What is a Jackknife Brake Accident?

A jackknife brake accident occurs when a truck’s trailer swings forward, so that it is at a perpendicular angle to the truck. When big-rig trucks cause jackknife brake accidents, a thorough investigation often reveals that the truck’s brakes became locked, which led to brake instability. Coupled with the weight and speed of the truck, a jackknife brake accident can wreak havoc on roads and can lead to catastrophic injuries. If your loved one was injured in a jackknife brake accident, we at Scarlett Law Group can assist you during this trying time.

Our team of San Francisco catastrophic injury attorneys is committed to helping seriously injured victims obtain the maximum compensation they are entitled to by law. We create results-driven strategies in order to help our clients obtain the monetary damages they need to pay for their medical care, wage loss, and need for physical therapy. We are passionate about protecting the rights of the men and women we represent.

Attorney Randall H. Scarlett, our firm’s founder, has been distinguished with the following:

  • A 10.0 “Superb” rating on Avvo – a perfect score
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Our firm also represents the surviving family members of those who have died in negligence-related trucking accidents. If you are grappling with the loss of a loved one, we can help you file a wrongful death claim.

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How Jackknife Accidents Occur

In analysis of jackknife accidents, it was found that in an improperly set brake system the trailer axles are locked sooner than the tractor axles under heavy braking. Jackknife could occur even when the lateral acceleration is at extremely low levels. Rollover and jackknifing accidents are responsible for a significant percentage of the accidents and casualties of commercial vehicles.

Brake imbalance is another common cause for losing control of the air-braked trucks causing an accident. If a truck does not have good brake balance, it will have a tendency toward either jackknifing or trailer swing-out. Jackknifing occurs when the tractor's drive axles achieve a higher level of braking force than the trailer axles. When this happens in an emergency or low traction situation, the tractor drive axles will likely lock up while the trailer axles are still rolling. With the tractor's drive axles locked, they will lose directional stability and the un-braked trailer load will push the tractor into a rotation around the king pin. Trailer swing-out is similar to a jackknife, but occurs when the trailer axles achieve a higher level of braking force than the tractor. With the trailer brakes locked and directional stability lost, the tractor will drag the trailer, which will then begin to swing out.

There are three brakes in an 18-wheeler tractor-trailer truck:

  • The steering axle brakes
  • The drive axle brakes, and
  • The trailer axle brakes.

When the steering axle brakes lock up, the driver cannot steer and the truck will move straight ahead regardless of the wheel angle. When a tractor-trailer’s drive axle brakes lock up, jackknifing will occur. When the trailer axle brakes lock up, you will get trailer swing-out, affecting the directional stability of the truck.

The basic problem is that pneumatic tires only offer certain traction and if that is completely used in braking, there is nothing left to resist even a small lateral force. If you can keep the axles from locking up, even 5% short of lock up, you can generally preserve directional stability and even some steering capability. But this can be hard to do without ABS (anti-lock brake system), especially with unbalanced brakes or a poorly distributed load. Thus, ABS can prevent jackknifing. However, many trucks are missing ABS for one, or more of these braking systems.

San Francisco Catastrophic Injury Lawyers Passionately Protecting Your Rights

Each catastrophic personal injury case is different, which is why our legal team handles each one with a different approach. As soon as you retain our services, we will carefully review all the details and evidence pertaining to your accident in order to determine who should be held financially liable. We also consult with a network of experts in order to further solidify your claim.

To learn more about how our skilled legal team can assist you, please give us a call.

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