Cellar Fires and the Cellar Stairway

FEATURES

Cellar Fires and the Cellar Stairway

FIREFIGHTING TACTICS

The cellar fire presents the firefighter with a most serious fire attack situation. This is due in no small measure to the limited prospects of ventilation and the fact that the attack team, to initiate the extinguishment effort, must descend into the cellar in the face of heat and smoke produced by the fire.

Within the context of the fire attack, the cellar stairway takes on considerable tactical significance. It’s the attack team’s only route into the cellar and its only means of egress. It’s also the primary channel of fire extension and ventilation.

In light of the tactical significance of the cellar stairway, and, hence, of stairway operations, we must consider the relationship between the cellar, as fire compartment, and the cellar stairway relative to fire dynamics; the hazards the stairway holds for the attack team; and procedures that might make stairway operations safer and more effective.

Since the prospects of ventilating cellar fires are poor at best, the cellar stairway becomes the primary exhaust outlet for the combustion products emerging from the cellar during a fire. Heat and fire gases, thermally buoyant and seeking an outlet to the atmosphere, rise to the cellar ceiling; with their upward path blocked, they travel horizontally along the ceiling to the nearest vertical channel—the stairwell —where they will once again rise and confront the attack team. The fire products traveling up the stairway are propelled by all of the heat and pressure supplied by the fuel load. Quite literally, the attack team’s descent into the vertical channel of the cellar stairway—the primary path of fire ventilation and extension—is like a descent down a chimney into a furnace.

The cellar stairway door

The stairway’s transformation into an exhaust outlet places heavy significance on the cellar stairway door. Regardless of whether it’s located at the top or bottom of the stairway, a closed cellar door becomes the primary barrier to fire extension via the stairway. When the door is opened, the pressure of the fire propels the products of combustion out through the doorway, endangering the occupants, the attack team, and the entire structure. Therefore, the opening of the cellar stairway door must be viewed as a significant event within the fire attack.

The stairway door must not be opened prematurely or arbitrarily; rather, as a useful, temporary fire barrier it provides the incident commander with the time to formulate and initiate the plan of attack. Only when all attack and backup lines are in position, manned by fully protected firefighters ready to commence operations, should the door be opened. All firefighters involved in the attack must communicate and coordinate their efforts prior to that event.

Once the firefighters are in position and the attack plan communicated and understood, the attack team leader must assess, through a critical examination of the door, the severity of the fire on the other side. A serious cellar fire may be in progress when

  • a cellar stairway door is extremely hot to the touch;
  • flooring near the door is hot to the touch;
  • there’s passage of smoke and/ or heat through the cracks between the door and its frame; and/or
  • there are indicatidns of pyrolytic damage (that is, heat-induced chemical decomposition) to the door.

Any or all of these conditions should be immediately relayed to the incident commander. The high probability of a serious fire may indicate revision of the attack plan or request of additional fire-suppression resources to the scene.

Once assessment of the cellar door is completed and the order is to proceed, the stairway door is opened and the attack initiated. Remember: When the door is opened, a fire barrier is removed. The attack and backup teams can expect to be confronted by severe levels of convective heat, a heavy smoke, and the possibility of an advancing fire front. Therefore, it’s essential that the attack and backup teams be absolutely ready to initiate the fire attack before the cellar door is opened.

The door is opened….

In beginning the attack, I suggest that the attack line be directed down the stairwell and operated in the straight-stream mode so as to ensure maximum stream reach and penetration with minimal air introduction by the hose stream. The objective of the attack line is to cool the atmosphere of the cellar, the combustibles adjacent to the cellar stairway, and the stairway itself, all in an effort to retard fire growth while the line is advanced down the stairway. Thus, the nozzle should be rotated so as to deflect the stream off the cellar stairway and ceiling. The resultant broken stream is an acceptable compromise between fog stream (with its higher heat absorption and air entrainment levels, but lower reach and penetration capabilities) and straight stream (with its higher levels of reach and penetration, but lower levels of heat absorption and air entrainment). The rotation of the solid or straight stream will help to ensure a reasonable rate of heat absorption, stream reach, and air entrainment for the attack team as it operates within the relatively unventilated atmosphere of the cellar.

The initial application of water is critical, since the attack team—due to bulky turnout gear, nozzle reaction, and insecure footing—may not be able to operate the attack line during their descent of the cellar stairs. Accordingly, the initial discharge must sufficiently retard fire growth to allow the attack line to advance to the base of the stairway and the first backup line to move to the top of the cellar stairs. If the cellar door is located at the bottom of the cellar stairway, the attack evolution is less punishing, as the advance down the stairway will be done under the protection of the closed stairway door.

Descent begins….

During the descent of the cellar stairway, the attack team must remain aware that the stairway may be unsafe. Because it’s usually cheaply constructed, and because it lies directly in the path of fire extension, the cellar stairway can be expected to fail early in the fire attack, often without warning, dropping the attack team into the fire area without a means of egress. The stair thread and riser construction may be of uneven dimensions, and the stairway itself may be used for storage. This further increases the chances of falling down the stairway, which could mean serious injury from the fall itself or from exposure to products of combustion in the event of dislodgement or failure of the firefighters’ protective equipment.

For the firefighter who’s following fire attack procedures, descending the cellar stairs represents an unnatural and physically awkward movement. For generations, firefighters have been taught —and rightly so —to advance slowly and remain close to the flcfor in an effort to stay under heat and smoke conditions. However, bulky turnouts and SCBAs make the descent even more awkward and place the firefighter’s center of gravity further forward than normal, increasing the likelihood of a firefighter losing balance and falling down the stairs.

To minimize this risk factor, I submit that each firefighter in the attack team descend the stairway on his right side in a feet-first, step-by-step, sliding motion. To control the speed of the descent, the firefighter places the right forearm on the chestor shoulder-level stair thread; the right thigh on the next or second-next stair thread, whichever is the more comfortable, in an almost sitting position; and the right foreleg on the nextlower stair thread, with the left hand grasping the attack line. In this feet-first descent, the firefighter’s center of gravity is in a more stable position, and weight is distributed over a larger area of the stairway.

Should there arise the need to withdraw during the descent, the firefighter merely rotates onequarter turn and crawls up the stairs on all fours, with the backup line operating as necessary to cover the withdrawal. Some have put forth that the attack team should advance in a sitting position, one step at a time. This method is counterproductive: Limited stair thread dimensions, bulky turnouts, and (hopefully) mandatory use of SCBAs prevent even the smallest of firefighters from sitting on stairway threads.

At the cellar floor…

Now at the bottom of the cellar stairway, the attack team must quickly ascertain, by review of fire, smoke, and heat conditions, the location of the main body of fire. Typically, in the reduced-visibility conditions that are characteristic of cellar fires, the attack team advances in the direction from which the heat is most severe. Depending on the fire and smoke conditions present, the attack team leader may want to consider delaying the second application of water in the hope that the fire might exhibit flaming behavior, thereby revealing the location of the main body of the fire. The blind and continuous application of water is unproductive. It increases the accumulation of water on the cellar floor, increases water damage, and further reduces visibility— all of which makes the task of locating the main body of the fire more difficult.

At this juncture, the attack team is particularly vulnerable to several serious hazards.

One such hazard is the firefighters’ loss of orientation to their position within the cellar. This is very dangerous because

  • the stairway is the only means of egress;
  • firefighters who lose their way could expend their SCBA air supply;
  • cellars are usually loaded with combustibles, creating the poten-
  • tial for a serious fire while, at the same time, making firefighter movement more difficult; and
  • disorientation creates psychological disturbance —and even panic—which could hinder firefighting safety and efficiency.

Attack team members must stay in physical contact with the attack line and with each other to preserve their directional orientation with the stairway; they must also maintain verbal communication to provide each other with encouragement and reassurance.

Equally important, the attack team must note, prior to opening of the stairway door, the orientation of the stairway with respect to the structure as a whole. Awareness of whether the stairway will lead them to the middle or the periphery of the cellar is a great help.

An equally dangerous hazard results from the stairway’s natural tendency to serve as exhaust outlet for the fire. The fire—propelled by the thermal buoyancy of its gases as well as by the air flow induced into the cellar by the operation of the attack line—may advance up the stairway at any moment, trapping the attack team.

If this occurs, two elements of the attack assume critical importance: the use of a straight stream by the attack team and the prudent placement of backup lines. Straight streams move less air into the cellar and reduce the possibility of a large air flow propelling the fire up the stairway. For a residential cellar fire I recommend at least one backup line. It will support the attack line and preserve the stairway’s escape integrity.

The backup lines

When the attack line advances to the bottom of the cellar stairs, the backup line should assume a position at the top of the stairway from which it can protect the stairway or assist should the attack line encounter a volume of fire beyond its capability. The backup line maintains a fire-suppressive presence that’s capable of supporting the fire attack, preventing interior fire extension, and preserving the escape integrity of the stairway.

At a residential cellar fire of a significant magnitude, two backup lines with the primary attack line ensure that the attack effort will always be supported and protected by at least one additional line. If only one backup line is used and that line is committed to operations on the cellar floor, then there won’t be a line available whose sole purpose is to protect the stairway as a means of egress. A second backup unit ensures stairway protection and attack support. Advancement of the backup lines must closely follow advancement of the attack line; accordingly, the stairway door must not be opened until all lines are operational.

The cellar fire represents a difficult and serious fire situation. As the attack forces initiate the extinguishment effort, they must descend into the fire area in the face of heat and smoke. There’s no doubt that the cellar stairway is of great tactical importance in cellar fire attack operations. It’s the primary path of fire extension, ventilation, attack, and egress, and its integrity must be preserved.

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