"Petzl are constantly developing new arborist specific products"
Sometimes it will be inappropriate or perhaps even impossible to gain access to a tree via exterior means, such as ladders or platforms. To overcome this problem an arborist will adopt a rope progression technique suitable for the task. The technique used will consist of an anchor and static rope positioned from the ground using a throw bag and throw line, an ascending / descending system and a means of additional work positioning would also be included. Rescue is an important factor for arborists to consider as they are often working in small teams. Reversible rescue anchors are discussed in further detail below.
We have gathered together a selection of diagrams to illustrate how Petzl and Beal products can be used to improve the efficiency of common arborist tasks.
Work positioning with an adjustable lanyard
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Here an additional work positioning lanyard has been connected to each lateral work positioning ring on the users harness. The lanyard has been used to encompass a limb of the tree creating a second anchor. The user is now able to balance between the two anchor points helping him to steady himself and providing a safety back-up should either connection be damaged. Here the Petzl Grillon Hook has been used. The Petzl Grillon Hook has an adjustable cam which provides the user with a greater selection of working positions negating the need to move the entire lanyard for small positioning adjustments.
Ascending using a double rope technique
| ||This example illustrates the 'foot lock' technique, here it has been combined with the Petzl Ascentree twin handled ascender. The Petzl Ascentree has been connected to the users Petzl Sequoia harness using a Petzl Swivel and Petzl Jane lanyard. This traditional method is quite physically demanding and requires skill to lock the rope between your feet. |
| ||In this example the user is wearing a Petzl Pantin on either foot. The Petzl pantin works in the same way as the Petzl Ascentree, locking the ropes movement in one direction using a toothed cam. This method of ascent is more efficient as no height is lost through slippage of the rope between the users feet. |
Ascending using a single rope technique
| ||For longer ascents or those wishing to use a single rope technique the Petzl Sequoia SRT should be chosen. The Petzl Sequoia SRT has an additional fixing point at the rear of the waistbelt and a ventral attachment at the front, these provide attachemnts for the Petzl Croll. With the Petzl Croll in place a handled ascender such as the Petzl Ascension can be used in conjunction with a foot loop to ascend the rope. Each time the user stands up in the foot loop (using the Petzl Ascension for support) the Petzl Croll will grip the rope at the new resting point, this repeated over and over again to ascend the rope. |
Installing arborist ropes
The above three rigging methods illustrate examples of reversible anchor points. The ropes have been anchored to the tree by larks footing a webbing anchor sling around the trunk. The rope has been passed through a Petzl I'd and then tied off using a releasable mule knot, the loop created by tying off the Petzl I'd should be clipped into a separate connector anchored to the trunk. By clipping the loop of the tied off Petzl I'd there is no chance of it accidentally pulling through the device or the anchor being released unexpectedly.
These systems are releasable from the ground and provide a controlled decent of the user and their working ropes in the event of an accident or emergency e.g. a wasp or hornet attack. It should be noted however that running ropes over branches when under load will decrease their usable life. By installing a cambium saver such as the Petzl Treesbee (as used in the first image of this page) your ropes will receive less wear and ultimately last longer.