Petzl Professional 2015 | Page 15

14 Tree care Tree access • Double-rope ascent technique: The arborist ascends his access rope (purple). In case of a hornet attack (or other problem) he can self-evacuate with the work rope (blue). A mule knot, or releasable knot, secures the ZIGZAG. This ascent technique is very efficient. ZIGZAG ASCENTREE ZIGZAG SEQUOIA Movement within the tree: returning to the trunk PANTIN The ZIGZAG is installed on an adjustable attachment bridge. The bridge is extended, allowing improved ergonomics when returning to the trunk. The space created between the ZIGZAG and the harness allows pulling with both hands on the free end of the rope.