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16 August 2024
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Featured FRI Magazine article: Evidence based fire prevention programme targeting high risk communities by Rodney Eksteen (FRI Vol 2 no 7)
It is essential to crib properly in order to ensure that the load does not shift and potentially fall on the victims or rescuers
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2: Coordination between fire fighters on the cribbing and on the airbag controls is a must
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Wedges are extremely versatile and are used mostly to fill the spaces that are not in contact with the load or the ground
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Freeing a victim from underneath a bucket of the backhoe, by setting up for a lift of the arm of the backhoe using airbags at the top of the trench
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https://www.frimedia.org/uploads/1/2/2/7/122743954/fri_vol2no7_lr.pdf
This week’s featured Fire and Rescue International magazine article is: Working with high pressure air bags written by Colin Deiner, chief director, Disaster management and Fire Brigade Services, Western Cape Government (FRI Vol 2 no 7). We will be sharing more technical/research/tactical articles from Fire and Rescue International magazine on a weekly basis with our readers to assist in technology transfer. This will hopefully create an increased awareness, providing you with hands-on advice and guidance. All our magazines are available free of charge in PDF format on our website and online at ISSUU. We also provide all technical articles as a free download in our article archive on our website.
Working with high pressure air bags
By Colin Deiner, chief director, Disaster management and Fire Brigade Services, Western Cape Government
The two biggest challenges that fire fighters will face: fire and gravity. We have dealt often and in some detail with fire over the last few months. This month we will discuss gravity, or how to defy gravity, maybe just for a short while.
During the course of your career of a fire fighter or rescuer, you will from time-to-time be called to an incident where someone is trapped by a heavy load. It could be a structural collapse, trench rescue, large motor vehicle accident or person trapped by heavy machinery. In many of the above cases your standard heavy hydraulic rescue equipment may not be the ideal tool of choice. Their size, shape and capacity might limit their use in confined spaces and with particularly heavy loads. Air bags provide the kind of versatility that you won’t need every day but could give you that critical advantage that no other tool could give.
Types of air bags
Air bags are available in two configurations: low pressure and high pressure. Low pressure bags are generally designed to provide higher lifting heights with low tonnage capacity and are most commonly used to provide stabilisation of loads over a larger surface. Low pressure bags range in capacity from 0,5 to 1 bar.
High pressure bags provide much greater lifting force but have a limited height capability which sometimes requires that two or more bags must be placed on top of each other to achieve the desired result. High pressure bags are also made from thicker and more robust rubber and provide more resistance to possible mechanical damage than low pressure bags.
Both types are found in four main shape configurations, square pillow shape, rectangular pillow shape, cylindrical sidewall shape and rectangular sidewall shape.
The square pillow shape is used mostly for high pressure bags and offers the best power versus lifting height ratio. This shape is relatively stable at low lifting heights with heavy loads but become more unstable with lighter loads or at greater lifting heights when it assumes a ball-like shape.
The rectangular pillow shape is used for both high pressure and low pressure bags but does not provide as good a power versus height ratio as the square shape. This shape does however have the big advantage that when it inflates, it shapes like a log making it stable in one direction at any height.
The cylindrical side wall shape and rectangular side wall shapes are used for high lift bags and should not be considered stable at any height especially during the lifting process. Stability is only achieved at full lifting height when the sidewalls are fully extended provided the bag is not higher than its maximum diameter.
Airbag tie-downs are used in many air bag configurations to eliminate the instability caused by the ‘pillowing’ effect caused by airbags. This design does provide some stability to the bag but only after the maximum height is reached and the ties are under tension. Although a more stable platform is created here remember that you are dealing with massive loads and the lateral load stability must always be considered.
Airbag components
The airbag system has five main components: the air supply, regulator, hoses, controller, remote shutoff valves and air bags. The air is normally supplied by a self-contained breathing apparatus (SCBA) cylinder. It can also be supplied by other sources such as the air system on a vehicle; however, this limits the position of the controller. The SCBA cylinder is ideal as it can easily be transported into remote rescue areas.
The pressure regulator is attached to the air supply and has both high- and low-pressure gauges. The high-pressure gauge indicates the pressure coming from the air supply while the low-pressure gauge reflects what the pressure is that is being reduced by the regulator. The regulator has a control knob that is used to increase or decrease the pressure that is being supplied to the rest of the system. When the equipment is stored, take care to ensure that the pressure gauge is lowered. The reason for this is to reduce the pressure on the gauges tensioned spring that can wear out if not brought down. This constant tension on the spring can make it impossible to increase the pressure to the necessary output required to operate the system.
The controller is attached to the regulator and is capable of operating one or two airbags. When doing a high lift and operating two air bags, it is advisable to do it with a duel controller. The reason for this is that you will not inflate one bag fully before starting on the second one due to the instability that may occur. Inflating both bags to a certain point may show that they are not equally aligned and may call for a repositioning. Controllers are also equipped with low-pressure gauges and relief valves for each air outlet. The relief valve is designed to prevent the bags from being overinflated above their recommended operating pressure.
The final parts of the system are the pneumatic hoses that send the operating pressure to the specific air bags. Hoses are available in different lengths and colours. It is important that the hoses are different colours for each air bag being used in the lift. The operator of the controller may not be able to see the bags that he/she is controlling. By having different coloured hoses the person coordinating the lift can tell the operator which colour to inflate or deflate.
Some basic rules for lifting
In the previous section I have mentioned the basic components of airbags. One of the most important components is one that doesn’t connect to the system at all but must be available (in abundance) when any lifting evolutions are attempted. I am referring to cribbing. Always ensure that you have enough cribbing in the form of 4x4s (100mm x 100mm timbers), a good assortment of wedges and a few base plates to ensure a smooth surface on which to place your airbag.
I know cribbing takes up a lot of space and doesn’t display very well on your rescue truck but you need to look past that. A rescue truck without cribbing is not a rescue truck, simple.
As mentioned earlier, an airbag is by its nature unstable. The only way that the load can be secured and stabilised is to ensure that cribbing is placed strategically as the load is lifted. More on this later.
As in any heavy lifting evolution, there are a number of things to keep in mind when using air bags for lifting:
• Don’t work directly in front of the bag. Should the bag be displaced laterally due to some uncontrolled load, it could do so at such force that it will shoot out at a high velocity and hit or injure whatever is in its way.
• When a part of the load is being lifted, no other part should come down as a result. This could place undue lateral pressure on the load.
• Never consider any inflated airbag as being stable.
• Don’t ever stack low or medium pressure bags.
• Don’t crib on top of an air bag.
Air bag capacities
The maximum lifting capacity of a bag is always clearly indicated on the bag and is presented in tons. The lift capacity is based on the surface area of the bag. As the air enters the bag under pressure, this is spread evenly across the bag’s entire surface and creates lift force. The greater the surface area, the greater the lift force, which results in increased lift capacity.
Air bags also have a maximum height to which it can be inflated. This is known as the ‘lift height’. It must be, however, appreciated that the lifting capacity of the bag will decrease as the lift height increases. The maximum capacity can also only be achieved at the direct centre of the bag. All bags should be placed in such a way that maximum advantage is derived from this.
When two bags of the same capacity are placed on top of each other, the total capacity will not increase. Should two bags of uneven capacity be stacked on top of one another, the maximum capacity will be determined by the smaller bag. The only time you can increase the capacity of an airbag is by placing two bags alongside one another. This increases the surface area of the load to be lifted.
Cribbing
As mentioned previously, cribbing is an essential part of air bag lifting operations. Cribbing is a temporary base to support the load as well as the airbags. It is essential for members to crib properly in order to ensure that the load does not shift and potentially fall on the victims or rescuers.
Although cribbing is available in a wide range of shapes, sizes and materials, the most common material is timber. In recent years there has also been a shift to composite materials. I personally prefer using timber for a number of reasons. Firstly, it’s cheaper and easier to acquire. Secondly, it won’t slip easily and will provide a warning when it is overstressed. And finally, you don’t have to fill in all that paperwork if you lose one.
The various sizes of cribbing blocks will range from 50mm x 100mm, 100mm x 100mm and 150mm x 150mm. There is no specific requirement to the length of the cribbing and this will generally be determined by the type of air bags in your department, the rescue unit’s carrying capacity or some other reason. A good standard length should however be in the region of 60cm.This will provide a stable base to work from.
Also ensure that you have a good supply of wedges available that are cut to standard lengths to ensure compatibility with the cribbing blocks. Wedges are extremely versatile and are used mostly to fill the spaces that are not in contact with the load or the ground.
The most common cribbing structure when using air bags is the box crib. Box cribs consist of a series of timbers placed perpendicular to one another to support a load. Box cribs are not just used to support and stabilise the load being lifted, but the air bags themselves.
Box cribs provide a strong, solid base and can be constructed from 100mm x 100mm or 150mm x 150mm timbers. The weight of the load will determine the size of the timbers to be used and if two or three timbers are used on each layer. Remember that you want to maintain a stable load at all times and the moment the height of the box crib exceeds the base by more than triple, it becomes unstable.
Calculating the capacity of the cribbing is reliant on a number of factors including the type of wood, dimensions and points of contact. The commonly accepted capacities for the various box cribs using a perpendicular load capacity of 500PSI are:
• 100mm x 100mm @ 2 timbers per layer (4 points of contact) = 12 tons
• 100mm x 100mm @ 3 timbers per layer (9 points of contact) = 27,5 tons
• 150mm x 150mm @ 2 timbers per layer (4 points of contact) = 30 tons
• 150mm x 150mm@ 3 timbers per layer (9 points of contact) = 68 tons
Take note that these loads are based on the weight of the load being distributed across all points of contact on the system. It will be reduced if the load is placed between the points of contact.
When deciding on which type of timber to use for cribbing, I would prefer a softer timber. Softer timbers will bite into the surface of the load making it more stable. The soft timber is also better when working with an unknown load capacity because it will provide warning signs of failure. It will start to fail by cracking and splitting slowly and this produces a loud cracking noise.
Safety
Safety will, as always, be the prime consideration when responding to incidents in which people are trapped by heavy loads. Look out for running machinery, leaking chemicals or fluids around the lifting surfaces and any sharp objects that may penetrate or damage a lifting bag. The most important safety consideration will be the possibility of a load shifting and becoming unstable.
Incidents requiring the use of airbags could be inside factories or buildings to which you can’t get close with your rescue truck. Ensure therefore that all the equipment you might need is stored together and can be easily removed from the truck and carried to the work site. Don’t forget the cribbing.
When assessing the load to be lifted, ensure that it is stable in the position it is currently in. You might need to anchor the load using steel rigging or wheel chocks. Next try to determine the surface from where the lift will be done. It should be as level as possible. The first layer of box cribbing must be constructed to spread the load evenly across the entire surface especially when you are working on soil, asphalt or similar surfaces.
Next, you will need to plan the positioning and possible upwards movement of the load. Ensure that the load will be able to move unobstructed into the direction you intend and take care that no cribbing is placed in the way of the airbags or load movement path.
Building a box crib will require working under the load. Rescuers must at all times avoid placing their hands under the load when placing the cribbing into position. Using one block to push another block into position is the generally accepted method of achieving this. Whilst doing this try to get each timber to overlap the next by a minimum of 100mm. You might need a lot of cribbing, make sure you have it.
Patient care
Your patient will obviously be the main focus of the operation. You will want to release the patient from the load with the minimum lift. Make sure however that the amount of lift achieved is sufficient to release the patient entirely. You do not want to have to find that a foot is still trapped and end up trying to drag him/her out of the space only to cause further injury.
The victim’s condition will be an indicator of how the extrication will proceed. In a highly unstable situation (it might happen), you might want to just get enough lift to drag him/her out of there whereas a more stable situation might require a slower more controlled evolution. The critical condition known as crush syndrome will most likely present when a person has been trapped for an extended period. Determining exactly how the victim is trapped should provide you with sufficient information to determine his/her medical condition and suspect the possibility of crush syndrome.
Getting your medical team in there to start treatment before the extrication is commenced will be vital if the victim is to survive. They will start administering fluids prior to any release of weight off the victim, in order to counteract the toxic condition that will be brought about by the crush injury. Fluid therapy is the first choice in the management of crush syndrome because the development of shock and acute renal failure can be avoided by the early provision of fluid resuscitation. Too many times I have seen an excellent rescue of a victim from a heavy load entrapment only to have the person die in hospital a short while later from shock, acute renal failure or other systemic complications.
The medical crew should also set up a treatment area in a space safely away from the load and ensure that it is equipped with all the resources needed for the treatment of a serious crush trauma injury. During the lift, the medic must at all times be in communication with the incident commander to make sure that the lift does not compromise the patient’s condition in any way.
Controlling the lift
As with any emergency response, incident command must also be established here. Although you will not need a large command structure for such an operation, communication and coordination is vital and a clear line of communication must be established between the team doing the lift and the medical team.
They are normally quite close to one another and this should not be a problem. There might, however, be a challenge when the person operating the regulator is stationed in a position remote to where the extrication is happening.
To add the incident command’s headaches, the extrication might be happening in a confined space where he/she does not have sight of the incident.
The command staff should consist of the incident commander, a safety officer, a medical officer and a rescue officer.
The safety officer should always focus on all the safety aspects of the operation. If possible, place lookouts in strategic positions to monitor the lift, ensuring that there is no shifting of the load and that it is being sufficiently cribbed.
He/she should also ensure that no persons are positioned so that they are exposed to any prevailing hazards. The moment the lift starts, people tend to get fixated on what is happening and might get distracted from their task. Care must be taken to ensure that this doesn’t happen.
The medical officer will coordinate the medical management in the extrication sector, the treatment sector and the transport sector. I have already discussed the medical management of the victims and all that is necessary to add here is that all sectors under his/her control must focus on the continued emergency care as the patient moves through their hands. All sectors must focus on reversing the crush syndrome and it is therefore vital that they know what treatment was provided prior to the patient being handed over to them.
The extrication sector will have the most staff and need to be carefully coordinated. The person controlling the airbag regulator might need a few observers to monitor the lift. At least two people will be needed for the cribbing and they might have to be placed in various positions around the load. You will also need rescues to remove the victim and it might be advisable to have a ‘gopher’ to fetch additional kit from the staging area or rescue rig.
Lifting the load
Once the lift starts, all the attention should be focussed on this.
Some important points to remember here:
In closing
High pressure air bags are one of the most versatile tools in your rescue arsenal. Don’t be afraid to train with them and use them. As with any rescue kit, it can’t function on its own. Everybody needs to understand this and be comfortable with all the parts that make up the system.
Stay safe.
This week’s featured Fire and Rescue International magazine article is: Working with high pressure air bags written by Colin Deiner, chief director, Disaster management and Fire Brigade Services, Western Cape Government (FRI Vol 2 no 7). We will be sharing more technical/research/tactical articles from Fire and Rescue International magazine on a weekly basis with our readers to assist in technology transfer. This will hopefully create an increased awareness, providing you with hands-on advice and guidance. All our magazines are available free of charge in PDF format on our website and online at ISSUU. We also provide all technical articles as a free download in our article archive on our website.
Working with high pressure air bags
By Colin Deiner, chief director, Disaster management and Fire Brigade Services, Western Cape Government
The two biggest challenges that fire fighters will face: fire and gravity. We have dealt often and in some detail with fire over the last few months. This month we will discuss gravity, or how to defy gravity, maybe just for a short while.
During the course of your career of a fire fighter or rescuer, you will from time-to-time be called to an incident where someone is trapped by a heavy load. It could be a structural collapse, trench rescue, large motor vehicle accident or person trapped by heavy machinery. In many of the above cases your standard heavy hydraulic rescue equipment may not be the ideal tool of choice. Their size, shape and capacity might limit their use in confined spaces and with particularly heavy loads. Air bags provide the kind of versatility that you won’t need every day but could give you that critical advantage that no other tool could give.
Types of air bags
Air bags are available in two configurations: low pressure and high pressure. Low pressure bags are generally designed to provide higher lifting heights with low tonnage capacity and are most commonly used to provide stabilisation of loads over a larger surface. Low pressure bags range in capacity from 0,5 to 1 bar.
High pressure bags provide much greater lifting force but have a limited height capability which sometimes requires that two or more bags must be placed on top of each other to achieve the desired result. High pressure bags are also made from thicker and more robust rubber and provide more resistance to possible mechanical damage than low pressure bags.
Both types are found in four main shape configurations, square pillow shape, rectangular pillow shape, cylindrical sidewall shape and rectangular sidewall shape.
The square pillow shape is used mostly for high pressure bags and offers the best power versus lifting height ratio. This shape is relatively stable at low lifting heights with heavy loads but become more unstable with lighter loads or at greater lifting heights when it assumes a ball-like shape.
The rectangular pillow shape is used for both high pressure and low pressure bags but does not provide as good a power versus height ratio as the square shape. This shape does however have the big advantage that when it inflates, it shapes like a log making it stable in one direction at any height.
The cylindrical side wall shape and rectangular side wall shapes are used for high lift bags and should not be considered stable at any height especially during the lifting process. Stability is only achieved at full lifting height when the sidewalls are fully extended provided the bag is not higher than its maximum diameter.
Airbag tie-downs are used in many air bag configurations to eliminate the instability caused by the ‘pillowing’ effect caused by airbags. This design does provide some stability to the bag but only after the maximum height is reached and the ties are under tension. Although a more stable platform is created here remember that you are dealing with massive loads and the lateral load stability must always be considered.
Airbag components
The airbag system has five main components: the air supply, regulator, hoses, controller, remote shutoff valves and air bags. The air is normally supplied by a self-contained breathing apparatus (SCBA) cylinder. It can also be supplied by other sources such as the air system on a vehicle; however, this limits the position of the controller. The SCBA cylinder is ideal as it can easily be transported into remote rescue areas.
The pressure regulator is attached to the air supply and has both high- and low-pressure gauges. The high-pressure gauge indicates the pressure coming from the air supply while the low-pressure gauge reflects what the pressure is that is being reduced by the regulator. The regulator has a control knob that is used to increase or decrease the pressure that is being supplied to the rest of the system. When the equipment is stored, take care to ensure that the pressure gauge is lowered. The reason for this is to reduce the pressure on the gauges tensioned spring that can wear out if not brought down. This constant tension on the spring can make it impossible to increase the pressure to the necessary output required to operate the system.
The controller is attached to the regulator and is capable of operating one or two airbags. When doing a high lift and operating two air bags, it is advisable to do it with a duel controller. The reason for this is that you will not inflate one bag fully before starting on the second one due to the instability that may occur. Inflating both bags to a certain point may show that they are not equally aligned and may call for a repositioning. Controllers are also equipped with low-pressure gauges and relief valves for each air outlet. The relief valve is designed to prevent the bags from being overinflated above their recommended operating pressure.
The final parts of the system are the pneumatic hoses that send the operating pressure to the specific air bags. Hoses are available in different lengths and colours. It is important that the hoses are different colours for each air bag being used in the lift. The operator of the controller may not be able to see the bags that he/she is controlling. By having different coloured hoses the person coordinating the lift can tell the operator which colour to inflate or deflate.
Some basic rules for lifting
In the previous section I have mentioned the basic components of airbags. One of the most important components is one that doesn’t connect to the system at all but must be available (in abundance) when any lifting evolutions are attempted. I am referring to cribbing. Always ensure that you have enough cribbing in the form of 4x4s (100mm x 100mm timbers), a good assortment of wedges and a few base plates to ensure a smooth surface on which to place your airbag.
I know cribbing takes up a lot of space and doesn’t display very well on your rescue truck but you need to look past that. A rescue truck without cribbing is not a rescue truck, simple.
As mentioned earlier, an airbag is by its nature unstable. The only way that the load can be secured and stabilised is to ensure that cribbing is placed strategically as the load is lifted. More on this later.
As in any heavy lifting evolution, there are a number of things to keep in mind when using air bags for lifting:
• Don’t work directly in front of the bag. Should the bag be displaced laterally due to some uncontrolled load, it could do so at such force that it will shoot out at a high velocity and hit or injure whatever is in its way.
• When a part of the load is being lifted, no other part should come down as a result. This could place undue lateral pressure on the load.
• Never consider any inflated airbag as being stable.
• Don’t ever stack low or medium pressure bags.
• Don’t crib on top of an air bag.
Air bag capacities
The maximum lifting capacity of a bag is always clearly indicated on the bag and is presented in tons. The lift capacity is based on the surface area of the bag. As the air enters the bag under pressure, this is spread evenly across the bag’s entire surface and creates lift force. The greater the surface area, the greater the lift force, which results in increased lift capacity.
Air bags also have a maximum height to which it can be inflated. This is known as the ‘lift height’. It must be, however, appreciated that the lifting capacity of the bag will decrease as the lift height increases. The maximum capacity can also only be achieved at the direct centre of the bag. All bags should be placed in such a way that maximum advantage is derived from this.
When two bags of the same capacity are placed on top of each other, the total capacity will not increase. Should two bags of uneven capacity be stacked on top of one another, the maximum capacity will be determined by the smaller bag. The only time you can increase the capacity of an airbag is by placing two bags alongside one another. This increases the surface area of the load to be lifted.
Cribbing
As mentioned previously, cribbing is an essential part of air bag lifting operations. Cribbing is a temporary base to support the load as well as the airbags. It is essential for members to crib properly in order to ensure that the load does not shift and potentially fall on the victims or rescuers.
Although cribbing is available in a wide range of shapes, sizes and materials, the most common material is timber. In recent years there has also been a shift to composite materials. I personally prefer using timber for a number of reasons. Firstly, it’s cheaper and easier to acquire. Secondly, it won’t slip easily and will provide a warning when it is overstressed. And finally, you don’t have to fill in all that paperwork if you lose one.
The various sizes of cribbing blocks will range from 50mm x 100mm, 100mm x 100mm and 150mm x 150mm. There is no specific requirement to the length of the cribbing and this will generally be determined by the type of air bags in your department, the rescue unit’s carrying capacity or some other reason. A good standard length should however be in the region of 60cm.This will provide a stable base to work from.
Also ensure that you have a good supply of wedges available that are cut to standard lengths to ensure compatibility with the cribbing blocks. Wedges are extremely versatile and are used mostly to fill the spaces that are not in contact with the load or the ground.
The most common cribbing structure when using air bags is the box crib. Box cribs consist of a series of timbers placed perpendicular to one another to support a load. Box cribs are not just used to support and stabilise the load being lifted, but the air bags themselves.
Box cribs provide a strong, solid base and can be constructed from 100mm x 100mm or 150mm x 150mm timbers. The weight of the load will determine the size of the timbers to be used and if two or three timbers are used on each layer. Remember that you want to maintain a stable load at all times and the moment the height of the box crib exceeds the base by more than triple, it becomes unstable.
Calculating the capacity of the cribbing is reliant on a number of factors including the type of wood, dimensions and points of contact. The commonly accepted capacities for the various box cribs using a perpendicular load capacity of 500PSI are:
• 100mm x 100mm @ 2 timbers per layer (4 points of contact) = 12 tons
• 100mm x 100mm @ 3 timbers per layer (9 points of contact) = 27,5 tons
• 150mm x 150mm @ 2 timbers per layer (4 points of contact) = 30 tons
• 150mm x 150mm@ 3 timbers per layer (9 points of contact) = 68 tons
Take note that these loads are based on the weight of the load being distributed across all points of contact on the system. It will be reduced if the load is placed between the points of contact.
When deciding on which type of timber to use for cribbing, I would prefer a softer timber. Softer timbers will bite into the surface of the load making it more stable. The soft timber is also better when working with an unknown load capacity because it will provide warning signs of failure. It will start to fail by cracking and splitting slowly and this produces a loud cracking noise.
Safety
Safety will, as always, be the prime consideration when responding to incidents in which people are trapped by heavy loads. Look out for running machinery, leaking chemicals or fluids around the lifting surfaces and any sharp objects that may penetrate or damage a lifting bag. The most important safety consideration will be the possibility of a load shifting and becoming unstable.
Incidents requiring the use of airbags could be inside factories or buildings to which you can’t get close with your rescue truck. Ensure therefore that all the equipment you might need is stored together and can be easily removed from the truck and carried to the work site. Don’t forget the cribbing.
When assessing the load to be lifted, ensure that it is stable in the position it is currently in. You might need to anchor the load using steel rigging or wheel chocks. Next try to determine the surface from where the lift will be done. It should be as level as possible. The first layer of box cribbing must be constructed to spread the load evenly across the entire surface especially when you are working on soil, asphalt or similar surfaces.
Next, you will need to plan the positioning and possible upwards movement of the load. Ensure that the load will be able to move unobstructed into the direction you intend and take care that no cribbing is placed in the way of the airbags or load movement path.
Building a box crib will require working under the load. Rescuers must at all times avoid placing their hands under the load when placing the cribbing into position. Using one block to push another block into position is the generally accepted method of achieving this. Whilst doing this try to get each timber to overlap the next by a minimum of 100mm. You might need a lot of cribbing, make sure you have it.
Patient care
Your patient will obviously be the main focus of the operation. You will want to release the patient from the load with the minimum lift. Make sure however that the amount of lift achieved is sufficient to release the patient entirely. You do not want to have to find that a foot is still trapped and end up trying to drag him/her out of the space only to cause further injury.
The victim’s condition will be an indicator of how the extrication will proceed. In a highly unstable situation (it might happen), you might want to just get enough lift to drag him/her out of there whereas a more stable situation might require a slower more controlled evolution. The critical condition known as crush syndrome will most likely present when a person has been trapped for an extended period. Determining exactly how the victim is trapped should provide you with sufficient information to determine his/her medical condition and suspect the possibility of crush syndrome.
Getting your medical team in there to start treatment before the extrication is commenced will be vital if the victim is to survive. They will start administering fluids prior to any release of weight off the victim, in order to counteract the toxic condition that will be brought about by the crush injury. Fluid therapy is the first choice in the management of crush syndrome because the development of shock and acute renal failure can be avoided by the early provision of fluid resuscitation. Too many times I have seen an excellent rescue of a victim from a heavy load entrapment only to have the person die in hospital a short while later from shock, acute renal failure or other systemic complications.
The medical crew should also set up a treatment area in a space safely away from the load and ensure that it is equipped with all the resources needed for the treatment of a serious crush trauma injury. During the lift, the medic must at all times be in communication with the incident commander to make sure that the lift does not compromise the patient’s condition in any way.
Controlling the lift
As with any emergency response, incident command must also be established here. Although you will not need a large command structure for such an operation, communication and coordination is vital and a clear line of communication must be established between the team doing the lift and the medical team.
They are normally quite close to one another and this should not be a problem. There might, however, be a challenge when the person operating the regulator is stationed in a position remote to where the extrication is happening.
To add the incident command’s headaches, the extrication might be happening in a confined space where he/she does not have sight of the incident.
The command staff should consist of the incident commander, a safety officer, a medical officer and a rescue officer.
The safety officer should always focus on all the safety aspects of the operation. If possible, place lookouts in strategic positions to monitor the lift, ensuring that there is no shifting of the load and that it is being sufficiently cribbed.
He/she should also ensure that no persons are positioned so that they are exposed to any prevailing hazards. The moment the lift starts, people tend to get fixated on what is happening and might get distracted from their task. Care must be taken to ensure that this doesn’t happen.
The medical officer will coordinate the medical management in the extrication sector, the treatment sector and the transport sector. I have already discussed the medical management of the victims and all that is necessary to add here is that all sectors under his/her control must focus on the continued emergency care as the patient moves through their hands. All sectors must focus on reversing the crush syndrome and it is therefore vital that they know what treatment was provided prior to the patient being handed over to them.
The extrication sector will have the most staff and need to be carefully coordinated. The person controlling the airbag regulator might need a few observers to monitor the lift. At least two people will be needed for the cribbing and they might have to be placed in various positions around the load. You will also need rescues to remove the victim and it might be advisable to have a ‘gopher’ to fetch additional kit from the staging area or rescue rig.
Lifting the load
Once the lift starts, all the attention should be focussed on this.
Some important points to remember here:
- Lift slowly: This will allow the cribbing to be placed and the medical management to be more effective. It also allows for better monitoring of the load and detection of any shifting thereof.
- Crib-as-you-go: Remember the golden rule: ‘Lift one inch crib one inch’. This ensures that in the event of a failure, the load will only drop a very short distance.
- When using two stacked bags, inflate the lower bag only enough to allow the top bag to settle snugly into it. The main lift should then be done by the top bag. Should the top bag be fully inflated and the victim is still not free, revert to the lower bag taking care that it remains softer than the top bag.
- Sometimes you might need to elevate the bags to achieve a desired height. In this case, you might need to place the bags on a base of timber. This can occur when you have to lift a vehicle. When doing this make sure that your lifting bags are placed on a solid base. Never, never, place any blocks on top of a bag. Should such a timber become dislodged due to instability, the lateral force will turn it in a missile and it will ……………. anything in its way.
- Only lift as high as is necessary to free the victim. The higher you lift the more unstable your load becomes.
In closing
High pressure air bags are one of the most versatile tools in your rescue arsenal. Don’t be afraid to train with them and use them. As with any rescue kit, it can’t function on its own. Everybody needs to understand this and be comfortable with all the parts that make up the system.
Stay safe.