Self-belay: one single rope with two ascenders


Self-belay for solo climbing with a fixed belay rope

Installation on one single rope with two ascenders:




  • Solo climbing is not recommended: climbing with a partner remains the best solution
  • Climbing is inherently dangerous, you are responsible for your actions and decisions
  • Self-belayed solo climbing must only be undertaken by experts
  • This case deals with climbing with a fixed belay rope, without loading the rope (except to rest). Ascending on the rope (caving, big wall, crevasse rescue, alpinism, etc.) is not addressed here.
  • If an accident results in unconsciousness (fall, rockfall), rescue will be difficult. Wearing a helmet is strongly advised. DO NOT CLIMB without one. Do not climb solo without informing a person of your destination and when you will return
  • No solution is universal; you must be able to adapt our proposed technical solutions to your chosen terrain
  • A good understanding of the solutions proposed in this supplementary information requires that you have consulted, understood and assimilated the Instructions for Use for all devices concerned
  • The proposed systems are complex; any modification can stop them from functioning properly
  • Only the techniques shown in the diagrams that are not crossed out and/or do not display a skull and crossbones symbol are authorized

Failure to heed any of these warnings may result in severe injury or death.


SELF-BELAY ON A FIXED ROPE: complete installation

Self-belay on a fixed rope


Installation on the harness and TORSE with two ascenders:


The primary ascender is connected to the harness belay loop with an OK carabiner.
The secondary ascender is connected to the harness attachment points with a quick link (PRESTO or GO), an extension (17 cm EXPRESS sling + STRINGs) and an OK TRIACT-LOCK carabiner. It will be held up and pulled by the shoulder strap (TORSE C26), connected to the eye of the quickdraw.

After installation, verify that each ascender slides correctly on the rope in the up direction, and jams instantly in the down direction.
Before climbing, verify that all connectors are locked.

Slide 1
Slide 2
Slide 3

Play Pause


Gear necessary for the self-belay system:

  • one EN 892 dynamic single rope or EN 1891 semi-static rope of 10 mm minimum diameter
  • a primary ascender (ASCENSION, BASIC, MICRO TRAXION) and its OK connector
  • a different secondary ascender (MICROCENDER, BASIC, MICRO TRAXION, MINI TRAXION) and its OK connector
  • TORSE shoulder straps
  • an EXPRESS 17 cm sling
  • A PRESTO or GO quick link, tightened with a wrench

WARNING, repeated rubbing against the rock can quickly cut your only rope.




  • The quickdraw helps avoid collisions between the devices, but should not interfere with comfort: adjust its length so the strap does not pull on the neck during a rest or fall
  • The two ascenders must not be connected to the same point on the harness: they can collide and be damaged during a fall
  • Respect the recommended ascender position: BASIC above and ASCENSION below The reverse position turns out to be tricky when changing systems from ascending to descending.
  • Always carry a descender (GRIGRI) and a footloop/ascender combo (TIBLOC + ANNEAU) to ascend the rope in case of failure to complete the climb
  • Roofs and traverses complicate the system: they require numerous directional points and additional precautions. Do another risk analysis for these particular cases

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 capture the rope in the carabiner.



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.

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

Use of the MINI TRAXION pulley:
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 selfbelayed solo climbing with a fixed rope.


Non exhaustive risk analysis
The risks vary with the situation: do your own analysis!

Introduction to the 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 and falling = factor 2. Always stay below your anchor point, making sure your setup allows for this during access and return

risks risks