Lightning Protection

[Tree Reb]

I think I'm in the wrong thread

http://www.merriam-webster.com/dictionary/lightening

 

[Blinky]

I've never seen a lightning protected tree that was actually killed by lightning.... has anybody?

LP systems on comm tower sites are hit all the time. They work on the same principle but they're a LOT beefier than tree systems. You can't usually tell if they were hit because they did their job and grounded the strike.

 

[Burnham]

I've installed a couple of lightning ground systems on fire lookout towers. They work. Usually.

 

[Al Smith]

It works on everything else so it should work on a tree .

I've seen some funny looking trees after they got nailed with a bolt from outta the blue .One silver maple grew branchs that looked like cork screws .

 

[treelooker]

Yes several have been hit that had fuses to show it. Little/no tree damage.

I put one in the fairchild oak last saturday. 82' tall. re pita climbing them, true, so it is best to run the conductor on the underside of branches and stems. This protects the conductor from impact by falling limbs and whatever as well as ropes and tree climbers.

Nick it is not all that much money. Lok at Mrsir's pic--how much would that removal be? And how much is that tree worth? LPS can be cheap insurance.

a good ppt on selling this service:

www.isa-arbor.com/publications/Lightning/PowerPoint/Johnston_LP_Sales_edit.pps

and when a tree gets hit....

http://www.isa-arbor.com/publications/Lightning/Summaries/Meilleur7.2.07_LP_edit.pdf

lots more at the isa website--just search lightning

 

[FJR]

Lightning Protection Systems can be cheap insurance.

That is a great statement to tell a client when selling a potential LPS. I have put a bid on installing a system in a beautiful Black Walnut, but I didn't get the job. I am looking forward to trying it someday.

 

[stehansen]

I am the only person that I know of that has lost a large tree because of lightning.

 

[MasterBlaster]

Yes several have been hit that had fuses to show it. Little/no tree damage.

Lordy, what type of fuse would that be?

 

[Al Smith]

Evidently a lightning fuse . Never heard of one myself .

 

[Burnham]

Why would you want the protection system fused? Seems like a good way to be left unprotected from a second strike. No fuses on the tower installs I made or repaired.

Or am I missing something?

 

[Mr. Sir]

The fuse is hooked up in parallel on the downlead, not in series, so it will blow if the system is energized, but it doesn't compromise the grounding system. Does that make sense? It's just an indicator.

 

[Burnham]

Ah yes, I understand.

Be a bit of a waste of time and materials on a fire tower. Some of them get hit multiple times every single year...even dozens of times.

 

[Mr. Sir]

It would be a cool thing on a tree, though. You could show the customer that the system took a hit and saved their tree.

 

[Burnham]

Yes, I can see that...if you were to decide to stop by and check.

You'd need to do that in your part of the world most every summer afternoon .

 

[treelooker]

It would be a cool thing on a tree, though. You could show the customer that the system took a hit and saved their tree.

Yup: this from the june 2008 tci article: Professionals Providing Protection

With lightning systems, blowing a fuse can be a good thing. The researchers at Bartlett wanted to know if their systems worked, so they shopped around for specially made lightning counters to attach to them. The price of $100. seemed a little high, so they designed an induction loop with low amperage fuses. Working with the Franklin Institute in Philadelphia, Graham developed a similar device, also using household-type electrical wire and a fuse made for vehicles. He noted that fuses “have great potential for improving sales. Imagine Mrs. Jones coming home after a horrific thunderstorm, finding that fuse blown, and knowing that her prized tree is fine. Not only will she consider protection for other trees, but she will be sure to repeat her testimonial to friends and neighbors.”




Arborists have been doing electrical work throughout recent history, installing lightning protection since the 1800’s. In 1933, J. B. Whitehead at Johns Hopkins University observed 61 protected trees around the campus of Johns Hopkins University in Baltimore, Maryland. Many systems in historic trees around landmarks such as Mount Vernon, Monticello, and the Hermitage have been in service for over fifty years. In 2007, a veteran post oak (Quercus stellata) tree at Andersonville National Historic Site had to be removed due to irreversible damage by lightning. Superintendent Fred Boyles does not want to lose any more. He now has enough material to protect at least fifteen veteran trees from future lightning strikes. The region receives on average over ten lightning strikes per square mile per year, so the odds were too great to risk that another tree would not get struck.

Proving effectiveness
The southeast region of the US may get more lightning overall than the rest of the country, but no place or tree is immune. Also, there are microsites elsewhere that get a lot of strikes. The west-facing slope of the Morris Arboretum, above the University of Pennsylvania’s main campus in Philadelphia, is one such “hot spot’. Because of the many strikes there, the university began installing lightning protection systems in the early 1980’s. A metallic communication cable near one protected tree was burned out several times, presumably by lightning strikes, which demonstrated that system’s effectiveness. The metallic cable was finally replaced with fiberoptic cable. After studying the patterns of strikes and systems on this hillside for over 33 years, arborist Bill Graham concluded that the protection zone was under 65’.

Lightning strikes have been recorded on four of the seventy-five protected trees at the Bartlett Tree Research Laboratory in Charlotte, North Carolina. Two exited the system according to plan, out the bottom end of the ground rod. One flashed over to an unbounded irrigation wire two feet away, destroying the electrical components of that system. One strike did not reach the ground conductor, which was in dry soil. Instead, it flashed over to a moist buttress root, damaging the tree. In Philadelphia, a red oak in a park had two systems with two grounds, because girth was a factor in the old standard. The branch conductors were fastened with staples—no standoffs were used, so the cable was swallowed in places. Lightning struck twenty-three feet below the air terminal, where it melted part of the copper cable, the conductor. Then it burned some of the ivy that grew on the trunk. Finally it blew away soil that was covering the ground rod. The evidence indicated that the system successfully grounded the strike, even with several defects that fell short of the old standard. The standard was relaxed in 2002, and other best management practices changed as well.

 

[MasterBlaster]

Anyone have a link to these fuses?

 

[Mr. Sir]

There was an article in one of the tree mags several years ago that had detailed instructions for installing the fuse. I'll try to find it.

 

[treelooker]

just search the isa site for lightning and look for bill graham's paper. smiley described it in his, too.

 

[MasterBlaster]

Yea I'll get right on that.

 

[Mr. Sir]

Give us the link when you find it.

 

[treelooker]

Give us the link when you find it.

Guys, I ran to the site one time for you already, and fetched.

Once was enough. Mr. Sir, as an ISA member you oughta be able to use their site.

It's easy.

Try it.