universal sculpture base

[jsimms]

Several years ago I developed a method of easily and relatively quickly and securely mounting sculptures such that they were well anchored to the earth.

I just installed four of my large pieces at a gallery in Santa Fe, NM, and took only 30 minutes to set the bases.

The method utilizes an expanding steel anchor designed for power line guy wires. In average soil conditions, the anchor will resist a pull of 20 to 30,000 pounds!

The attached imageshows a drawing of my system, and an image on the next post shows the anchor before (50 sq in.) and after (135 sq in.) expansion.

Required pieces and parts:

one #88135 Chance brand "bust anchor"

one 8" disc of 1/4" steel

one 30" length of 8" pipe

one 36" length of 1" steel allthread

two 1" nuts and a washer

one 12" disc of 1/2" steel with 1.25" center hole and an array of three 5/8" x 2.5" bolts welded on

one 2" x 5' heavy wall pipe to be used as a drive hammer

one 2 man gas powered 8" earth auger

Directions:


Use auger to bore a 30" deep hole

place 8" disc at bottom of hole

insert allthread thru anchor and into nut in cage at base of anchor and lower to bottom of hole

slip 2" pipe over allthread and hammer downward forcefully until you feel the anchor had fully expanded

Slide the 8" pipe down the hole to rest on the expanded anchor.

Place the 12" plate on top and tighten it to firmly to the pipe with the 1" nut and washer.

That's it!

The base of the sculpture must terminate with a plate to mate with the 12" disc. Leveling is done by use of two nuts per 5/8" bolt.

Questions?
john

[jsimms]

here's the anchor
j

[RuBert]

Thanks for including such specific instructions.

Interesting system, I can't say I've ever seen anything exactly like that. Has a engineer helped or had to sign off on it in any of your projects?

You have a nice website by the way.

[Araich]

Is it necessary to dig a 2 foot hole to get it out? Say, if you could not leave any material behind.
It looks pretty good, though I don't know exactly what a 'bust anchor' is, and whether I could get one here... is that a costly thing? (thinking temporary exhibit)

[sculptorsam]

That is quite the slick system. If you had to remove it, you could probably just unscrew the threaded rod, remove the 8" pipe and leave the anchor down there. Otherwise, I'm sure the answer is to dig, dig, dig. For quite large pieces, you could probably use two or even three of them spaced a couple feet apart? What is the tallest/heaviest work you have anchored with just one?

Sam

[jsimms]

Sam is right, just unscrew the allthread and pull out all but the anchor. It will eventually go the way of all things.

Also, use two or more to greatly increase resistance to tipover forces.

The anchors run less than $20, and are available from utility distributers such as Hubbell.

http://www.hubbellcatalog.com/hps/datasheet.asp?PN=88135&FAM=earth_tension_anchor

Araich should check with www.britech.com.au

Actually, it would be pretty easy, though not cost effective, to fabricate one yourself. That's how I originally came across it.
I was designing a similar unit when I checked patents and came across the Chance patent.
john

[jsimms]

I've not had to have an engineer sign off on it, but was assured that it was sufficient as I have used it. I do have a friend who is an engineer, and will have him check out the specs. The anchors are also available up to 12" anchor (300 sq in), and of course an array would be way supportive.
john

[Araich]

I guess that with the 1" allthread or the fixing points being the critical area for failure, periodic corrosion checking would be desired for a more permanent use.
I think it looks like an excellent tool. I'm even considering it for Sculpture by the Sea (http://www.sculpturebythesea.com) this year, where I'm sited on a rise in the parkland.
I had planned on a largish heavy plate, but it would be nice to have a hidden support.
I've submitted a work similar to this (http://www.artwise.com.au/hague/113.htm) scaled to around 7 foot. A good match for your technique.

John, I've written to Britech. Thanks for taking the time to hunt that down. I appreciate it :)

[jsimms]

I'd say for more permanent installation, I'd put some gravel in the hole below the anchor for drainage and use tar liberally over the anchor. They are available galvanized. Also, I'd use stainless allthread and nuts and bolts.

If you (Araich) have a problem coming up with an anchor, I could ship one to you, along with some bronze maybe. The anchor weighs about 10 pounds.
j

[warren01]

John, I really like your anchoring system. I guess you probably use it in the warm, dry climate areas. Around here we have to go 42” down for frost line. No problem there, just dig a deeper hole, make the 8” pipe longer along with the threaded rod. We also have a high water table. They insist that everything have a concrete footing. Keeps a thing from floating, at least that is what they say. Have you ever used the system with either of those circumstances?

warren

[jsimms]

I'm in Jackson, Wy, where a few days of -50 to -60 is not unusual, and frost line at 6'.
I've seen no effect such as heaving. Since the anchor expands into the surrounding soil, floating should be no problem. Pull out in average soil is something like 10 tons! The anchors are available galvanised.

I use the 30" depth only because it is the easiest depth with a two man auger.
j

[Araich]

As a foot note, I installed my work at Sculpture by the Sea, it coming in a t 7 foot tall and around 150kg. Instead of the usual large heavy base plate (it is for only 3 weeks) I decided to bury the footing.
I welded a cross, 1.5m long across, out of 60mm pipe. On which I welded 4 nuts (to match holes on sculpture) and some seperators (50mm pipe) so that the sculpture stood 50mm over the cross.
I gascut some holes in the ends of the pipe, and made up some long (500mm) pegs out of 12mm rod.
onsite, I just dug a cross shape down 130mm or so, and sunk the cross, levelling it. Hit in the pegs at angles over the pipe legs. Walked on the sculpture and screwed it down onto the nuts. Burying the cross to finish.

It took an hour onsite, but the result is worth it. After having had an ugly base plate for the exhibition in previous years.

[ironman]

For a quick and easy temporary anchor just fill a 2 & 1/2 or 5 gal. bucket with concrete and have an appropriate bolt sticking out of it. Weld wings or flanges on the bolt so it wont loosen and turn in the concrete. I've used this method for multi point mountings that were temporary and it worked fine. It's also vandal proof unless of course the vandal is godzilla. I've also include the bucket and bolt with the sale of a couple of pieces.

[ironman]

Hi, I forgot to mention, if you haven't figured it out already that you bury the bucket in the ground! Also, I use plastic buckets with handles for easy removal.