Architects turn metal tubes into wind-powered musical outdoor sculpture

September 2012- Perched on a slope of the Pennine mountain range overlooking the market town of Burnley in Lancashire, England, a tree “grows.” But unlike its organic counterparts, this tree is made up of approximately 3 tons of galvanized steel tubes crafted to capture and turn the region’s wind currents into a harmonic song that is sometimes discordant. Designed by architects Mike Tonkin and Anna Liu, the metal sculpture is part of a Panopticons Arts And Regeneration Project created by the East Lancashire Environmental Arts Network. ELEAN established the project to set up a series of panoptical structures [built to permit the viewing of all parts] across East Lancashire.

“Mid-Pennine Arts held a competition for four sites in Lancashire because they wanted to draw people back into the countryside,” says Tonkin of Tonkin Liu, London. “When we were invited to participate we asked what the sites had in common with each other. Their answer was wind. So we decided to focus on sound as well as the site itself.” Tonkin Liu is an award-winning firm that combines architecture, art and landscape. The company’s designs are tailored to location, people and culture to create projects of significance. 

Tonkin and Liu developed a special drill with the capability to drill backwards cutting holes in the underside of the tubes at a specific angle much like a flute. The architects first experimented with plastic tubes by driving area roads and holding them outside the car window until they achieved a sound. “It took us nearly three months before we got the first sound,” says Tonkin. “After cutting holes at different angles we conducted further experiments to identify the right sounds.”

The architects performed a structural analysis to target areas of stress since compressive strength was a critical performance requirement. To meet budget and functional requirements Tonkin and Liu selected mild steel tubing with a center thickness of 8 mil and an end thickness of 3 mil. The tubing was hot-dipped galvanized to give it a 25-year lifespan before being prefabricated as a kit. “Each tube was laid out in a circle with a ring on the top and bottom making it easy to bolt them down,” says Tonkin. “Since the layers of tubes were heavy, they couldn’t be very large.”