Fireground Strategies: Fighting Shaft Fires

BY ANTHONY AVILLO

As a fire officer, consider the following scenarios.

Scenario 1: You arrive at the scene of a fire in a wood-frame multiple dwelling that is attached on both sides. Fire is showing from side A on the second floor. There is heavy smoke. As you are deploying your resources, you observe that the fire has somehow “jumped” and is now also showing in exposure D on the third floor. What happened here?

Scenario 2: You are responding to a reported working fire in the cellar of a three-story old-law tenement of ordinary construction. You are getting reports of heavy smoke at the roof. The next report is that fire is showing above the roof. What happened here?

Scenario 3: It is 0300 hours. You are first on-scene at a working fire on the ground floor of a three-story multiple dwelling of ordinary construction, attached on both sides. There are four apartments on each floor, two on the right and two on the left, front and rear, respectively. As you look into the first floor, you observe what looks like a bonfire in the apartment. The absence of smoke at the front of the building is unusual. What happened here?

The common thread among these three scenarios is that a shaft was involved, which created a potentially puzzling condition for the incident commander (IC). Failure to recognize the fire spread potential when a shaft is involved has led to firefighter injury in addition to the destruction of many buildings and, unfortunately, blocks of buildings.

In the first scenario, fire issuing from the second-floor window spread by both radiant and convected heat to the higher window on the third floor of the adjacent exposure. This fire travel occurred in the shaft, either completely or partially concealed between the two buildings but undistinguishable from the A side of the building.

In scenario 2, fire took the most effective path of least resistance, which is usually in a vertical direction before a horizontal direction, and found the shaft and spread upward. It is possible here that the fire (smoke?) was too rich to ignite in the shaft, but when the gases properly mixed with oxygen at the more open-air roof level, they ignited, creating the report of fire above the roof. ICs should be aware that a report of fire at the roof level may not be the same as fire through the roof. Only investigation will reveal this.

Scenario 3 presents a fire that is obviously venting somewhere other than within the IC’s view. Since it is nighttime, the smoke condition at the roof level may not be visible. All fires vent smoke and heat. The key is to recognize where that vent point is, especially when it is not expected in a particular type of building.

SHAFTS

Light and air shafts have been with us since before the turn of the 20th century. Their function was, as the name implies, to provide light and air to apartment rooms located on the interior of the building. This was essential to city living before the advent of electricity and air-conditioning; the function of these shafts was to provide air circulation to parts of the building that otherwise would not have had any. Along with the transom, a glass window above apartment entrance doors, these shafts used the building’s natural stack effect to effectively ventilate and provide air movement in the structure. In fact, the greater the difference between the interior and the exterior temperatures, the greater the airflow provided. This was an efficient system that, unfortunately, was made more efficient when a fire occurred inside the building. At that point, the flow of air (and fire, smoke, and gases) would rapidly rise in the shafts, spreading fire to not only the upper floors of the fire building but also to the adjacent exposures.

There are several types of shafts. They generally fall into two categories, enclosed, or surrounded on all sides by the building or buildings, and nonenclosed, where the shaft is open at the front or rear or—in the case of an H-shaped building—both (photos 1, 2).


(1) Enclosed shafts are often visible only from the roof or the building’s interior (if it is noticed). On the extreme left, the shaft is shared by two buildings. The two shafts in the center and on the right appear to be exclusive to only one building. Only recon will confirm this. (Photos by author unless otherwise noted.)

 


(2) Unenclosed shafts may be visible at the front, at the rear, or in both places. In this double H-type multiple dwelling, shafts are present at the front and the rear. The throat is in the center.

The construction of the exposure also has a tremendous influence on the spread of fire in the shaft. Buildings of wood-frame construction, with their combustible exterior, are a much more serious concern during a fire that has originated in or spread to a shaft than a building of ordinary construction. In the former, not only are windows and walls exposed and subject to ignition and autoexposure, but the wood roofing materials are also. In the latter, since the walls are noncombustible, the threat, while still existent, is minimized by this construction-influenced feature (photo 3).


(3) Note the “V” pattern-like fire damage on this combustible asphalt shingle wall. The half-diamond shaft vented fire that ignited the siding. Note how the shaft has been covered over.

The size of the shaft will also bear significantly on the fire spread and the vulnerability of upper floors and the exposure. The velocity of the smoke and hot gases up a narrow shaft will be more destructive than the same gases in a larger shaft. That is because in the smaller shaft there is less room for the gases to dissipate and entrain cool air. Higher temperatures result in increased gas pressure, which results in increased velocity. This will cause a more pronounced heat buildup in the shaft. As the shaft increases in square footage, the more the gases will tend to slow, since the size of the shaft allows for more dispersion of heat. Thus, a narrow shaft in a wood-frame building will present the worst-case scenario when you are confronted with a fire that has originated in or spread to the shaft. Combustible walls and open windows, as well as wood roof materials beneath metal flashing, will be particularly susceptible.

DETECTING THE PRESENCE OF SHAFTS

Shafts may also have been covered over completely by renovations or by the addition of skylights or scuttles to keep the heat in the building. This will create firefighter safety and ventilation concerns. Firefighters have fallen into shafts covered over by nothing more than tar paper. I once heard a story from a fellow firefighter of steel chain-link fencing covering the shaft opening. There was a self-service laundry below, and the lint coming from a broken vent system accumulated on the fence, making it look like a blanket. This may be visible during the day but will be extremely hazardous at night.

Covered shafts create other concerns. They will cause gases to mushroom and ignite combustibles, such as combustible exterior walls and adjacent apartments. Covered shafts may also cause superheated gases to permeate sealed areas and create backdraft conditions. If the covering is made from substantial materials, backdraft conditions can build up in the shaft and permeate the cockloft. A firefighter from my department lost his life searching a top-floor apartment for a reported victim when a simultaneous shaft and cockloft backdraft trapped him. The shaft was covered by a thermal pane skylight. It did not allow the gases and fire to vent (photo 4).


(4) Covered shafts can create backdraft conditions inside the shaft and in the cockloft. Roof Division firefighters must report this to Command immediately. This one is covered with fiberglass and has a vent pipe from somewhere below inside it.

A major key to fighting fires in shafts is to recognize the shaft’s existence. Most, if not all, old attached buildings will have shafts between them. If they don’t, you are lucky (not likely), or they have been covered over and you will need to investigate why the fire is spreading so quickly vertically between two adjacent buildings.

Shafts may be recognized in some other ways as well.

Roman Candle Condition

Companies arriving to see a rocket-like plume 20 to 30 feet above the building must recognize that the fire is likely venting into and traveling through a shaft. This is not necessarily a bad condition, as the fire is doing what the personnel on the roof would be doing—bringing the fire up and out so it doesn’t spread laterally. This should not be confused with a “through-the-roof” condition. Do not stick a ladder pipe or other master stream here (photo 5).


(5) The Roman candle condition is indicative of a shaft fire. Allow the fire to keep venting in the upward direction. Pinch it off by stretching lines to all areas on the shaft. Do not use master streams from above; they will push the fire back into the building. (Photo by Ron Jeffers.)

 

Half Shaft on a Corner Building or on a Building Unattached on Only One Side

Although rare on a corner building, because it usually has a flat side wall facing the street, the half shaft will usually be present if a fire or a demolition (or both) have eliminated what once was an attached exposure. If you see a building with a half shaft, assume there is an identical half shaft on the other side, which may also be complemented by a half shaft in the adjacent building. This occurs in many old-law wood-frame tenements where what is termed a “half-diamond shaft” exists. You may see only the half diamond where the building is unattached, but there may also be another half diamond on the other attached side and possibly on the exposure, making for a full diamond shaft between the two attached buildings. This diamond shaft may have four windows opening to it on each floor, potentially exposing, on all floors, many windows at once in the tiny shaft. If not, and an unpierced wall is present on the exposure, there is still the potential for combustible wall ignition and burn-through through the half-diamond shaft (photo 6).


(6) This photo is taken from the C side. Note the half-shaft condition on the B side of the building. This can be seen from the yard behind the B exposure. This is a tip-off to a half shaft on the D side. Note that the D-side shaft is enclosed. It is likely that the exposed wall of the D exposure is unpierced. Make sure of this through recon.

 

Roof Division Reconnaissance

Especially in attached buildings, someone must get to the roof to recon the rear and sides and provide a report as soon as possible. This report should include, among other things, the presence of any shafts, whether they are open or enclosed, and whether there are victims or fire or both in them. Firefighters accessing the roof from the attached exposure must use extreme caution when crossing over to the roof of the fire building. Shafts can be open at the front or rear, or they may be totally enclosed. They may or may not be protected by parapets. A firefighter may be able to step onto the adjacent building roof at the front of the building but not at the back, and vice versa. In these cases, firefighters can step over a parapet and take a three- to four-story fall into a shaft or, if there is no parapet, can just walk off the side of the building (photo 7).


(7) Although there are parapets between these two sister buildings, there is an open shaft at the rear. You can cross over at the front but will step into a five-story shaft at the rear. Always probe for a support before taking a step.

Heavy smoke can mask conditions on the roof, so always probe areas before stepping onto what you believe is an adjacent roof. To assist in preventing shaft falls, Roof Division firefighters should beware of parapets that do anything but run in a straight line. When these walls angle off at a 45° angle or even a 90° angle, especially in the center of the roof, beware: There is usually a shaft on the other side.

In addition, heavy smoke conditions often mask the presence of shafts; therefore, personnel going to the roof of the exposure for access to the fire building should make it a habit to investigate their surroundings, namely the other adjacent buildings. These buildings are often built identically in rows so that the locations of shafts are consistent from one building to the next. For instance, if a team of firefighters is going to the roof by way of the B exposure, they should look at the orientation between the B exposure and the B1 exposure. If there is a diamond shaft or open half shaft at the rear between exposures B and B1, chances are there is an identical shaft between the B exposure and the fire building (and possibly between the fire building and the D exposure, and so on). Although this is not an absolute, it is a pretty good rule of thumb (photo 8).


(8) Note that there is a parapet at the front of the building but none at the back. Note also how the roof angles off at 45°. Check the adjacent roofs for orientation here. This is a four-story drop.

 

Perimeter Reconnaissance

If the shafts are not completely enclosed, then personnel assigned to recon the rear and sides of the structure should see these shafts and must report their presence to Command. If the shaft is at the front, all personnel should see it. Be aware, however, that in a very heavy fire and smoke condition, what can appear as two adjacent buildings may be joined by a shaft 20 or so feet back from the A side between the two buildings.

Windows on Side Walls of Attached Buildings

Interior firefighters can use this cue. If the buildings are attached, common sense says that there should be no windows on side walls. If there are, you can draw only one conclusion: A shaft is present. In old-law buildings, shaft windows are usually present on side walls inside the apartments and are usually smaller in dimension, joining each other at a 45° angle. In new-law buildings, shaft windows are usually present in both hallways and in apartments, so personnel may see them earlier. They are not angled. They are usually much larger, too. In either case, you must report them, and Command must take steps to stop fire spread into them (photo 9).


(9) These windows, located inside an apartment in an old-law tenement, open on a half-diamond shaft. There are usually large amounts of ignition-prone garbage at the bottom of these shafts

 

Ground-Floor Store-Attached Mixed-Use Occupancies

To maximize the square footage of the store area, in these buildings, the shaft does not start until the second floor. In this case, it will be visible only from the roof or the interior, inside an apartment. This will apply to older attached buildings with stores on the ground floor and apartments above. Some jurisdictions call these “taxpayers” (photo 10).


(10) The shaft above this store does not begin until the second floor. There is an identical shaft on the other side between this building and the attached exposure.

 

STRATEGIES

Strategically, the key is to slow the gases in the shaft. Slower gases are cooler gases. This is accomplished in one of two ways: Either cool the gases at their source, which we can control, or hope the shaft they are venting into is wide enough for the gases to dissipate, which we cannot control. In fact, the more quickly water is applied to the seat of the fire, the sooner the gases will slow in the shaft and the less influence they will have on nearby fuel packages.

In addition, a successful IC is always thinking ahead of the fire. What this boils down to in this case is to assign task forces to both the fire building and the threatened exposures as quickly as possible.

The objective of the task force should be to focus on keeping the fire out of the exposure. To this end, it is prudent to consider the activities required to accomplish that objective. Using the CRAVE (Command, Rescue, Attack, Ventilation, Extension Prevention) acronym in regard to interior firefighting, we will discuss fire building and exposure operations and how they relate to shafts.

Command

Fire Building. To operate safely and most efficiently, it is critical to decentralize Command. Most of the time, designating only an Interior Division supervisor in the fire building will suffice. However, if there are multiple wings or areas of operation remote from each other and critical to the operation, additional Interior Divisions can be created as required, such as Interior Alpha (A wing) and Interior Bravo (B wing). The assignment of division supervisors not only in the fire area but also in affected exposures because of a shaft, a close exposure, or a common cockloft will allow for an efficient and immediate exchange of information between the critical operational areas. It is the best way to keep Command informed through regular progress reports so better decisions can be made on behalf of these threatened areas.

Shaft Exposures. A division supervisor must be assigned to each threatened exposure to directly supervise the operation in that exposure. Companies can then be fed as task forces (the most efficient manner of assigning companies) to designated divisions. In fact, decentralizing Command is the single most important action to take when faced with an exposure issue through shafts (or at any fire with multiple area-related concerns). Reduced radio traffic, less redundancy in orders, a better fireground organizational structure, and improved accountability are all by-products of efficient decentralization. This all equates to fireground safety.

Any area delegated must be announced over the radio. A simple statement such as, “Dispatch from Main Street Command, be advised, Battalion 1 is Interior Division supervisor; Battalion 2 is now Delta Division supervisor,” will be sufficient.

When a fire originates on a lower floor and threatens to extend to a shaft, areas of concern will be the floors directly opposite and above the fire apartment. These areas will be exposed to radiant and convected heat as a result of the rapid thermal updraft flowing into the shaft. Timely, well-placed, and competently directed fire forces can intervene to thwart any extension into adjacent buildings.

On a top-floor fire, Command may be faced with extension through the shaft and into a common or adjacent cockloft. The upside of this situation is that above the top floor and cockloft are only the roof and the sky; thus, upward fire extension problems are minimal compared with a lower-floor fire unless, of course, the fire building is not as tall as the exposure. When this occurs, additional concerns, such as the need to protect the upper floors of the exposure, will be present. Early reports from the Roof Division must alert Command as to the presence and location of shafts so the proper supervisory and operational personnel can be assigned to affected areas as soon as possible.

When the fire originates in the shaft, all of the above mentioned concerns will be present, and then some. Often, tenants throw garbage into the shaft; over time, it can accumulate right up to the bottom of the first-floor window. One errantly tossed cigarette can be deadly. Two buildings will be simultaneously exposed. Which one to protect first may be decided by wind direction, building construction, and current and forecasted conditions.

Attached building fires, and shaft fires in particular, are personnel sponges. Transmit additional alarms early if you want to keep up with the fire spread potential. In addition, don’t forget that you will need a tactical reserve of at least a task force of two engines and a ladder company to provide for relief, reinforcement, and the need to address unplanned for concerns. Also request Command officers early. The more personnel needed, the more the supervisory demand.

Rescue

For both the fire building and shaft exposures, you must conduct primary search and evacuation of all exposed areas immediately. There is no such thing as protection-in-place here. This will necessitate more than the services of only one ladder or rescue company. In fact, if personnel are in short supply, especially in the initial phases of the operation, engine companies stretching lines to exposed areas can also be pressed into service searching off hoselines and evacuating those areas.

In some new-law buildings, fire escapes may also be present inside shafts. This potential life hazard must be recognized and addressed especially if fire is threatening the shaft (photo 11).


(11) Note the fire escape inside this enclosed shaft. If doors in the courtyard have been sealed, victims may be at the bottom with nowhere to go. It might be best to direct them to the fire escape, if present, in an adjacent wing and then take them out through the front door of the uninvolved exposure. If no fire escape is present, a short ground ladder may be needed.

 

Attack

This is where engine companies get eaten up quickly. You will need to stretch lines to all apartments bordering on the shaft in both threatened buildings. For speed of stretch, use 13⁄4- or two-inch handlines in all areas unless conditions and reports dictate otherwise.

Fire Building Operations. If the fire is in one of the apartments bordering on the shaft, the first line must be stretched here. It will be necessary to keep the door closed if occupants are evacuating down the stairs or ladder company personnel are going up the stairs to search. The next line may have to go to the top floor, since this is where the most fire may be other than in the fire apartment. Get additional lines in place to back up the attack and cover additional floors as soon as possible. For fires that originate in a shaft, the first line must go to the top floor to head off the fire. Close the doors of apartments bordering on the shaft on the way up so fire is not pulled into the stairwell below you. You must also stretch lines to protect the stairwell and then to enter all apartments bordering on the shaft in the fire building. In fact, if fire is noticed in any apartment on a lower floor, because a door was left open, the attack will have to start there so the company does not get trapped above the fire. Notify Command immediately in this case; again, try to close the door until the stairwell is clear of evacuating occupants.

The last shaft fire to which I responded was for a fire that originated in the shaft and was visible 30 feet above the roofline on arrival. There was a three-story, wood-frame multiple dwelling, which we will call the fire building for lack of a better term. A two-story, wood-frame dwelling was attached and adjacent on the B side. The fire was venting between these two buildings. The walls of this B exposure were unpierced on the shaft but were covered with asphalt siding. The fire was so intense in the shaft that it burned through the side walls into the exposure building, breaking out in the bathroom on the first floor. Quick line placement stopped this extension. There was also a three-story frame dwelling on the D side, where there was another shaft between buildings. Lines quickly stretched to the top floor of the fire building were able to keep the fire out of the center stairwell and controlled in the cockloft so that the fire never made it to the D side shaft. There was heavy smoke on the top floor of the three-story fire building. It took 10 lines to control the fire. Four lines were stretched into the fire building, two to the top floor. Three lines were stretched to the B exposure, including one to the roof, where it was able to extinguish fire and support exterior precontrol overhauling of the shaft and adjacent areas on the third-floor exterior of the three-story fire building. Three more lines were stretched to the D exposure, since we were concerned with fire spread into the cockloft.

In retrospect, I have to come to a conclusion regarding line stretching and shaft fires. Not only do they have to be stretched without delay, but many have to be stretched almost at once. Whoever said “Don’t ever stretch more than two lines into any one opening” never went to a good shaft fire. We had four lines stretched through the front door of the fire building. I don’t necessarily condone this, but sometimes you have to do what you have to do.

Shaft Exposures. Companies operating lines from adjacent exposures at shaft fires must take caution to avoid directing streams across the shaft and into the fire building, or interior companies will want to have a serious word with them after the fire. If the offensive attack fails in the building of origin, these streams may then be used to knock down the fire and protect the exposure; however, while offensive interior operations are being conducted in the fire building, the streams in the exposures should direct water only to protect that exposure and support the extension prevention operation. This must be coordinated by the division supervisors or company officers assigned to these individual areas.

Ventilation

Ventilate carefully so fire is not drawn into an exposed apartment. Natural openings above the stairwell must be opened, but this work must be coordinated so fire is not pulled from the shaft into the stairwell. Communication is crucial here. Any firefighter entering an apartment bordering on the shaft must have a hoseline or must immediately close the door. The reason for this is that updraft in a hallway caused by an open bulkhead door, scuttle, or broken skylight may pull fire from a broken or open window right though the apartment and into the common hallway, trapping firefighters on upper floors. Ensure that a hoseline is available and charged before doors of apartments bordering on the shaft are opened, because when the line is stretched through it, the door will remain open, as will the front door to the building. If the line is not charged, fire may be drawn toward the stairwell and overrun the entering team. For additional ventilation, once lines are in place, it may be advantageous to open windows that do not border on the shaft, provided this will not pull fire in an unwanted direction. Test the fire’s reaction to this tactic before committing to it. Don’t ever do this without a line in place unless the fire is definitely out.

Extension Prevention

In attached exposures, although extension prevention operations are probably going to be conducted on all areas bordering on the shaft, a good bulk of the operation will take place on the top floor. Open the ceiling adjacent to the exposure all the way across for about three feet. This will give a good angle for stream penetration should fire be extending from the adjacent cockloft or shaft. Ensure that enough personnel are available, since many of these old buildings have tin ceilings, which are extremely work-intensive to pull. Use thermal imaging cameras to assist in pinpointing where fire may come across from the adjacent building, both on the top floor and from the roof. If there is a good fire going in the shaft, closing windows and removing combustibles will probably not work; you will more than likely need the window as a vantage point to hit fire in the shaft while keeping it out of the apartment. However, if conditions permit, keeping a window closed is still a viable tactic in extension prevention (photos 12, 13).


12.

 


(12, 13) Not only will the small shafts in these photos—the top unenclosed and the bottom enclosed—spread fire that will be extremely difficult to stop, but also firefighters stepping into them will crack their kneecaps on the other side. In both these cases, taking a look at the exposure will tip off the Roof Division firefighter to the hazard.

Be aware that in fire situations where shafts are present, uncoordinated extension prevention operations can pull fire in many unwanted directions. Do not overlook the cockloft backdraft or shaft backdraft. Enclosed areas, such as covered shafts and old dusty cocklofts, are potential hiding spots for backdraft conditions to develop. Always be on the lookout for signs of rapid fire development, have two ways out of any area, and open the roof—or at least the natural openings—before pulling ceilings. Also ensure ceilings are pulled with quick egress in mind.

Don’t overlook the roof of a lower exposure to overhaul the areas on the exterior that border on the shaft of an adjacent, taller building.

In addition, salvage should always be foremost in the mind of Command and the assigned division commanders. Don’t trash stuff. People will not remember what a great job you did in saving their structure; they will remember how you trashed their apartment. Take a few seconds to move furniture into another room or at least to the other side of the room before pulling the ceiling. This is especially true in exposed apartments where no fire has entered. The objective is to keep damage to a minimum. If we do a great job of saving the exposure but destroy the apartment in the process, we are defeating the purpose. The value of a great stop may be lost because of unprofessional extension prevention operations.

•••

Shafts can cause fire extension to adjacent buildings, deadly firefighter falls, and false reads on the fire’s location and extent. Recognizing the presence of the shafts and communicating their presence are the keys to safety and fire control.

ANTHONY AVILLO, a 23-year veteran of the fire service, is a deputy chief of North Hudson (NJ) Regional Fire & Rescue, assigned as platoon commander of the 1st Division. He has a B.S. in fire science from New Jersey City University and is an instructor at the Bergen County (NJ) and Monmouth County (NJ) Fire Academies. Avillo has been a H.O.T. instructor and speaker at FDIC. He is also an editorial advisory board member of Fire Engineering and the author of Fireground Strategies (Pennwell, 2002) and Fireground Strategies Workbook (Pennwell, 2003). The second edition of Fireground Strategies is scheduled for release in April 2008.

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