COLLAPSE SEARCH AND RESCUE OPERATIONS: TACTICS AND PROCEDURES

COLLAPSE SEARCH AND RESCUE OPERATIONS: TACTICS AND PROCEDURES

Part 1: Collapse Voids and Initial Void Search

This is the first article in a series on collapse search-and-rescue operations. This series will provide a practical, hands-on approach to operating safely and effectively in collapse rescue situations. Discussion will be limited chiefly to wood and brick-andjoist (ordinary-constructed) buildings. Future articles will emphasize the various types of shoring and cribbing techniques vital to collapse rescue operations, and they will address void size-up, safety at collapse operations, tools used in voids, and void operational procedures.

As the country gets older, so do its buildings. Buildings have a life cycle. They start to age the minute they are erected. They constantly are fighting nature’s elements and the ever-present stress of gravity. If structures are maintained and repairs are promptly and properly made, most will last for a long time. However, if improperly maintained, they will deteriorate rapidly until structural integrity is compromised. and they can fall under their own weight. In the last several decades, whole areas of inner cities have been left abandoned and unmaintained, precipitating an alarming increase in the number and severity of building collapses.

While neglect of building maintenance remains one of the primarycauses of collapse, explosions, collision impact, natural disasters, overloaded floors and roofs, vibrations, alterations and renovations, and fire all have resulted in collapse incidents. The potential for building collapse exists in every community, and all fire departments must be prepared to operate in this kind of emergency.

COLLAPSE VOIDS

Generally, wood and brick-and-joist buildings collapse in five characteristic ways: the pancake, the supported lean-to, the unsupported lean-to, the V-shaped, and the A-frame (see illustrations). The collapse type depends on which structural elements fail. Each collapse type creates distinctive voids within the rubble. The five voids are named according to the collapse type; that is, the void created by a supported lean-to is called a supported lean-to void, the void created by an A-frame collapse is an Aframe void, and so on. In addition, individual voids, created when objects in the building break the pattern of the collapse, occur in every collapse situation. It is not uncommon to find more than one type of void in a single collapsed building.

Pancake collapse!voids. A pancake collapse can result from the failure of a bearing wall or a sudden impact load on the roof or floor. In such cases, floors fail as a unit and fall in a stacking effect. A pancake collapse may send all floors crashing down into the basement. In general, voids occurring in a pancake collapse are individual voids, created by machinery, appliances, or furniture that interrupts the stacking effect. Victims may be located on several floors, and almost anywhere; survivors of the collapse usually are found in these individual voids. The pancake collapse requires extensive searching procedures and prolonged debris-removal operations.

(Photos by Tim Klett.)

Natural openings, such as stairwell openings, are effective points from which to begin void exploration in pancake collapse operations. In general these natural openings, located near hallways where there usually is much less debris, provide a relatively easy and quick access to voids. However, in the event that stairwell location and extent of collapse make these entry points inaccessible to void spaces, you must find an alternative means of void entry. The starting point of second choice usually is through the flooring between the joists, spaced 16 or 24 inches apart. Work between the joists by cutting through the finished flooring—usually tile in bathrooms and kitchens and wood in the rest of the building. The flooring is approximately one-half to three-quarters of an inch thick and the subflooring generally is wood that is only three-quarters of an inch thick, so cutting between the joists can make accessing these voids quick and relatively easy.

Supported lean-to collapse!voids. The lean-to collapse is caused by the failure of one bearing wall or the floor beams pulling away from their supports on one side of the structure. Beams may pull away for several reasons, including foundation failure of one of the exterior walls, causing it to lean outward; rotting beam ends due to prolonged exposure to weather; fire weakening the connection between the beams and the exterior wall; and vibrations from machinery, fatiguing the beams’ end supports.

Whatever the cause, in a supported lean-to the floor fails at one end and stays anchored at the opposite end. The floor falls until it rests on top of machinery, furniture, debris, or the next floor. Thus, both ends of the collapsed floor are supported. Occupants most likely will be found at the bottom of the lean-to near the wall, surrounded by debris; possibly hung up on large objects part of the way up the lean-to; or on the floor below the collapsed floor under the large void created at the opposite end of the failed connections.

Unsupported lean-to collapse! voids. The most unstable —and therefore the most dangerous —type of collapse is the unsupported lean-to. The causes (if this type of collapse are the same as those of the supported lean-to variety. However, in an unsupported lean-to, the failed end hangs precariously suspended, with no solid support. The flooring and subflooring nailed to the beams help keep the floor together in one piece.

It is not uncommon for the floor to be hung up on electrical cables or plumbing pipes. You must deal with this extremely hazardous situation immediately. The slightest additional impact could cause a secondary collapse—the most deadly problem faced at any collapse operation. In all unsupported lean-to collapses, you must secure and safely shore the unsupported floor before search operations can be conducted. Surviving victims in such a collapse may be located below the unsupported floor near the wall, under the lean-to near the bearing wall, or hung up on objects part of the way up the lean-to.

V-shaped collapse!voids. This type of collapse can occur when floors arcoverstocked with supplies and equipment, when vibrations from heavymachinery induce beam failure in a commercial occupancy, or when structural deterioration from water damage or dry rot occurs in a residential occupancy. They also can result from the failure of a column, an interior bearing partition, or an archway. The loss of structural integrity causes the floor to break near the center and fall to the floor below while “hinged” to the exterior walls, thus forming a “V” shape.

Depending on the type of building and its structural design, such as a large “framed” building, this type of collapse can be relatively localized.¹ Voids are created on both sides of the load failure. Occupants on the floor below, located only a few feet from these areas, usually have a high survival rate, due to the sheltering effect of the collapsed floor, which prevents the debris from landing on them. Victims on top of the collapsed floor usually are at the bottom or near the center of the “V” and trapped in the rubble in various places. Because of the large amount of debris concentrated in one area, the survival rate for these victims is not high.

A-frame collapse!voids. This is the opposite of the V-shaped collapse. The A-frame collapse occurs when the flooring separates from the exterior bearing walls but still is supported by one or more interior bearing walls or nonbearing partitions. This possibly may be due to major foundation failure that causes the walls to lean outward Earthquake vibrations, the excavation of adjoining areas, and extreme water damage to the foundation-all can cause this type of collapse.

The highest survival rate for victims trapped in this type of collapse is for those found near the partition wall at the center of the collapse. The victims of the floor above will be pinned in the debris near both exterior walls and, therefore, will have a lower survival rate.

Individual voids. Individual voids exist in almost every collapse situation. They are created by the presence of large objects that support the collapsed flooring in several or many different areas. In commercial occupancies, items such as machinery, stock, office equipment, and furniture contribute to the formation of these voids. In residential structures, the voids may be created by furniture or large appliances.

Floors in structures of lighter weight, such as single-family dwellings and attached wood-frame houses, weigh approximately 10 to 20 pounds per square foot. Common appliances and furniture break the fall of this kind of floor, so many voids can exist throughout the collapsed area. In heavier masonry buildings, floors weigh approximately 120 to 150 pounds per square foot, so voids are limited due to the large amount of crushing debris caused by the extra weight. In any event, the search of individual voids is a key undertaking in almost all collapse search-and-rescue operations.

VOID EXPLORATION

At all collapse situations, the safe rescue of trapped victims is the firefighter’s primary concern. After extinguishing the fire and removing the surface victims, initiate a systematic search of all collapse voids. This is the most difficult and dangerous component of the collapse operation.

Void search rescue team. As safety precautions are being addressed and needed shoring is being erected, a void search (rescue) team should be established and be put into operation. If the collapse operation is extensive or an entire structure is involved, more than one team may be needed.

The primary function of the void search team is to search any existing natural voids (voids that already have been created by the collapse) instead of debris trenching and tunneling, which is an extremely complicated, extensive, and time-consuming operation. These voids will be the fastest and easiest to explore, and the majority of victims found alive will be trapped in them.

A specially trained six-member void search team, consisting of one officer and five firefighters, generally works well. The team is split into two subteams, the search team and the support team. The search team consists of the void team officer, the void entry firefighter, and the shoring firefighter. The support team is comprised of the void expander firefighter, the support firefighter, and the tools/equipment firefighter. These two groups working together can use tools and equipment to search numerous voids and extricate multiple victims.

Debris removal. During void exploration, natural props and supports should he removed only when absolutely necessary and when, in the judgment of experienced crew members, including the void team officer, it is considered safe to do so. Beams supporting other debris, sections of floors, doors, stairs, and so on, should be left in place if possible. Use all the natural bracing that has occurred to facilitate your rescue efforts. Shoring structural members is preferred over removing them, since removal significantly diminishes the margin of safety under which void firefighters operate. Increased debris handling makes for less efficient operations; the less material removed, the safer and more efficient the operation will be.

Shoring and bracing. Accessing the void from an alternate route should be considered before deciding to remove elements supporting debris. If, however, lumber supporting a substantial amount of debris must be cut, it first must be properly shored. You must take the time to examine the debris to determine the best method for shoring it. Bracing from more than one direction may be needed.

The shoring and bracing operation is extremely dangerous and must be performed by highly trained personnel, or tragic results may occur. Use only the minimum number of people needed to complete the task. Under the direction of the void team officer, firefighters working in the void should be relieved on a continuous basis.

Following are duties of the members of the void search team.

VOID ENTRY TEAM Void Team Officer

1. Control of void operations. The void team officer is in charge of the team and responsible for safe void exploration operations. He evaluates each step of the exploration and determines whether to continue or adjust the operation based on a wide variety of scene factors. Safety dictates that, in general, the officer take a position that allows him to closely supervise the void entry team, usually at the void access point, and yet be able to monitor actions of the support team. He must be in constant communication with team members, particularly those operating in the void, and provide status reports to the operations chief or the incident commander.
2. Team assignments. The void team officer gives assignments to each member of the rescue team, based on his knowledge of each member’s experience, training, and expertise. Experience is probably the most important asset that should be considered. Team members who have collapse experience are invaluable to the officer. Their knowledge and experience will contribute substantially to the success of the operation.
3. Direction of tactics and procedures. The void team officer selects void entry routes and tactics/procedures/tools to be used in the void, based on initial and continuing sizeup, including type and size of collapse, type of building construction, type and size of void, and last known victim location. He constantly monitors the void for stability and safety and will be greatly assisted in this effort if the void entry team members have had previous collapse experience.
4. Coordination of victim assistance and removal. The void team officer coordinates the efforts of medical personnel assigned to treat the victim; requests the professional medical assistance of a doctor, paramedic, or EMT to determine the extent of injuries and administer immediate care to prevent crush syndrome injury prior to packaging and removal; and determines the route by which the victim is to be removed from the collapse debris. Usually, this route is the same void opening that firefighters used to access the victim; however, as collapse operations are carried out simultaneously throughout the demolished structure, another void closer to the victim and the egress point of the building may be penetrated and cleared of debris, providing an alternate route.
5. Crew rotation/relief. The officer must keep constantly alert for the first signs of fatigue in any of his team members. Using tired firefighters is dangerous and counterproductive. Firefighter relief is a judgment call by the officer based on the severity of the collapse, the amount of debris to be removed, the degree of the victim’s entrapment, the duration of the operation, the distance between the victim and the access point, the necessity for multiple tools and the length of the cutting operation, and the physical conditioning of the firefighters performing the operation. These factors vary at every collapse situation, and the officer must take all of them into account when evaluating the need for personnel relief.

Void Entry Firefighter

1. Void entry. The void entry firefighter is the first to enter the collapse void area. The main objective is to locate existing voids, penetrate them, and search them under the supervision of the team officer, who, with an accurate void size-up, can direct the firefighter to probable areas of victim entrapment. The void entry firefighter must be a knowledgeable and experienced firefighter who can operate in confined void spaces with minimal adverse effects. This firefighter probably is subject to the most danger during the void operation and must evaluate each action completely and methodically for safety and effectiveness.
2. Debris removal. The void entry firefighter determines which material to remove. Loose debris, bricks, wood pieces, small furnishings, and the like, can be moved quickly and easily. If the void is large enough, the material can be moved aside, out of the way of the extrication, and still leave enough room for operations and victim removal. If the void is too small, the loose debris must be passed back and brought out of the void. As the firefighter gets closer to the victim, he must handle each piece of debris carefully to ensure that no material will come loose and jeopardize the victim’s safety.
3. Recommendations on what to cut. As the firefighter removes debris, he must determine if structural members have to be cut and removed for greater void penetration. Beams or other structural members can be cut only if there is a visible free end or if the structural element is loose, indicating that it is not supporting other debris. If the structural member is tight within the debris, it must be determined whether it can be removed safely with the proper shoring and bracing. Main structural elements—beams, columns, arches, girders, and bearing walls—should not be disturbed unless absolutely necessary, and then only after having been properly supported. This phase of the operation is extremely dangerous and should be attempted only after having exhausted all other options for victim access.

Shoring Firefighter

1. Assisting the void entry firefighter. The shoring firefighter is the second member to enter the collapse void. His primary function is to assist the void entry’ firefighter whenever necessary—whether it be by passing debris out of the hole, shoring structural members, or searching in tandem. The shoring firefighter must always stay in visual and voice contact with the void entry firefighter and must stay in close physical proximity in case problems should arise.
2. Constant communication. The shoring firefighter functions as the additional eyes and ears of the void entry’ firefighter. He must maintain constant communication with the void team officer, monitoring the continuing changes in the operation and relaying progress reports and any pertinent information. This leaves the void entry firefighter free to concentrate on extricating the victim.
3. Void safety. The shoring firefighter must make certain the void is as safe and stable as possible. He must make sure that the egress for himself and the void safety’ firefighter remains open and that a secondary collapse does not occur. The shoring firefighter erects structural shoring members wherever necessary, with the assistance of the void entry firefighter or the void expander whenever necessary. If the void is deep and debris removal extensive and time-consuming, the shoring firefighter continually must check that the existing shoring has not moved, or that wedges have not loosened, and must erect additional shoring as required.
4. Debris removal. An additional responsibility of the shoring firefighter is to remove collapse debris fed to him by the void entry firefighter. He may elect to slide this debris out of the way (if this option is available) or remove it completely out of the void area. It can’t be emphasized enough: The void egress must be kept open at all times in case an immediate withdrawal from the void becomes necessary.

SUPPORT TEAM

Void Expander Firefighter

1. Initial position at mouth of toid. A versatile firefighter with a varied range of experience should be assigned the duties of the void expander firefighter, the member of the support team closest to the void entry’ team. He may be called on to perform functions of both the entry and support teams. The void expander firefighter’s initial position will be at the mouth of the void, from where he can pass debris out of the void or pass tools and equipment in or out. Since he is positioned at the mouth of the void, he is in the best position to relay information from the officer to the void entry team, and vice versa. He stays in direct contact with the entry team throughout the operation.
2. Widening the void. If the void entrance is small and confined, the void team officer may decide to widen it and establish better access and egress. If so, the widening operation becomes the responsibility of the void expander firefighter, who is assisted by the support firefighter, who makes sure that any material removed is taken away from the void entrance. It must be stressed, however, that only in certain conditions will it be safe to widen the access while rescuers are in the void. The officer very carefully must evaluate the safety aspects of such action, as any cutting, moving, or shifting of debris or structural elements could result in a secondary collapse.
3. Assisting the void entry team. The void expander firefighter may become an additional member of the void entry’ team, conditions warranting. For long voids—if the victim is 15 feet away from the void entrance, for example—it improves safety if the void expander firefighter enters the void area. Doing this enables the firefighters to stay in close physical proximity’ should problems arise. From this position, the void expander assists with debris removal and shoring operations.
4. Entry’ team relief. Under the direction of the void team officer, the void expander firefighter relieves one of the void entry’ firefighters if it becomes necessary to do so. Usually, the void entry firefighter is the first team member to be relieved, since this position is the most strenuous. Stationed at the mouth of the void, the void expander firefighter is in support mode and, therefore, fresh and in perfect position to relieve one of the void entry’ team members if the void is not deep or extensive.

Support Firefighter

1. Passing back debris. The support firefighter, the second member of the support team, clears debris as it is passed out of the void entrance to an area of safety away from the operation. Usually, this debris is passed to other fire personnel who have formed a human chain to quickly and easily remove material out of the building. Once removed outside the collapse zone, the debris can be examined by legal authorities, if necessary, without interrupting the search and rescue operations. Larger pieces of debris such as wood and furnishings can be removed by hand. Smaller pieces of debris easily can be placed in buckets and then quickly and efficiently removed from the building.
2. Tool delivery. The support firefighter requests and receives from the tools/equipment firefighter tools and equipment needed by the void entry team. He makes sure that all tools are operational and set up properly before sending them into the void. He ensures that hoses and cables have enough slack to make the stretch into the void and do not become entangled in debris.
3. Assisting in void expansion and shoring. If necessary, the support firefighter assists the void expander firefighter in enlarging the mouth of the void and shoring near the void entrance. The cutting of shoring members generally should be done remote from the void entrance, in which case the support firefighter relays measurements to the cutting team outside the immediate collapse area and coordinates the relay of shoring material from the cutting area to the void entrance, from where the material is fed to the awaiting firefighter. In select cases, the cutting may be done relatively close to the void entrance, in which case the support firefighter can do the cutting and work directly with the void expander firefighter. It is vital to note that cutting relatively near the void entrance and expanding and shoring the mouth of the void while firefighters are operating inside the void can jeopardize the safety of the operation. When making these decisions, therefore, the team officer must carefully consider the possible safety repercussions of such actions. Before making these decisions, the officer must scrutinize a variety of factors, including the size of the collapse, the stability of the debris, the size of the opening, and so forth.
4. Personnel relief. The void team officer, in monitoring the condition of operating personnel, may utilize the support firefighter to relieve a member of the void entry team. However, depending on the location and severity of the collapse and the position of the apparatus and equipment, the support team may be as heavily engaged as the void entry’ team. If this is the case, the officer will have to relieve the entire void search team and substitute a fresh team.

Tools/Equipment Firefighter

1. Tool staging. The third member of the support team sets up the tool staging area, the point from which all tools and equipment are sent into and received from the collapsed structure. The more organized the tools/ equipment firefighter is and the better he knows the apparatus, the faster the equipment will get to the proper area in working condition; therefore, the driver/operator generally is assigned to this position.

For maximum efficiency, the tools/ equipment firefighter should set up as close to the operation as possible, while, of course, staying within safety guidelines. A 20by 40-foot tool staging area would not be considered too large for an average collapse operation. This size area provides sufficient room to lay out all the equipment and move several items at once so that personnel picking up and returning equipment do not interfere with each other.

2. Tool test. Any tools sent into the collapse operation must be examined and tested to make sure they are working properly. Blades or bits should be checked to ensure that they are sharp, properly installed, and sufficiently tightened. Tools with blades should be sent with a backup to the void entrance so that when the blade gets dull, the replacement can be sent in immediately. The void space is not the place where one should be changing a bit or a blade.
3. Requesting additional personnel. The tools/equipment firefighter generally needs additional personnel to set up the tool staging and unload the tools and equipment off the apparatus. These firefighters are requested through his officer or the chief in charge. Whichever protocol is to be followed, it is up to the tools/equipment firefighter to request and obtain the staffing needed to get the job done. For smaller collapse rescue operations, two or three additional firefighters may be needed to get the supplies to the collapse area. For extended operations in which numerous tools are needed or the apparatus are not close to the collapse zone (which is typical of most collapse operations), numerous firefighters are needed. It is not uncommon to use at least 10 firefighters to accomplish the job properly.
4. Maintaining the tool log. Tools removed from the apparatus must be recorded on a master tool log along with the following information: the name of the individual requesting the tool; the time of the request; the name of the deliverer of the tool; the floor or area to which the tool was sent; and the time the tool was returned, the name of the individual who returned it, and the party to whom it was returned. Because of the confusion and activity typical of operations involving multiple agencies, such as collapses, a tool inventory log is necessary.

This is an overview of the considerations that should be addressed in collapse rescue training and in your collapse rescue plan. Regardless of how you organize your collapse rescue team or the names you assign to collapse positions, you cannot expect to function safely and efficiently at a collapse search and rescue operation without ongoing and comprehensive training, experienced members, teamwork, the appropriate equipment, and a sufficient number of on-scene personnel beginning with the early stages of the operation *

Endnote

1. In wall-bearing or “unframed” buildings, the load is carried by the walls. Failure of any of these walls can cause extensive collapse. In “framed” buildings, the walls and floors are hung on a structural skeleton of steel, concrete, or heavy timber. If failure of one element occurs, the collapse can be localized, as the remaining skeleton can transfer and support the additional load. So-called “wood-frame” buildings are a misnomer in that they actually are wall-bearing buildings. For details, see Building Construction for the Fire Service, Third Edition, Francis L. Brannigan (NFPA, 1992), pages 97 and 270.