We’ve all heard the stories about firefighters doing stupid things on duty or off. Firefighters committing arson, breaking and entering, driving intoxicated, failing work-related random drug screening tests, abusing their domestic partners…the list goes on and on. As one of the replies to the Cumberland Valley Volunteer Fireman’s Association’s recent White Paper on Ethics in the Fire Service says, the report is a “litany of the obvious”. The ethical problems that plague the fire service include “Cheating, arson, theft, alcohol and substance abuse, harassment, discrimination, and misuse of departmental and personal information technology… “
It makes one wonder if the Fire Chief's uniform should include this shirt;
Here are a few examples of less-than-smart and ethically-impaired firefighter behavior I found in a Bing search that took about 10 minutes:
Firefighter investigated for arson at his own home.
Firefighter investigated for arson at his own home (another one)
Firefighter sets fire to another firefighter’s home
Firefighters involved in two separate break-ins
Firefighter DUI case
Firefighter arrested for DUI, spits in police officer’s face
Still another firefighter DUI
Firefighters charged with assault in bar brawl
Firefighter charged with child sexual assault
Another fire station noose incident
Here’s another twist – noose planted in fake firehouse racism incident
Firefighter charged with arson and convicted of bomb threat
Firefighter hospitalized after firehouse prank goes wrong
Ex firefighter gets prison for firehouse arson
Junior firefighter shot in leg during firehouse hazing
Peeping Tom firefighter arrested, peered from ceiling at female paramedic as she showered
Firefighters fired for obscene and harassing prank phone calls to female lieutenant
Female firefighter sexual harassment lawsuit settled
Female firefighter harassed
Son of late fire chief guilty of embezzlement
FireGeezer has several other stories about embezzlement from fire companies here
How do we reconcile this with the recent public opinion polls that rate firefighters as the most trusted profession in the U.S. and Great Britain?
How do we, as a profession, reduce or eliminate the ethical problems that will inevitably knock us from the position of high trust we hold? Whose responsibility is it? Is it the fire chief’s responsibility? Does the responsibility lie with the officers, senior firefighters, or with instructors at the fire academy? Does it lie with a new fire recruit’s parents and family? Does the school system that has spent the last three decades teaching “value-neutral” education share the responsibility? Does a pop culture that downplays the role of religion share in the blame? Does the switch to playing computer games and baring our inner thoughts via social networking sites instead of learning a trade and the value of productive work contribute?
Without designing a multi-year sociological study, the short answer is that all of the above share in the responsibility and the blame. More importantly, what do we do about the problem?
When we accept a new fire recruit, we have to understand them for what they are. We can’t give them a two-parent home, send them to church, or give them a meaningful job outside the fire service. We can’t help them re-live their formative years. We can’t eradicate the computer gaming and social networking culture from the new firefighters – those are here to stay.
Potential Solutions
We can make our expectations clear.
We can provide supervision, leadership, mentoring, and Big Brother/Big Sister-type programs for our new members.
We can assign a reliable veteran to mentor every new firefighter not only in fire/rescue and EMS skills, but in ethics and the role of good behavior and public trust as essential to our mission.
We can institute smart business solutions including internal and external audits of department funds and business practices, frequent reports to the membership, and a fully-transparent annual report.
We can set firm rules for firefighter conduct and behavior.
We can make it clear that serious rules violations will result in termination and if appropriate, a referral to law enforcement for prosecution.
We can enforce the rules equally, regardless of rank or position.
We can lead by example.
We can limit or eliminate alcohol at fire department and related events. Alcohol doesn't make you smarter, funnier, better behaved, or more trustworthy.
We can develop an Organization and Discipline training course and require that every new member complete it prior to granting full membership in the organization.
We can develop a Fire Service Ethics training course and require that every new member complete it prior to granting full membership in the organization. (The CVVFA’s program is a good start.)
We can develop a program to review case studies involving the financial, criminal, family, and personal costs of firefighter misbehavior with new members, and periodically, with the more seasoned veterans.
The candidate pool is what it is. We can’t go back in time to better prepare our new members, we have to work with what we get. We can ensure that candidates are screened, supervised, and mentored to reduce the impact of bad firefighter behavior on the profession and upon individual departments. We can also make it clear that bad behavior will not be tolerated, and that if the new firefighter wants to become a veteran firefighter, good choices and ethical behavior are not just expectations – they are essentials.
I don't know how to say this any more strongly - If you're going to engage in unethical, racist, sexist, criminal, or stupid behavior, particularly while representing your Fire/Rescue or EMS department, GET OUT OF THE PROFESSION! The CVVFA White Paper shows the way to ethical firefighter behavior. It is a road map for maintaining the strong position of public trust we enjoy. This job is supposed to be the province of the people who can best do the job, who are the most trustworthy, and who demonstrate responsible behavior. Let's all commit to helping prevent a few bad apples from screwing it up for the rest of us.
Sunday, March 21, 2010
I'm with STUPID
Labels:
arson,
behavior,
Ben Waller,
code of ethics,
embezzlement,
expectations,
racism,
sexism
Monday, March 8, 2010
The Bathtub Collapse, Part 2
Part 1 of this series was an introduction to Bathtub Collapse problem identification, exterior size-up, strategy considerations and development, and safety considerations. Part 2 discusses tactical considerations, interior size-up, victim recovery, investigations, and incident termination.
Tactics
In order to make a bathtub collapse rescue safe and efficient, the operation must follow a logical sequence. The first step in this sequence is to support the sides of the bathtub. If the bathtub is formed by structural walls or columns, start by shoring them. Raker shoring systems are a good way to support exterior walls.(1) For masonry or wooden walls, traditional raker shore types are appropriate. Modified split sole rakers may be used to provide columns with lateral support. Visibly stressed walls or columns should be shored first. If the wall or column is leaning or cracked, it’s stressed.
Extrication Strut as a temporary door shore
The next step is to support natural entry points, then open them. Door and window openings can be shored as in any other structural collapse. You may need to frame the edges of the opening with a raker system prior to shoring the actual opening. Once the door opening is supported, additional bathtub components such as metal Q-decking, rebar grids, and other metal components may be cut away to clear the opening for access and egress. Cutting operations create sparks, open flames, or both. Ensure that the building’s gas supplies are shut off and that the area is well-ventilated prior to using cutting tools that create ignition sources. Also ensure that both water and dry chemical extinguishers or a charged hoseline are nearby curing cutting operations.
Cutting Q-decking and rebar obstructions with a rotary saw
Once the interior of the bathtub is accessed, it may be necessary to use strongbacks and tiebacks to support inward-leaning walls. Picket systems or large, well-secured anchors should be used to anchor the exterior tiebacks. Place towels, blankets, etc. over the tieback cables to reduce whipping in the event of cable failure. Once the tieback system is complete, keep everyone out of the immediate area.
Widowmakers
Once the bathtub walls are secure, it’s time to take care of overhead hazards. Identify all widowmakers and eliminate falling object hazards by using one of the following methods;
1. Secure the widowmaker by tying it to solid structural components with cables, chains, come-alongs, etc.
2. Remove the widowmaker by bolting it, then tensioning it with a crane, and cutting it loose from the structure.
3. Avoid the widowmaker by marking and enforcing a collapse zone beneath the widowmaker. This may not be possible, as the victims may be trapped directly below the widowmaker.
Search Tactics
Once the surrounding structure is secured, the interior search can begin. Start by searching voids and by manually removing selected debris.(2) Voids may be searched visually with flashlights, thermal imaging cameras (TICs), USAR or fiber optic search cameras, and by probing voids with pike poles. It is important to note that wet concrete produces heat, and this heat may mask the heat signature of a human body when searching with TICs. Remember that TICs cannot “see” through solid materials such as structural components.
Simultaneously with the void search and light debris removal, other crews may start searching through the wet concrete in the bathtub. You may manually search for gaps in the horizontal Q-deck by simply using gloved hands to probe through the wet concrete and any gaps in the edges of the Q-decking.
Victim Search in a Bathtub Collapse
It is also important to create horizontal openings in the vertical Q-decking parts of the bathtub. This allows horizontal removal of some of the concrete while it is still wet. Hoselines can be used to keep the concrete wet and dilute as long as the water will not run into voids and drown the victim or cause hypothermia. Scoop shovels and even stiff-bristled push brooms can be used to move wet concrete through the bathtub openings.
Hose Stream dilutes and moves wet concrete
Bathtub Collapses into Basements
If it is necessary to lift wet concrete out of a basement, simple bucket-and-rope systems may be used, but they are manpower-intensive. Vacuum trucks may be useful, but the concrete may be too heavy for the vacuum to lift it very far. Large amounts of water will probably be required to dilute the concrete enough for a vacuum truck to lift it, and that much water may drown the victim prior to completing the rescue. Water also adds weight to an already-damaged structure, which may cause additional collapse. It may be necessary to move large volumes of wet concrete in order to locate the victim. It also may be possible to use a trash/solids pump to move dilute concrete out of a basement if the aggregate size is small enough to make it through the pump without clogging it. A bathtub collapse into a crawl space is generally similar to a collapse into a basement, but may allow grade-level access to one or more sides of the bathtub.
Victim Extrication
Once the victim is located, determine the body position and attempt to expose the airway. If the victim is alive, follow local blunt trauma and crush/compartment syndrome protocols. If the victim is deceased, ensure that all other potential victims are accounted for. If other victims are not accounted for, it will likely be necessary to continue in Rescue mode. If all victims are accounted for and have been determined to have died, then shifting to Recovery mode is more appropriate.
It is likely that rebar will be submerged or semi-submerged in the concrete. Large sections of the rebar grid may be cut away with minimal effort by locating the rebar and cutting it around the outside edge of the area you desire to expose. Cut rebar grid away with hydraulic cutter or large bolt cutters if it is submerged in the wet concrete. Rebar cutters, reciprocating saws, and/or torches may be used to cut any exposed rebar, particularly if only one hydraulic cutter is present.
Hydraulic cutters being used to cut rebar
Removal of rebar grid section
To extricate the victim, it is useful to locate the Q-decking edge closest to the victim. Once this edge is located, it can be used as a purchase point to move concrete and steel away from the victim. A variety of tools and techniques may be successful. Once the Q-deck edge has been located, start moving wet concrete away from it. A good rule of thumb is to move wet concrete away from the hole at least three times the depth of the remaining concrete. This will help prevent wet concrete from running through the hole in the Q-decking and burying the now-exposed victim.
Once adequate amounts of wet concrete and rebar have been removed, it is time to attack the Q-decking. You can start by using the exposed Q-deck edge as a purchase point and lifting the edge with hydraulic rescue spreaders. As you open the spreaders, the Q-decking will start peeling back. You can extend the cuts with hydraulic spreaders or reciprocating saws. If power tools are not available, even hacksaws can be used to cut the Q-decking. Small rescue air bags may be used to lift the Q-deck, but remember that sharp rebar ends or Q-decking edges may cut or puncture the air bags. If using air bags, pad them with sections of rubber matting such as old tractor-trailer mud flap material or short sections of old large-diameter fire hose. Bottle jacks or small scissor jacks can also be used to lift the Q-decking.
Hydraulic spreader used to roll up exposed Q-decking edge
It is not necessary to remove all of the concrete from the Q-decking prior to cutting it. Additional personnel can be used to continue moving concrete away from the victim with scoop shovels. As with any other heavy lifting operation, cribbing must be installed to support the lift. Use the “Lift an inch, crib an inch” cribbing method. It may be possible to use a come-along to support rebar grid sections that are too large for complete removal.
If it is becomes necessary to remove very large sections of Q-decking or other metal components, several cutting methods may be employed simultaneously. These can include alternating hydraulic spreader lifts with hydraulic cutter relief cuts, lifting with a spreader while extending the cut with reciprocating saws, or by removing concrete and steel in an area away from the victim in order to create an intermediate location in which to move materials away from the victim. If using torches, make sure that you do not burn the victim. If using torches remotely from the victim, use an atmospheric monitor near the victim to ensure that torch byproducts are not compromising the victim’s clean air supply.
If it is possible to quickly move a large amount of wet concrete out of the bathtub, consider making purchase points with a hole saw or core drill, inserting short sections of heavy-duty rebar or pickets, and attaching cables in order to lift a large section of steel away.
Prior to removing most of the wet concrete, air chisels and reciprocating saws will be of very little use, since they are designed to use in open air. Pneumatics may have limited utility, but electric tools will quickly burn out and become useless when submerged in wet concrete, due to the saw’s inability to radiate heat into the air.
If the victim is pinned over a secondary void, install supplemental shoring beneath the victim if possible. It may be necessary to install an improvised lifting harness on the victim if a secondary fall possibility is created by the extrication process. If the secondary void is very deep, it may be necessary to have rescuers shore beneath the extrication operation. This is highly dangerous, and is recommended ONLY as a last resort and with IC and Safety Officer approval.
Patient Care
As with any other extrication, provide medical care during the extrication if the victim is alive. If the extrication is prolonged, it will be necessary to provide protection from ambient temperature, extremes of weather, and to provide specialized crush syndrome care. USAR Medical Specialists and paramedics and physicians specializing in cave or mine rescue may be very useful in this situation. USAR medicine may require medications and medical protocols outside of normal EMS procedures. USAR medicine protocols should be approved by local and/or state EMS authorities in advance. It may be necessary to conduct a field amputation in order to save the victim’s life. If possible, a field-qualified physician should make the amputation, as amputations require training and equipment outside the normal paramedic scope of practice.
Once the victim is completely disentangled, package the victim, take any required steps to move the victim outside the structure, and turn the victim over to the transporting unit. All rescuers working near the victim should wear any necessary body substance isolation (BSI) personal protective clothing. If advanced life support (ALS) procedures are in use, EMS personnel should have a sharps container at the patient’s side for IV needles other contaminated sharps disposal.
Third-Party Investigations
If one or more victims are deceased, a scene investigation will be necessary prior to moving the body. The coroner, medical examiner, and/or law enforcement agencies will want to photograph and diagram the scene, interview witnesses, and determine whether any foul play is suspected. If the coroner or medical examiner staff is not trained to enter collapse zones, they may ask that rescuers take scene photos and/or measurements for them. If possible, put the coroner in a location where he/she can direct the rescuers as they take photos and measurements, but do not compromise responder safety to investigate a death.
OSHA investigators may also be on the scene. It is important to note that OSHA investigators do not generally have the authority to interfere with body recoveries, and they do not have the authority to interfere with the rescue of live patients. Fire-rescue and EMS personnel should document any actions they take on behalf of an investigating authority.
It is also important to inform coroner, medical examiner, law enforcement, and OSHA investigators that time is of the essence due to concrete curing. If the concrete hardens with the victim’s body still entrapped, a one or two-hour recovery may become a multi-hour or multi-day recovery operation. Once the body is removed, place it in a body bag, secure it in a Stokes basket, SKED, or other rescue litter, and remove the body from the collapse zone.
Decontamination and Clean-Up
USAR decontamination considerations generally involve cleaning equipment and PPE that may have been exposed to biohazardous wastes and cleaning concrete dust, powdered glass, or other building components from personnel and equipment. Bathtub collapses require an immediate additional step.
Several charged hoselines should be present to remove concrete from responders and equipment while it is still wet. This is particularly true for exposed skin and any tool that was submerged in the wet concrete. Exposed skin is vulnerable to thermal burns from the warm concrete, chemical burns from concrete components, and traumatic injury from rough aggregate or sharp metal edges encountered during the rescue. Concrete will find every nook and cranny in hydraulic rescue tools, bottle jacks, pneumatic hose couplings, pneumatic strut feet, or any other equipment that may have been placed in the concrete. Two or three engine companies assigned exclusively to decon will enable responders and gear to be cleaned quickly, efficiently, and thoroughly.
Termination
As with any other incident, all tools, equipment, and apparatus will need to be returned to service, cleaned, and inspected. Any equipment damaged, destroyed, or contaminated beyond salvage will need to be reported and replaced. Powered equipment will need to be serviced and fueled. It may be necessary to replace large quantities of cribbing and shoring materials, contaminated life safety rope, or other materials that it is unsafe to recover. Do not risk personnel to recover a few pieces of wood that can be easily and cheaply replaced.
Any personnel injury or exposure will need to be treated, reported, and receive any necessary follow-up care. An accurate incident report should be completed, anticipating third-party investigations and possibly criminal or civil actions due to the collapse. An after-action review should be held as soon as all the incident facts can be determined. The critique should involve all personnel and units that participated in the response.
Conclusion
Bathtub collapses have not been previously identified and traditional USAR training does not specifically address collapses involving wet concrete. Wet concrete is not easy to shore or support. Wet concrete adds a new degree of difficulty to USAR searches, as you can’t just drill a hole and look through it with a search camera or fiber optic scope. Wet concrete flows to the lowest point and collects, which can concentrate structural weight in a small portion of the supporting structure. Bathtub collapses add an entirely new set of challenges, even for well-trained and experienced USAR teams. One of the most critical elements is time – the concrete won’t stop hardening while we call resources, shore the structure, or search for the victims.
Concrete buildings may be constructed virtually anywhere. All concrete structures are vulnerable to collapse while under construction. With the increasing demand for structures to house people, businesses, and to repair our country’s aging infrastructure, it is anticipated that bathtub collapses will become more common. Any fire-rescue and EMS agency may be faced with a bathtub collapse. Preparation, safety, equipment, training, and above all, anticipation are important to keep responders safe and to successfully conclude the response to complex and dangerous bathtub collapses.
References
(1) U.S. Army Corps of Engineers
US&R Structures Specialist Field Operations Guide, 3rd Ed.
U.S. Army Corps of Engineers Readiness Support Center, 2001, pp IV-42 – IV-48
(2) Goodson, Carl, et al
IFSTA Essentials of Firefighting, 5th Ed.
IFSTA, Stillwater, OK, p 364
All photos courtesy of Hilton Head Island Fire & Rescue
About the Authors
Ben Waller is a Battalion Chief with Hilton Head Island Fire & Rescue, currently assigned as the Training Chief. Ben is a paramedic, a hazardous materials technician, and a USAR rescue specialist. He is Safety Officer for South Carolina USAR Regional Response Team 4 and is an adjunct faculty instructor in the fire, rescue, and incident command programs at the South Carolina Fire Academy. He is a member of the South Carolina Fire Academy’s Rope Rescue and Water Rescue Technical Development Committees. Ben’s education includes a Master’s of Public Administration degree and undergraduate Fire Administration and Paramedic/Allied Health degrees.
Jason Walters is a Lieutenant with Hilton Head Island Fire & Rescue, currently assigned to an engine/medic company. He is a Rescue Manager with South Carolina USAR SCTF-1 and is the Team Coordinator for South Carolina USAR Regional Response Team 4. He is an EMT-B, a hazardous materials technician, and a USAR rescue specialist. Jason is an adjunct faculty instructor in the fire and rescue programs at the South Carolina Fire Academy. His education includes an Associate of Fire Science Degree from Luzerne County College. Jason has 18 years of experience in fire-rescue, EMS, and hazardous materials response. He has 34 years of experience in fire-rescue, EMS, and hazardous materials response.
Tactics
In order to make a bathtub collapse rescue safe and efficient, the operation must follow a logical sequence. The first step in this sequence is to support the sides of the bathtub. If the bathtub is formed by structural walls or columns, start by shoring them. Raker shoring systems are a good way to support exterior walls.(1) For masonry or wooden walls, traditional raker shore types are appropriate. Modified split sole rakers may be used to provide columns with lateral support. Visibly stressed walls or columns should be shored first. If the wall or column is leaning or cracked, it’s stressed.
Extrication Strut as a temporary door shore
The next step is to support natural entry points, then open them. Door and window openings can be shored as in any other structural collapse. You may need to frame the edges of the opening with a raker system prior to shoring the actual opening. Once the door opening is supported, additional bathtub components such as metal Q-decking, rebar grids, and other metal components may be cut away to clear the opening for access and egress. Cutting operations create sparks, open flames, or both. Ensure that the building’s gas supplies are shut off and that the area is well-ventilated prior to using cutting tools that create ignition sources. Also ensure that both water and dry chemical extinguishers or a charged hoseline are nearby curing cutting operations.
Cutting Q-decking and rebar obstructions with a rotary saw
Once the interior of the bathtub is accessed, it may be necessary to use strongbacks and tiebacks to support inward-leaning walls. Picket systems or large, well-secured anchors should be used to anchor the exterior tiebacks. Place towels, blankets, etc. over the tieback cables to reduce whipping in the event of cable failure. Once the tieback system is complete, keep everyone out of the immediate area.
Widowmakers
Once the bathtub walls are secure, it’s time to take care of overhead hazards. Identify all widowmakers and eliminate falling object hazards by using one of the following methods;
1. Secure the widowmaker by tying it to solid structural components with cables, chains, come-alongs, etc.
2. Remove the widowmaker by bolting it, then tensioning it with a crane, and cutting it loose from the structure.
3. Avoid the widowmaker by marking and enforcing a collapse zone beneath the widowmaker. This may not be possible, as the victims may be trapped directly below the widowmaker.
Search Tactics
Once the surrounding structure is secured, the interior search can begin. Start by searching voids and by manually removing selected debris.(2) Voids may be searched visually with flashlights, thermal imaging cameras (TICs), USAR or fiber optic search cameras, and by probing voids with pike poles. It is important to note that wet concrete produces heat, and this heat may mask the heat signature of a human body when searching with TICs. Remember that TICs cannot “see” through solid materials such as structural components.
Simultaneously with the void search and light debris removal, other crews may start searching through the wet concrete in the bathtub. You may manually search for gaps in the horizontal Q-deck by simply using gloved hands to probe through the wet concrete and any gaps in the edges of the Q-decking.
Victim Search in a Bathtub Collapse
It is also important to create horizontal openings in the vertical Q-decking parts of the bathtub. This allows horizontal removal of some of the concrete while it is still wet. Hoselines can be used to keep the concrete wet and dilute as long as the water will not run into voids and drown the victim or cause hypothermia. Scoop shovels and even stiff-bristled push brooms can be used to move wet concrete through the bathtub openings.
Hose Stream dilutes and moves wet concrete
Bathtub Collapses into Basements
If it is necessary to lift wet concrete out of a basement, simple bucket-and-rope systems may be used, but they are manpower-intensive. Vacuum trucks may be useful, but the concrete may be too heavy for the vacuum to lift it very far. Large amounts of water will probably be required to dilute the concrete enough for a vacuum truck to lift it, and that much water may drown the victim prior to completing the rescue. Water also adds weight to an already-damaged structure, which may cause additional collapse. It may be necessary to move large volumes of wet concrete in order to locate the victim. It also may be possible to use a trash/solids pump to move dilute concrete out of a basement if the aggregate size is small enough to make it through the pump without clogging it. A bathtub collapse into a crawl space is generally similar to a collapse into a basement, but may allow grade-level access to one or more sides of the bathtub.
Victim Extrication
Once the victim is located, determine the body position and attempt to expose the airway. If the victim is alive, follow local blunt trauma and crush/compartment syndrome protocols. If the victim is deceased, ensure that all other potential victims are accounted for. If other victims are not accounted for, it will likely be necessary to continue in Rescue mode. If all victims are accounted for and have been determined to have died, then shifting to Recovery mode is more appropriate.
It is likely that rebar will be submerged or semi-submerged in the concrete. Large sections of the rebar grid may be cut away with minimal effort by locating the rebar and cutting it around the outside edge of the area you desire to expose. Cut rebar grid away with hydraulic cutter or large bolt cutters if it is submerged in the wet concrete. Rebar cutters, reciprocating saws, and/or torches may be used to cut any exposed rebar, particularly if only one hydraulic cutter is present.
Hydraulic cutters being used to cut rebar
Removal of rebar grid section
To extricate the victim, it is useful to locate the Q-decking edge closest to the victim. Once this edge is located, it can be used as a purchase point to move concrete and steel away from the victim. A variety of tools and techniques may be successful. Once the Q-deck edge has been located, start moving wet concrete away from it. A good rule of thumb is to move wet concrete away from the hole at least three times the depth of the remaining concrete. This will help prevent wet concrete from running through the hole in the Q-decking and burying the now-exposed victim.
Once adequate amounts of wet concrete and rebar have been removed, it is time to attack the Q-decking. You can start by using the exposed Q-deck edge as a purchase point and lifting the edge with hydraulic rescue spreaders. As you open the spreaders, the Q-decking will start peeling back. You can extend the cuts with hydraulic spreaders or reciprocating saws. If power tools are not available, even hacksaws can be used to cut the Q-decking. Small rescue air bags may be used to lift the Q-deck, but remember that sharp rebar ends or Q-decking edges may cut or puncture the air bags. If using air bags, pad them with sections of rubber matting such as old tractor-trailer mud flap material or short sections of old large-diameter fire hose. Bottle jacks or small scissor jacks can also be used to lift the Q-decking.
Hydraulic spreader used to roll up exposed Q-decking edge
It is not necessary to remove all of the concrete from the Q-decking prior to cutting it. Additional personnel can be used to continue moving concrete away from the victim with scoop shovels. As with any other heavy lifting operation, cribbing must be installed to support the lift. Use the “Lift an inch, crib an inch” cribbing method. It may be possible to use a come-along to support rebar grid sections that are too large for complete removal.
If it is becomes necessary to remove very large sections of Q-decking or other metal components, several cutting methods may be employed simultaneously. These can include alternating hydraulic spreader lifts with hydraulic cutter relief cuts, lifting with a spreader while extending the cut with reciprocating saws, or by removing concrete and steel in an area away from the victim in order to create an intermediate location in which to move materials away from the victim. If using torches, make sure that you do not burn the victim. If using torches remotely from the victim, use an atmospheric monitor near the victim to ensure that torch byproducts are not compromising the victim’s clean air supply.
If it is possible to quickly move a large amount of wet concrete out of the bathtub, consider making purchase points with a hole saw or core drill, inserting short sections of heavy-duty rebar or pickets, and attaching cables in order to lift a large section of steel away.
Prior to removing most of the wet concrete, air chisels and reciprocating saws will be of very little use, since they are designed to use in open air. Pneumatics may have limited utility, but electric tools will quickly burn out and become useless when submerged in wet concrete, due to the saw’s inability to radiate heat into the air.
If the victim is pinned over a secondary void, install supplemental shoring beneath the victim if possible. It may be necessary to install an improvised lifting harness on the victim if a secondary fall possibility is created by the extrication process. If the secondary void is very deep, it may be necessary to have rescuers shore beneath the extrication operation. This is highly dangerous, and is recommended ONLY as a last resort and with IC and Safety Officer approval.
Patient Care
As with any other extrication, provide medical care during the extrication if the victim is alive. If the extrication is prolonged, it will be necessary to provide protection from ambient temperature, extremes of weather, and to provide specialized crush syndrome care. USAR Medical Specialists and paramedics and physicians specializing in cave or mine rescue may be very useful in this situation. USAR medicine may require medications and medical protocols outside of normal EMS procedures. USAR medicine protocols should be approved by local and/or state EMS authorities in advance. It may be necessary to conduct a field amputation in order to save the victim’s life. If possible, a field-qualified physician should make the amputation, as amputations require training and equipment outside the normal paramedic scope of practice.
Once the victim is completely disentangled, package the victim, take any required steps to move the victim outside the structure, and turn the victim over to the transporting unit. All rescuers working near the victim should wear any necessary body substance isolation (BSI) personal protective clothing. If advanced life support (ALS) procedures are in use, EMS personnel should have a sharps container at the patient’s side for IV needles other contaminated sharps disposal.
Third-Party Investigations
If one or more victims are deceased, a scene investigation will be necessary prior to moving the body. The coroner, medical examiner, and/or law enforcement agencies will want to photograph and diagram the scene, interview witnesses, and determine whether any foul play is suspected. If the coroner or medical examiner staff is not trained to enter collapse zones, they may ask that rescuers take scene photos and/or measurements for them. If possible, put the coroner in a location where he/she can direct the rescuers as they take photos and measurements, but do not compromise responder safety to investigate a death.
OSHA investigators may also be on the scene. It is important to note that OSHA investigators do not generally have the authority to interfere with body recoveries, and they do not have the authority to interfere with the rescue of live patients. Fire-rescue and EMS personnel should document any actions they take on behalf of an investigating authority.
It is also important to inform coroner, medical examiner, law enforcement, and OSHA investigators that time is of the essence due to concrete curing. If the concrete hardens with the victim’s body still entrapped, a one or two-hour recovery may become a multi-hour or multi-day recovery operation. Once the body is removed, place it in a body bag, secure it in a Stokes basket, SKED, or other rescue litter, and remove the body from the collapse zone.
Decontamination and Clean-Up
USAR decontamination considerations generally involve cleaning equipment and PPE that may have been exposed to biohazardous wastes and cleaning concrete dust, powdered glass, or other building components from personnel and equipment. Bathtub collapses require an immediate additional step.
Several charged hoselines should be present to remove concrete from responders and equipment while it is still wet. This is particularly true for exposed skin and any tool that was submerged in the wet concrete. Exposed skin is vulnerable to thermal burns from the warm concrete, chemical burns from concrete components, and traumatic injury from rough aggregate or sharp metal edges encountered during the rescue. Concrete will find every nook and cranny in hydraulic rescue tools, bottle jacks, pneumatic hose couplings, pneumatic strut feet, or any other equipment that may have been placed in the concrete. Two or three engine companies assigned exclusively to decon will enable responders and gear to be cleaned quickly, efficiently, and thoroughly.
Termination
As with any other incident, all tools, equipment, and apparatus will need to be returned to service, cleaned, and inspected. Any equipment damaged, destroyed, or contaminated beyond salvage will need to be reported and replaced. Powered equipment will need to be serviced and fueled. It may be necessary to replace large quantities of cribbing and shoring materials, contaminated life safety rope, or other materials that it is unsafe to recover. Do not risk personnel to recover a few pieces of wood that can be easily and cheaply replaced.
Any personnel injury or exposure will need to be treated, reported, and receive any necessary follow-up care. An accurate incident report should be completed, anticipating third-party investigations and possibly criminal or civil actions due to the collapse. An after-action review should be held as soon as all the incident facts can be determined. The critique should involve all personnel and units that participated in the response.
Conclusion
Bathtub collapses have not been previously identified and traditional USAR training does not specifically address collapses involving wet concrete. Wet concrete is not easy to shore or support. Wet concrete adds a new degree of difficulty to USAR searches, as you can’t just drill a hole and look through it with a search camera or fiber optic scope. Wet concrete flows to the lowest point and collects, which can concentrate structural weight in a small portion of the supporting structure. Bathtub collapses add an entirely new set of challenges, even for well-trained and experienced USAR teams. One of the most critical elements is time – the concrete won’t stop hardening while we call resources, shore the structure, or search for the victims.
Concrete buildings may be constructed virtually anywhere. All concrete structures are vulnerable to collapse while under construction. With the increasing demand for structures to house people, businesses, and to repair our country’s aging infrastructure, it is anticipated that bathtub collapses will become more common. Any fire-rescue and EMS agency may be faced with a bathtub collapse. Preparation, safety, equipment, training, and above all, anticipation are important to keep responders safe and to successfully conclude the response to complex and dangerous bathtub collapses.
References
(1) U.S. Army Corps of Engineers
US&R Structures Specialist Field Operations Guide, 3rd Ed.
U.S. Army Corps of Engineers Readiness Support Center, 2001, pp IV-42 – IV-48
(2) Goodson, Carl, et al
IFSTA Essentials of Firefighting, 5th Ed.
IFSTA, Stillwater, OK, p 364
All photos courtesy of Hilton Head Island Fire & Rescue
About the Authors
Ben Waller is a Battalion Chief with Hilton Head Island Fire & Rescue, currently assigned as the Training Chief. Ben is a paramedic, a hazardous materials technician, and a USAR rescue specialist. He is Safety Officer for South Carolina USAR Regional Response Team 4 and is an adjunct faculty instructor in the fire, rescue, and incident command programs at the South Carolina Fire Academy. He is a member of the South Carolina Fire Academy’s Rope Rescue and Water Rescue Technical Development Committees. Ben’s education includes a Master’s of Public Administration degree and undergraduate Fire Administration and Paramedic/Allied Health degrees.
Jason Walters is a Lieutenant with Hilton Head Island Fire & Rescue, currently assigned to an engine/medic company. He is a Rescue Manager with South Carolina USAR SCTF-1 and is the Team Coordinator for South Carolina USAR Regional Response Team 4. He is an EMT-B, a hazardous materials technician, and a USAR rescue specialist. Jason is an adjunct faculty instructor in the fire and rescue programs at the South Carolina Fire Academy. His education includes an Associate of Fire Science Degree from Luzerne County College. Jason has 18 years of experience in fire-rescue, EMS, and hazardous materials response. He has 34 years of experience in fire-rescue, EMS, and hazardous materials response.
Saturday, March 6, 2010
The Bathtub Collapse: Part 1
This article is co-authored by my friend and colleague Jason Walters. Jason is the Team Leader for USAR SC-Regional Response Team 4.
Introduction
FEMA’s USAR system, basic firefighting texts, and other fire-rescue references describe how to recognize and respond to a variety of structural collapse situations. These collapse types are specific to structures with rigid components. Freshly-poured concrete isn’t rigid, and collapses involving wet concrete create a unique set of circumstances not described in typical structural collapse references.
Collapses have traditionally been classified in four categories. These are the Lean-To Collapse, the V - Collapse, the Pancake Collapse and the Cantilever Collapse.(1) Some USAR documents now describe an additional collapse type – the A-Frame Collapse.(2, 3) The A-Frame Collapse is also known as a Tent Collapse. An A-Frame Collapse is essentially two back-to-back Lean-To collapses that share a common wall or other upright structural component.
There is another collapse type that has recently been identified. This collapse type involves concrete that is still wet. We call it the Bathtub Collapse. Unlike cured concrete, wet concrete does is not solid and when freshly poured, it does not form slabs and or give off dust. Wet concrete runs to the lowest point available, then collects like water in a bathtub. Bathtub collapses have some things in common with other collapse types, but there are several significant differences. The most important are the difficulty in stabilizing a collapse involving wet concrete, handling concrete that does not stay in one place, and the relatively short time it takes for the wet concrete to harden.
Typical Bathtub Collapse
Concrete Weight
Wet concrete is slightly heavier than a corresponding volume of dry concrete. When concrete cures, some of the water evaporates, but much of the water stays in the concrete. Water binds chemically to the solids in the concrete, and thus concrete retains much of the water weight when it cures. Concrete loses some weight as it cures, but surprisingly, that weight loss is relatively small.
The rule of thumb for the weight of a cubic foot of wet concrete with aggregate mix is 4000 lbs/yard3, or approximately 162 lbs/ft.3. The rule of thumb for the weight of a cubic foot of dry concrete with aggregate mix is 3700 lbs/yard3 or 150 lbs/ ft3. (4) The bottom line is that all concrete is heavy. Remember, the primary difference between wet concrete and dry concrete – wet concrete flows to the lowest point and then collects there.
A factor that construction personnel may not take into account is that once a concrete slab is poured, water, wet burlap, or other wet material is often left on the concrete surface to assist in insulating and hydrating the concrete as it cures. This water adds additional weight that may not be considered in the design of the shoring system that supports the pour. If that additional water weight is not accounted for in the shoring system, then a collapse is more likely.
Building Construction Factors
Virtually any type of building construction may be involved in a bathtub collapse. Bathtub collapses usually occur when construction personnel pour a concrete floor at an elevation above the lowest structural level. Bathtub collapses occur in one of three basic configurations. The first is when the collapse rests on the ground or on a slab at grade level. The second bathtub collapse type involves collapses above grade level. The third type is a bathtub collapse into a basement or other below-grade area. Bathtub collapses will most commonly occur at or below grade. Bathtub collapses that begin above the second floor are rare, as the collapse of an upper floor often causes a progressive pancake collapse that destroys the entire structure.
Basic bathtub collapse strategies are based on grade-level collapses. Above-grade and below-grade bathtub collapses involve the same basic strategy as a grade-level collapse, with a few additional considerations.
Construction Process Factors
The collapse of a concrete floor during or immediately after a pour may be due to one or more of the following factors:
• Inadequate shoring beneath the pour
• Wall-floor structural connector failure
• Shoring material failure
• Excessive amount of concrete poured
• Excessive pour concentration
• Failure of walls, beams, or other supporting structural materials
The Bathtub Collapse Sequence
Steel span drops with the outside edges supported, forming a rough bathtub shapeWet concrete runs to the center of the bathtub
Wet concrete runs out of small openings in the edges of the bathtub. These may be quickly blocked due to the heavy concrete viscosity or obstructions outside the bathtub. If small openings are blocked, the concrete in the bathtub will form a larger and deeper pool. This will make size up and extrication more difficult.
Concrete forms a thicker but smaller diameter puddle than the original pour
Rebar, Q-decking or other steel sheeting, and shoring materials are twisted and mixed into the wet concrete
Supporting beams and damaged overhead structural materials may create widowmakers
Supporting beams may fall into the bathtub prior to or during the rescue operation
Size-Up and Strategy
Size-up should be completed in accordance with standard structural collapse protocols. This should include the situation, potential entrapment problems, specific hazards, and a 360-degree look at the structure. When possible, include an elevated look at the collapse. An aerial ladder or nearby building may be used as an elevated observation post. When size-up is complete, Command should develop the Incident Action Plan (IAP) goals, communicate the IAP to all responders, make tactical assignments, and ensure that the personnel accountability system is fully implemented.
Important strategy considerations include:
Define the building factors including construction type
Identify the most likely victim locations
Develop and communicate the IAP
Safety considerations
Shoring
Remove easily accessible victims
Make the rescue vs. recovery decision
Estimate the concrete cure time
Wet concrete removal methods
Bathtub Collapse Incident Management
Command should consider appointing at least a Safety Officer, a Liaison Officer, and a Rescue Group Supervisor for even a small bathtub collapse.(5) The Safety Officer can help isolate the scene and identify the primary hazards. The Liaison Officer can work with the construction company to determine how many workers are missing or known to be entrapped. The Liaison Officer should communicate with the construction supervisor, gather information, and keep construction personnel available to assist if needed. The Rescue Group Supervisor can concentrate on rescue tactics and needs and allow the Incident Commander to keep his/her attention focused on the overall incident strategy and safety.
Resources
Structural collapses typically require more resources than may seem likely during the early incident stages. It is important to have at least one engine company for water supply, one truck company for tools and an aerial device, a heavy rescue or USAR unit for tools and shoring materials, and additional manpower. A large law enforcement presence may be required to keep bystanders, construction personnel, or distraught relatives out of the collapsed structure. Additional construction personnel and heavy equipment such as cranes, front-end loaders, and other machinery may be useful in the rescue effort. If in doubt, call for additional resources early and often. Structural collapse rescue is hard work, and personnel may quickly become exhausted, especially in extremes of temperature and/or
precipitation.
Safety Considerations
One of the first priorities is to assign an Incident Safety Officer. This should be an officer who has a good basic knowledge of building construction, collapse types, USAR strategy and tactics, and common USAR safety problems. The Safety Officer should ensure that a safety zone is established. Collapse zones should be established to exclude responders from areas exposed to potential secondary collapse, particularly in areas beneath widowmakers. The Safety Officer should ensure that building utilities are shut down. Construction company generators and other power supplies should be shut down to reduce electrical hazards and atmospheric contaminants. Construction personnel should be kept on standby, as their generators may be useful power sources later in the incident.
Assessing the outside of the bathtub
The Safety Officer
A Safety Officer should be appointed early in the response. The Safety Officer should don the appropriate PPE and the Safety command vest. Once search and rescue operations begin, the Safety Officer should be located at an elevated observation point, if possible. Observing from an elevation gives the Safety Officer the ability to observe conditions in the bathtub as well as the condition of supporting walls, columns, and the stability of the surrounding structure. Most importantly, an elevated observation point gives the Safety Officer a better perspective on how rescue operations may change structural and personnel safety. For example, if wet concrete piles up against the base of a column that is already leaning, it may topple that pillar and cause an additional collapse. A properly-positioned Safety Officer will be able to anticipate this problem, advise Command, and ensure that the concrete flow is diverted prior to impinging on the damaged column.
Safety Officer’s view into the bathtub from an elevated observation point
Personal Protective Clothing
Standard USAR PPE is usually adequate for bathtub collapse operations. Lace-up safety boots are the most appropriate footwear. Wet concrete has a consistency very much like quicksand, and fire boots may be pulled off of firefighters who walk in it. Leather construction gloves, mechanics gloves, or extrication gloves are adequate for most hand protection, but medical exam gloves will be required for patient care.
Modified Turnout Gear Ensemble used for heavy cutting PPE
This concludes Part 1. Part 2 will discuss discusses tactical considerations, interior size-up, victim recovery, investigations, and incident termination.
References
(1) Goodson, Carl, et al
IFSTA Essentials of Firefighting, 5th Ed.
IFSTA, Stillwater, OK, pp 362-364
(2) English, Leslie, et al
NFPA 1670, Standard on Operations and Training for Technical Search and
Rescue, 2004 Ed.
NFPA, Batterymarch Park, MA, pp 25-27
(3) U.S. Army Corps of Engineers
US&R Structures Specialist Field Operations Guide, 3rd Ed.
U.S. Army Corps of Engineers Readiness Support Center, 2001, p VI-3
(4) http://corlissconcrete.com/Q&A.htm#4
(5) Jones, Jeff
NIMS Field Operations Guide, 1st Ed.
InforMed, Tigard, OR, pp 14-20
All photos courtesy of Hilton Head Island Fire & Rescue
Introduction
FEMA’s USAR system, basic firefighting texts, and other fire-rescue references describe how to recognize and respond to a variety of structural collapse situations. These collapse types are specific to structures with rigid components. Freshly-poured concrete isn’t rigid, and collapses involving wet concrete create a unique set of circumstances not described in typical structural collapse references.
Collapses have traditionally been classified in four categories. These are the Lean-To Collapse, the V - Collapse, the Pancake Collapse and the Cantilever Collapse.(1) Some USAR documents now describe an additional collapse type – the A-Frame Collapse.(2, 3) The A-Frame Collapse is also known as a Tent Collapse. An A-Frame Collapse is essentially two back-to-back Lean-To collapses that share a common wall or other upright structural component.
There is another collapse type that has recently been identified. This collapse type involves concrete that is still wet. We call it the Bathtub Collapse. Unlike cured concrete, wet concrete does is not solid and when freshly poured, it does not form slabs and or give off dust. Wet concrete runs to the lowest point available, then collects like water in a bathtub. Bathtub collapses have some things in common with other collapse types, but there are several significant differences. The most important are the difficulty in stabilizing a collapse involving wet concrete, handling concrete that does not stay in one place, and the relatively short time it takes for the wet concrete to harden.
Typical Bathtub Collapse
Concrete Weight
Wet concrete is slightly heavier than a corresponding volume of dry concrete. When concrete cures, some of the water evaporates, but much of the water stays in the concrete. Water binds chemically to the solids in the concrete, and thus concrete retains much of the water weight when it cures. Concrete loses some weight as it cures, but surprisingly, that weight loss is relatively small.
The rule of thumb for the weight of a cubic foot of wet concrete with aggregate mix is 4000 lbs/yard3, or approximately 162 lbs/ft.3. The rule of thumb for the weight of a cubic foot of dry concrete with aggregate mix is 3700 lbs/yard3 or 150 lbs/ ft3. (4) The bottom line is that all concrete is heavy. Remember, the primary difference between wet concrete and dry concrete – wet concrete flows to the lowest point and then collects there.
A factor that construction personnel may not take into account is that once a concrete slab is poured, water, wet burlap, or other wet material is often left on the concrete surface to assist in insulating and hydrating the concrete as it cures. This water adds additional weight that may not be considered in the design of the shoring system that supports the pour. If that additional water weight is not accounted for in the shoring system, then a collapse is more likely.
Building Construction Factors
Virtually any type of building construction may be involved in a bathtub collapse. Bathtub collapses usually occur when construction personnel pour a concrete floor at an elevation above the lowest structural level. Bathtub collapses occur in one of three basic configurations. The first is when the collapse rests on the ground or on a slab at grade level. The second bathtub collapse type involves collapses above grade level. The third type is a bathtub collapse into a basement or other below-grade area. Bathtub collapses will most commonly occur at or below grade. Bathtub collapses that begin above the second floor are rare, as the collapse of an upper floor often causes a progressive pancake collapse that destroys the entire structure.
Basic bathtub collapse strategies are based on grade-level collapses. Above-grade and below-grade bathtub collapses involve the same basic strategy as a grade-level collapse, with a few additional considerations.
Construction Process Factors
The collapse of a concrete floor during or immediately after a pour may be due to one or more of the following factors:
• Inadequate shoring beneath the pour
• Wall-floor structural connector failure
• Shoring material failure
• Excessive amount of concrete poured
• Excessive pour concentration
• Failure of walls, beams, or other supporting structural materials
The Bathtub Collapse Sequence
Steel span drops with the outside edges supported, forming a rough bathtub shapeWet concrete runs to the center of the bathtub
Wet concrete runs out of small openings in the edges of the bathtub. These may be quickly blocked due to the heavy concrete viscosity or obstructions outside the bathtub. If small openings are blocked, the concrete in the bathtub will form a larger and deeper pool. This will make size up and extrication more difficult.
Concrete forms a thicker but smaller diameter puddle than the original pour
Rebar, Q-decking or other steel sheeting, and shoring materials are twisted and mixed into the wet concrete
Supporting beams and damaged overhead structural materials may create widowmakers
Supporting beams may fall into the bathtub prior to or during the rescue operation
Size-Up and Strategy
Size-up should be completed in accordance with standard structural collapse protocols. This should include the situation, potential entrapment problems, specific hazards, and a 360-degree look at the structure. When possible, include an elevated look at the collapse. An aerial ladder or nearby building may be used as an elevated observation post. When size-up is complete, Command should develop the Incident Action Plan (IAP) goals, communicate the IAP to all responders, make tactical assignments, and ensure that the personnel accountability system is fully implemented.
Important strategy considerations include:
Define the building factors including construction type
Identify the most likely victim locations
Develop and communicate the IAP
Safety considerations
Shoring
Remove easily accessible victims
Make the rescue vs. recovery decision
Estimate the concrete cure time
Wet concrete removal methods
Bathtub Collapse Incident Management
Command should consider appointing at least a Safety Officer, a Liaison Officer, and a Rescue Group Supervisor for even a small bathtub collapse.(5) The Safety Officer can help isolate the scene and identify the primary hazards. The Liaison Officer can work with the construction company to determine how many workers are missing or known to be entrapped. The Liaison Officer should communicate with the construction supervisor, gather information, and keep construction personnel available to assist if needed. The Rescue Group Supervisor can concentrate on rescue tactics and needs and allow the Incident Commander to keep his/her attention focused on the overall incident strategy and safety.
Resources
Structural collapses typically require more resources than may seem likely during the early incident stages. It is important to have at least one engine company for water supply, one truck company for tools and an aerial device, a heavy rescue or USAR unit for tools and shoring materials, and additional manpower. A large law enforcement presence may be required to keep bystanders, construction personnel, or distraught relatives out of the collapsed structure. Additional construction personnel and heavy equipment such as cranes, front-end loaders, and other machinery may be useful in the rescue effort. If in doubt, call for additional resources early and often. Structural collapse rescue is hard work, and personnel may quickly become exhausted, especially in extremes of temperature and/or
precipitation.
Safety Considerations
One of the first priorities is to assign an Incident Safety Officer. This should be an officer who has a good basic knowledge of building construction, collapse types, USAR strategy and tactics, and common USAR safety problems. The Safety Officer should ensure that a safety zone is established. Collapse zones should be established to exclude responders from areas exposed to potential secondary collapse, particularly in areas beneath widowmakers. The Safety Officer should ensure that building utilities are shut down. Construction company generators and other power supplies should be shut down to reduce electrical hazards and atmospheric contaminants. Construction personnel should be kept on standby, as their generators may be useful power sources later in the incident.
Assessing the outside of the bathtub
The Safety Officer
A Safety Officer should be appointed early in the response. The Safety Officer should don the appropriate PPE and the Safety command vest. Once search and rescue operations begin, the Safety Officer should be located at an elevated observation point, if possible. Observing from an elevation gives the Safety Officer the ability to observe conditions in the bathtub as well as the condition of supporting walls, columns, and the stability of the surrounding structure. Most importantly, an elevated observation point gives the Safety Officer a better perspective on how rescue operations may change structural and personnel safety. For example, if wet concrete piles up against the base of a column that is already leaning, it may topple that pillar and cause an additional collapse. A properly-positioned Safety Officer will be able to anticipate this problem, advise Command, and ensure that the concrete flow is diverted prior to impinging on the damaged column.
Safety Officer’s view into the bathtub from an elevated observation point
Personal Protective Clothing
Standard USAR PPE is usually adequate for bathtub collapse operations. Lace-up safety boots are the most appropriate footwear. Wet concrete has a consistency very much like quicksand, and fire boots may be pulled off of firefighters who walk in it. Leather construction gloves, mechanics gloves, or extrication gloves are adequate for most hand protection, but medical exam gloves will be required for patient care.
Modified Turnout Gear Ensemble used for heavy cutting PPE
This concludes Part 1. Part 2 will discuss discusses tactical considerations, interior size-up, victim recovery, investigations, and incident termination.
References
(1) Goodson, Carl, et al
IFSTA Essentials of Firefighting, 5th Ed.
IFSTA, Stillwater, OK, pp 362-364
(2) English, Leslie, et al
NFPA 1670, Standard on Operations and Training for Technical Search and
Rescue, 2004 Ed.
NFPA, Batterymarch Park, MA, pp 25-27
(3) U.S. Army Corps of Engineers
US&R Structures Specialist Field Operations Guide, 3rd Ed.
U.S. Army Corps of Engineers Readiness Support Center, 2001, p VI-3
(4) http://corlissconcrete.com/Q&A.htm#4
(5) Jones, Jeff
NIMS Field Operations Guide, 1st Ed.
InforMed, Tigard, OR, pp 14-20
All photos courtesy of Hilton Head Island Fire & Rescue
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