Understanding the Functionalities and Importance of Safety Chains on Ambulances and School Buses

When traversing the roads, many emergency vehicles and school buses are equipped with chains that hang from the rear axle. These are known as safety chains or drag chains. These chains serve a critical purpose in ensuring the safety and stability of these vehicles. This article delves into the specifics of these chains and their importance, particularly for ambulances and school buses.

The Role of Safety Chains in Emergency Situations

These chains primarily function to enhance safety in several scenarios. They can activate emergency braking systems and provide stability in the event of brake failure or other mechanical issues. Additionally, they play a key role in preventing the detachment of vehicles from their trailers.

Emergency Braking

In some vehicles, the chains are designed to engage the brakes if the vehicle experiences a loss of air pressure in its braking system. This is particularly essential for larger vehicles that depend on air brakes. By providing an immediate secondary braking mechanism, these chains can help prevent accidents and protect both the vehicle and its occupants.

Vehicular Stability

Should a vehicle experience a brake or mechanical failure, the safety chains can help stabilize the vehicle. They prevent excessive swaying or becoming unmanageable, which is crucial for maintaining control of the vehicle and ensuring the safety of passengers or cargo.

Preventing Detachment in Tow Vehicles

For vehicles that tow, the chains serve to keep the trailer connected to the tow vehicle. If the primary hitch fails, the chains can prevent the trailer from completely detaching, which is vital for ensuring the safe transport of goods or passengers.

Additional Traction Devices: Autochains

Other important traction devices include autochains, which are designed to provide additional friction traction on snowy or muddy roads. These are mounted permanently under the vehicle and are operated from inside the cab. Unlike traditional tire chains, autochains can be deployed with a simple button push, providing an easy and effective way to enhance traction.

To activate autochains, you typically need your vehicle to be in motion. If the chains are not in place or are not spinning, they may not provide the necessary traction. Therefore, it's important to use them at the right time to ensure their effectiveness.

Deployment Process

The autochains work by dropping down under the driving tires once they are in position. They come down on an arm and, once in place, they need to spin to engage properly. If you activate them while your vehicle is stationary, they may not work as intended.

Conclusion

Overall, safety chains and autochains are crucial components for the safety and stability of emergency vehicles and school buses. They help prevent accidents, ensure stability in critical situations, and maintain control during emergencies. These chains, while not universal, are particularly important for the critical roles these vehicles play in our society.