"Sphere of Heights", Input/Output, ME Departments, May 2006

input/output

by Michael Abrams, Contributing Editor

Sphere of Heights

Beginning with Pythagoras and Plato, many of the world's greatest thinkers have considered the sphere the finest shape in nature. And yet when in nature lesser minds have tended to commune with their surroundings in odd polygonal tents, from within boxy automobiles, or in the shapeless open air.

However, if you happen to take a walk in the old-growth forests on Vancouver Island, you may come across something that more closely approximates perfection: Dangling from the towering trees are what appear to be the plucked eyeballs of giants, or possibly the eggs of a large, fish-like alien.

In fact, they're homes. Imagined and built by power engineer Tom Chudleigh, who calls them Free Spirit Spheres, they can hang as high as 100 feet, are outfitted with electricity, a microwave oven, and a refrigerator, and can be shuttled to a new location on the back of a pickup truck.

The two wooden prototypes, named Eve and Eryn, have diameters of 9 feet and 10 1/2 feet, respectively. Eryn can sleep a family of four and in freezing weather the pods can be heated with a small 1,500-watt space heater. It takes three men and a lot of rope and pulleys to hang one, but the sphere, spiral staircase, and rigging can be removed within 24 hours without leaving a trace. At less than 1,000 pounds, the spheres could easily be transported into the deepest of back woods with a small helicopter.

Chudleigh came to the idea of tree spheres while attempting to make a vehicle that would float. "I was thinking of building a spherical houseboat, 25 feet in diameter, on steel pipe pontoons," he said. "So I thought I should start with spheres. I made a 9-foot sphere first and about halfway through I got the tree idea."

Chudleigh built the wooden prototype using two perpendicular layers surrounded by two layers of clear woven fiberglass, which give the wood the appearance of having a thick coat of varnish.

"It's a lot like boat building—you get inside and you've got nowhere you can take a measurement. No corners to measure from to get a diagonal or check for square ends," he said.

Tom Chudleigh's first proto-sphere, Eve, stares out over woods on Vancouver Island. The staircase, bridge, and pod are hung entirely with rope.

After establishing a top dead center and a bottom dead center, Chudleigh ran a wire from pole to pole. On the wire he attached a platform so he could spin and take measurements from the center. "Everything's done in radials and angles instead of vertical and horizontal measurements." Traditional hinges don't work so well on the doors, so Chudleigh came up with a pin system that keeps the door in place. When the handle is turned, the door pops out before swinging open.

Upon completion of the 9-foot Eve, Chudleigh attached hanging brackets instead of the initially conceived base brackets and "popped it up in the trees—it worked like a charm." For something like stability, Chudleigh uses the spider's stratagem. He hangs the pods from several trees with several lines of rope. Should a tree fall and snap one of them, the remaining threads will keep the ball suspended without difficulty. The multiple lines also keep the spheres from swaying much.

In the worst-case scenario—a fall—Chudleigh is sure that at least the sphere would survive. "The very first time we were slinging it between three trees we had a rope let go and she bounced like a Ping-Pong ball on a pendulum—about four feet in the air." Eve survived the drop with little more than a scratch.

Chudleigh is able to take such risks, thanks to something like a loophole in Canadian law: As long as he doesn't lay a foundation, his structures don't fall under the building code.

But spans of any size do fall under the bridge code and Chudleigh will have to get a permit to fulfill his ultimate dream of a retreat made of a dozen-odd spheres connected by suspension bridges. "Everything has to be capable of holding 20,000 pounds, even if it's just for walking," he said.

To achieve his cluster aim, and to help spread his pods throughout the world, Chudleigh has begun making fiberglass molds, which are both cheaper and faster to build. Potential pod purchasers can have a wooden one for $125,000 or a fiberglass one for $35,000. But Chudleigh is still largely driven by the need to commune with nature himself.

"I've spent hundreds of nights in them," he said. "That's my retreat—a great place to get away from it all. And I dream things I wouldn't normally dream."