In Part 1 of this series, we discussed the need for supplemental support systems and the reasons we rely on cabling systems to serve as solutions for many structural vulnerabilities. In this article, we will cover some needed clarifications regarding the new A300-2023 as it applies to cabling. We then will revisit “proactive” vs. “reactive” cabling. Finally, we will cover the two primary types of cabling systems, commonly used hardware options, the tools we rely upon and the primary steps we take for proper installation.

Cabling hardware: Shown here is an EHS cable with a Tree-Grip termination, a type of dead-end grip, attached to a standard eyebolt.
Inset: A Preformed Wedge-Grip Dead-End, which is another option for termination.
All photos courtesy of the authors.

For many of you, this will be a refresher, but hopefully everyone reading this will either learn a new skill or have greater success preparing their crews for implementation of these often-overlooked arborist practices.

ANSI and BMPs considered

We abide by the ANSI A300-2023 Tree Care Standards for all things tree work. Many of you may still be referencing ISA’s “Best Management Practices, Tree Support Systems: Cabling, Bracing, Guying, and Propping, Third Edition (2014).” This BMP was the companion to the ANSI A300-2013 Part 3 – Supplemental Support Systems. With all 10 of the previous ANSI “parts” combined into one volume, the information on tree-support systems can now be found in Clause (section) 7 of the new ANSI A300-2023 Tree Care Standards.

There was little change in the content in this section of the revision, but there may be some confusion about the types of termination hardware specified in the newest version. The A300-2023 lists all the hardware most of us have come to know intimately, but unlike previous versions, it did not specifically mention cable-stop or swage-stop termination devices, such as the Rigguy Wire Stop EHS wire-
termination systems and the Preformed Line Products (PLP) Wedge-Grip Dead-End systems.

Both systems are widely used by arborists installing extra-high-strength (EHS) steel cables. This style of terminations can likely be partnered with the dead-end-grip terminations highlighted in 7.6.18.

Because we consistently utilize these types of terminations, we thought it wise to seek clarification before we set about sharing our possibly out-of-date methods!

Rooted Arbor Care’s Mateusz Bronakowski, ISA Certified Arborist, drills the cabling hole for the hardware in a silver maple.

Getting started

Cable installation is an excellent tool for the arborist seeking to mitigate risks for their clients’ prized trees, but it is important to remember that there is no one-size-fits-all solution to cabling.
For the sake of brevity, we are going to assume you are local experts regarding tree species and regional weather considerations, such as prevailing winds, temperature extremes and other forms of inclement weather. We also are going to take the liberty of assuming you have already read Part 1 of this series, which identifies many of the primary objectives of cabling.

Once we have identified our species and objectives, it’s time to start selecting the type of system we want to implement, determine the specifications needed and get to work installing our system. We highly recommend that you reference the A300 Supplemental Support Systems Process Flowchart found in the aforementioned ANSI A300-2023 Tree Care Standards, Clause 7.

Cabling systems

It’s worth repeating here the difference between proactive vs. reactive cabling, mentioned in Part 1 of the series.
Proactive installations are carried out for both prevention and protection.
Reactive cable installations are implemented after a tree has begun to show signs of mechanical failure, such as cracking, splitting or tearing.

Dynamic cabling

Dynamic systems are typically employed proactively. As the name implies, dynamic systems allow the tree to still enjoy considerable freedom of movement. These systems are principally employed to reduce hyperextension of limbs and branches during atypical situations, such as uncommonly high winds or ice storms.
Because these systems are relatively unrestrictive, the trees with dynamic systems still move naturally, which encourages optimal growth habit and the continued ability to respond with typical wind conditions. These systems do not require drilling into the tree, and require little investment in specialty tools.
It’s important to note that dynamic systems require routine inspections (semiannual) to ensure that they are appropriately tensioned, that there is no evidence of limb girdling and that there are no signs of UV degradation. It also is worth noting that these systems rely on ideally located branch unions to support the system.
There are several dynamic systems currently on the market that have a range of installation methods unique to themselves. Some of the more common types of systems used are Cobra systems, Dryad Synthetic Cable (Notch) and Tree Guard (Drayer). Most of these systems require basic rope-splicing tools such as commercial-grade scissors, electrical tape and the appropriately sized splicing fids.

We have really enjoyed using these systems throughout the years because of their ease of installation. Each of the systems mentioned above has companion guides with excellent illustrations of installation procedures.

Static cabling

Mateusz Bronakowski employs a Milwaukee Force Logic EHS Cable Cutter to trim the excess cable.

Static or steel systems are typically the best solution for reactive cabling, but also can be employed in a variety of proactive situations. Static systems are installed to greatly restrict the movement in the union we are trying to protect. These rigid systems are ideal for branch unions showing signs of potential failure, such as cracking, splitting or tearing, or unions that may demonstrate a predisposition to failure, such as bark inclusions or over-extended branches.

These systems are incredibly strong, but they limit a tree’s natural mobility and introduce wounds into the trunk caused by drilling. Historically, arborists have used common-grade and extra-high-strength (EHS) cable and myriad termination hardware when installing static systems. We only use EHS cable in 3/16, 5/16 and 3/8 varieties, and we typically use a combination of dead-end grips in conjunction with eye bolts and cable/swage stops.

Steel-cable prep work

Review specific installation guidelines specified in A300 7.5 and 7.6 before following these simplified steps:

Install access tool lines and/or trolly systems to assist with the movement of hardware and tools. Be sure to have appropriate gear storage and tool lanyards at your disposal. It is vital to minimize the amount of loose gear you take into the canopy.

After accessing the canopy and determining the location of your cable (typically 2/3 the distance from the branch union you are attempting to protect and the top of the canopy), you must measure the distance of the gap between connection points. It’s generally a good idea to add approximately 6 to 12 inches of cable length on the end of your measurement to account for any minor deflections or mistakes.

If using through-hardware, such as eye bolts, measure from the inside of each side of your termination points to determine your cable length. If you are using cable/swage stops, be sure to measure to the outside of your termination point while accounting for the additional length of the termination hardware.

We typically use an open-reeled, fiberglass-style measuring tape. These tapes are softer than metal-blade tapes. Most fiberglass tapes will accommodate a carabiner and throw weight to make passing the tape to your co-worker much easier. You also can use the tail of your climbing line with a corresponding knot to mark your distance.

1) Milwaukee Force Logic EHS Cable Cutter, 2) Husky ball-peen hammer, 3) Tree Stuff throw bag (12 ounce), 4) Preformed Lag Spinner, 5) Craftsman 7/8-inch ratcheting box wrench, 6) line-worker’s pliers, 7) A.R.T. Cocoon Pulley, 8) Preformed Wedge-Grip Dead-Ends, 9) Ship Auger 20-inch bits, 10) Eye-bolt terminations, 11) Rock Exotica 1.5-inch Omni Block, 12) Klien Havens Grip, 13) Milwaukee M18 7/16-Inch Hex Utility High-Torque Impact Wrench, 14) DMM 6-liter tool bag, 15) 100-foot nylon tape.

Drilling and cutting

Once the measurement is taken, pass along the measurements to your ground assistants and begin drilling your holes. It’s important to note that your drill size should be approximately 1/16-inch larger than your through-cable or hardware. After using gasoline-powered drills for years, we made the switch to much lighter and easier-to-use battery drills. Our two favorite drills to use are the Milwaukee M18 7/16-inch Hex Utility High Torque Impact Wrench (line-worker’s drill) and the Makita 36V (18V X2) LXT Brushless Cordless 7/16-inch Hex Right-Angle Drill.

“We like to use a lag-turner tool and ratcheting box wrenches to dial in our tension on the dead-end Tree-Grip side of the system,” says Jones.

After drilling our first hole, we like to use a laser pointer to shine through the hole to identify our alternate drill site. As a reminder, through-hardware, such as eye bolts, should be drilled and installed in alignment with the planned cable pathway.

After drilling the holes, either you or your ground team should measure and cut the EHS cable. We prefer to use the Milwaukee M18 Force Logic Cable Cutter equipped with the EHS cable-
cutting jaws. We used to use grinders or hack saws, but after looking for a safer and more efficient tool, we found this. This tool eliminates sparks and greatly reduces the risk of accidental rope contact when aloft.

Once the cable is cut to the appropriate length, use a Haven’s Grip Wire Pulling Tool to safely haul wire to aerial workers. We always have our ground team pre-
assemble a termination system consisting of a PLP Cable-Grip Dead-End, galvanized thimble, eye bolt and EHS cable.

Installation

Start by installing the pre-assembled dead-end-grip termination system to the tree. We prefer to use two nuts in conjunction with our washer. The secondary nut acts as a lock nut.

If the cable is to be installed perpendicular to the branch, we recommend using a cable-/swage-style stop such as the Wedge-Grip from Preformed or the Rigguy Wire Stop. These grips are significantly faster to install and have the added benefits of drilling a hole that is smaller in diameter and just slightly larger than the cable itself.

If your cable is not perpendicular to your target anchoring wood, then you install a second Preformed dead-end grip assembly anchored to an eye bolt with a galvanized thimble. When the cable runs perpendicular to both anchor points, you can use cable/swage stops for both connectors.

Tensioning

After initially installing hardware, use an appropriate rigging system to slightly pull anchoring branches together. The amount of tension is subject to numerous variables, including species, seasonal foliage weight, level of desired movement and several other site-specific conditions. Our typical rule of thumb is hand taut without foliage, and tight (maybe not banjo tight) when the tree is in full leaf.

Andy Jones uses a ball-peen hammer to peen the threads on the eye bolt to keep the nut from backing off the bolt.

Depending on the situation, we will use a plethora of tensioning systems, such as a Good Rigging Control System (GRCS), CMI Rope Jack 5:1 hauling system or even the tail of our lines with some accessory pulleys for small-scale projects. It’s important to capture whatever tension you apply.

Once tension is applied, remove all slack from the cable and tighten hardware. We like to use a lag-turner tool and ratcheting box wrenches to dial in our tension on the Dead-End Grip side of the system, then slowly release tension to ensure the desired cable tension is set.

Once your cable is properly tensioned, use a ball-peen hammer to peen threads on the eye bolt (mitigates risk of nut backing off bolt). Use cable-cutting
tools to remove excess cable on the cable/swage-stop side of the system.

After finalizing cable installation, perform one final cable inspection and remove all tools and rigging. Take great care not to have climbing or rigging ropes conflict with newly installed cables.

Conclusion

Cabling trees is one of the best ways to preserve beautiful trees and protect people and the property around them. There is no one-size-fits-all approach to tree cabling. We encourage you to judiciously study the A300, BMPs and manufacturers’ instructions, and, most important, to glean knowledge from your local experts.

Although this guide is not at all exhaustive, we hope it makes the idea of tree cabling more palatable – and that you consider implementing these types of services into your arborist tool chest!

Andy Jones, CTSP, is an ISA Certified Arborist, production climber and co-founder of Rooted Arbor Care, a TCIA member company based in St. Louis, Missouri. He also is a member of TCI Magazine’s Editorial Advisory Committee.

Nicholas Greenwood, CTSP, ISA Certified Arborist, is a climber in Chicago with Bartlett Tree Experts, an accredited, 49-year TCIA member company based in Stamford, Connecticut.