COLLAPSE SEARCH AND RESCUE OPERATIONS: TACTICS AND PROCEDURES
PART 15: AIR BAG OPERATIONS
BY JOHN P. O`CONNELL
One of the only times it may become necessary to lift collapse debris is when it is necessary to extricate a victim trapped or pinned by the debris. Lifting and removing loose debris to reach a victim usually is not a problem, although it may be time-consuming. The problems arise when a victim is pinned by debris or larger structural elements that are supporting large areas of debris or other structural elements. In this situation, the decision must be made whether to remove debris by hand or use an air bag lift.
The high-pressure air bag (which generally operates at between 116 and 118 psi) is a unique tool that can be used in a wide variety of rescue operations as well as structural collapse situations. The air bag system consists of four main components: the regulator, controller, hose, and bag. It has many advantages other tools lack when it comes to rescues in tight areas such as void search operations.
Training in this equipment is essential; lifting a specific section of collapse debris to free a victim can be a very tricky operation. You must be proficient in setting up and operating this equipment, especially the controller (the dual safety relief and control valve used to inflate and deflate the bags), prior to using it at an incident.
There are several styles of controllers; you will have to decide which you prefer. With the “deadman”-type controller, positive pressure must be applied to the inflation valve or it will not operate, an excellent safety feature when operating in unstable collapse situations. This is a push-button-type of controller: For inflation, press the inflation valve; to stop inflation, release the valve. This controller is safer to operate than the conventional, standard controller, which has two inflation valves operating independently: They are turned counterclockwise for inflation and clockwise to stop air flow.
KEY SAFETY PRECAUTIONS
Following are safety tips for air bag operations.
Check your air source; make sure you have enough to do the job properly.
Visually check all regulators, controllers, hoses, and bags for obvious defects or damage before placing them in service.
Make absolutely sure that all valves are in the closed position before you turn on the air source. This prevents any sudden or unauthorized lifts from occurring. One person should be assigned this task; he should report to the person operating the air source before it is turned on.
Generally, have the hose connected to the bag prior to placing the bag under the load. This minimizes personnel exposure to the unstable load area.
Always inflate air bags slowly to minimize the possibility of the load`s shifting and becoming unstable.
Always crib or shore the load as it is lifted to the desired height. Never work under a load that is supported only by air bags.
In general, do not inflate the bag to its fullest height. This creates a pillowing effect, possibly making the load unstable and causing the bag to kick out from under the load.
When using two bags, always place the larger bag on the bottom for additional stability, and inflate it first. Place the bags so the nipples are on opposite sides.
Never inflate the bags against sharp objects or on heated surfaces above 200°F–this will damage the bags and possibly cause them to fail.
Maximize the contact surface of the bags to the load at all times.
Do not place blocking or cribbing between two air bags.
Try to use two bags whenever possible.
For safety reasons, have only one member give the orders to raise and lower the bags.
When using lumber less than three inches thick for blocking, make sure it is plywood. Dimensional lumber, such as one- and two-inch-thick boards, may split easily, making it ineffective and unsafe.
In structural collapse operations, always use blocking on the top and bottom of the air bag to protect it from cuts and punctures.
Make sure all personnel wear proper protective equipment when operating.
Always center the bag under the load for a stable lift.
Make sure each bag has a separate color hose for proper identification.
Maximize the surface contact of the bag for the most efficiency.
When using a two-bag lift with both bags inflated, the maximum lift you can attain is that of the smaller-capacity bag. For example, if a 7.5-ton bag is on top of a 12-ton bag and both are inflated, the maximum lift is 7.5 tons. However, if just the bottom bag is inflated, the maximum capacity is 12 tons with a shallower lift.
Always pressurize the system and the bags slowly or damage may result.
Have a safety officer observe the entire operation to check for any movement or sudden shifting of collapse debris, which may endanger the operation.
For the safety of all personnel, have only one person in charge of the operation.
As in any rescue operation, safety of victims and rescuers is of paramount concern. The rescue team must use the normal complement of proper protective equipment.
Remember, trapped victims who are pinned with excessive amounts of weight applying pressure to their muscle mass may have crush syndrome. (For more on crush syndrome, see “Medical Treatment at Collapse Rescues,” December 1990, page 27, and “Crush Syndrome,” July 1994, page 64.)
OPERATIONAL PROCEDURES
You must hook up the system in the proper order at each incident. For the sake of uniformity and safety, each rescue team member should know the proper hookup. Following are some general steps.
When attaching regulators, controllers, and relief valves, make sure they are in the closed position. This will prevent accidentally charging the system before the lift is ready.
Attach the regulator in the closed position to an air source. Check the source in advance to make sure there is enough air to complete the objective.
Connect the air supply hose(s) to the regulator outlet valve, making sure it is in the closed position.
Connect the hose to the controller`s air inlet, making sure the inflation valves are in the closed position.
Assign one member to operate the controller; he should be in a safe area where he can observe the lift. In collapse rescues and void searches and rescues, conditions can change quickly; the controller operator must not let the tool out of his hands at any time, for safety reasons.
While the above steps are carried out, the void entry team can place the bags in position for the lift. Generally, it is easier to attach the hose bag prior to installation. Remember, when using more than one bag, make sure the hoses are color-coordinated.
The member who is operating the controller should connect the hose to the controller`s air outlet. Again, the inflation valves must be in the closed position prior to hookup.
The officer in charge of the lift should make sure that all personnel are in a safe area; he is the only one who should give orders to the controller operator.
Charge the system by turning all valves on slowly. When the controller operator has the proper pressure in the system, he in-forms the officer in charge that they are ready to proceed. The officer then tells the operator which bag to inflate by the color of the hose attached to it–this is the simplest and safest method.
RECTANGULAR BAGS IN COLLAPSE OPERATIONS
The use of rectangular-spaced air bags can have a positive effect on the timely rescue of trapped victims in many scenarios. In the more common types of framing methods used in ordinary construction, the beam and joist spacing is generally 16 inches on center. Using rectangular air bags, you can lift several joists at the same time, if necessary. The rectangular bag is more stable than a square bag when inflated. It can lift a greater section of material, which is a great advantage if a victim is pinned by two or three floor joists, for example; and the lift can be done in one motion with the rectangular bag, saving time and effort. You might need a dual lift with the square bags, which is a more complicated and time-consuming operation.
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Your rescue team should evaluate different air bag systems and select the one with which you feel most comfortable. As with any tool or piece of equipment, always follow the manufacturer`s recommendation on the care and maintenance of each component in the system. Also, stringently follow the testing guidelines for the equipment for the safety of your rescue personnel. n
JOHN P. O`CONNELL has been a firefighter with the City of New York (NY) Fire Department for 15 years and, as a member of Rescue Company 3 in the Bronx, has more than seven years of collapse rescue experience. He is an instructor of shoring and building collapse at FDNY`s Training Academy and has been involved in the writing and teaching of the department`s collapse and shoring training curriculum. O`Connell is a New York state-certified fire instructor and spent more than 10 years in the building construction industry. He conducts seminars on collapse and shoring operations around the country.
