USING AIR TOOLS AS RESCUE TOOLS
BY VICTOR PETRUCELLI
Some conditions may preclude the use of hydraulic tools for cutting or forcible entry at emergency sites. Among them are the following: the location of the incident, limited clearance space between the victim and the object of entrapment, an uncontrollably moving object, and the pressure and tearing effects exerted by the tools when spreading or cutting the involved object. When faced with such conditions, you will find that air tools work just as quickly as hydraulic tools and will allow you to fully control movement of the object without tearing or snapping metal components, minimizing damage to the object in a nonlife-threatening situation.
SOME AIR TOOL APPLICATIONS
Following are examples of some of the types of incidents at which the Jersey City (NJ) Fire Department has successfully used air tools:
Passenger removal at a minor motor vehicle accident. The patient was in the rear passenger seat and complaining of neck and back pain. The patient`s size and weight made it difficult to remove him.
Air Tool Use: Rescuers removed the floor bolts of the two front seats with an air ratchet. This provided more room for packaging and removing the patient and caused no additional damage to the car.
Hand entrapment at an industrial plant (recycling plant). The victim was on a catwalk 15 feet above ground level; his hand was trapped in a conveyor belt between a 200-pound roller and a metal I-beam frame. The location, height, and amount of space around the victim and the machinery made it difficult to use hydraulic extrication tools.
Air Tool Use: While EMS was attending to the victim`s medical needs, rescuers used an impact wrench to remove the bolts to the cover guard and roller-bearing housing. The roller was lifted and the victim`s hand was freed without damaging the machine; plant operations were resumed after an investigation of the accident was completed.
A worker pinned underneath an auto on the top ramp of a car-carrier truck. On arrival, the victim`s two legs were wedged under the auto and between the truck`s frame post. The driver-side door was folded back against the front fender and pressing against the victim`s legs. The height, instability of the vehicle on the ramp, and door`s pressing against the victim were factors.
Air Tool Use: Rescuers removed the six bolts at the door hinges with an air ratchet. The door was then slid out from between the front fender and the truck`s frame post, and the victim`s legs were freed.
A fire in a hopper at a metal manufacturing plant. Fire had extended into the duct system alongside the building and up to the roof.
Air Tool Use: With air ratchets and im-pact wrenches, rescuers removed several inspection plates throughout the duct system to extinguish and overhaul the fire. Damage to the system was kept to a minimum.
The air ratchet and impact wrench have been the tools of choice of auto and truck mechanics for many years. They are available in different sizes, speeds (rpm–revolutions per minute), and torque ranges, as well as in heavy-duty and lightweight versions.
We have found the 38-inch drive air ratchet and the 12-inch drive impact wrench to be especially effective. Some manufacturers make a 12-inch drive air ratchet that can be used with one type of socket. Depending on the manufacturer, the 38-inch air ratchet will have a torque range of from five to 60 lb. ft. and a free speed (with no-load) of 150 to 180 rpm and will work off an air pressure of 90 pounds per square inch gauge (psig). The 12-inch impact wrench will have a torque range of from 50 to 1,000 lb. ft. and a free speed (with no-load) up to 9,000 rpm and also will operate at 90 psig. Even though the torque range of the 38-inch air ratchet might be lower than that of the impact wrench, the offset position of the handle allows the rescuer to get into tight areas not accessible with the impact wrench. The impact wrench is more durable in larger spaces and on nuts and bolts that have a high torque range because of the pressure needed to hold the two components together.
SELECTING AIR TOOLS
When planning to purchase any of these tools, consult with your local auto or truck mechanic. He will be able to show you how the tool performs in the work environment and might even let you try the tool to see if it meets your extrication needs.
Don`t buy the cheapest brand. As is true of any tool, if you buy a reputable brand, you will save money in the long run on maintenance costs and downtime for repair.
Sockets. When selecting sockets for your air tools, choose impact sockets that are designed for the tool. Standard sockets or cheaper brands not designed for the air tool will crack or round out in a short time. Impact sockets are manufactured from a hardened metal and have a thicker shell that withstands higher torque ranges. Impact sockets are available in standard and metric sizes; you will need both.
Sockets come in six-point, eight-point, and 12-point versions. The six-point socket fits more securely over the nuts and bolts, preventing it from slipping off the nut or bolt, stripping the head of the nut or bolt, or wearing out the socket`s inside over time.
A deep wall socket may be used for nuts when the bolt`s screw threads protrude past the nut and prevent a standard socket from fitting over it. The same rule applies when purchasing sockets: Do not buy the cheapest brand. Most reputable brands offer a lifetime guarantee and free replacement of broken sockets.
Extension bars. These bars can be used when the nut or bolt cannot be reached because the air ratchet or impact wrench is hitting obstacles around it. Try to keep the length of the extension bar between one and five inches. Longer extension bars do not transfer all of the torque power from the air tools because of the twisting action; this could also allow the socket to slip off the nut or bolt.
Extension bars are available in the standard square head or the flexible (bevel) head version, which allows the extension bar to move about 16 degrees in all directions. Flexible extension bars can be helpful when the air tool cannot be properly aligned with the nut or bolt, but it may allow the socket to slip off at high speeds or high torque ranges. The locking mechanism on extension bars can be a friction ball or snap-ring.
Air lines. Air tool air lines are basically two types: rubber air hose and self-coiling nylon tubing air hose. A 38-inch-diameter hose is recommended for these types of air tools. Rubber air hose generally has a working pressure of 300 psi with a bursting strength pressure of 1,200 psi. The self-coiling nylon tubing air hose is rated at 200 psi working pressure with an 800-psi bursting strength. The rubber air line is a lot stronger and does not kink easily over sharp bends or crush when accidentally stepped on, but it is subject to dry rot cracks, and the jackets can break down when exposed to petroleum products.
The self-coiling nylon air hose can kink very easily when fully extended and forced over a sharp bend, causing a permanent weakness in the hose. At one incident, we had a frost buildup on the entire length of the nylon hose when using a pneumatic reciprocating saw (high-rpm tool) constantly for a long time. The self-coil hose allows the rescue member to operate the air tool freely when the arms are fully extended or slightly above the head, whereas rubber air hose has a tendency to be heavy and place a drag on the tools.
Hose lengths vary in size; the most popular sizes are 25 to 50 feet. Make sure all hose connectors (male and female) are self-locking to prevent air hose from disconnecting accidentally.
Air supply. The air supply for air tools can be from a single SCBA cylinder, an air cart (two or more SCBA cylinders), an air compressor, or an apparatus air brake system. The recommended air pressure is 90 psig. Less than 90 psig will reduce the performance of the air tool; more than 90 psig will raise the performance beyond its rated capacity and could damage the tool`s internal components. The air supply should be maintained at 90 psig, and the reserve tank should have the capacity to provide the proper pressure while the tool is being used.
A single SCBA cylinder can be used as a backpack, allowing the rescue member to move freely at many different locations or heights due to its light weight. The drawback is its limited amount of air when the tool is in constant use. This air supply will deplete rapidly when using air tools with higher rpms such as a pneumatic reciprocating saw or cutter (wizzer).
The SCBA air cart provides a longer air supply and enables you to change an empty cylinder while operating off the other cylinder without interrupting the air tool`s operation. The only disadvantage in some situations is that the weight of the air cart can make it difficult to move the cart around, under, or over objects. To solve this problem, longer lengths of air hose can be used, but the longer length will create an excessive drag on the tools when moving between locations.
The air compressor provides a continuous air supply and a larger reserve holding tank to maintain the proper pressure. This unit is larger than the SCBA air cart and a lot more difficult to move around. Also, most air compressors are supplied by 120 volts AC and need the proper electrical source to supply it.
Using the air supply from the apparatus brake system can be quick if the apparatus can be positioned close to the incident and air tools with lower rpms are used. Trying to maintain the 90-psig pressure needed to run the air tools will be difficult. Most apparatus air brake reservoirs will be depleted in a very short time, especially when using air tools with higher rpms. The brake system compressor cannot supply the air fast enough, and the brake reservoirs are not large enough to maintain the proper pressure when the tool is in constant use.
In most of the incidents at which we have used the air ratchet and impact wrench, the single SCBA cylinder was sufficient for a short-term operation. However, when using a pneumatic reciprocating saw or cutter, we would go through at least two or more cylinders.
MAINTENANCE
Maintaining air tools is relatively easy. Standard maintenance includes the following checks/tasks:
They must be properly lubricated. During inventory inspection, place a few drops of the lubricant oil recommended by the manufacturer in each air tool and run the tool for a few seconds to allow the oil to circulate inside the tool.
Check the air exhaust ports to make sure they are free of debris and that air flows out freely. Place the tool out of service for repair if air is blocked from the exhaust ports.
Examine the exterior body of air tools for oil or air leaks. A small amount of lubricant oil may come out of the air exhaust ports; this is normal when too much oil is used. Excessive leaks require that the air tool be placed out of service for repair.
Visually check the locking mechanism of the square drive head to see if the friction ball or snap-ring is in place. Place a socket on the square drive head to see if the socket locks in place. Repair or replace the locking mechanism if the socket falls off freely.
Check all sockets for internal or external cracks and for wear inside the socket. Place the socket out of service if any damage has occurred.
Check all air couplings for dirt or moisture, and clean them. WD-40 or a similar lubricant can be used to clean the self-locking mechanism on the female coupling.
Check all air lines for air leaks, loose couplings, kinks, dry rot cracks, wear, cuts, and separation of rubber liners. Place damaged air lines out of service for repair, or replace them.
TIPS FOR OPERATING AIR TOOLS
The following are some safety and helpful tips for operating air tools:
Always wear safety goggles or have your face shield down when using any air tool.
Before connecting the air line to the air tool, open the air supply slightly to blow out any dirt or moisture in the air line.
Make sure the air tool is properly lubricated before and after each use.
Hold the air tool firmly when in use. The torque range of the air tool can jam your hand against an object.
When using the air ratchet, first use the handle to loosen the nut or bolt without air pressure before pressing the air trigger. This will allow the nut or bolt to turn freely without jamming your hand.
Use power or impact sockets designed for the air ratchet; use impact sockets only with the impact wrench.
Always use the correct socket size; be aware that nuts or bolts can be standard or metric.
Keep the socket setup simple. Use a deep wall socket instead of an extension bar when possible. If an extension is needed, keep it to a minimum–one to five inches.
Do not use worn, cracked, or damaged sockets. Flying material from broken sockets can be dangerous.
Make sure that the wrench and socket fit securely on the nut or bolt. An improper angle or too long an extension bar can cause the socket to slip off and disconnect from the air tools.
Do not use the air tool beyond its rated air pressure (90 psig) or the capacity for which the tool was designed.
The above information is based on emergency situations in which air tools have worked successfully for us. We have found that the air ratchet and impact wrench worked just as quickly as hydraulic tools when they had to be used. They are not meant to replace, and are not considered superior to, hydraulic extrication tools. They have their limitations. However, they give rescuers more options for handling an emergency situation. Throughout our fire service training, we have been taught to pry, cut, or tear our way through obstacles that block our path. Maybe we should add another technique–disassemble. n
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(Above left) The air ratchet is used to remove the bolts of an automobile door hinge. Most older cars have six 12-inch (13 mm) bolts. Newer cars may have 10-mm bolts, or the hinges might be welded in place. (Photos by author.) (Above) Here, the air ratchet is used to remove the bolts of the car`s front seat. Most of these bolts are easily accessible. Sometimes they may be covered by a plastic molding that can be easily removed.
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An air ratchet or impact wrench can be used to remove numerous nuts or bolts on inspection or access plates.
n VICTOR PETRUCELLI is a 16-year veteran of the Jersey City (NJ) Fire Department, where he is a captain assigned to Rescue Company 1.
