The Gravitrams are a series of rolling ball kinetic sculptures created by Shab Levy and his company, Levy Designs, Inc. They are exhibited in various museums around the world, and are both attractive and interesting pieces of art, and impressive and intriguing exercises in engineering.

The most noteworthy thing about these Gravitrams is their addictiveness. Just watching the darn things. It's incredible. You can literally stand in front of one for hours watching the balls rattle around the contraption, trying to figure out where they're going to go and what they're going to do. I first discovered this beguiling creature going to Questacon as a kid, and growing up (such as I have) hasn't reduced its appeal. But more on that particular Gravitram later.

In The Beginning ...

... there was Shab Levy, who was inspired by other kinetic artists, Jean Tinguely among them. Also having an interest in industrial design, he decided to produce kinetic sculptures that were "whimsical, attractive and complex all at the same time". Tinkering with mechanical devices designed to conduct balls along various pathways, he developed the idea for the "Gravitram", or Gravity Tramway.

The first Gravitram was created in 1973 by Shab and a friend at the Oregon Museum of Science and Industry, taking an estimated 500 hours to complete. It resides within a 4' x 4' x 10' glass cage, and runs 1 inch ball bearings on tracks built from 1/8" mild steel rods. To make things more interesting, the device contains a number of cleverly sequenced gates and switches, such as the 'flip-flop' gate, which has two possible states, and changes state whenever a ball passes through it, diverting the next ball onto a different path. There are also gadgets which hold a ball in place until another ball arrives, providing enough weight to tip the switch and release both balls. The balls trace their intricate path down to the base of the machine, where they are taken back up to the top by one of two elevator systems, an auger or a chain elevator. This piece has been repaired many times, but it's still in good working condition at the OMSI.

The Basement Years

Over the next decade or so, Shab built four more Gravitrams, and two variations on the same idea, in his home over a multitude of weekends and evenings.

Gravitrams 2 and 3 were very similar in style and composition to the original, and were commissioned by the Omniplex Science Center in Oklahoma City, and the Science Museum in Lahore, respectively.

The most atypical of these sculptures is the "Hydro-Gravitram", the kinesis in this case provided not by balls, but by water. The structure was made from copper plate. The piece was requested by the City of Portland, Oregon in 1983 for a water conference, and subsequently donated to the Portland Children's Museum. A few years later, the museum destroyed it due to lack of funds for maintenance.

The "Gravitrek" was unusually shaped, in that it was designed to be installed against a wall, and hence only viewed from one side. It was 9 feet hight, 18 feet long but under 2 feet in depth. The five inch plastic balls travelled along hardwood tracks, and this was the first of the Gravitrams to include musical chimes, designed to play when a ball rolled past the trigger mechanism. This piece was given to the Portland Children's Hospital by the commissioner, but was also eventually destroyed.

Gravitram 4 transitioned to 2 inch hard plastic balls, and added a few interesting features, such as a chaotic pendulum that was powered by the motion of the balls. It went to the Museum of Science and Industry in Louisville, Kentucky.
discofever adds that this Gravitram now uses billiard balls.

Gravitram 5 is the artifact I've spent so many hours gawking at. Features include swinging gates, flipping switches, chimes that play that infernal Big Ben tune, spirals and helical descent ramps that move the balls at remarkable speeds. Like its immediate predecessor, the balls are 2" hard plastic, and I believe there are about twelve of them dashing about inside at any given time. As mentioned earlier, this piece can be found at Questacon, in Canberra, Australia.

D'you think he's compensating for something?

In 1989, Shab was able to move his operation into more capacious premises, a 6,000 square foot building in Portland. Thus equipped with plenty of space, and more advanced tools, he started working on a rather more impressive scale.

Commissioned by the Weizmann Institute of Science in Israel, Shab and his team constructed a Gravitram that was designed to use 4" hard plastic balls, 3/8" stainless steel rods, and to operate outside without a protective shell. Oh, and its dimensions are 108" x 108" x 160". This piece was completed in 1992.

The next opus was built for the Jeddah Science Center, Saudi Arabia, on a similar scale and in a similar vein - although this one was designed to be exhibited indoors. The most notable feature of this Gravitram is the trampoline. That's right, a trampoline. The ball shoots downwards from a track, onto the trampoline, and bounces up to be caught by a funnel! Sweet!

However, it simply doesn't get any cooler than the one at the University Museum in Porto Alegre, Brazil. Constructed using the same scale of track and ball as the Israeli and Saudi Arabian Gravitrams, this one incorporates pneumatic systems to allow the visitor to control the operation of the gates and switches! Using a touch screen interface, you lay in any combination of positions and sequences, and start the balls rolling. If I ever become absurdly wealthy, this machine is going to be my first crazy rich man purchase.

The final piece Shab constructed was for the Petersen Automotive Museum in Los Angeles, and is dimensioned much like the 'basement' Gravitrams, although the years of additional experience and access to improved equipment have lent this one a very polished, precise look.

And the final, final piece was designed and built by Shab's son Ariel Levy in 1999, and appears to be every bit as elegantly complex and well engineered as his father's work. It's located at The Science Place, Dallas.

So, Now What?

Apparently, that's all folks. According to the website, "At present, Levy Design is not an active company", so I won't hold my breath waiting for the appearance of the next Gravitram. But perhaps I'll build my own ...

The official website is at (you guessed it) and has not only a whole lot more information, but pictures of the Gravitrams.