Cutting & spreading tools & ARFF rescue
Published: 01 September, 2006
Powered hydraulic tools have effectively revolutionised the process of penetrating aircraft fuselages in recent years. Energised by hydraulic fluid supplied through special hoses from a pump - although there are a few pumps which are operated by compressed air - most are powered by electric motors, petrol-powered motors or water pressure.
Either made to be portable and carried with the tools mounted on a rescue vehicle which supplies hydraulic pressure though a hosereel line, there are four basic types of powered hydraulic tools: spreaders, shears, combination spreader/shears and extension rams.
Powered hydraulic spreaders are useful for a variety of different operations involving either pushing or pulling. Depending on the model, these tools can produce up to 22,000 psi (154 000 kPa) of force at the tips of the tool. The tips of the tool may spread as much as 32 inches (813 mm) apart.
Individual hydraulic shears are also available to complement the spreader tools. Capable of cutting almost any metal object that can fit between their blades, some models of cutting shears cannot cut case-hardened steel. The shears may also be used to cut other materials such as plastics or wood. Shears are typically capable of developing about 30,000 psi (206 850 kPa) -of cutting force and have an opening spread of up to about 7 inches (175 mm). Cutters are useful as forcible entry ARFF tools as they can cut away structural members to allow entry.
Combination tools
Electric, pneumatic or petrol-powered hydraulic spreaders and cutters have some application in aircraft accident response. The spreaders have a limited usefulness as forcible entry tools as they simply tear the aluminium skin and bend the structural members. They are useful for lifting heavy items and pulling seats, however.
There are many combination spreader/shears tools on the market. They are sometimes used alongside extension rams which are designed primarily for straight pushing operations, although they are effective at pulling as well. They are also especially useful when it is necessary to push objects further than the maximum opening distance of the hydraulic spreaders.
Some of these extension rams can extend from a closed length of 36 inches (14 mm) to an extended length of nearly 63 inches (600 mm). They open with a pushing force of about 15,000 psi (103 425 kPa). The closing force is about 50% of the opening force.
Using chisels on-scene
Pneumatic-powered chisels (also referred to as impact hammers, air chisels or pneumatic hammers) have a role to play in extrication work.
Designed to operate at air pressures between 100 and 150 psi (700 kPa and 1050 kPa), during periods of normal consumption, the pneumatic chisel will use about 4 to 5 cubic feet (113-litres to 142-litres) of air per minute. It can be especially effective in vehicle extrications - it can cut through the roof, roof support columns or doorjambs, seat bolts, and even door lock assemblies. Effective for cutting medium-to heavy-gauge sheet metal and for popping rivets and bolts, they must be used cautiously in areas containing hazardous atmospheres.
Pneumatic handtools are lightweight and highly manoeuvrable. The disadvantages include the noise and vibration often associated with their operation and the need for a pressurised air supply.
There are five basic components of a pneumatic tool system: a pressurised air source; an air pressure regulator; air hoses with matched fittings/couplings; the pneumatic tool; and various supporting components and tool attachments.
Using high speed cutters
The reciprocating hacksaw is a tool which is effective in confined space rescue operations. The small, hand-held reciprocating hacksaw can be used in tight quarters with little potential to harm to entrapped passengers.
Two other pneumatic tools, the high-speed circular cut-off saw and the pneumatic reciprocating hacksaw, are excellent tools for cutting light metal, plastic, lexan, fibreglass, and sheet metal. The high-speed circular cut-off saw is available with a gear drive or air vane drive. The gear drive does not bind up as fast as the air vane type (it is said) and will handle heavier material. However, the air vane type is often the tool of choice when working right next to the patient’s body. It is often better in tight, confined spaces to have a tool that may stop or bind up rather than continue to cut regardless of the material encountered. This tool is particularly useful when dealing with plastic and fibreglass on aircraft interiors.
There are a number of different types of blades available for cutting different types of materials. Plastic, fibreglass, and metal are the three most common materials that the rescue team will attack with a high-speed circular saw.
Power saws can be equipped with carbide tip blades to cut through metal or concrete. Chainsaws and sabre-saws powered by electricity, petrol or compressed gas bottles can also be useful in forcible entry situations.
Flathead and pickhead axes are used for many general-purpose duties. The flat-head axe is more adaptable to striking, but the pick-head axe is more multi-functional when it comes to firefighting operations.
Prying tools, on the other hand, use leverage to provide a mechanical advantage - a person using a prying tool as a lever can generate a quite considerable force.
Typical applications for prying tools might include using them to open aircraft doors or hatches.
Cutting or snipping
Cutting or snipping tools are used in situations where the material can be cut in a controlled fashion. They are most effective on small objects that can easily fit within the jaws of the tool. They are generally safer than other types of cutting devices when working close to a victim.
Bolt cutters are used as a forcible entry tool to cut iron bars, bolts, cables, padlock hasps, and other objects. Wire cutters are used to cut fences and wire other than electrical.
Opposing jaw metal cutters are the cutting tools most commonly misused. This ‘family’ includes wire cutters, bolt cutters, and energized-wire cutters.
