This is the third and final installment in a series on training for collapse operations. In the previous columns, I discussed how to establish your collapse rescue training needs are, an overview of the five stages of collapse rescue operations, and stages I and II in greater detail. This article will elaborates on stages III to V of collapse operations and the pre-planning and training required to conduct such operations.
Stage III Void Entry
As the surface rescue stage of the collapse rescue plan is completed the void entry phase begins. Before initiating void entries, among other factors, notice the type of collapse. As previously mentioned Federal Emergency Management Agency engineers use the collapse patterns as one criteria to determine the viability of survivors and to prioritize searches. Examining these patterns provides potential routes of egress into the collapsed structure and indicates the areas with the greatest potential for survivability.
The most common method for classifying collapse patterns breaks them into five types: supported lean-to, unsupported lean-to, A frame or tent, V shaped and pancake. Both the NFPA and the Fire Chiefs Handbook use this system with minor deviations.1 Other sources such as FDNY’s collapse procedures2 and Deputy Chief Vincent Dunn’s Collapse of Burning Buildings describe other collapse patterns, but the five previously mentioned are generally taught in regards to void entry.
Supported lean-to collapse – this pattern occurs when one end of a floor or roof drops down while the other remains up-forming a lean-to.
A frame or tent collapse - this pattern is basically two supported lean-to collapses with the floor, or roof dropping down, on the outsides while remaining supported in the center.
V shaped collapse – this pattern like the A frame collapse also involves two supported lean-to collapses. However, in this case, the floor or roof fails in the center and remains supported on the outside of the pattern.
Unsupported lean-to collapse–this pattern resembles the supported lean-to collapse. However, unlike the previously mentioned collapses where both ends of the structure remain supported, the failing floor or roof ends up suspended in the air. Since one end remains unsupported, this pattern is particularly prone to secondary collapse.
Pancake collapse – in this pattern, the roof and/or floors fall straight down and resemble a stack of pancakes.
In general, viable victims in these collapses are found in the void created under the lean-to effect and at the bottom of the slope created on the top of the lean-to effect. In the case of the pancake collapse, viable victims are found in voids created where the collapsing structure came to rest on a substantial object such as a desk or a piece of machinery. 3
After identifying the voids and the most likely locations of viable victims, begin the void search. Visually look into the void or enter to visually search the area. A hailing search is another simple and effective method of search. In this type of search the rescuer simply calls out and asks if anyone is inside. This callout is followed by a brief period of silence to allow anyone who is trapped to answer. These are manpower-based methods of search.
Another category of search is canine. Canines are great assets that in many circumstances can search a large area in a short period of time. There are several items to keep in mind when deciding whether or not to utilize canines as part of aplanned response. One, are these assets trained and certified? In a disaster, responders can be subjected to well-meaning but not necessarilyy helpful people. Another factor to consider is availability. If a collapse is a localized incident, a mutual aid agreement to have canine assets respond works. However, in a large scale incident such as an earthquake. These assets are most likely unavailable.
The final category is technical search. In this method rescuers search with items such as fiber optic cameras and seismic/acoustic listening devices. While useful technical devices are expensive and require advanced training. Canine and technical search assets are not “cure alls,” they are just tools.
In some cases, it may be necessary to install shoring before entering a void. Shoring consists of temporary structures for the purpose of supporting the collapse. This provides a protected area for search and rescue operations. Shoring is commercially made or built with wood. While a basic level of shoring competency is easily obtainable, anything beyond that requires specialized training. For specifics on shoring construction, DHS has a manual on the latest shoring techniques.4 Many techniques developed in London when it was bombed during World War II have been highly refined by FEMA.
When conducting a search, it is important to record all the areas searched. This ensures that the entire collapse zone gets searched and avoids duplication of effort which is bad for two reasons. One is that it wastes time and manpower resources searching the same area twice when it could be searching fresh territory. Another reason is that it needlessly puts rescuers in harm’s way. In a simple collapse scenario, such as a single small structure, the FDNY reports search results to the chief (incident commander) who records these results. In any incident of greater magnitude than the above, the actual structure should be marked with the results of the search utilizing the standardized USAR marking system. Searched areas are painted with an X. The first slash of the X is painted at the beginning of the search and the second when the search is completed. Information written with the X includes: who conducted the search, time and date of the search, results of the search and any hazards found. For a detailed explanation of this marking system, consult the USAR FOG manual.5
Stage IV Selected Debris Removal
As a general rule, the selected debris removal stage begins after the void entry stage is completed. This may not applyin situations such as when there is a confirmed victim or a large scale operation. Selected debris removal is performed to reach a particular location, such as the victim or an area of the structure with possible viable victims. Undertake any cutting, breeching or breaking operations must be untaken with extreme care. Thought must be given to not just the structure’s reaction to the item being cut but also to the vibrations and other byproducts of tool operation. In a simple wood frame structure, these operations can be performed with little more than a reciprocating saw. On the other hand, in a reinforced concrete structure collapse, numerous specialized tools may be required. All requiring specialized training.
Stage V General Debris Removal
The general debris removal phase of operations generally begins when the other stages are completed and people are still missing but presumed dead. In this stage, the scene is systematically delayered, often using heavy equipment, with the debris spread out in a designated area and searched before being reloaded and removed. This should be recorded in a demolition debris removal log and the operations continued until all persons are accounted for.
To illustrate the potential importance of a facility having some level of collapse training, since the last installment of this series I have responded to several collapses including a truck crashing into a facility dealing with compressed gasses, a gas explosion in a private dwelling, and a concrete pump truck that crashed into a structure. This last incident killed the driver, injured several others, resulted in the structure being a total loss, required three wreckers and eventually a crane to extricate the vehicle from the structure. Collapse scenarios are not uncommon. That being said, it is rare facility that requires the capability to carry out operations at the highest levels. To operate at these levels requires a substantial commitment to equipment and training. Some examples of facilities benefiting from a higher level of training areisolated or overseas facilities in areas with limited local response capabilitiesor facilities in danger areas such as earthquake zones, where planned resources would be stretched thin when needed most.
After obtaining an initial level of training, collapse rescue training can be broken down into its component skills when conducting refresher training. This training could include shoring, void entry with selected debris removal, breeching and breaking, search marking systems, and reviewing building types and collapse patterns.
Those who are interested in the training requirements for the various levels of response are encouraged to review the collapse rescue portions of NFPA 1670 Standards on Operations and Training for Technical Search and Rescue Incidents.
James Kiesling is a captain with the FDNY’s Special Operations Command. He holds a bachelor of arts in fire and emergency services from John Jay College of Criminal Justice and an associated degree in occupational studies in fire protection technology from Corning Community College.
1 National Fire Protection Association (NFPA). NFPA 1670 Standards on Operations and Training for Technical Search and Rescue Incidents 2009 Edition, Quincy Massachusetts.
* This is the primary method of classifying collapse patterns found in Building Collapse Patterns, 1st section of Annex J and is followed by other methods of collapse classification.
2 Fire Department City of New York, Firefighting Procedures, Collapse Operations, 2007, Brooklyn, New York.
3 Much of the collapse of the WTC did not conform to any of these patterns, often resembling a large pile of pick up sticks
4 Department of Homeland Security (DHS), Department of Homeland Security Field Guide for Building Stabilization and Shoring Techniques, 2011 available at http://www.dhs.gov/xlibrary/assets/st/st-120108-final-shoring-guidebook.pdf.
5 Urban Search and Rescue, Field Operations Guide, 2006, available at http://www.fema.gov/pdf/emergency/usr/usr_23_20080205_rog.pdf