they are trapped in the north stair above the fire floor, cannot breathe in the super-intense smoke, and cannot exit the stairs or find a re-entry floor that is open. The chief glances down at the pre-plan and notes that all stairwell doors are mechanically locked, except for reentry/crossover floors every five levels. Knowing that nearly all his initial resources are committed to the fire attack and search efforts on floor 38, a sense of apprehension grips the chief as he begins to ponder if he hasn't made a mistake in opening the stair doors. He wonders how he will address the mass-rescue effort on those upper floors as the second- and third-alarm crews are just now arriving at the building, passing through the opened lobby entrance doors after fighting their way through heavy rush-hour traffic and major congestion around the building site. They then have to face the daunting task of climbing 40 to 50 floors of stairs, maneuvering their way past panicked tenants to reach the trapped victims, hoping they will still be alive when they get there. What happened at this fire to cause the problems presented to the first responders, seemingly confounding their every effort? Is it possible that the natural phenomena of "stack effect" could be involved? Second Edition 01/11/22 91 What Is "Stack Effect"? All buildings experience some degree of stack effect. Even one-story ranch homes use soffit vents to pull air into the attic during warm weather to assist in ventilating the hot air trapped in this enclosed space by way of static or mechanical venting units mounted on the pitched roof. The hot air contained within this space naturally rises and is discharged to the exterior via these roof vents. This process demands "make-up air," which is drawn into the attic through the soffit vents at the base of the roofline. In a high-rise building, the same method of air movement holds true, except the effect is more complicated and pronounced. The impact this has on firefighting operations is significant, yet poorly understood. Consider looking at a high-rise as a "chimney", which is what it truly is for all intents and purposes. Since hot air rises and cool air descends, when a building's interior is heated or cooled by its heating, ventilating, and air conditioning (HVAC) system, a natural draft takes place within the core area where stairs, elevators, and other various shafts are typically located. Consider these shafts to be the "flues." Especially within shafts that are not well sealed (such as elevator banks), air races in and out and moves up or down, depending on the temperature/pressure differential between inside and outside the building and the location/level within the tower. This movement of air within the building is enhanced by the temperature of the outside air, as air will either be attempting to enter or escape the building, depending on the temperature/pressure difference, through any available opening, generally lobby entrances. Consider these entrance doors at the base of the building to be the "dampers." It is important to look at why high-rise buildings act like a chimney and understand air travel within the building into and out of vertical shafts. Everyone knows that warm air rises, and cool air descends, but how do these rising and falling air currents affect the day-to-day operation of a high-rise building and, more importantly, how does it affect firefighting operations? Summer Stack Effect (See Figure 2) Click Here to View Video Showing an Example of the Summer Stack Effect When tenants and visitors enter a tall building in warm weather through a swinging door, they feel cool air generated by the HVAC system rush past them from the interior to the outside environment. These buildings install revolving doors to contain the loss of cold and warm air during the summer and winter seasons and encourage their use by the public. Note that contrary to established fire codes, sometimes swinging doors can be found locked to demand use of revolving doors. The author visited one fully occupied 40-story office building in the Deep South midday last summer where every swinging door was locked, and one of three revolving doors was also locked. I asked a guard why the exits were secured and was told it kept everyone funneled through one entrance point, making it easier to track visitors for security reasons and to conserve air conditioning. I then asked how they would manage a mass evacuation if a fire or other serious event were to occur, not even mentioning the need for fire personnel to make entry with gear and equipment. He then said he would unlock all the secured doors. I then asked him to locate and show me the key. He stated he did not have it, as it was with the security supervisor. Second Edition 01/11/22 92 I asked where the supervisor was and was told he was at lunch. Marvelous. I explained to him the dangers of this practice, that it probably violated local fire codes and that they had a responsibility to create a safe, efficient means of egress from the building during emergencies for the occupants. He assured me he would discuss it with his supervisor when he returned. Common practice there, I suppose. The reason why this summertime downward draft (or "reverse stack effect") is important to be aware of during fires is that if the lobby doors are opened to expedite the movement of firefighters and equipment into the building, it must be considered that if the fire is below the "neutral pressure plane" (typically somewhere between half and two-thirds of the building height, where the pressure differential between inside and outside the building is almost even, or "neutral"), the smoke can easily be drawn down through the core of the building -sometimes many floors below its origin. The fire department's staging floor, typically two floors below the fire, can then be expected to be lost, as smoke migrates out onto these floors, mostly through elevator seals, mail chutes, and stair doors being opened, sometimes even by HVAC systems that are not being effectively managed. Repositioning the staging floor farther down below the fire creates myriad logistic problems for personnel attempting to maintain a continuous assault on the fire, perform searches, and carry out other activities. They are getting farther and farther away from where they are needed. During summer, lobby doors should be kept closed as much as possible. Remember that what you do at the bottom of the building may affect what occurs at or near the fire floor. One fire on the 12th floor in a Texas high-rise on an extremely hot and humid summer day resulted in untenable conditions in the lobby due to the "reverse stack effect" (downward airflow or downdraft), forcing the command post to be relocated in the street. Second Edition 01/11/22 93 Winter Stack Effect (See Figure 1) When tenants and visitors enter a tall building in cold weather through a swinging door, they feel cold air rush past them into the building's lobby. These doors are acting as "dampers" for the "chimney" (the building). The bottom of the chimney is temporarily opened; warm air is allowed to rise rapidly through internal shaft ways (the "flues" within the "chimney") as cold air acts as replacement air, entering the building's base. The air flow rises with increased velocity, mostly due to the substantial temperature differential as well as the tower's height and internal/external pressures. If it is 26 degrees outside and 70 degrees inside, there is a 44-degree temperature differential between inside and outside air. Thus, the air movement (stack effect) is very pronounced. If lobby entrance doors are opened and the stair doors opened as well (if they indeed exit into the lobby -- some exit to the outside and even below grade), then one can expect a rush of air to enter the building and shoot up the stairwells. Keep in mind that the strategy of venting stairs using this method may not work in many cases, as a greater volume of smoke will enter the stairs from the fire floor, due to it being drawn to these shafts by the convection currents, thus contaminating the stairs even more than just leaving the stairs sealed at lobby and roof levels and having some (but not significant) smoke migration/contamination from the fire floor occur in the stairwells. This venting action/tactic with internal staircases in an enclosed core would essentially turn the stairwell into a "smoke tower/fire tower" (a designed evacuation/escape stairwell system where there is a vestibule between the floor's tenant space and stairwell that has either an open shaft with a railing or a dedicated smaller air shaft on the wall next to the walkway to prevent smoke from following fleeing tenants into the exit stairwell). In this scenario, however, the stairwell itself would then become the smoke shaft. It is widely agreed upon that using a smoke/fire tower as the attack stair is poor strategy, due to the chimney effect that will occur since the smoke and fire will be rapidly drawn toward that stairwell location, almost always overwhelming the attack crew (even with 2½-inch hose lines). This has occurred in several major city fires where the attack teams were completely overwhelmed due to this action, including the use of 2½-inch lines. The same thing can occur Second Edition 01/11/22 94 when ventilating a common, standard stair shaft -- a flue is created. This action may also pull smoke from the fire floor into elevator shafts and move it to upper floors, endangering building occupants as the fire and its byproducts are drawn towards the core area -- the same area where people are congregating and fleeing. There may then be significant pockets of carbon monoxide (CO), a poisonous gas, now present on upper floors and points in between, increasing the risk of multiple fatalities occurring, mostly in the stair shafts or installed elevators on these floors where people may be trapped. Remember that CO is a lighter-than-air gas and will easily rise to floors well above the fire. A 2% concentration in air in as little as two minutes can be fatal. Rapid contamination of upper floors will occur and many tenants will be endangered. In the past 10 years alone, there have been two multiple fatality fires where the victims were found well above the fire floor in the stairwell, perishing from CO poisoning. There may also be a stratification taking place, where in tall buildings the smoke rises up until it cools and levels off on a given upper floor or floors (similar to ground fog on a cool evening). This is more likely though to happen during the summer when the air conditioning will increase the probability of this occurring. This generally takes place in and around the "neutral pressure plane." Case Study Here's a case study of an actual incident, the 1993 World Trade Center bombing, involving upward draft/"winter stack effect": It is February, with snow flurries. It is 35 degrees outside and 70 degrees inside the complex, a 35-degree temperature differential. Just 4½ minutes after the bomb detonated on the B2 level of the parking garage, there was heavy smoke on the 110th floor of nearby Tower 1 (the bomb destroyed the base of the skyscraper's elevator and stair shafts, exposing the shaft ways up into the tower above). This meant that smoke traveled 112 floors and almost 1,400 feet in less than five minutes! This was a classic example of "stack effect" as it relates to smoke movement. A 110story "chimney" sat almost directly above the bomb-laden truck and acted as just that when the attack unfolded. The importance of this occurrence escaped nearly everybody, including firefighters in countless cities with high-rise buildings. Yet, it was such a valuable lesson to be learned (and studied) in the natural stack effect that takes place in multi-story structures -- especially skyscrapers containing thousands of people. In this case, the vertical air/smoke movement could not be controlled due to the bomb's effects, but this same type of stack effect can be greatly controlled by rigidly managing the opening and closing of both lobby and stairwell doors. At a fire in Paris three years ago in a high-rise residential building, a small open window at the top of an emergency exit stairwell created a Venturi effect, turning the stair into a virtual wind tunnel and resulted in the deaths of 17 occupants. Second Edition 01/11/22 95 Can you have a "winter stack effect" in the summer and a "summer stack effect" in the winter? It is important to note that you can have a winter or summer stack effect in opposite times of the year, if there is a chilly day in June or warm day in December, since the air movement will directly relate to outside vs. inside temperatures and pressures. Oddities I entered a high-rise office building in Atlanta on a hot summer day and the air was rushing past me into the building (as it would in the winter) as I passed through a swinging door. It suddenly occurred to me why, as I walked into the main floor to discover that there was a large open floor of equal size below me that led out onto the lawn behind the building, some 20 feet below the grade-level main entrance. This meant that the air was being drawn down to that level by the air conditioning/reverse stack effect, accentuated by doors being opened on the main lobby level, mimicking a winter stack effect on that floor in the middle of the summer! I noted one day years ago in the 100-story John Hancock Center in Chicago (which has three exit core stairwells) while taking pictures of U-return stairs that when I walked from the stairwell onto the 13th floor, the door did not close behind me. I turned around and noticed that the self-closing door stayed open approximately one foot due to the draft taking place at that location. It was mid-winter and what was apparently occurring was the building's natural draft (openings at the top may have been present -- even stair doors) drawing make-up air from the floor into the stair shaft as the air ascended at a rapid rate with the significant temperature differential between inside and outside the building -- the draft was actually holding the door open and not allowing it to close. Although the draft was barely perceptible, it was just enough to prevent the door's self-closing device from functioning properly. This is important to note that in this circumstance, if tenants were to flee floors at the bottom of this building, many stairwell doors may not be closing behind the escaping occupants, thereby enhancing the stack effect. In addition to pulling the fire itself toward the core area, this action also increases smoke movement to upper floors -- especially if the fire is on a lower floor. This could easily draw enough smoke into the stairwells to move a considerable amount of smoke to upper floors within minutes, while also possibly making the stairwells untenable for evacuees. Remember what happened at the previously noted incident at the World Trade Center in 1993. The question is, would the incident commander in the lobby even think of or be aware of this strange phenomenon occurring above his head in the tower while commanding the event? Or would he just be forced to react to the ramifications of what is happening and have to dispatch precious resources to upper floors to assist trapped occupants, when the solution may be as simple as having first-arriving search and attack crews to the fire floor ensure that the only door left open is the door to the attack stair so endangered tenants above have a path of escape if they have chosen not to stay in place? Also remember that the upper portion of this tall building is probably experiencing the reverse of this effect, meaning that the air rushing up the stair shafts will be compressing at the top of these shaft ways, creating above-normal back-pressure against the exit doors, making them more difficult than normal for tenants to open when fleeing their Second Edition 01/11/22 96 floors during a fire. Doors leading into smoke tower vestibules would have even more pronounced drafts, but it should not affect the exit stair past the second doorway if it is kept closed -- another good reason to avoid this as the attack stair. One other item of concern (as mentioned in the scenario at the beginning of this article) is that air rushing into a lobby of a high-rise can easily prevent elevator doors from closing at lobby level, thus precluding their use by firefighters trying to reach upper floors. This draft can be incredibly strong in taller buildings. It may even prevent elevator cars from being automatically or manually recalled to the lobby if this same action is taking place on floors above with car doors not closing. The exception to this situation would be if it is a modern high-rise possessing not just stair pressurization, but elevator shaft pressurization system capabilities as well that are activated on alarm. This may likely counteract the rush of air into these shaft ways. However, this would only apply to the newest of buildings (post 1980) and even then only in cities that require it. Summary Maintain the integrity of the base of the "chimney" as much as possible during a high-rise fire, as what you are doing in the lobby in the way of propping open lobby doors and collapsing revolving doors, can have a tremendously adverse effect on what is happening further up the tower. Coldweather fires will push smoke upward into the building in a very pronounced, rapid fashion. If lobby stairwell doors are propped open as well, this can turn the stairwells into virtual chimneys. The attack stair where the fire floor door is propped open for hose deployment will be considerably worse, especially if windows have popped, feeding the fire fresh (make-up) air on the fire floor -- even more pronounced if the broken windows are on the windward side of the building. This will make that stair identical to what the conditions were in the Paris fire -- the stair will be a wind tunnel. Also, firefighters on the fire floor will be quickly overpowered by the fire being drawn towards this flue effect occurring and will be forced to abandon their attack, hopefully without any members being burned. (Note: In cold-weather fires, if elevator doors are not closing due to wind racing up the shaft ways, make certain all entrance doors are at least temporarily secured. This should let firefighters regain use of individual cars to access upper floors. This is exactly what occurred in the story at the beginning of this article.) Venting stair shafts may offer beneficial results on some fires, depending on the height of the building, the conditions, and the use of the stair (attack or search/rescue), but they mostly will end up serving to enhance the smoke condition within these shafts, usually making a bad situation worse by drawing the byproducts of fire towards and into the shaft(s), thereby defeating its purpose as a means of egress for building occupants. If all occupants have been accounted for above the fire floor, then it may be safe to use at least one stair for smoke evacuation if the stair terminates at roof level and conditions are right for this to be done (best in cold-weather fires). Second Edition 01/11/22 97 There are exceptions to every rule and fires have occurred where this tactic proved beneficial to the cause. It is mostly agreed, though, in occupied high-rise building fires, that pressurizing the stairs is a better choice than trying to vent them via the roof, but be careful not to over-pressurize them if using fire department fans, which might inhibit people in the tower from opening exit stair doors when fleeing their floors due to excessive back pressure. Also remember that many buildings' exit stairwells do not terminate at roof level, though most buildings have at least one that does. Some buildings do not even possess a roof that is accessible, with architectural spires or sloped roofs in place. This should be noted in the building's pre-fire plan, if one exists. Stack effect plays such a major role in these fires that it should be stressed heavily in officer training for high-rise district company and chief officers, as well as being a prominent aspect of a city's existing high-rise standard operating procedures/standard operating guidelines (SOPs/SOGs) -- especially since it is a vitally important topic not well understood in the fire service. Controlling air movement will play a positive role in the outcome of a serious incident. Survivors of a fire in these edifices will owe you their lives. CURTIS S.D. MASSEY is president of Massey Enterprises Inc., the world's leading disaster-planning firm. Massey Disaster/Pre-Fire Plans protect the vast majority of the tallest and highest-profile buildings in North America. He also teaches an advanced course on High-Rise Fire Department Emergency Operations to major city fire departments throughout the U.S. and Canada. Massey also regularly writes articles regarding "new-age" technology that impacts firefighter safety. Very special thanks to District Chief Matt Stuckey of the Houston Fire Department (ret.) and Deputy Chief Roger Sakowich of the FDNY for assisting in the technical critique of this rather complicated article. Second Edition 01/11/22 98 STAIRWELL DESIGNS STAIRWELL OVERVIEW ● There are three different stairwell types firefighters will encounter in high-rise buildings: ○ Return Stairs ○ Scissor Stairs ○ Access Stairs ● Stairwells are required to be labeled. (Roof access, Basement access, etc.) ● The floor number should be on every floor landing RETURN STAIRS ● The most common stairwell type ● Enters and exits on the same side of the core ● Standpipe outlets are usually on the floor landing ● Newer construction is placing the standpipe outlet on the half landing ○ This requires an extra half floor down to make the standpipe outlet connection ○ Potential need to add an additional section of hose based on the fire location Stairwell core with Return Stairs Second Edition 01/11/22 99 SCISSOR STAIRS ● Not as common, but several buildings in Columbus have them ● They are installed in pairs in the same core structure ● They are divided by a fire rated wall ● Generally, they are a straight run of stairs (no mid-landing) ● Firefighters should choose the stair that will place them on the fire side of the core ○ Otherwise, they will have to stretch around the core to the fire Stairwell core with Scissor Stairs Second Edition 01/11/22 100 ACCESS OR CONVENIENCE STAIRS ● Designed to give access to multiple floors owned or rented by the same tenant ● Can be found in both residential and commercial properties ● These stairs do not have to be enclosed or fire rated ● Can create a fall hazard from the floor above or an exposure problem if the fire is located on the floor below Access stairs for employee convenience Second Edition 01/11/22 101 FIRE CONTROL ROOM OVERVIEW ● The Fire Control Room is the “Brains” of the fire protection system ● Depending on the system complexity, firefighters will find either a whole room devoted to the controls, or just a single panel at the entry point ● Inside the control room, firefighters may find the following: ○ Full Control Annunciator Panel ○ Remote Fire Panel (Typically at the entry point of the building) ○ Elevator Control Panel ○ Smoke Control Panel ○ Building Communication Systems FULL CONTROL ANNUNCIATOR PANEL ● Typically found in more complex systems ● Provides a central location to access the building fire protection system, which can help firefighters accomplish the following tasks: ○ Determine more specific locations of fire alarms ○ Silence alarms and determine the alarm system status, such as “Trouble” ○ Make public address announcements ○ Communicate directly to designated fire phones Annunciator panel with PA and building communications Second Edition 01/11/22 102