REMOVING SECURITY BARS
BY BILL GUSTIN
Fear of crime has forced many residents of urban areas to become prisoners in their own homes, living behind iron bars and heavy gates that protect their doors and windows from intruders. The actual or perceived threat of burglary and home invasion has risen to the point in some communities that the citizens have a greater concern for security than they do for fire safety.
Fire departments are largely fighting a losing battle in their efforts to educate the public about the dangers of security bars that block escape from a fire. Sadly, fear of intruders far outweighs any concern about being trapped in a fire by iron bars.
The crime problem and resulting installation of security bars are growing at a time when many fire departments are experiencing budget cuts. Consequently, fewer personnel may be available to perform the labor-intensive task of cutting, pulling, or bending iron bars that obstruct rescue and delay fire attack.
Security bars, once found only in the inner city, now are common in many suburbs. Their growing use has prompted many departments to purchase additional forcible entry tools and develop new techniques for dealing with this challenge.
SIZE-UP FOR FORCIBLE ENTRY
A careful size-up should precede forcing security bars, just as it should any fireground operation. Take a few moments to look at the bars before working on them. Selecting the right tool and technique for forcing bars depends on the following considerations, observed during size-up:
thickness of the bars,
whether bars are solid or tubular,
where individual bar components are joined together,
where bars are mounted (for example, on the outside surface of a wall, on the inside of a wall, or within a window or door opening),
how bars are fastened to a building,
construction and strength of what the bars are fastened to (for example, wall, window, or door frame), and
access. (Can the bars be reached from the ground, or is a ladder necessary? Are the bars within range of a vehicle that can be rigged with a tow chain?)
The key to successful forcible entry is to always attack a barrier at its weakest point. A careful size-up may indicate, for example, that bars that at first glance appear to be very strong are actually weakly fastened to the wall. It often is faster and easier to attack fasteners than it is to cut the bars them-selves.
A size-up should note how horizontal and vertical members of a bar assembly are joined together. This can determine the location and sequence of cuts that will clear the opening with the least amount of cutting. Bars seldom have to be completely removed from a wall to gain entry. Rather, cutting in strategic places or attacking certain fasteners may allow the bars to be hinged away from the opening.
TOOLS AND TECHNIQUES
Rotary saw. A rotary saw, equipped with a metal-cutting aluminum oxide blade, can be fast and effective at cutting bars, especially bars mounted on the outside surface of a wall. Such bars typically are fastened at flat tabs welded to each corner of the bars and, possibly, every two to three feet along the outer perimeter of the assembly. Fasteners such as lag bolts, masonry anchors, and carriage bolts hold the bars on the wall at these mounting tabs. It is much faster and easier to cut the flat mounting tabs than it is to cut bar stock.
If possible, avoid cutting thick, solid security bars with a rotary saw. An abrasive blade rapidly wears down as it grinds its way through thick steel and wrought iron. Thick vertical bars mounted on the inside of a wall or within a window opening are particularly difficult to cut with a saw. Because their fastening points are not readily accessible, the saw operator may have to cut each vertical bar twice–at its top and bottom. This task involves a considerable amount of time, blade material, and operator strength. The saw must be held with steady hands in an almost horizontal position as it cuts each vertical bar inside the window opening. This requires considerable strength and skill; otherwise, the blade can bind and break, scattering fragments at 6,000 rpm.
Operating a saw on bars overhead or from a ladder can be difficult and dangerous. A company ordered to cut security bars should bring several spare blades and a set of blade-changing wrenches in a pouch or bag to each saw operation.
Torch. A torch has some advantages over a saw, although it takes somewhat longer to set up. Its advantages are realized when cutting bars that are overhead and when operating inside a window opening. You can operate a torch with one hand, at arm`s length, and from a windowsill or ladder. A compact, portable acetylene or other fuel gas torch is a very quick and effective tool for cutting thick, solid bars, especially in the hands of a skilled operator with experience in burning iron and steel. An exothermic torch rapidly cuts through metal bars of practically any thickness or composition; however, it consumes cutting rods very quickly–some in as fast as 45 seconds.
Operate an exothermic torch with extreme caution. It issues a two-foot jet of flame that will evaporate protective clothing and severely burn underlying flesh. The exothermic torch also produces a shower of sparks as it cuts, which can ignite combustible contents or construction.
Air chisel. A heavy-duty air chisel, designed for rescue work, can be very effective at forcing bars fastened with lag bolts, carriage bolts, or masonry anchors. A momentary burst of the air chisel drives its curved cutter bit in between the bars and their mounting surface (wall, window frame, etc.). A second burst will shear the fastener in a few seconds.
Hand tools. No strategy should ever depend on the success of one tool or method to force entry. Power saws have a way of not starting at a critical moment, composite blades break, and a portable torch can run out of fuel. Power tools may not be available when they are needed. Most departments cannot afford to equip each company with a torch or saw. Thus, a proactive fire officer takes all this into consideration when formulating a plan for for-cible entry and al-ways has a “Plan B”–an alternate way to get into a building.
Common hand tools, carried by practically all fire companies, can be used to force security bars. The effectiveness of hand tools depends primarily on the skill, strength, stamina, and ingenuity of the firefighters who use them.
Bars that are set in masonry window openings sometimes can be freed with the striking force of a maul. Striking the center of each bar may cause it to bend sufficiently to dislodge one end from its socket (in the masonry). Additional blows at or near the end still set in masonry can loosen the bar and allow it to be pulled from its socket.
This method may not be effective when concrete reinforcing rod is used for window bars. Larger rebar often is used for windows at the rear of a building, where aesthetics are not a concern. Rebar is resilient and difficult to bend. A maul usually bounces off thick rebar with little effect.
Another method that can be used as an alternative or in conjunction with bending bars involves striking the masonry that holds the bars. This can loosen and free the bars from the surrounding masonry. A flathead axe driven by a 10-pound maul delivers a tremendous amount of shearing and spreading force.
The axe-maul technique is particularly effective when used to shear fasteners that anchor a set of bars to a wall or window frame. Bars that are installed on existing buildings typically are fastened with lag bolts, masonry anchors, or carriage bolts. Carriage bolts extend completely through a wall and are secured with a nut and a large washer on the inside of the building. The key to this technique is to drive the axe blade in be-tween the bar assembly and its mounting surface at fastening points. A couple of taps on the maul will “set” the axe blade in position at a fastener. Then a few forceful blows usually will shear the fastener and spread the bars away from the wall or window frame.
Occasionally, a fastener will not shear completely but instead will loosen and partially pull out of its mount. In this situation, the axe blade, wedged between the bars and their mounting surface, provides a sufficient purchase point to insert a halligan or other tool and pry the bars clear of the opening.
Pulling security bars off a building is, of course, not a new concept. Fire departments have used this method before the age of the power saw, and it continues to be an effective tactic. Small four-wheel-drive vehicles, such as rescue-utility trucks and command vehicles, have the potential to be very powerful forcible entry bar-pulling tools when equipped with a strong chain. Of course, no one method will always be successful. Clearly, sufficient access is necessary to maneuver a vehicle into position, attach a reasonable length of chain, and exert a pull perpendicular to the bars. However, when there is sufficient access, nothing is faster for forcing bars than pulling them off a wall with a vehicle.
Large apparatus certainly have the power to pull bars, but their size and function (for example, pump and ladder operations) usually make their use impractical.
A winch is an excellent bar-pulling device, and a cable come-along can be successful in places where there is no access for a vehicle. At some incidents, resources outside the fire department have been utilized quite successfully. At a recent incident, Metro-Dade (FL) firefighters commandeered a passing tow truck to pull an iron gate free from the front door of a residence. At another fire, water and sewer workers used their backhoe to tear bars off an apartment building before fire companies arrived.
Chain is available in a wide variety of styles, strengths, and materials. Chain used in industry is selected according to its intended use. There are a multitude of uses for chain in the fire and rescue service; however, select only chain rated for heavy-duty applications. Grade 80 alloy chain is rated for the most demanding applications and is the only one rated for overhead lifting.
Three-eighths-inch alloy chain is a good choice for pulling bars and other applications because it strikes an excellent balance of size, weight, and strength. Its relatively light weight allows it to be rapidly rigged and deployed with minimal personnel.
Never exceed 38-inch alloy chain`s working load limit of 7,100 pounds. However, a 4:1 safety factor gives the chain a breaking strength of more than 28,000 pounds. This strength is more than adequate because most bar assemblies fail at a fraction of the 7,100-pound working load limit. It is unlikely that the chain will ever break in this application if it is used properly. A vehicle pulling an unyielding set of bars will lose traction and begin to spin its wheels long before you reach the chain`s working load limit. Accessories such as grab hooks and shackles, which facilitate shortening the chain and connection to bars and vehicles, should have a comparable strength rating.
Regardless of the type or strength of chain, it can fail if it is misused or abused. Chains are not designed for sudden application of a load. Shock, or impact loading, such as when a vehicle accelerates and jerks the chain before the slack is taken out, multiplies the stress on the chain and can cause it to fail. All slacks and twists must be removed from a chain before a load is applied; then, the pulling force must be exerted slowly and gradually.
Chain exposed to high temperatures can lose its strength. When you pull bars from a window or doorway that is issuing fire, apply a cool hose stream. If this is not possible, wrap the chain on the lower portion of the bars, on the windward side of the opening.
SAFETY CONSIDERATIONS FOR CHAIN
As a general rule, the more powerful the tool, the greater its potential to inflict serious injury. A vehicle pulling bars is exerting a powerful force that must be applied with control. This method of forcible entry should be implemented only after careful consideration of the dangers involved.
The greatest danger in pulling bars is that doing so can precipitate the collapse of a fire-damaged or otherwise weak wall. If the need for rescue outweighs the risk of wall collapse, make sure the chain is long enough to allow the vehicle to pull from outside the collapse zone (a distance from the building that is greater than the height of the wall). All personnel should stand clear of the operation to avoid being struck by the vehicle, bars, the wall, or a broken chain.
CHAIN VS. NYLON WEB RIGGING
Metro-Dade has been field-testing rigging made of nylon web sling material as an alternative to chain. The device consists of three plys of two-inch by 14-inch lifting sling and alloy steel links, shackles, and hooks. The rigging is assembled locally for the Special Response (SWAT) Team of the Metro-Dade Police Department. The police use the device extensively at drug raids to pull iron doorway gates.
The web sling rigging has some distinct advantages over chain:
It is much stronger, lighter, and more flexible.
Its 12,000-pound safe working load is comparable to 12-inch chain but at a fraction of the weight.
The web material has a stretch factor of 10 percent, which makes the device much more tolerant of shock loading.
Although it is not recommended, sudden acceleration multiplies the force exerted by the vehicle to such an extent that the results can be quite dramatic: Strong bars that otherwise resist pulling usually “blow” off a wall and land several feet from the building.
The sling rigging has some important limitations that merit consideration in fire operations:
Although durable, nylon web cannot withstand abrasion from rough surfaces the way a chain can.
The most serious limitation that affects its use on the fireground is its low resistance to heat. This necessitates the use of a chain or cable leader that can be attached to bars exposed to high temperatures.
WATER FOG AND PPV IN BUILDINGS WITH SECURITY BARS
Fog nozzles and positive-pressure blowers can have a powerful influence on the involvement of fire and its products of combustion inside a structure. Fog patterns and PPV work well under ideal conditions: when they can force heat and smoke out of a ventilation opening close to the seat of the fire. Conditions at occupied structure fires, however, are seldom ideal.
PPV and fog may increase the comfort level of firefighters who attack the fire from the uninvolved portion of a structure but increase the likelihood of serious injury or death to occupants trapped between the fire and the ventilation opening. This situation is common in buildings that have windows equipped with burglar bars. Usually, the windows opened or broken by occupants trapped by iron bars are among the few ventilation openings in buildings otherwise closed to contain heating or air-conditioning. Application of PPV or use of a fog pattern prior to search and rescue can make conditions much worse for those unfortunate occupants because smoke and heat will be driven toward the windows where they are trapped. Never implement fire attack with water fog or PPV without first considering its effect on occupants who may be trapped.
There are applications for water fog and PPV that can improve conditions for victims awaiting rescue from windows equipped with burglar bars. Applying the fog pattern or operating a blower directly at the opening where occupants are trapped can push smoke and heat away from the victims while rescuers work to force the security bars. The success of this tactic, however, depends on the fire`s finding an alternate path (for example, an open doorway or another window) when pressurization is applied.
Victims trapped at windows equipped with iron bars are in a desperate situation; their survival is doubtful unless firefighters take immediate action to effect their rescue. Firefighters must be aware of the presence of such victims before they can take action–this is where the importance of accurate, thorough size-up comes in.
* * *
Many of the problems affecting society today have made the firefighter`s job more difficult and dangerous. Certainly, violent crimes, civil disturbances, and communicable diseases have had a significant impact on the way fire departments operate. Security bars are a direct result of a growing crime problem. Departments can improve their ability to force these barriers through training, familiarization with bar installations in their jurisdictions, and having the proper tools and equipment. n
Photo by Paul Blake.
(Top left) A rotary saw is used to cut flat tabs where the gate is fastened to the exterior wall with masonry anchors. Bars mounted vertically on the inside of a wall or within a window opening are difficult to cut with a rotary saw. (Photo by Tom Kenney.) (Top middle) A flathead axe driven by a 10-pound maul shears masonry anchors that fasten the gate assembly to the wall. Shearing fasteners on one side allows the assembly to be hinged away from the doorway of this residence. (Photo by Tom Kenney.) (Top right) A heavy-duty air chisel rapidly shears fasteners–such as lag bolts, masonry anchors, and carriage bolts–that typically attach bars to a wall. (Photo by Ray Bell.) (Botom left, right) An exothermic torch rapidly burns through bars of practically any thickness or composition. The torch must be operated with extreme caution because of the flame and sparks it produces. The sparks can ignite combustible construction or contents. Cuts were planned to allow bars to hinge away from the opening while still partially attached to the building. (Photos by Bill Gustin, Jr.)
(Top left) A four-wheel-drive battalion chief`s vehicle pulls a set of iron bars mounted on the inside of the wall with nylon web rigging. (Photo by Dave Wood.) (Top right, bottom left, bottom right) Rigging made specifically for pulling bars stretches as tension is applied and then recoils when the bars are pulled free. (Photos by Bill Gustin, Jr.)
Tow hooks allow a battalion chief`s vehicle to be quickly rigged with chain or webbing. (Photos by Dave Wood.)
Positive-pressure ventilation should never be implemented without first considering what effect it may have on occupants trapped at exhaust openings. PPV can push fire toward windows where occupants are trapped by iron bars. (Photo by Paul Blake.)
BILL GUSTIN is a captain with the Metro-Dade County (FL) Fire Department and a lead instructor in the department`s officer training program. He has taught cruise ship crews firefighting skills, has instructed in Caribbean countries, and was a member of the International Rescue Task Force for the U.S. Office of Foreign Disaster Assistance. He is an editorial advisory board member of Fire Engineering.