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Coldplay’s Inflatable LED Spheres

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The four large video spheres in Misty Buckley’s production design for Coldplay’s Music of the Spheres look deceptively solid. Wonderfully round, covered in 25mm pixel pitch LED strips, they’re actually soft surfaced inflatables. Contributing a lot to the sustainability efficiencies of the tour—the spheres are lighter in weight, take up far less truck space, and require much less labor to install/dismantle. They inflate in about two minutes and deflate in about seven minutes. Each sphere hangs from one chain motor, and each has a custom dolly cart for storage and transport.

The inflatable spheres were conceived of and developed by Frederic Opsomer and his team with PRG Projects. “If they were hard shell spheres, that would be a problem in transport,” comments Opsomer. “That would have required a lot of trucks—two trucks per hard sphere. We started looking at the potential of making them inflatable. The design has four spheres—two are 5m (16.4’) in diameter and two are 3m (9.84’) in diameter. All four spheres’ dollies fit in one truck. We did a lot of studies on how to transport them; how we could hang them. We spoke with people familiar with fabrics and inflatables. We spoke with an engineering company on strength that we needed to have; the strength of the thread that is used; wind-loading, etc.” The 5m sphere weighs 1,323 lbs. (600 kg) and the 3m sphere weighs 992 lbs. (450 kg).

The LED strips covering the surface of each sphere was part of the weight considerations pushing on the surface. “We definitely wanted to have a very nice round sphere,” says Opsomer. “We didn’t want to have a ‘whatever’ shape because of weight issues. So, we had to calculate the air pressure inside so it could support all the weight and keep the shape. Also, since they’re used outdoors, the wind is an additional factor. You are going to have wind on the sphere, which pushes one side, but on the other side, actually, you get a suction force. All of this had to be calculated carefully.”

Each is comprised of an inside sphere and an outside skin. The inside sphere keeps the pressure and that has minimal holes perforated in it. The air pressure is maintained by a built-in blower. Once the power is cut off the sphere begins to deflate. The outside skin has the LEDs attached to it. There’s an element at the top, which Opsomer calls the mushroom, which contains all the power supplies, the data processor, the air blower, and serves as the pickup point for hanging the sphere itself. Most of the mushroom actually sits inside the sphere. “We are using NovaStar processing,” Opsomer says. “The fabric skin and blower elements were purchased from ShowTex. The LED strips were developed by PRG, with a Chinese manufacturing partner. With a lot of the LED strips, if you bend them too much, they fail, so we decided to develop our own to meet our specifications. This has resulted in a new product, the PRG LED Strip with a 25mm pixel pitch, although as the Strip bends around the sphere the pixel pitch varies. We wanted to make sure it’s durable, especially in the wind and weather conditions.”

When the sphere is deflated, hanging from the chain motor, it looks a lot like a sock hanging down. “We don’t fold them,” says Opsomer, “so, to protect the electronics and LEDs, we attach one side to the dolly and lower it down. As it comes down, it lays nicely in the dolly and the top of the mushroom has pins that line up with sockets on the top of the dolly frame. It sits securely in place so there’s no damage to the electronics. In terms of troubleshooting, the sphere has to be down; it can’t be serviced up in the air, but the LEDs can be serviced or replaced either inflated or deflated.”

This was the first time Opsomer had worked with Buckley, noting, “Misty is a very creative designer, I have to say. Her design goals match our goals at PRG Projects very well. Sustainability, ease of use, and fit for purpose are always at top of mind for myself and every member of our team. We want to fully support concert tours, broadcast, and live events with the tools creative designers need to realize their visions. We were happy to realize the video elements for Misty’s extremely innovative design for Coldplay.” And before you ask, Opsomer and the PRG Projects team are already experimenting with different shaped inflatables, because they know that question will definitely come in the future.

For a video, go to www.plsn.me/spheres