All attempts must be made to ensure that fire attack operations and evacuation operations are performed in separate stairwells. (Photo by Alessio Damato.)
When fires occur in multiple-story buildings, many of the operations that must be performed must be adjusted as compared to when fires occur in single-story buildings. One of the tactical decisions that must be made at fires in multiple-story buildings that does not have to be made at fires in single-story buildings is the selection of the stairwell that will be used for the fire attack operation. In addition to selecting the stairway that the fire attack operation will be conducted from, the stairwell must also be selected that evacuating building occupants will use. All attempts must be made to ensure that fire attack operations and evacuation operations are performed in separate stairwells. Avoid performing fire attack operations and evacuation operations in the same stairwell whenever possible, as this decreases the effectiveness of both operations.
Everybody knows that, regardless of who the initial arriving officer is on the scene of a fire - whether it be the engine company officer, truck company officer, squad/rescue company officer, or chief officer - he must provide a size-up report. At fires in multiple story buildings, stairwell designation must be included in this initial size-up report. Both the fire attack stairwell and the evacuation stairwell must be designated during the initial size-up report. Lack of stairwell designation in the initial size-up report will result in a lack of coordination of efforts once other responding units arrive on the scene. This lack of coordination of efforts will result in a decrease in the effectiveness of the fireground operation as a whole.
Stairwell designation does not typically refer to open stairwells. Open stairwells are those that are not located within their own enclosure within the building. Open stairwells instead are stairwells that are located throughout a building and are open along one or both sides of the stairwell and are vulnerable to fire spread. Instead, stairwell designation typically refers to stairwells that are located within their own enclosures within the building. Because of the types of stairwells involved in stairwell designation, stairwell designation is typically not necessary at fires in one- or two-family dwellings regardless of the fact that these buildings may be multiple stories in height. Instead, it is in multiple-story, multiple-family dwellings; some multiple-story apartments and hotels/motels; and multiple-story commercial buildings where stairwell designation becomes an issue. A common building design that will require stairwell designation is a multiple-story apartment building that contains two enclosed or smokeproof stairwells on the ends of the building and a common hallway that travels from one stairwell to the other with all the apartments on each floor located along the common hallway. In this type of building, one of the stairwells should be designated the fire attack stairwell, and all fire attack operations should be performed from that stairwell; the other stairwell should be designated the evacuation stairwell, and all evacuation operations should be performed from this stairwell.
Enclosed and Smokeproof
There are two types of stairwells that are typically used during stairwell designation: enclosed stairwells and smokeproof stairwells. An enclosed stairwell is a stairwell that is located within its own enclosure within the building. The enclosure that contains an enclosed stairwell is designed to prevent fire from spreading into the stairwell. These enclosures are typically constructed of concrete. Unless a door into an enclosed stairwell remains open, a fire should not be capable of spreading into the enclosure of an enclosed stairway. Enclosed stairwells also require the use of automatic closing devices on enclosure doors to prevent doors from being left open and allowing for fire spread into the stairwell to occur.
The other type of stairwell that is typically used during stairwell designation is smokeproof stairwells. A smokeproof stairwell is like an enclosed stairwell in that it is located within its own enclosure within the building, and the enclosure is designed to prevent fire spread into the stairwell. Smokeproof stairwells also include another feature that enclosed stairwells do not: the presence of a ventilation shaft. These stairwells use a fan to pressurize the enclosure of the stairwell. This pressurization forces smoke that enters the enclosure of the stairwell into the ventilation shaft, where it is no longer a hazard to firefighters or evacuating building occupants. The pressurization of smokeproof stairwells has led to these stairwells many times being called pressurized stairwells.
Type and Location
When selecting the fire attack stairwell and the evacuation stairwell, consider two primary stairwell characteristics: stairwell type and location. Both must be evaluated and, in some instances, both stairwell type and location will indicate that a specific stairwell should be designated for fire attack and another stairwell should be designated for evacuation. There will also be situations where stairwell type and stairwell location will both indicate that a specific stairwell would be the best stairwell for fire attack but would also be the best stairwell in which evacuation efforts should be performed. When you encounter this situation, you must decide which operation will benefit the most from being performed in that specific stairwell.
Stairwell type is important during the stairwell designation process because of the safety features of the different stairwell types. Enclosed stairwells prevent fire spread into the stairwell while smokeproof stairwells prevent fire spread into the stairwell as well as possess a ventilation shaft and a fan that pressurizes the stairwell and removes smoke through the ventilation shaft. It is best for evacuation efforts to be performed in smokeproof stairwells. The pressurization of these stairwells and the ability of these stairwells to ventilate smoke that enters the stairwell though the ventilation shaft make smokeproof stairwells the best stairwells for evacuation operations.
The same characteristics of smokeproof stairwells that make them the best choice for evacuation operations also make them the best option for fire attack operations. Not all buildings will have multiple smokeproof stairwells though. If the building has a single smokeproof stairwell and another, nonsmokeproof enclosed stairwell, the smokeproof stairwell should be used for the evacuation effort and the enclosed stairwell should be used for the fire attack operation. An important characteristic of an enclosed stairwell is a roof access. If there are multiple enclosed stairwells and only one of the enclosed stairwells contains a roof access, the enclosed stairwell with a roof access should be selected for the fire attack operation.
On entering the enclosed stairwell, a firefighter should be sent to the top of the stairwell to open the roof access to create a vertical ventilation opening for any smoke that enters the stairwell. This firefighter should also ensure that the stairwell door on each floor is closed to prevent smoke that enters the stairwell from the fire floor from spreading to additional floors of the building through an open stairwell door. A positive pressure ventilation (PPV) fan can also be positioned at the entrance to the enclosed stairwell and used to pressurize the enclosed stairwell just like smokeproof stairwells are pressurized. Once the enclosed stairwell has been pressurized by a PPV fan and the roof access has been opened, a smokeproof stairwell has essentially been created. The PPV fan will force any smoke that enters the stairwell to the top of the stairwell where the roof access is located, and the smoke will then be ventilated through the open roof access. Gas-powered PPV fans should only be positioned at exterior entrances to enclosed stairwells, as the carbon monoxide production from a gas-powered PPV fan will create an inhalation hazard if the fan is positioned at an interior entrance to the stairwell.
Stairwell location is the other important stairwell characteristic that must be considered during the stairwell designation process. The stairwell that is located the closest to the fire area should be designated as the fire attack stairwell. The stairwell that is located the farthest from the fire area should be designated as the evacuation stairwell. Designating the closest stairwell to the fire area assists the fire attack operation by shortening the distance that the fire attack hoselines must be advanced from the fire attack stairwell to the fire area. Designating the stairwell that is the farthest from the fire area benefits the evacuation operation, as it directs evacuating building occupants to the area of the building that is the farthest from the hazard. Most importantly, it directs the evacuating building occupants away from the smoke produced by the fire. The stairwell that is the farthest from the fire is also the least likely stairwell for both fire and smoke to enter. As evacuating building occupants do not have any form of respiratory protection to shield them from smoke inhalation, positioning these building occupants away from the smoke produced by the fire improves the safety of the evacuating building occupants.
When the stairwell type and the stairwell location evaluations both indicate that the same stairwell should be used as the fire attack stairwell, the incident commander must evaluate the building and the fire conditions and designate the stairwells in a manner that will allow for the most effective operation to be performed. The smokeproof stairwell may be able to be designated as the evacuation stairwell even though it is the closest stairwell to the fire area when the result of designating the closest stairwell to the fire area as the evacuation stairwell will only extend the distance that the fire attack hoselines will need to be advanced to reach the fire area by 15 to 20 feet.
In other situations, designating the closest stairwell to the fire area as the evacuation stairwell because it is the only smokeproof stairwell that the building has may result in greatly increasing the distance that the fire attack hoselines lines must be advanced. The incident commander must evaluate all conditions and determine which stairwell will allow for the most effective operation to be performed and designate the stairwells in that fashion.
The importance of stairwell designation at fires in multiple-story buildings cannot be stressed enough. Allowing both fire attack operations and evacuation operations to be performed in the same stairwell only limits the effectiveness of both operations. Evacuating building occupants traveling down the same stairwell that firefighters are attempting to ascend will result in both the evacuating building occupants traveling down the stairwell slower as well as slowing the progress of the ascending firefighters. By designating a fire attack stairwell and an evacuation stairwell at the onset of the incident, both the fire attack operations and the evacuation operation can be more effective. Even when stairwells are properly designated, there will still be instances where both evacuating building occupants and firefighters end up in the same stairwell; this is unavoidable, but by minimizing the occurrence of both firefighters and evacuating building occupants occupying the same stairwell, the effectiveness of both operations is improved.