Professional Cabling in Large Trees

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Jomoco,

Since this is a great thread about cabling in general (Mitchell's thread very educational as well, but more single job specific) I will ask my questions about wirestops here.

The "Rigguy" wirestops cabling system: Doesn't the fact that the interior side of the drilled hole never gets "plugged" mean that it will be a permanent route for moisture migration along the cable? That this moisture and small accretions of crud will then surely persist on that very part of the cable that you cannot inspect?

Also: Wouldn't the movement of the cabled limb in even gentle winds result in a constant side-to-side "radiusing" of the through hole, in effect negating the trees every attempt to establish the 4th CODIT wall, possibly setting up a permanent site for fungal attack?

Now, I've never seen a wirestop installation, just the vids on the "Rigguy" website. But several years ago I responded to a cabling failure with a conventional through bolt that had never been properly snugged up, and all of the concerns I list above were factors in the failure, persistent moisture migration resulting in degradation of the eyebolt, but most significantly - side-to-side motion transfer of friction to the limb/eyebolt juncture instead of the thimble resulting in decay of the limb at the point of cabling.

Needless to say this was a cable installation that had not been properly re-inspected, properties change hands, tree companies go out of business...

So I was wondering if anyone with experience with cablestops might address these concerns.


RedlineIt
 
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Jomoco,

Since this is a great thread about cabling in general (Mitchell's thread very educational as well, but more single job specific) I will ask my questions about wirestops here.

The "Rigguy" wirestops cabling system: Doesn't the fact that the interior side of the drilled hole never gets "plugged" mean that it will be a permanent route for moisture migration along the cable? That this moisture and small accretions of crud will then surely persist on that very part of the cable that you cannot inspect?

Also: Wouldn't the movement of the cabled limb in even gentle winds result in a constant side-to-side "radiusing" of the through hole, in effect negating the trees every attempt to establish the 4th CODIT wall, possibly setting up a permanent site for fungal attack?

Now, I've never seen a wirestop installation, just the vids on the "Rigguy" website. But several years ago I responded to a cabling failure with a conventional through bolt that had never been properly snugged up, and all of the concerns I list above were factors in the failure, persistent moisture migration resulting in degradation of the eyebolt, but most significantly - side-to-side motion transfer of friction to the limb/eyebolt juncture instead of the thimble resulting in decay of the limb at the point of cabling.

Needless to say this was a cable installation that had not been properly re-inspected, properties change hands, tree companies go out of business...

So I was wondering if anyone with experience with cablestops might address these concerns.


RedlineIt

Hey there Redlineit, I believe I have a good understanding of the wirestop system, and I share the same concerns you have expressed about their potential drawbacks and weaknesses.

Hopefully someone here who has more hands on experience using wirestops will chime in on the pros and cons of using them.

I'll stubbornly stick to the old school drop forged galvanized steel cabling components, they have a well known proven track record that has never failed me yet.

All my nice new cabling tools and alignment tubes are now covered in friggin ficus sap! Moreton bay figs are magnificent trees though!

jomoco
 
I put on my helmet cam and took a stroll around this moreton bay fig after I finished cabling it today. I spent 3 days in this tree, it had 12 cables in it when I started. I got rid of all 12, and it now has only 4 new cables.

http://uk.youtube.com/watch?v=5avqx5bSyRo

According to the plaque on this tree, it's been around since 1877, and it is the very first tree I used my new cabling alignment tubes in to ensure my cables and hardware were perfectly aligned.

I'll be starting the big torrey pines next week, and should get some good footage of the job as it progresses.

jomoco
 
I hate to sound ungrateful but...

Video was way boring--bat got your tongue? How about using a laser pointer and showing where the cables are and were and why? Better yet to do some from in the tree, too, at least next time.

Thanks--it is a grand tree, and great to see how others value and protect trees.
 
3 days to install 4 cables and clip out some old ones. Why so long?

Boy, you guys are a tough crowd lately. The answer to your question is that this magnificent tree should have never been cabled at all period. Moreton bay figs are monsterously powerful trees quite capable of holding themselves up with no help from arborists trying to make a sell.

The real problem I faced with this tree was deciding which cables were extraneous and should go, and which cables the tree actually had grown dependent on and should be replaced?

My answer was 4 new cables installed correctly, and 12 old cables incorrectly installed being cut out.

I have lots of still pics of the old and new cables in this tree, but I'm having trouble posting them as they are all over 700 kb, and this site has a 300 kb limit on pic size.

I mav be getting older and slower these days it's true, but these people are after the highest quality work they can get when they hire me, not the cheap shoddy improper work they pay me well for to correct.

jomoco
 

It's funny you post pics of what I believe is the Moreton Bay Fig in front of the Natural History Museum in Balboa Park.

The reason it's funny is that particular ficus tree is also packed full of cables that should have never been installed as well. And guess who had to replace all twenty something of them about 5 years ago? It took me over two weeks to do that one tree.

It's entirely clear to me that at some point in San Diego's arboricultural history, some very prominent arborist with alot of pull and popularity made the mistaken determination that these hearty trees need cabling support, and successfully sold that false notion to the city heads and tree community of the times. It could have easily been as long ago as World Expo that laid the groundwork for Balboa Park in the early 1900's. I think Teddy Roosevelt attended.

I of course appreciate that these early arborists and the many subsequent arborists that have worked on and maintained these marvelous trees over the last 100 plus years were all doing their best for these trees as I have everytime I'm granted the privilege of being paid well to care for them and make sure they're done right.

I am torn about posting pics of amateur cabling mistakes made by my predecessors that cabled these trees originally, but I ask myself how else can we learn from our mistakes unless are willing look at and discuss them?

I hope I never get to old to quit learning from others as well as my own many mistakes over the years.

jomoco
 
Great thread! When it comes to proper alignment, what factors are considered?

A long enough drill bit to drill through a large branch at an angle (using the Rigguy system) ... the hypotenuse is always longer.
 
Great thread! When it comes to proper alignment, what factors are considered?

Accuracy of the hole drilled in the branch for the eyebolt connector being perfectly true to the cable lay on both ends is essential to prevent the cabled branches from twisting in the wind.

I achieved perfect alignment holes by stringing a rope attached to alignment tubes at each end where the proposed cable is to be installed. Once the tubes are tied in place in close proximity to the proposed drill hole, the rope between the tubes is pulled tight and tied off under tension, then I slide a round pnuematic pistol grip pilot drill into the center of the tube through milled out slots in them allowing me to drill a perfectly aligned 3/8ths inch pilot hole hole about ten inches deep into the wood where the eyebolt will eventually go. Once both pilot holes are drilled I remove the alignment tubes and ream the pilot holes out to 1/2 inch with a standard two stroke reversible drill motor going all the way through the wood at the correct angle.

It takes a little longer for sure, but the dead on accuracy of the holes drilled perfectly straight are well worth the effort and time if quality of your work is the end goal. I don't think any arborist could drill holes as straight by eye, including myself, which is the reason I invented these new tubes about a month ago.

Cool things like this can be made possible at cool arborist websites like this when egos butt heads, I was kinda arguing with JPS when I got the idea of these simple alignment tubes going off in my head like a firecracker.

I obviously enjoy having intellectual discussions and arguments with my peers here at AS.Com, it's neat to bounce things around with other experienced guys that do the same work I've done my whole adult and teenage life.

There are pics of my tubes in this thread somewhere I believe, you guys feel free to copy them and make your own. If you need help on specs and materials to build them, just PM me and I'll help as best as I can.

Here's a vid of the tubes and drill I made shortly after my brother made them for me on a mill at the machine shop he works in.

http://uk.youtube.com/watch?v=DNy6SdUFdEk

jomoco

jomoco
 
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I really like EHS 7 strand for supporting serious weight, however, if you use tree grips and thimbles at the eyebolts, there is no need to bend EHS cable. it definitely doesn't like to bend at all, using tree grips, all I have to do is cut it to length for each span, very accurately of course.

The strength ratings between EHS and soft lay cable is staggering.

I'm startin cablin next week, so I should have some decent vids of 3 different cabling jobs in the coming weeks, right up to new year.

jomoco

The tables I've seen show both 3/8" 7x19 and EHS cable/wire rope to have minimum breaking strengths in the neighborhood of 15 kips, but more to the point:

I don't believe the strength of the cable is ever going to be utilized, because it is, by far, the strongest link in the cabling chain. The weakest link is going to be the wood (assuming the terminations are proper), where the grain is under perpendicular compression at the washer at the end of the through-bolt. Given the relative ease of cutting and bending 7x19, why bother using EHS?

I can run the calcs for the compressive failure of the wood grain of various wood types, but we are talking about a couple square inches of wood supporting more than 10 kips - and it's simply not possible.

Feel VERY free to call me a dumbass and tell me why I am wrong. It wouldn't be the first time by a long shot.

Thanks,
Chris
 
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