Crane Job

[Mark Chisholm]

Did a descent sized Silver maple removal today for a very good client. It was 64" dbh and had two sets of lightening protection systems in it and four cables. I had cable cutters with me all day! It was on the Navesink river and the wind was whippin'!

The very first thing I did was install a bull rope and a ratcheting tie-down (10,000#) between the four leads before I removed any cables. Does anyone else practice this?

 

[Oxman]

ANSI does say to install new cables prior to clipping the lower set. If you are hanging off a bucket or man-basket it would probably make you feel better when the cables are removed, even with the snubbing up above.

I like to take weight out first. One large, horizontal limb I decabled one time had a freefall dropzone below it. Topping out the end of this limb de-tensioned the cable, so that it was no longer piano-wire tight.

Makes you think about the short lifespan of Silver maples. They grow so fast, and rot so quick, perhaps it shouldn't have been allowed to get 5 feet in diameter.

What was going through their minds way back when, when they put all this hardware in the tree? That it was going to last forever? If we would just think how big a deal it will be to take it apart after another decade or two adds its growth on, maybe we wouldn't get so carried away trying to 'preserve' a tree.

A high value tree like this one was probably over a house. What was underneath, and how did the crane snake it out of that black hole?

Ox
Link to my home page

 

[Mark Chisholm]

Oxman, I agree with the detensioning of the cables first. I actually took four parts of the head out right down to the cables before clipping them. One of which was still "piano wire" even after the tip was gone (tip weighed 2,800#). When I cut the wire free, nothing was near the drop zone and I had strapped it to the crane with some tension as well. I even had the crew move the chipper and truck out of the area. No one protested the move

.

This tree stood just in front of the the carport- dead center of this 10,000 sq.ft. mansion near Rumson, NJ (where people like Bruce Springsteen and Jon Bon Jovi live). It had "nightscapes" lighting under it and was the center peice of the circular drive. It was a very important tree to our clients. Though I would tend to agree that Silver maple is one tree you won't see me plant or recommend for anything but removal.

There was a lot of grass under it, but the carport, lights and belgian block driveway all were a consideration. The main reason for the crane was to minimize lawn and light/ driveway damage and to enable us to get the wood down and loaded quickly. The 32 Ton Taxi King did just that. At most of our picks spots, we were capable of 9,600#, but the lowering zone and cable placement in the tree left us a bit lower.

Also, some of the tree leaning over the house would've needed to be rigged. This tree was plenty hollow from midway up. Not easy minded rigging.

[ May 04, 2002: Message edited by: MARK CHISHOLM ]

 

[Randyboy]

Hey there "SLAP SHOT" I got ripped to shreds on the way back with all those cables in the front seat of the bucket truck. We couldn't put them any where else because the truck's where over flowing.

But anyway I was wondering if you guy's ever tried ALTERNI MATS? It's a great investment for driving on the lawns.

 

[Riggs]

Mark ,
I've replaced the cables with rope may times . Placing a ratcheding lowering device to the base , using a block and bull line or just a simple rope come along with a sheep shank. Only a fool cuts tight cables. Sometimes it doesn't matter how much weight you get off a cable lead and they are still tight . Cranes are tough though since you are taking off huge chunks at a time , I've choked some pieces and let the crane get the tension off than cut them . Always a touchy situation . East Coast , the land of over cableing .

 

[joe]

Hi, Mark;

I don't use a tie-down strap. Alternative techniques known to me are, single purchase tackle, or double whip tackle to replace the support of the cable before it's cut. Lashing the leads at the crotch as per Ashley and like you're describing with the tie-down strap.

Joe