© Stephen Rinaldi, MBA, NRP

Introduction

One experience that seems universal when a medic or EMT reveals their occupation, is the initial reaction of “you must love blood and guts. After sharing that in reality only 10-15% of all EMS calls nationally are trauma related, and that of those only 27% are motor-vehicle crashes they often seem confused. The sensationalized media and entertainment industry has trained the public to believe that EMS manages trauma – when we actually handle medical related emergencies more than any other.

Despite this reality, when the call for a motor vehicle, agricultural, machinery or industrial accident does come in, we must be prepared and trained to respond. In this article, we will focus on the very small portion of accidents that require extrication – statistically 1:20. But when extrication is necessary, an orchestrated execution is critical. In this article we will review some basis elements of extrication, as mastery of this skill, requires deep didactic and practical application; both of which are outside the scope of this series.

Vehicle extrication remains one of the most technically demanding and high-stakes operations in the fire and rescue service. Unlike the early days of extrication when brute force and cutting through everything was the standard, modern heavy rescue emphasizes scene safety, systematic assessment of vehicle construction, and technique selection based on injury patterns and vehicle kinematics. This article focuses on the operational perspective of the truck and rescue squad member responsible for managing extrication from initial size-up through patient delivery to EMS.

Rescue operations fall across various teams in public safety depending upon a number of factors including the complexity and extent of entrapment or accessibility. If rescue is limited to cutting a seat belt, then the first responding unit whether police officer; bystander or firefighter may initiate the rescue. In other cases, EMS may pop a door or a window using a Halligan and glass punch to gain access. In the most complex of cases rescue and extrication requires heavy equipment and specialized training.

Safety First: Rescuers must approach all motor vehicle, industrial, agricultural and similar related emergencies involving entrapment or rescue with scene safety first and foremost. Securing vehicles/machinery appropriately is necessary before attempting or conducting rescue work.

Understanding Vehicle Construction and Collapse Mechanics

Before deploying any tools, rescue personnel must understand how vehicles fail under load and during accidents. Modern vehicles are designed with crumple zones that absorb impact energy, meaning the passenger compartment becomes progressively more rigid as you move from the bumpers toward the frame rails. This fundamental principle drives every tactical decision in extrication.

There are two primary vehicle designs to consider: body on frame, and unibody. In body on frame construction a steel ladder frame carries the engine, suspension and load. The body is bolted onto the frame, often on rubber isolators. The frame is the primary load path in a collision. This frame is stiff by design so it can tow, haul and twist-offroad without cracking body panels. These characteristics are useful for utility but problematic in high-energy collisions.

In a low speed crash, the cabin often looks intact while the other vehicle is crushed, because the frame resisted. High speed crashes result in greater absorption of force by occupants, because the rails do not fold. Deceleration is sharper and deceleration trauma is a greater risk. Modern trucks do have frame crush initiators and cabin cages, but the energy path is still frame first, and body second.

Rescue Implications: Body panels can be removed more easily than the rails which are thick, high-strength steel and hard to cut. If the cab has walked on the frame, a third door or dash roll may not behave as it does on a car.

A unibody is an entirely different design where there is no separate frame. The floor pan, rails, rockers, pillars roof and such are welded into one structural shell. The body is the chassis, and this remains the default design for passenger cars, most crossovers and many midsize SUVs. Crash energy is managed by programmed deformation. Front and rear structures are designed to fold, buckle and crush so the passenger “cell” stays as close to the original shape as possible and the occupants protected. These crush zones lengthen the time of the crash and lower peak force on occupants. High strength steels are placed in the cab at the A/B/C pillars, rockers and roof rails and in specific crush members. The wreckage is the system working, although vehicles are often not repairable.

Rescue Implication: Crush is more predictable if you know the models’ cut points, but steel is mixed and not uniform. Cutting the wrong pillar can stall a tool or throw sparks onto restraints and other hazards. Tighter packaging means cutting requires occupant protection and caution.

Vehicle Approach Strategies by Impact Type

The kinematics of trauma – or determining/predicting injuries based upon the trauma scene and the mechanism of injury is vitally important in evaluating motor vehicle accidents. Information regarding the kinematics can be further identified or confirmed during extrication. If you observe that the engine has been separated from its mounts (a circumstance I have witnessed on multiple occasions) you can immediately appreciate the force necessary and speed involved.

In this article we are separating our review of injury patterns and kinematics into three categories – front, side and rear impacts and at three speeds low speed (less than 20mph), moderate speed (20-40mph) and high speed (over 40mph).

Modern vehicles with supplemental restraint systems such as steering wheel air bags, side curtain air bags, dashboard air bags, collapsable/reactive seats and accident-avoidance technology are combining to reduce mortality and morbidity of motor vehicle accidents. It is important to note however, that there remain many vehicles on the road without this equipment, and even those with SRS’s are not immune to physics of force, mass and speed.

In an accident the body is in motion, and remains in motion, until acted on by another force. In these cases the force is the seatbelt restraint, the airbag or the steering wheel, dashboard, A or B post and similar. Therefore, there are two primary considerations: blunt force trauma and deceleration trauma.

Rear-end collisions create different injury patterns than frontal impacts. Passengers in rear seats experience rapid acceleration injuries, often resulting in hyperextension of the neck and thoracic spine. However, structural entrapment from rear-end impacts is less common because the rear of the vehicle crumples without typically trapping occupants between solid structures.

When rear-end impacts do cause entrapment, it's usually because the trunk has collapsed forward, pinning occupants to their seats, or because the impact has buckled the frame sufficiently to jam doors.

Side-impact crashes create the most complex extrication scenarios because the intrusion occurs perpendicular to the vehicle's length, compressing the occupant compartment from the side. Understanding the anatomy of the posts is essential.

The A post is the forward-most vertical member, located between the windshield and the front door. It bears significant load and is typically very rigid. Side impacts frequently crush this post inward, pinning the upper arm and shoulder.

The B post is the middle vertical member between the front and rear doors. This post typically bears less structural load than the A post and collapses more readily in side impacts. However, the B post also anchors the seat mechanisms and shoulder belts, making it structurally important for occupant safety.

The C post is the rearmost vertical member. In some vehicles (particularly SUVs), there's also a D post that supports the rear roof and cargo area.

In side-impact collisions, the intrusion pattern tells you exactly where occupants are pinned. A vehicle struck on the driver's side will have the left A, B, and C posts driven inward, compressing the driver and front passenger. Critically, the degree of intrusion at each post level varies.

Scene Size Up and Heavy Rescue Approach

Establish scene safety first. Place apparatus at least one vehicle length behind the wreckage to protect operating personnel. Establish a hot zone with traffic control at a minimum of 100 feet in all directions on roadways. Once scene safety is established, the rescue crew performs a 360-degree size-up, noting the direction of impact, degree of intrusion into the passenger compartment, and any hazards like downed power lines or fuel leaks. Frontal, side and rear collisions require different approaches to heavy rescue and extrication. These approaches may be further impacted by the type of vehicle – engine in front or rear, hybrid or electric and similar characteristics. Electric and hybrid vehicles are discussed further in the article.

The heavy rescue team is not always dispatched from onset and may be part of a secondary tone-out after initial units arrive and determine that heavy rescue is needed. This varies by region and response protocol. Unless the caller notes entrapment, many volunteer districts do not start heavy rescue, but in other urban or city environments it is common to dispatch a truck company or rescue squad to MVAs.

On calls of this nature there are a few core fire department roles: (1) Incident command and safety; (2) Technical rescue operations; (3) Fire suppression and hazard control. Practically the roles are separate into rescue and extrication operations and hazard mitigation. There is always an extrication group supervisor who is often the rescue squad or truck lieutenant. One FF or EMS teammate is assigned to interior stabilization and patient care. This is often the most experienced rescue technician on the crew. They assess the interior, provide c-spine manual stabilization, and provide shielding from extrication risks. Another key/assigned role is the extrication tool operators who are working on cribbing, step chocks, struts, spreaders, cutters and rams. This work and the instability of the post collision vehicle require fire suppression – with a charged and ready hoseline (typically 1 ¾). Some alternatively use dry chemical or foam extinguishers near the edge of the hot zone to protect victims and rescue teams. It is also this team that is responsible for disabling electrical systems and managing spills from engine fluids.

The internal and external size-up determine that type of extrication necessary. The routine of securing the vehicle with chocks, cribbing, disconnecting the battery and fire suppression are necessary at accident scenes even if tool-oriented extrication is not necessary. By this I mean, if a patient needs to be removed from the vehicle with a short-board, Kendrick Extrication Device or similar rescuers must be in, around or near the vehicle requiring life safety steps as described.

Essential Extrication Tools and Their Application

The tools used in extrication may be as simple as a Halligan, a glass punch, or a knife to cut a seat belt. The more defined tools that we are focusing upon in this article are hydraulic – cutters/spreads, rams and struts, saws, air bags, and specialized combination tools. The table below outlines each item and their use for both MVA and machinery-oriented rescues.

It is important to note that sometimes creativity needs to be used to resolve complicated or challenging extrications. Manual pulling, rigging and tensioning are often necessary to provide critical mechanical advantage in situations where hydraulic systems lack a solid pushing base or space is tight. Some of these techniques have been around for decades. These techniques are built upon the basics of the simple machines including the lever, pulley, inclined plane, wedge and screw. The table below depicts each with an example, mechanical advantage and rescue application.

As an example, one can roll or displace a dashboard by using a come-along to pull a steering column or instrument panel off a driers lower extremities. An anchor chain can be secured around a structural point on front bumper or frame, a 4x4 rocker is placed on the hood and the chain connected to wheel or dash. On tension the force will pull the dash up and off the occupant.

Electric and Hybrid Vehicle Extrication: Unique Risks and Operational Considerations

Electric vehicles present a fundamentally different extrication environment than conventional gasoline-powered vehicles. While EV structural design often surpasses traditional vehicles in occupant compartment rigidity, the high-voltage battery systems, energy storage density, and thermal runaway potential create hazards that demand specialized knowledge and operational protocols.

Modern electric vehicles store energy in large lithium-ion battery packs, typically mounted in the vehicle's floor pan between the wheels or along the spine of the chassis. A Tesla Model 3, for example, carries a battery pack weighing 400 to 600 pounds with a nominal voltage of 350 volts DC. High-performance vehicles and larger SUVs may exceed 500 volts. This is fundamentally different from the 12-volt electrical systems in conventional vehicles and creates electrocution risk that cannot be safely managed with standard rescue protocols.

For perspective, 500 volt of DC is roughly 4+ times as many volts as a standard household outlet, and close to the supply necessary for some heavy equipment. Although one is DC and one is AC both dissipate the same electrical power and thermal energy, but the physiologic difference is worth understanding. 500V DC tends to cause a massive single myocardial depolarization into asystole vs. ventricular fibrillation common with AC.

The battery pack itself is not uniformly dangerous. Individual cells are contained within protective modules, and the entire pack is enclosed in a steel or aluminum housing with integrated management systems that disconnect the high-voltage system during collisions. However, structural damage from extrication activities (cutting, spreading, or ram operations) can breach the battery housing, exposing modules to moisture and oxygen. A damaged battery pack may develop an electrical fault hours after the collision, creating fire risk long after the patient has been transported. Therefore, all battery main connections will be severed by rescue personnel.

Fire risk is real and can be more of a threat than is present with gasoline vehicles due to thermal runaway. Thermal runaway occurs when a lithium-ion battery cell overheats uncontrollably, triggering a cascade of chemical reactions that generate extreme temperatures (often exceeding 1000 degrees Fahrenheit). Once initiated, thermal runaway cannot be stopped by conventional means; it can only be managed by removing oxygen or immersion in coolant. A single cell entering thermal runaway can trigger a chain reaction across the entire battery pack, resulting in dense white or gray smoke, spontaneous fire, or violent venting of combustible electrolyte.

The fire risk from EV batteries has two distinct phases. The immediate phase occurs within minutes to hours after structural damage. If the battery pack has been compromised and a cell has begun to fault, fire may start spontaneously. The delayed phase occurs during transport or even after the vehicle has been taken to a facility. A damaged battery pack may smolder for hours before flaring into open fire.

The primary agent for these fires remains copious amounts of water – but it does not smother the reaction, it simply supports heat absorption and battery cooling to drop the temperature below the runaway threshold. Most vehicles require 2,500 to 8,000 gallons with sustained application of 1 – 4 hours if a thermal runway event is occurring. Research by the NFPA and Department of Energy note that dry chemical powders, Class A foams and carbon dioxide are ineffective at arresting thermal runway.

The operational approach to EV extrication is maintains application of the techniques described earlier, but adds a critical safety level due to fire and battery risk.When deploying hydraulic tools, minimize damage to the battery pack. In a front-end impact, the battery pack may extend from the front axle to the firewall or beyond. Cutting or spreading A-pillar materials may not directly contact the battery, but shock waves and vibration from tool operations can damage cells. Perform the minimum amount of cutting necessary to achieve your objective. Prefer removing non-structural elements (doors, roof) and strategic column displacement over aggressive spreading that sends force throughout the vehicle frame.

If your rescue approach requires cutting through the floor pan or central tunnel area (where large battery packs are typically mounted), exercise extreme caution. Alert fire personnel immediately, position apparatus for rapid response, and have suppression personnel standing by with appropriate equipment. Some departments recommend performing this work only after the vehicle has been isolated from traffic and fire suppression is ready to attack immediately if thermal runaway begins.

Special Considerations for Specific EV Models

Different EV manufacturers use different battery configurations and safety systems. Tesla vehicles, for example, employ a flat battery pack integrated into the floor structure, which provides excellent occupant compartment protection but means damage to any area of the floor may compromise the battery. Chevy Bolt vehicles use a similar design. Ford F-150 Lightning electric trucks mount the battery under the truck bed and extend toward the front axle, creating a long battery pack that requires wider isolation zones.

Familiarize yourself with the EV models common in your response area. Many manufacturers provide extrication guides or quick-reference cards that specify battery locations, high-voltage system disconnect points (if available to rescue personnel), and recommended techniques. These resources should be reviewed during pre-incident planning and provided to crews before EV calls if possible.

Tesla Rescue Guide

F150 Rescue Guide

Conclusion

Vehicle extrication is far more than the application of hydraulic tools. It is a disciplined process that combines scene safety, knowledge of vehicle engineering, an understanding of crash kinematics, and coordinated teamwork. At the center of this exercise is a life – injured, trapped and scared where every moment counts. Each collision presents a unique set of challenges, requiring rescuers to evaluate hazards, anticipate injury patterns, and select the least invasive and most effective method of disentanglement. Experience and pre-call education/training, such as this article, can prepare the rescuer for these situations.

As vehicle technology continues to evolve with advanced safety systems, high-strength construction materials, hybrids, and electric propulsion, rescue personnel must evolve as well. Continuous training, familiarity with emerging vehicle designs, and frequent hands-on practice are essential to maintaining operational readiness. The rescuer who understands not only how to use a tool, but why a particular tactic is being employed, is better prepared to solve complex problems under pressure.