We have posted before about using dynamic cabling to support smaller splits and/or limbs or branches that can use additional support. In the last year, we have been deploying a steel ring as a hub in static (metal/no stretch) cabling systems. This case study shows what we saw in a recent sugar maple and how we decided to install a hub with four legs (cables) to hold this large and valuable tree together.
Reassessing the Need for Support
When I first looked at this tree it had a broken dynamic cable in it, which had been originally tasked with holding this 38” sugar maple together. Clearly this application (the dynamic nylon cable) was not sufficient because the cable broke but the tree did not fail. Essentially, the tree created so much force that the cable broke but the tree was fine.
This tree COULD be fine with out support; it’s impossible to say with certainty. But we found a couple unions that do tend to split in sugar maples and the client wanted to proactively invest in preserving the tree. Cabling is a great way to invest a little time, energy and money now, which could extend the life of the tree 25 - 75 years (or more!).
Installing Proactive Support for Susceptible Cracks
A major trunk crack goes all the way to the ground on this sugar maple.
A secondary weak branch union calls for support. Notice how thin the wood is where the line stops at bottom left.
We had several areas of concern with this tree so we installed four spokes (cables) and a hub to help support all the areas of concern. The first photo is the main crack in the trunk that goes nearly to the ground. The second photo is of a secondary seam that we were pretty concerned about because its over the house. If you follow that seam down the section of wood holding this branch on gets really thin at the end of the seam. Its been there for many decades without support so its potentially fine, but we felt it warranted added support.
Four steel spokes attach to each major branch of the tree, connecting to a common steel ring at center.
Overview of the Static Cabling Support System
The last photos (above and below) are of the actual system. The circles are where the system is located. This one went in particularly nicely, no issues with it rubbing branches and the ring ended up nearly in the center of the tree. In the end this system can’t guarantee against failure, but installed a static cable system adds significant strength to trees that are structurally deficient. Contact Heartwood if you feel any of your trees may need attention.
The hub and spoke system, seen from the ground.