Appendix 4: Precautions and introduction to risk analysis - Petzl USA

Appendix 4: Precautions and introduction to risk analysis


  • 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.

Attaching the ASCENSION and BASIC for self-belaying:

The device must be installed correctly on the rope, connected by the upper attachment hole, taking care to pass the rope through the carabiner.

Attaching the ASCENSION and BASIC for self-belayingAttaching the ASCENSION and BASIC for self-belaying dangerAttaching the ASCENSION and BASIC for self-belaying dangerAttaching the ASCENSION and BASIC for self-belaying danger


In these situations with fall factor less than one, the ascender's teeth do not damage the rope.

Despite their aggressive appearance, the teeth on the BASIC or ASCENSION are not harmful to the rope in normal use.

The spring pushes the cam against the rope and causes it to engage the rope without sliding (and therefore without tearing), especially if the teeth are new and pointy.


Use of the MINI TRAXION pulley:

Use of the MINI TRAXION pulley dangerWarning! 

Petzl has studied the current usage of the MINI TRAXION as a self-belay device on a fixed rope. Serious accidents and many handling errors have been reported.

The risk of using the device with the cam held open is significant, as well as the possibility of accidental opening of the cam when climbing.

Consequently, the MINI TRAXION must be paired with a different ascender: ASCENSION, BASIC, MICROCENDER...

Petzl does not recommend using a system consisting of only two MINI TRAXION for self-belayed solo climbing with a fixed rope.

Attention: in this photo, the MINI TRAXION's ascender function is deactivated.



Non exhaustive risk analysis

The risks vary according to the situation: do your own analysis!

Introduction to installation risks:

- Access from above presents a risk of falling before the rope is installed, be vigilant when approaching the anchor

- Beware of rockfall while accessing the route from above, and when the rope is moving

- Anchor or rope failure: adapt your installation to the site, choose a solid anchor on two triangulated points, avoiding rub points against edges or protrusions. A rope protector (PROTEC C45) may be required

- Risk of ground fall: in the first few meters of the climb, even with a properly installed system, you can hit the ground in case of a fall, due to the elasticity of the rope. The static elongation of a rope is around 10 %. If your route is 50 m, there is a risk of ground fall in the first 5 meters of the climb, even from simply resting on the rope

Introduction to handling risks:

- Sliding of the device: improper attachment, opening of the cam during use (rubbing, interference from foreign objects)

- Device loss: when changing systems from ascent to descent, putting the descender on the weighted rope is tricky

- Rope loss: If you are tied off to an anchor on a slab route, do not detach yourself completely from the rope: a slight pendulum can move the rope out of your reach

- Slack rope: if the rope is not sufficiently weighted, the system cannot slide fast enough to keep pace with the climb and loops of slack are created between you and the anchor. The potential fall length will increase

- Passing the belay station and falling = factor 2. Always stay below your anchor point, making sure your setup allows for this during access and return