Extrication Basics: Vehicle Stabilization

Many of the nation’s fire departments and rescue squads provide technical rescue services to their respective communities. One arena that is very common to many organizations is motor vehicle extrication. While newspapers and other media are...

While the Inner Circle Survey is being done, another team of rescuers shall be performing an Outer Circle Survey as well. An Outer Circle Survey is a complete walk around the entire accident scene, facing outward (away from the incident). These rescuers are looking for additional issues related to the incident, such as damaged buildings that need structural support, ejected victims away from the incident, victims struck away from the incident, walking wounded victims, vehicles involved in the accident that came to rest away from the incident, and utility damage away from the incident. These situations may not be identified by the arriving crews, due to tunnel vision and focusing on the obvious victims; do not fall victim to this trap, be sure to do thorough surveys when arriving on the accident scene.


Now that we have identified some of the important points of the response and the on-scene size-up, it is imperative to stabilize the vehicle. Stabilization is the application of equipment and techniques designed to stop the vehicle from moving in any direction. We accomplish this by focusing our stabilization concerns in three different categories.

Horizontal Stabilization involves stopping vehicular movement from front to back, which can employ chocking tires, deflating tires, putting the vehicle in park, and setting the parking brake.

Vertical Stabilization stops vehicular movement up and down, by use of step chocks, box cribbing, and rescue struts.

Box Cribbing is the stabilization process of choice by many rescue teams. This technique uses wood or plastic crib materials (usually dimensional timber, 4" x 4" or 6" x 6") and stacked in a perpendicular fashion to support the weight of the vehicles (see Photo 8).

Plastic composite cribbing material strength is determined by the manufacturer, while the rule of thumb for wood cribbing is 500 pounds per square inch of surface contact area. For example, if a rescue crew uses 4" x 4" cribbing, stacked two per tier, we can determine the strength of the crib by measuring the surface contact area. 4" x 4" timber is actually 3.5" x 3.5", which when multiplied, equals 12.25". There are four points of contact in a two-tier box crib, which when multiplied by the surface area equals 49" (12.25 x 4 = 49"). Multiply the total surface area by 500; the strength of this specific box crib equals 24,500 pounds of strength, per box crib. If the crew deploys four points of stabilization using box cribbing, then the weight that can be supported can be significant.

Along with cribbing materials, there are many manufacturers of vehicle stabilization kits that can be utilized for stabilization of vehicles. These kits include rescue struts with a complement of various bases and adaptors to adapt to the condition of the wreckage. These kits serve as great tools of choice for vehicles that wind up on their sides and on their roofs. When choosing which kit to employ in your response area, it is important to research the many different options that are offered in some of these kits, and then decide which one works best for your department.

Interior Stabilization is the last category of stabilization. This includes putting the vehicle in park, shutting off the ignition, removing the key from the vehicle, rolling down all of the windows, opening the truck and the hood when applicable, moving power seats back slowly if capable, lifting tilt-wheel settings, and moving electric pedals out of the way for the operation. This will require a rescuer to get into the vehicle and make patient contact; therefore, be sure to provide both horizontal and vertical stabilization prior to sending a rescuer into the vehicle for any reason.


As you can see, there are a lot of steps and considerations that must be taken into account before the rescuer can begin to displace any metal from the vehicle. It is vital that crews act quickly and efficiently to perform these initial activities so that the actual disentanglement and extrication can take place within the “Platinum Ten” time frame. Next month, we will look at gaining access into the vehicle, purchase points, and some basic component displacement techniques.

Until next time, stay focused and stay safe.

MICHAEL P. DALEY is a lieutenant and training officer with the Monroe Township, NJ, Fire District No. 3, and is an instructor with the Middlesex County Fire Academy, where he is responsible for rescue training curriculum development. Mike has an extensive background in fire service operations and holds degrees in business management and public safety administration. Mike serves as a rescue officer with the New Jersey Urban Search and Rescue Task Force 1 and is a managing member for Fire Service Performance Concepts, a consultant group that provides assistance and support to fire departments with their training programs and course development. Mike has been guest on several Firehouse.com podcasts including: Successful Rescue Operations in Today's Fire Service, Preparing for Tomorrow's RIT Deployment Today and Basement Fire Tactics Roundtable podcasts. View all of Michael's articles and podcasts here. You can reach Michael by e-mail at: FSEducator@aol.com.