What is the primary purpose of the brake strand in the blocking of ATC?

The primary purpose of the brake strand in the blocking of an ATC (Air Traffic Controller) device is to prevent accidental release of tension. When rappelling or descending with a belay device, the brake strand ensures that the rope remains secure and under control, enhancing the safety of the operation.

By holding tension on the rope, the brake strand allows the user to smoothly manage their descent, while also ensuring that the load is maintained in the event of a slip or unexpected movement. This critical function significantly reduces the risk of uncontrolled falls, making it an essential component of the safety system in rope rescue and climbing scenarios.

Utilizing the brake strand correctly means the climber or rescuer can quickly respond to situations while relying on the assurance that the rope will remain securely in place throughout the procedure.