Issue 2 Aug 05
INTERNATIONAL FIRE TRAINING CENTRE FIREFIGHTER INITIAL
AIRCRAFT RESCUE - SPECIALIST EQUIPMENT Throughout this note he means he/she and his means his/hers. The areas in bold type are considered to be of prime importance.
INTRODUCTION Rescue equipment for the Airport Fire Service has evolved from common hand tools to sophisticated powered tools. There are many different manufacturers offering various types of lifting, forcing and cutting equipment and only through station training can you become competent in their operations. Most Airport Fire Services carry a complement of hand tools and powered equipment but this training note is by no means exhaustive of all specialist equipment available. AIM To introduce the student to rescue equipment and give a general overall view of different types, uses and associated problems and hazards of rescue equipment. OBJECTIVES At the end of the technical input and after detailed study of this training note you will be able to: •
Identify the types available
•
Identify rescue saws
•
Lifting and forcing equipment
•
Alternative cutting equipment
•
State common hand tools
•
Identify potential hazards
•
State the essential safety equipments prior to and during the use if rescue equipment at aircraft accidents
CONTENTS OF THE NOTE •
Types of Equipment Available
•
Rescue Saws
•
Lifting and Forcing Equipment
•
Alternate Cutting Equipment
•
Common Hand Tools
•
Potential hazards
•
Safety in the use of rescue equipment
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SCOPE AND OUTLINE OF THE INSTRUCTION This note which outlines various types of cutting, lifting and forcing equipment presently in use with Airfield Fire Services is intended to acquaint the student with some of the specialist items in use at many stations. Each of the various systems mentioned describes the type of power available to operate such equipment, control of the power source where fitted, the rescue device itself, and the relevant safety precautions to be taken. The subject will be dealt with under the following headings: Rescue Saws Lifting and Forcing Equipment Alternative Cutting Equipment THE TYPES AVAILABLE CAN FALL INTO THE FOLLOWING CATEGORIES • • • • •
Electric Hydraulic Compressed Air Self Powered Manual
RESCUE SAWS 305 mm Electric Rescue Saw A 303 mm high frequency metal saw blade with 115 mm effective depth of cut, is connected to the alternator by 61 metres of cable protected by connected, wormed, tough rubber sheathing. This is carried on a cable real equipped with a slip ring and mechanical rewind facilities. A three phase 230 volt, 200 cycle alternator vehicle mounted, provides power for the saw. Protection in the form of chassis insulation and guard rail are inbuilt into the installation. Control of the alternator is through a panel fitted with a hand throttle control, voltmeter, frequency meter and voltage adjuster. Output of the alternator at 2000 rpm is 5 kva. Drive is transferred from the engine on engagement of a power take-off lever. Use of the saw is a two person operation, No 1 being the operator and No 2 the safety person standing directly behind No 1 to handle cable and act as look out. Care should be taken that both persons have a firm and stable footing and full protective clothing should be worn. All Purpose Electric Saw This type is fitted with a reciprocation blade operating at 2300 strokes per minute giving a cutting stroke of 19 mm. Power is obtained from a gasoline driven, lightweight portable generator with 1.5 kva 110/220 volt AC output on automatic throttle setting. The voltage setting is selectable. Two power take off outlets are provided, giving the facility for operating two pieces of equipment simultaneously. The all purpose saw motor is universal, operating on either DC or AC current at 60 cycles or less. Simple blade adjustment allows both horizontal and vertical cutting angles to be achieved. The multi-position handle locks in any one of five positions over a 180º arc. Total weight of the saw is 2.75 kgs. The generator may be fitted with a harness to enable it to be carried as a back pack for extra mobility. When in use full protective clothing should be worn. 355 mm or 305 mm Hydraulic Power Saw A 355 mm rotary blade with retractable guard is fitted to the saw, which has a chain drive (enclosed) from an 8hp HYREVX motor, to the saw head. Connections to a hosereel are by quick release couplings, which allow substitution of tools without loss of fluid, feed or pressure.
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A hydraulic pump draws fluid from a reservoir of 54.5 litres capacity, on engagement of a power type take off lever. Twin piping (flow and return) is routed from the hydraulic pump, through a control panel fitted with a flow valve and hand throttle to the hosereel. The hydraulic pump has a flow rate of 36 litres per minute, giving an operating pressure of 70 bars to 140 bars which the saw drive converts to 4000 rpm maximum. A specially designed hosereel is equipped with 30 metres of twinned high pressure hydraulic hose. This completes an open circuit hydraulic system. A pressure relief valve set at 129 bars is incorporated in the flow line. Total weight of saw 7.2 kgs, overall length 670 mm. Use of the saw is a two person operation, No 1 being the operator and No 2 the safety man standing directly behind No 1. Care should be taken that both persons have a firm and stable footing and full protective clothing should be worn. Portable Pneumatic Circular Saw The saw incorporates a 305 mm metal saw blade, with an effective depth cut of 115mm and a duration of 2½ minutes with both cylinders fully charged. The saw consists of a light alloy motor housing which contains a rotary vane air motor. A retractable safety guard is fitted and a governor incorporated in the motor housing to restrict the saw speed whilst not under load. Power supply is obtained from two compressed air cylinders mounted in a light tubular steel back pack, fitted with harness straps for carrying. Compressed air is fed from the cylinders to the saw via a reducing valve and flexible supply hose, the hose being connected to the saw by a quick release coupling. Each cylinder has a capacity of 1250 litres at a pressure of 140 bars, the pressure reducing valve reduces this to 7 bars for the saw operating pressure. The length of air supply hose from cylinders to saw is 4.6 metres, this allows cylinder pack to be placed on the ground before use. Use of the saw is a two person operation, with No 1 being the operator and No 2 the safety man standing directly behind No 1. Both persons should have a firm footing and full protective clothing should be worn. Reciprocating Air Saw A lightweight air reciprocating saw weighting 2.3 kgs of alloy construction, with air piston bores specially treated for long wearing qualities. Blade and saw are cooled by exhausted air and oil. Power supply is obtained from a vehicle mounted compressor or portable air cylinders. If air cylinders are used the relevant information is as in the description outlined for the 'Rippagun' portable air pack. Operating pressure 6.1 bars to 6.9 bars. If using a portable air pack, duration is 12 minutes maximum. If using a vehicle mounted compressor a lightweight hose reel will accept up to 130 metres of hose length. All couplings are quick release hand operated. Full protective clothing should be worn. Portable Internal Combustion Engine Powered Saw A 12 inch steel blade often fitted with a pivoted head for easier cutting operations, some with the extra facility of a power take-off point for flexi-drive, to operate smaller diameter blades. Power supply obtained from its own lightweight two stroke engine, within the range of 3½ hp to 7 hp. Usually fitted with a diaphragm type carburettor with inbuilt fuel pump, to ensure continuous fuel supply at any angle. Drive transmitted belt and pulley to a 305 mm metal saw blade or abrasive cutting disc, operating at 5000 rpm. Average total weight of this type unit 11 kgs. It should be remembered that if an abrasive cutting disc is used, excessive sparking will result. Use of the saw is a two person operation with No 1 as the operator and No 2 the safety man standing directly behind No 1. Full protective clothing should be worn. LIFTING AND FORCING EQUIPMENT Hydraulic Rams This type of hydraulic powered equipment comprises a hand operated pump fitted with 1.83 metres of high pressure flexible hose, connected by quick release couplings to one of the following: • • •
A wedge jack (crocodile jaws), maximum spread 76.80 mm A 6 ton ram An 8 ton ram
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In this way the pump can be operated remote from the work in hand. Additional equipment to supplement these rams consists of: • •
Heads, flat, wedge and V shaped Base plates
Extension tubes, varying lengths up to 915 metres, which can be connected to the rams by means of double male and double female threaded adapters. By using different combinations of this equipment it is possible to achieve vertical jacking and horizontal forcing pressures Usually stowed in a metal case with an approximate weight of 43.5 kgs Air Operated Cushions A considerable range of air operated cushions are available to lift varying loads but for the purpose of this note, the description given will be limited to one specific size of air cushion. Inflation is obtained from either a vehicle mounted compressor or air cylinder at 210 bar pressure. Compressed air passes from the cylinder to a reducing valve, which reduces the pressure down to 2 bars; it then passes to an inflation deflation valve (supply demand) inbuilt into the cushion. Working pressure of the cushion is 0.5 bar and a pressure relief valve is fitted so that this figure is not exceeded. Construction of the cushions is as follows: • •
Top and bottom panels 9.3 mm think belting Side panels 793.8 gram Neoprene
Internal strapping is built in to ensure that the cushion takes up its correct shape and size on inflation. Dimensions: Shape Inflated height Diameter Deflated thickness Vertical lift
Cylindrical 584 mm 762 mm 25 mm 2200 kgs
Crowbars The crowbar is a tubular steel shaft which is used to apply leverage. Both ends are shaped: one (normally the handle end) is flattened and cloven to form twin chisel blades. The bladed end can be inserted into small apertures and this end is turned at an angle from the shaft so that the bend provides an integral fulcrum for leverage. There are three sizes of crowbar usually found in the service The small crowbar The medium crowbar The large crowbar
45.7 centimetres 106.7 centimetres 167.6 centimetres
The length of the large crowbar allows two persons to operate it but, where space permits, it is generally better to bring a second crowbar into use. ALTERNATIVE CUTTING EQUIPMENT The Rippagun Air Powered Cutting Tool The cutting tool consists basically of a piston which is free to move in a cylindrical barrel. Attached to one end of the barrel is an offset handle incorporating a trigger mechanism to control the air flow. The other end of the barrel accommodates a cutting chisel which is free to move within the limits of a 'Bee-Hive' spring retainer. Power to operate the cutting tool is provided from a back pack of light tubular steel, plastic dipped for protection against rust and housing two 1.17 cubic metres capacity compressed air cylinders. Both
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cylinders are retained within the pack by a wing nut and bar. High pressure flexible rubber tubing fitted with hand operated connections to the cylinders, supplies air to a reducing valve via non return valves. Cylinders may be replaced whilst a cutting operation is in progress without loss of air pressure. The pre-set reducing valve reduces cylinder pressure from 134 bars to an operating pressure of 6.1 bars to 6.8 bars. A contents pressure gauge is fitted to allow individual cylinder pressures to be checked, also a pressure release valve to exhaust residual from the system. Air pressure supplied to the cylinder forces the piston rapidly down the barrel so that a sharp blow is transmitted to the chisel. At this point air supply is stopped and used air exhausted through a port. The 'beehive' spring then returns the cutting chisel and piston to their original position ready for the cycle of operations to be repeated for as long as air pressure is supplied. The cutting tool is designed to operate at 1500 blows per minute at a pressure of 6.1 bars to 6.8 bars, with an air consumption rate of 0.566 cubic metres per minute. Total weight of pack and unit with charged cylinders 27 kgs. This equipment has an air supply line from cylinders to cutting tool of 4.6 metres, to enable pack to be operated from ground level. Full protective clothing should be worn. NOTE: It is also possible to operate the air operated reciprocating saw from the table pack. Hydraulic Cutter The cutter which operates on the hinged jaws principle has a maximum working pressure of 550 bars and will rapidly cut through car body pillars, seat fastenings, steering columns and similar components without sparking or untoward cutting noise. Can be operated from a hand pump, electrical pump, or vehicles hydraulic system if fitted. Hand operated pump of same design as found with hydraulic lifting rams, with approximately same length 3 m of high pressure hydraulic hose from hand operated pump to cutter. Electrically operated pump has a 220 volt AC single phase motor with 3m of high pressure hydraulic hose from pump to cutter. If the appliance is fitted with a hydraulic system to facilitate the operation of hydraulic saws etc., it is possible to operate from this system and dispense with the hand or electric pumps. Bolt Cropper 609.6 mm Bolt croppers of various design are carried on fire service appliances but the most common to this service is 609.6 mm. Although primarily designed for cutting bolts, hasps etc, they can also be used in circumstances where metal obstacles impede fire fighting or rescue operations. The jaws are operated on a double fulcrum and sometimes have semi-circular slots in each blade to enable the tool to retain bolts etc, whilst cutting. Other variations have the handles pivoted on ball joints, so that when necessary the head can be operated at right angles to the handles. There is a small buffer on the inner side of each handle. This ensures that the operators hands cannot be trapped if the section being cut gives suddenly. The handles are not insulated. Cable Cutter This tool consists of a spring loaded chisel blade within a tubular steel barrel, operated by an external lever. It is a compact tool for cutting wires or cables, whether they are slack or taut, in very cramped spaces where larger cutting tools with a shears action cannot be used. It is designed so that, if necessary it can be operated at arms length in an unstable position. The cutter is prepared for use by pulling the lever outward. This engages a pin on the collar of the chisel spring, which protrudes through a slot in the barrel and compresses this spring until a spring loaded pawl engages in the chisel collar. Large Crash Axe The large axe is a tool for two handed cutting with a full swing. It has a long, wooden shaft and a double edged steel head, specially shaped for cutting sheet metal. There is an acute angled point at each upper corner and an obtuse angled point at each lower corner. The cutting edge between each of these two points is short and straight and it is continued back at an angle to the haft so that there is no concave recess between the cutting edges and the haft. These features ensure that: •
The force of any blow with the axe is concentrated against a small section of the aircraft skin and the first penetration can be made with the upper point.
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•
When the cutting edge penetrates through an aircraft skin it is not then trapped under the skin (as an ordinary axe with a longer cutting edge and concave bottom edge would be) but the cut can be extended as the axe is withdrawn (i.e. pivoting against the top edge and cutting upward with the bottom edge, rather like a tin opener).
Small Crash Axe Similar to the above but with an insulated steel handle instead of a wooden shaft. Much smaller, designed for a one handed cutting operation of sheet metal. Can be stowed on the appliance or carried in a pouch as a personal tool. Quick Release Knife This knife has a slightly curved wooden handle and its blade is shaped in a slight reverse curve, so that the whole knife is formed into a flattened "S" shape. The purpose of the knife is to cut harness straps (when they cannot be released any other way) so the cutting edge is the concave curve of the blade. The knife blade therefore can be pushed in under harness straps without injuring the wearer and the pressure of the cutting action is exerted outwards while the reverse curve of the knife's wooden handle allows room for the user’s knuckles. A sawing motion is necessary to cut through webbing straps and it is not an easy task. Common Hand Tools The following range of ordinary tools are carried on most fire service RIV's or rescue tenders. They may be stowed separately within the same locker or contained in a toolroll or metal tool box. • • • • • • • • •
305 mm hacksaw with spare blades 0.9 kg engineer's type hammer metal snips General purpose double edged saw Screwdrivers, assorted Small cold chisel 204 mm pliers insulated Large adjustable spanner Small adjustable spanner
POTENTIAL HAZARDS WHEN USING EQUIPMENT Electric tools, portable lighting units First of all the main hazard could be using electrical items in or near water (firefighting). For this reason electrically powered tools should not be used during inclement weather or wet site conditions. However, if no other option is available, due care should be exercised by operators. During cutting operations using electric saws exists the possibility of creating an ignition source through the build up of sparks (Volatile fuel may be present). The cable and leads can be an obvious trip hazard, they can also become damaged by sharp debris at the incident. The potential for an electric shock must not be discounted when using any electrical rescue equipment, especially with connections trailing in water. The noise level of some types of equipment can be relatively high and may require the use of ear protection for operators and other personnel in the vicinity (including casualties). Eye protection must always be used when engaged in or in the vicinity of cutting, spreading or forcing operations HYDRAULICALLY POWERED RESCUE EQUIPMENT
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These types of equipment are designed for use in situations where maximum power is available to lift/spread or cut. They may operate at pressures around 720 Bar in order to ensure that, for example, the cutting pressure in the centre of the cutters pressure in the centre of the cutters is about 7 Tonnes. This type of equipment requires skilled operators to use and monitor the equipment and operations for that reason. The hose/connections must be free of dirt and debris, very difficult at an incident. Where possible replace dust or protective caps to prevent ingress or dirt or debris. The hose must be kept free from kinks as this can damage or rupture hose (high pressure – remember). Ventilation must be considered if using petrol driven pumps in confined, unventilated areas as this could lead to build up of fumes (carbon monoxide). As with any cutting operations the correct PPE should be used, visors down or recognised safety glasses and suitable gloves. When using the hydraulic rescue equipment operators should use tools slowly and concentrate. Small movement of the blades can involve moving sections some distance away. COMPRESSED AIR RESCUE EQUIPMENT The possibility of high pressure (137 bar) is not uncommon, this may come from a cylinder or via an outlet on the appliance. Leaks may go unnoticed and operators should be aware of this. It could lead to cold burns to the skin, as a result of a leak from the connection to a piece of equipment. Cutting equipment may produce sparks and could form an ignition source. Eye protection must be used even with low speed equipment. The noise levels can be high and as such ear protection must be considered. Compressed air and grease can be violently reactive, all personnel should be aware. SELF POWER RESCUE EQUIPMENT Some types of equipment such as chain saws may stipulate that high levels of protection may be required. This can be in the form of aprons or full suits (bunker pants/jacket/gloves) made of leather/kevlar or metalic material. Fumes from the units can be hazardous in close or confined spaces therefore consider ventilation options. Possible ignition sources from sparks during cutting operations. These types of equipment produce high noise levels and ear protection is definitely required. The need for eye protection should be no greater than any other piece of equipment, however all disc type cutting equipment have the potential for a disc/blade to shatter without warning. PROTECTIVE CLOTHING During rescue operations the safety of those involved is of paramount importance. Such safety can only be achieved by the provision of adequate protective clothing. An aircraft accident site is undoubtedly a hazard area in itself, with the additional requirement to use complex, sometimes heavy and always potentially dangerous rescue equipment, the need for full safety measures and protective clothing becomes obvious. This note assumes that all RFFS personnel at the scene of a major aircraft incident will be dressed in full fire fighting kit. In addition to this it is important that consideration is given to the following:
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High speed cutting equipment This equipment generates heat, sparks and leaves sharp ragged edges on material which has been cut. Protective clothing necessary when using this equipment includes boots with built in toe protectors, helmet either with visor down to protect eyes or visor up and the use of proper safety glasses, heavy duty gloves which will resist damage by sparks, heat and the handling of sharp metal debris. For some types of cutting equipment it is appropriate for the operator to wear a heavy leather (or similar material) apron. Ear defenders may also be necessary with certain types of equipment which emit high noise levels. Hydraulic jacking/forcing equipment Heavy duty gloves and the use of either the helmet visor or other approved heavy duty safety glasses in conjunction with full fire kit is considered essential personal protection. Casualties It may on occasion also be necessary for casualties trapped at the scene to be provided with some protection against the effects of cutting operations, this should always be considered. PROBLEMS AND HAZARDS It is important that all personnel working at the scene of an aircraft accident in which rescue work is necessary, realise that even without the additional implications of using rescue equipment at the scene, is already an extremely dangerous situation. The wreckage itself may be unstable and any slight movement of it could further injure the survivors or may in itself cause a spark or other source of ignition to occur and turn what was a survivable situation for some, into a non survivable one. Great care is required at all times when working at the scene of an aircraft accident. It is essential that post fire security and a stable working environment is maintained throughout the duration of the incident. Problems and hazards can be summarised as follows: The Scene • The wreckage may be unstable. • Conditions within the wreckage are likely to be cramped and extremely difficult owing to the accident damage including the likely collapse of overhead bins and linings. • Fuel may be leaking from ruptured fuel tanks. • Cutting operations necessary to release persons trapped in the wreckage may involve cutting into areas close to unseen fuel and power lines • High voltage may still be present on the aircraft in the early phases of rescue operations. • Inadequate illumination of the scene particularly inside the wreckage The equipment • Heavy and/or highly dangerous equipment may need to be used in confined spaces and in close proximity to casualties. • Certain types of high speed cutting equipment generate sparks, this can be extremely disconcerting for those being rescued and can also provide a source of ignition under certain conditions. • Noise levels of certain rescue equipment when in use can hamper the hearing of urgent instructions and also cause severe discomfort for any conscious survivors. Please note that the use of powered forcing equipment can sometimes cause a movement of the structure some distance from where the force is actually being applied. Personnel • Personnel will be working under extreme levels of stress and difficult conditions and may only be able to work under such pressure for limited periods of time. Relief crews may be necessary.
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•
The correct use of equipment whilst working under such conditions will only occur if all personnel have been thoroughly trained in its use.
THE SAFETY REQUIREMENTS BOTH PRIOR TO AND DURING RESCUE OPERATIONS The safety of Fire and Rescue operations at operational incidents has its foundations in clearly defined policies and practices. Such policies and practices will be clearly expressed in writing and understood and practised by all concerned on an ongoing basis. Such policies and practices will include the following: Equipment The equipment provided will be that which has been identified as that appropriate to the task and not merely that which a passing manufacturer has convinced someone is worth having. It will be subjected to a detailed test, inspection and maintenance programme which will seek to ensure that the equipment is in a functioning and operational condition throughout its operational life. Personnel All personnel who will be expected to operate the equipment, no matter how basic the equipment may appear to be, must be thoroughly trained in its use. The training will not only include the basic use of the equipment but will also include experience, as far as is practicable, of using the equipment under conditions similar to those which could be expected at the scene of a major aircraft accident. Basic safety at the scene On arrival at the scene the one priority is to stabilise the situation, that is, to prevent the situation from deteriorating further and to then make efforts to gain an improvement. Other available training notes deal with such matters as fire fighting and rescue, this note will confine itself to the situation where there is no obvious sign of fire on arrival. The scene must first of all be secured against fire, this will need to be achieved by ensuring that any hot areas of the site are subjected to cooling and that a blanket of aspirated foam is applied to all areas where it is known or suspected that a fuel spillage has occurred. This applied aspirated foam blanket must be maintained throughout the duration of the rescue operations. Charged lines should be made available throughout the accident scene in case a fire should develop unexpectedly as a result of the rescue operations. At least one fully replenished major foam tender equipped with a monitor should be manned and responsible for guarding the incident throughout the rescue operation. Secondly it will be necessary to stabilise the wreckage or parts of the wreckage in order that further danger and/or injury does not occur. It is essential that the wreckage is stabilised into position before entry is made into the various sections of the fuselage and rescue work commences. Failure to do so could result in the wreckage moving during rescue efforts and resulting in further injury to survivors and personnel involved in the rescue operation. The use of lines and timber blocks for stabilising the wreckage may be dispensable under such conditions. In an effort to improve safety at the scene during periods of reduced daylight adequate flood lighting should be made available. It is extremely difficult and dangerous to use high speed and high powered rescue equipment using hand held torches and this should be avoided. It is likely that survivors at the scene will be in various states of shock and pain, cutting out and rescue operations can take place more calmly if personnel can be provided to reassure those who are trapped but conscious. When cutting operations are taking place which are likely to result in the production of sparks any adjacent casualties should be protected by the use of fire resisting blankets.
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A charged hose line should be immediately available adjacent to cutting operations. When using jacking and other forcing equipment extreme caution should be taken throughout. Each movement of the wreckage should be immediately supported by the insertion of timber blocks, these blocks will provide the necessary support should the jack slip at any time during the operation. When using rescue equipment powered by internal combustion engines in a confined space efforts should be made to ensure adequate ventilation. Failure to do this may result in a build up of the lethal gas Carbon Monoxide. As it is extremely difficult for the operator of rescue equipment to concentrate on the wider area t the scene an individual responsible for ensuring safety at the scene should be nominated SUMMARY The rescue of casualties trapped in aircraft accident situations and the use of heavy and sometimes complex rescue equipment is a basic part of the airport fire fighter’s role. In order that lives can be saved it is of the utmost importance that: • • • • • • •
Equipment appropriate to the specific and anticipated demands is provided Equipment provided is maintained in operational condition throughout its working life Personnel are trained to use the equipment under conditions which are likely to prevail at the scene of a major aircraft accident Before any rescue work commences from a crashed aircraft fuselage it is essential that the structure is stabilised in position Charged hose lines are provided at the scene of any cutting operations An aspirated foam blanket is maintained throughout the duration of the incident over any fuel and hot debris A constant vigil is maintained over the entire accident site as a precaution against any unexpected outbreak of fire
