Cabling a Tree
Cabling requires installing specifically sized forged eyebolts and cable in the upper one-third of the canopy to attach two or more codominant leads. The company uses 1/4 to 5/8-inch diameter forged eyebolts and common-grade (galvanized) or extra-high-strength cables 1/8 to 1/4 inch in diameter, depending on the diameter of the limbs that need to be cabled. For example, a 5-inch-diameter limb requires a 1/4-inch-diameter forged eyebolt with a 1/4-inch-diameter common-grade cable.
Attaching one lead to another is called a direct cabling system. A tree with three leads may require a triangular system, where all three leads are supported by three cables attaching each lead together. It is important to attach the cables in the upper third of the canopy and to install the cable at the same angle as the eyebolt for optimal support.
This style of cabling is interesting for several reasons. First, by installing a forged eyebolt directly through the tree with a long drill bit, little damage is done to the vascular tissue of the lead being cabled. Secondly, as the laterals grow in diameter, they eventually grow around the eyebolt and part of the cable, which, over time, will strengthen the tree.
It is important to remember that as arborists we deal with organic material, and nothing is ever guaranteed. When we offer cabling on a tree, we are recognizing that the tree has a structural defect. We never promise that this will fix the problem; we are simply offering to provide the tree additional or supplemental support.
Pruning trees proactively when they are young is always the best practice for aesthetics and storm prevention, but if your customer has a mature tree, cabling is your best option to help reduce the chance of storm damage.
