Cracking the Egg: Extrication

Cracking the Egg

At first glance, “Cracking the Egg” may appear to be a junkyard trick that looks exciting but has little merit during an incident. On various extrication-related sites, bloggers occasionally mention the tactic but quickly dismiss it due to its perceived difficulty. But we offer this tactic, not as a replacement to the trusted practice of tunneling, but rather as another possible solution for accessing patients entrapped within a roof-resting vehicle.

What Does “Cracking the Egg” Mean?
Cracking the Egg was a name derived from Randy Schmitz who compared the tactic to an egg being cracked. Specifically, when you crack an egg on the edge of a bowl, the egg separates into two distinct parts with a hinge point on the opposite side of the shell. Once it is cracked and separated, the contents are easily removed. In extrication, the car is “cracked” into two distinct parts, and the patient can be easily removed.

During a Florida incident last year, rescuers used the “Cracking the Egg” technique to successfully extricate occupants from a high-energy rollover. The vehicle presented challenges with a compromised greenhouse and significant roof-post deformation. Rescuers cut through the roof and damaged support features over the back seat of the four-door, roof-resting, mid-sized SUV, and used a pulling device to lift the rear end of the vehicle open like the lid on a can of beans. Tunneling, though an option, would have provided limited patient access, so “Cracking the Egg” proved the better plan.


The Best Option?
This controversial tactic may be preferable for various reasons. A patient suspended in the front seat presents a challenge best handled by relocating as much of the surrounding material as possible. By displacing the rear of the vehicle, rescuers have better access and a clear view, ensuring a coordinated effort.

Further, the tactic proves to be a good option for roof-resting tunnel operations in which side access is limited by external barriers, such as ditches, jersey barriers, additional vehicles or embankments.

Tunneling may be the initial plan, but rescuers may have to reevaluate due to the state of the vehicle. A patient located in the rear seat of a vehicle may provide another hurdle to tunneling attempts, as it is much harder to remove the rear seat without manipulating the patient in this position.

Necessary Tools
When rescuers employ the “Cracking the Egg” tactic, set-up consists of four basic components:
1.    Anchor
2.    Pulling device
3.    High point
4.    Load attachment points

Anchor
This component provides a fixed point from which rigging can lift the rear end of the car vertically. The quickest and easiest anchor point will likely be a cross member that supports the motor. This type of structure is strong, easily accessible and positioned in a suitable area.

Pulling Device
The pulling device needs to be capable of managing a few hundred pound load. The average passenger vehicle weighs no more than 3,000–4,000 lbs. This tactic only requires the vertical relocation of the lighter third of the vehicle articulating from a hinge point. Examples of common pulling devices may include but are not limited to a chain winch, come-along, hydraulic ram, hydraulic spreader and hi-lift jack. The actual force needed by the pulling device is dependent on its relationship to the high point and, more importantly, the position of the attachment points in relation to the hinge point. The closer to the hinge point, the more force needed but the more clearance achieved per increment of pull. The farther from the hinge point, the lighter the lift but less clearance achieved per increment of pull.

High Point
The purpose of the high point is to initiate the movement of the vehicle’s rear section in the proper direction. The high point acts as a fulcrum for the pulling device and should be located forward of the fuel cell and the rear seat floor pan where there’s an already existing relief. Expect the cribbing surface to be uneven due to the exhaust or drive shaft occupying the tunnel space. As a minimum, ensure that the high point allows for at least eight inches of vertical lever movement away from the floor pan. Keep in mind that while building a taller high point will reduce the required load on the pulling device, it may decrease the stability of the high point crib itself.

Load Attachment Points
These are points in the rear end of the frame to which the pulling device—connected in the front to the anchor point—will attach in order to create the necessary tension to raise the rear end vertically. Resist the natural urge to create an attachment point on the rear suspension components. Compressing the travel in these components will reduce the distance by which the pulling device will work. This is especially important when utilizing a ram or spreader that has travel limited by its construction geometry. Additionally, suspension components are often compromised in high-energy roll-overs and cannot be relied upon to provide structural integrity. Suitable attachment points include chassis members, trailer receivers or drawbars, and OEM frame holes provided they are not compromised by corrosion or damage.

Step-by-Step
Rescuers will benefit from establishing individual groups, assigned to each aspects of the tactic. A rigging group should be responsible for set up and rigging operations during the incident. A disentanglement group should concentrate on the necessary tactics required to free the occupants. Two groups of two or three responders, working in a coordinated movement, should be able to establish an initial access point and an appropriate path of egress within 10 minutes. It’s imperative to train on this tactic prior to deploying it on the street, but it is not necessary for all the responders on scene to be proficient in its delivery. Place the trained responders on rigging, and direct the disentanglement group where and when to make cuts.

After rescuers separate into their various groups, they should take the following steps:
1.    Initially treat the incident as you would any other vehicle collision. Take the necessary steps to establish incident command, survey the scene carefully, call resources as necessary, control hazards and stabilize the vehicle in the position found. Always communicate with the medic and provide hard/soft protection as necessary. Breaking the rear window with a vehicle in the roof-resting position will rain glass in all directions, so take the necessary precautions to prevent injury. If the glass has already broken, rescuers should lay a blanket over the work area to protect personnel and patients during the removal phase. Also, it is important to clear the glass out as much as possible from the top edge of the window and, if warranted, to cover it with blankets or extrication wrap. If not managed appropriately, fragments may fall onto the ground or responders during the tactic and patient removal. When working on the undercarriage, ensure solid footing, and avoid hot vehicle components.
2.    Take time to remove as much of the exhaust pipe and driveshaft (if the vehicle has one) from where the hinge will be created. These two components, if left in place, may provide resistance or puncture the fuel cell as the pulling device bends the rear end upward.
3.    Establish the rigging system on the undercarriage of the vehicle including the anchor point, pulling device and load attachment points. The disentanglement group can prepare for the necessary cuts by managing rear doors and rear glass. Ensure the release of the rear doors, or the locking mechanism will prevent the rear section from moving in the intended path. It may seem contradictory to consider this tactic when side access is blocked, but experience has shown that the door only has to be slightly cracked to ensure success. Even if the door does not open, the responder only has to release the locking mechanism when operating the handle. If the handle does not work, then create a space in the door and sever the locking mechanism.
4.    Place the high point under the rigging assembly. Options for the high point include a half rim, cribbing or column master. If the pulling device cannot be reset and has a limited amount of travel (such as a hydraulic spreader or ram), cribbing should be the method of choice. The cribbing can be used to tighten the chain to maximize the pull distance.
5.    Place tension on the pulling device to prevent the rear section of the vehicle from dropping below the horizontal plane of the floor pan when the relief cuts are executed. This also prevents the rear posts from entering into a state of compression which may bind a reciprocating saw or chisel.
6.    Cut through the rocker panels in a similar location on both sides of the vehicle. This cut on a typical sedan should be aft of the rear seat floor pan and forward of the fuel cell. If using a cutter with a short blade, you may have to make a pie cut and a final cut to ensure the rocker panel is severed.
7.    Make a complete cut through the rear posts. For clarification, it does not matter whether the cuts are made in the rear posts or rocker panel first, as long as there is tension on the system. The group supervisor should make the most effective and efficient decisions possible based on the situation and the tools and personnel available.
8.    Pull the rear section upward at the hinge point with the pulling device until it has reached an almost perpendicular position. Once the rear has been displaced, access to the patient compartment should be sufficient to remove most victims, especially if they are lying on the roof with minimal secondary entrapment. However, in some cases there may be a need to complete front-seat tactics, such as displacing or removing the seat back. Consider tool selection and tactics very similar to any other tunneling situation. During the process, the supervisor should carefully monitor the movement of the rear section. It is relatively easy to detect the completion of the cuts based on the overall movement. If it takes excessive force or one side does not hinge correctly, it is likely that an incomplete cut remains. Stop any further movement and address the problem immediately.
9.    The pulling devices and set-ups should meet all applicable weight requirements and pose little threat of failure, but if any occurs, it may be at the anchor points, so take care in selecting them. Depending on your department’s standpoint, you may need to add a safety device. This may also give rescuers greater security if there is a potential of operating underneath the rear of the vehicle for an extended amount of time. A first option is to simply connect a ratchet strap between anchor points on the rear and front of the vehicle. If utilizing this safety device, make the attachments before beginning the lift. This will reduce set-up time once the lift is complete. And it will be easier to make the attachments to the rear while at a good working height. Try to use alternative attachment points rather than the pulling device. A second option is the placement of a strut against the raised portion. Although it provides a higher degree of safety, one disadvantage is the placement may partially block the path of egress.

Although the “Cracking the Egg” tactic is easier to complete on a four-door, unibody vehicle, it still can be accomplished with two-door or full-frame vehicles. Two-door vehicles will require side access and a small area between the rear of the door and the rear fender well. Side access is critical because rescuers must be able to utilize an air chisel or reciprocating saw to remove the outer panel and basically create a second door. From that point, the cut location will be the same as a four-door vehicle. Rescuers must also make the initial rocker panel cut with a hydraulic cutter and then use a spreader to rip the sheet metal down to the beltline support rail and make the final cut with the hydraulic cutter. With full-frame vehicles, complete the same process, cut the frame rails and ensure the drive shaft is severed as described in Step 2.

Potential Hazards
Manipulation of a vehicle’s fuel lines or fuel cell concerns many responders. Keep in mind, for a roof-resting vehicle, the fuel cell is already in the most vulnerable position—the tank is elevated above the fill neck. By pulling the rear into a vertical position, the tank is actually less likely to leak through the neck. The fuel lines typically will run along the bottom of the rocker panel. To avoid cutting through the lines, take a prying device and push away from the cut location. The line may become completely severed and leak, but this is easily mitigated by crimping or plugging the line. Also, responders should always have preventive measures in place, such as staffed hoselines and various extinguishers to prevent flash fires or vapor collection.

Another concern is the contents of the trunk: Some motorists may be transporting harmful materials. Although a vehicle involved in a collision may have come to rest on its roof and its contents may have shifted in the process, additional shifting and leaking may occur. Some vehicles’ rear seats fold down for access to the trunk, so when raising the rear of the vehicle, heavy contents could fall through the seats. Responders can open the trunk if not already opened and check for contents, or they can place a ratchet strap across the seats and hook it to the wheel assemblies or quarter panel.
    
In Sum
If employed properly and safely, “Cracking the Egg” can provide unimpeded patient access by significantly relocating the rear of a vehicle. This tactic can produce big results in a short time frame and provides an alternative to the conventional tunneling operations deployed on roof-resting vehicles.



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October 2017
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