Securing the ASCENTREE with the ZIGZAG - Technique for access and work on a single rope
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. When ascending using a frame-loaded rope clamp, the user must not fall if one or both of the cams on the rope clamp should open. The cams should be backed up, for example, by friction hitches. The user must be able to descend in an emergency, without significant change to the equipment setup.
Arriving at the top, the ZIGZAG is on the splice side, ready to be set up for the normal work configuration.
- Uses little equipment.
- The work rope is not carried by the arborist while climbing.
- The rope length, required for the work phase and the descent, is verified during access setup.
- The rope joining knots, placed at the top, ensure no knot passing in case of emergency descent, or rescue.
- The choice of EXPRESS sling allows the ergonomics to be adjusted for the ascent.
- Work is not possible during the access phase.
- Without an access rope left in place during the work phase, the possibilities of aid or rescue by the ground person are reduced
The ZIGZAG must be installed on the blocked rope strand.
The quick link on the ASCENTREE must be tightened with a wrench.
The knots must be moved up as close as possible to the branch for the strand to be correctly blocked.
Remarks on the ZIGZAG backup
- If the cam on the blocked strand opens, the ZIGZAG works normally in double mode
- If the cam on the other strand opens, the climber is held by the cam on the blocked strand (the rope must be tightened around the branch)
- Warning: if both cams open simultaneously, the arborist will be hanging from the ZIGZAG in single mode. This situation is acceptable in this special case, on the condition that the arborist dœs not move. It is recommended to quickly make a backup knot on the rope, below the ZIGZAG, before re-engaging the cams to continue the ascent
Variations for blocking the ends
Blocking one of the rope ends allows use of the ZIGZAG backup.
• A butterfly knot is very secure, but can be difficult to untie once you've arrived at the top
• Blocking with a friction hitch will be easy to disconnect in all situations. Beware of cantilever loading on the connector
Installing the access system
Arriving at the top
Once at the top and anchored in, the arborist can dismantle the access system and disconnect the ends of the access rope.
The ZIGZAG is close to the splice, in the normal work configuration.
Emergency descent (during the access phase)
Disengage the cam on the blocked strand and remove the rope from that side of the ASCENTREE. Close the cam.
Use the ZIGZAG normally in double mode.
Warning: do not disengage the two cams to attempt to descend with the ZIGZAG in single mode.
To identify which cam should be disengaged, install a carabiner in the upper attachment hole of the ASCENTREE, on the side of the strand that is not blocked. This carabiner dœs not affect system function.
Optimize the quality of placement for your connectors, to avoid any rubbing or poor positioning that presents a risk of opening or breaking the carabiner. In case of doubt, use steel connectors certified to the ANSI Z359.12 standard, which have locking sleeves that can withstand external and side loads of 16 kN. Note: this strength dœs not protect against the risk of accidental opening due to rubbing. If you are unable to mitigate the risks of rubbing and/or poor positioning of the connectors, use a different technique.