Access on single rope with ASCENSION and CROLL and ZIGZAG in double mode - Petzl Canada

Access on single rope with ASCENSION and CROLL and ZIGZAG in double mode

Technique similar to the doubled rope access technique, which saves time on aligning the rope ends. The alternating ascent technique on single rope is especially efficient for long ascents.


  • Carefully read the Instructions for Use used in this technical advice before consulting the advice itself. You must have already read and understood the information in the Instructions for Use to be able to understand this supplementary information.
  • Mastering these techniques requires specific training. Work with a professional to confirm your ability to perform these techniques safely and independently before attempting them unsupervised.
  • We provide examples of techniques related to your activity. There may be others that we do not describe here.

Note: in this document the name ZIGZAG means either the ZIGZAG or ZIGZAG PLUS models.

There are many access techniques suitable for different work objectives in the tree. The access technique includes a choice of rope installation, and the ascent technique itself.

Two precautions are recommended during access:

  • During ascent, the ASCENSION's cam must be backed up, for example with a friction hitch.
  • The user must be able to descend in an emergency, without significant change to the equipment setup.
ZIGZAG, access and work.
ZIGZAG, access and work.

During access, the ZIGZAG's rope is set up in double mode, with a redirect point on the ASCENSION. Following access, during the work phase, the arborist may choose to use the ZIGZAG either in double mode, or in single mode with CHICANE, and sets up the work rope accordingly.


ZIGZAG, access.


  • Rapid installation without aligning the rope ends.
  • A releasable anchor may be installed at the base of the tree.
  • The access rope stays in place and may be used by multiple arborists.


  • Special ascending equipment is used.
  • The load on the branch is doubled (during access) by the pulley effect.
  • Access rope exposed during the work phase.


The work rope must be long enough to return to the ground (doubled) from the top of the access rope and/or the chosen primary anchor point.

Emergency descent

To descend, disengage the CROLL, undo the mule knot and operate the ZIGZAG normally. The ASCENSION stays in place on the rope.

ZIGZAG, emergency descent.