Installing Cables in a Splitting Tree
One professional tree service we offer here in Wilmington, NC is to install cables in a splitting tree. That's called cable and bracing. It's such a technical task that it is sometimes referred to as Tree Surgeon work. We use cables to connect the branches, and install steel rods through the trunk at an active split. When done right, it can be beautifully engineered, with cables delicately arranged like strings on a fine instrument. When done wrong... it's a mess and dangerous. In addition to doing installations, sometimes we get called to inspect and correct the work of other local tree companies.
Recently, we got a call about a cable that failed. It hadn't been in the tree for very long, so we went to check it out. This is going to get a little technical, but Dennis likes to say we're the local tree nerds, so here you go!
I laid this out on the floor of our shop for demonstration purposes. The chunk of wood represents one tree branch. Off to the right, there would be a second tree branch, forming a vee with this one. Let's imagine the bottom of the vee is cracked. A cable connecting the two branches should stop the cracked vee from splitting apart. At first glance, this probably looks like two similar cables, but let's look more closely. The top cable was installed by another company, and it is broken. That's why we got called, to take it out of the tree and install a new cable. I just put the bottom one together to show a proper assembly. Let's start with how to do it right:
There are actually four steel parts here. From left to right they are as follows. An eye-bolt through the branch. A thimble through the eye so that no cables rub against the eye. A dead-end grip which wraps around the thimble, and then wraps around the cable itself. And then the actual cable, which you can see tucked inside the dead-end grip, the cut end is right at the orange indicator stripe, where it is supposed to be.
This picture shows the tail of the dead-end grip. Notice how the strands are all wrapped neatly around the cable. Now let's look at the bad/broken installation:
They did not use a thimble to protect the wires of the dead end grip. No surprise, the cables of the dead-end grip broke! Also notice that the end of the cable extends well into the eye of the dead-end grip. Sloppy work. If this cable failed during a wind storm, not only could the original crack break, but now you'd also have ten or twenty feet of steel wire whipping around! Total nightmare.
And look at the tail of their dead end grip. They didn't even finish wrapping it around the cable! Maybe it's hard to see in this picture, but again, just very sloppy work. Finally, I don't have a picture of it, but their installation was also at weird angles. The cable did not pull in line with the eye bolt.
We fixed all of their mistakes, and now the tree is secure. So remember, just because someone knows where to buy some parts, that doesn't mean they know how to install them properly, and it doesn't make them a Tree Surgeon! Call an Arborist who is Certified by the International Society of Arboriculture, and you'll have better odds at getting it done right. Or just call us here at Joshua Tree of Wilmington, and you'll be sure to get it done right!