Working principle - Petzl USA

Working principle


  • Read the technical notice before viewing the following techniques.
  • It is important to fully understand the information provided in the technical notice before using this complementary information
  • Mastering these techniques requires training.
  • Consult a professional before attempting to perform these techniques on your own.

The ASAP is a mobile fall arrester on rope; it moves along the rope without manual operation. At moderate speeds, the locking wheel turns freely in both directions.

A rapid downward movement accelerates the rotation of the locking wheel clockwise. The centrifugal force activates the weights inside the device, blocking rotation of the locking wheel. The arm then pivots on its axle and the rope is locked by pinching between the locking wheel and the body of the device.

To unlock the device, it must be pushed upward. During this movement, keep the locking wheel pressed against the rope, so that it turns counter-clockwise and unlocks the weights. The ASAP returns to its primary working mode, with the locking wheel turning freely in both directions.

Moderate speed

Working principle - moderate speed

Great speed

Working principle - high speed

Warning, the ASAP is a directional device and locks in only one direction.

Danger of death if the ASAP is positioned upside down on the rope: verify the proper locking direction at each installation.

Direction of use for products
Direction of use for products
Incorrect usage - product upside down