Why stabilize a vehicle that is upright and stationary on four tires?

The primary reason for stabilizing an upright vehicle is to minimize the vehicle’s suspension movement and create a solid, secure foundation. A vehicle’s suspension system allows the body to move up and down, which can cause further injuries to any victims inside, especially if spinal cord injuries are suspected. Proper stabilization is essential to prevent any movement that could worsen spinal injuries or lead to paralysis.

The goal is to reduce the suspension system’s flexibility and establish a balanced platform for rescue operations.

Creating a Balanced Platform and Minimizing Suspension Movement

1. Understand the Vehicle’s Structure
   Vehicles consist of a frame underneath their body. Once components like side panels and wheels are removed, the core frame—usually rectangular or square—becomes visible.
   To stabilize this frame, identify at least four solid points beneath it. Insert cribbing at these points evenly to achieve balance.
2. Cribbing Methods
   Use wooden box-style cribs or step chocks to stabilize the vehicle. Ideally, all four sides of the vehicle should be accessible. However, in real-world scenarios, you may only have access to one or two sides. In such cases, focus on stabilizing the accessible sides to minimize movement.
   • If the tires are fully inflated, place cribbing or wheel chocks near the front and rear tires to prevent forward or backward movement.
   • If the tires are deflated and the vehicle is already stable on cribbing, additional wheel chocks may not be necessary.
   • For vehicles on uneven ground, prioritize wheel chocking to prevent shifting.
3. Choosing Solid Points for Cribbing
   Solid points like the area behind the front tires or just in front of the rear tires are ideal for cribbing. Avoid weak areas such as the fender near the rear tires, as these can buckle under pressure. Ensure the cribbing placement does not obstruct door openings or rescue operations.

Preparing and Adjusting Cribbing

1. Adjusting Cribbing Heights
   Vehicles of different sizes require varying amounts of cribbing. For instance:
   • SUVs may need more cribbing than compact cars due to their height.
   • Step chocks, which are adjustable, allow for easier height adjustments.
2. Using Wedges or Shims
   If gaps remain after inserting cribbing, use wedges or shims to fill the space. This increases contact between the vehicle and the cribbing, enhancing stability.
   • For tall vehicles like SUVs, build a cross-platform cribbing base and place the step chocks on top.
3. Adjustable Step Chocks
   Some step chocks are steel and manually adjustable. These can be locked into position to suit various heights, ensuring secure stabilization.

Lifting the Vehicle for Cribbing

Lifting the vehicle slightly to insert cribbing is another stabilization method. This involves manually lifting only the suspension, not the entire vehicle.

Steps for Safe Lifting:

• Positioning: Stand near the front or rear wheel well.
• Using Force: Use your legs—not your back—to lift the suspension.

Key Considerations:

• Vehicle Type and Weight: Understand the approximate weight of the vehicle:
• Compact cars: ~2,000 kg
• SUVs or small trucks: ~3,500 kg
• Rescuer Condition: Ensure the rescuer is in good physical condition and not overexerting themselves.

Safety Precautions:
This method is effective but risky if performed incorrectly. Avoid trying to lift the entire vehicle, as this can lead to injury. Evaluate the situation carefully before deciding to lift.

Deflating Tires

A common debate is whether to deflate tires after inserting cribbing.

Benefits of Deflating Tires:

• Helps the vehicle settle firmly on the cribbing, creating a stable platform.
• Prevents the suspension from rising when lighter components like doors or roofs are removed.

Drawbacks:

• Deflation may destabilize the vehicle, causing unwanted movement.
• If objects or other vehicles are stacked on top, they may also shift.

The decision to deflate tires should be made by the incident commander. If deflation is necessary, the safest methods include:

• Using a Tire Valve Stem Remover: A simple tool to remove the valve stem safely.
• Using a Halligan Tool: This technique involves cutting the rubber stem, but it should only be used on specific types of wheels (rimmed wheels) and requires practice. Never use the pointed end of a Halligan tool to puncture the tire, as this is dangerous and unprofessional.

Basic Stabilization Principles

In addition to cribbing, consider these simple internal measures for stabilization:

• Put the vehicle in park.
• Turn off the engine.
• Engage the parking brake.

Final Steps

1. Recheck Cribbing: Ensure all cribbing is stable and positioned correctly.
2. Secure the Scene: Wear appropriate personal protective equipment (PPE) such as dust masks.
3. Communicate: Inform the commander once stabilization is complete.

By following these guidelines, rescuers can ensure safety and efficiency during vehicle stabilization operations.

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