Imagine the design parameters for a four-part object weighing 2,100 lb in freefall and safely stopping just over the heads of theater goers. Then imagine pulling off this stunt in every performance with the desired shock effect and with no one getting hurt.
Anyone who has seen Phantom of the Opera knows that the crashing chandelier scene in the Paris Opera House climaxes the performance. Of course, Phantom in Las Vegas’ opulent Venetian Hotel had to be bigger, scarier and more thrilling than competing productions in New York, London and Paris.
In what can be termed an unusual but classic mechatronics project, several contractors sought to all but crash an opera-house size chandelier in every performance at the Venetian. The chandelier has two major parts in the show. When the audience first comes in, they see a dilapidated chandelier broken into pieces to convey the sorry state of the Paris Opera House. As they are taken back in time to opera house’s glory days, the ruined chandelier – made up of four independent rings – reassembles into the beautiful chandelier it once was and ascends into the dome of the theater. As this happens, its dreary blue lights turn into warm reds.
Besides a few shakes and rattles, the chandelier stays put until the climax of the show when it free falls for 43 ft in 3.5 sec to just over the audience. However, before it comes to a stop, the theater goes black, leaving the audience to wonder if they are going to be struck by the plummeting chandelier. Of course it stops and within the six seconds of darkness, ascends back into the dome.
“From a complexity standpoint, the chandelier was a whole new ballgame and has been called the most complex piece of scenery anywhere in the world. As far as overall computing and number of parts working together simultaneously, it’s pretty hard core,” according to Scott Fisher, CEO and founder of Fisher Technical Services Inc. (FSTI), the project’s primary contractor. “When you get right down to it, the whole rig is like a 32-axis robot hanging from the ceiling.”
The Venetian usually prohibits photography of the chandelier, but let Design News in for a sneak peak via a photograph. The show’s owners believe releasing photos and video to the public would detract from its mystique and discourage some from attending the show altogether.
While Fisher, a 39-year-old electrical engineer who’s been building automated scenery for stage productions and motion pictures his entire career, focused on the structure, mechanics, software and control, the design of the chandelier itself was left to Rob Bissinger, a contractor working for planning, design and architecture firm The Rockwell Group.He characterizes the project in more theatrical terms.
“The chandelier is like a character in the show and has to evoke treachery, romance, beauty and opulence. It allows the audience to suspend their disbelief completely,” he says. “It is a stunning moment and one of the most satisfying moments in my career and in any theater.”
All theater productions have a tremendous amount of effort behind the scenes and this unique combination of art, winches, wire and computer control was no exception. Three mechanical engineers, two electrical engineers and six programmers toiled away on the $5 million project for 10 months. With equal parts electronic, control and mechanical engineering, Fisher applied a mechatronics approach to this inter-disciplinary project.
“Without mechatronics, we could not achieve the very integral aspects of the software with the mechanical to move the object in three dimensions. The addition of brains to the brawn pushes the project into the category of mechatronics,” says Fisher. “The primary challenges were mechanical and software. The controls for the chandelier are standard components we use for controlling anything in any theater.”
What made the project so innovative, according to Fisher, was controlling objects in the same three dimensional space and moving points around on a curved track from which objects were suspended. Moving the device in three dimensions and in circular fashion is vastly more complex than a symmetrical design with, for instance, a flying TV camera over a football field with fixed points.
"On top of that, the software is monitoring for any potential collisions between the four chandelier pieces and their suspension cables, the walls and ceiling of the theater, and the audience area. Once you’re suspended from [multiple] points, you can move the object to anywhere within that three dimensional space. If you have three points, you only have a triangular space. The more points you add, the more you get toward a circular flight space,” explains Fisher. “This is the most complex software project we have ever done. The math got insane.”
A full 3D simulation on how the chandelier works. Source: FTSI
How FSTI tests moving large objects around in three dimensions. Source: FTSI
While more basic, the flying camera shown here at an auto racetrack and popular , operates similarly to the Phantom chandelier. Source: FTSI
Do not try this at home! FSTI makes a Skidoo snowmobile fly around on stage. Source: FTSI
“We did not piece the chandelier together in our Vegas shop. We did a full 3D simulation and even before it was built, we had a 3D model to try it out. We built the entire rig off site so the first time we tried it was live in the theater. The real thing mimics the 3D model. It was just a matter of turning it on live,” says Fisher.
The chandelier itself is divided into four independent rings each suspended by four lines. In turn, each line is supported by four winches moving along a 52-ft long curved track in the domed ceiling. It was up to contractor Jake Bell to make sure the structural steel in the ceiling would house and securely hold the entire mechanism. Instead of the usual 5:1 safety ratio for steel, the margin was 8-10:1. That means loads imposed were 1/8 to 1/10 the rating of the steel.“We had limitations to how much each ring could weigh. We were in the 600-700 lb range so one or two went slightly over,” Bell says, adding that when it was done the rings averaged in the 500-lb range. The challenge of making sure the deceptively- grandiose chandelier remained svelte was left to Bissenger, who designed it using Autodesk Architectural Desktop.
Large room chandeliers often have hundreds of lights, but they add weight so the totals were limited 98 incandescent bulbs 60 LED strobe lights spread across the four rings. Each ring contains lithium ion batteries to power the lights so extending electric cables were not issue during the chandelier’s various flights. Jeweled and mirrored pieces gives the illusion there are more lights than there really are.
While few reading this story will build anything quite so unique, theatrical automation is comparable in nature to factory automation, according to Fisher. “The closest things are assembly lines that do packaging like folding a box. What we build are custom assembly lines for specific products. If you need to make a curtain go up and down, we have a standard machine we use. We’re not a scenery designer and we do not do the pretty. We built the framework.”
|This sideways view of the chandelier's four rings also shows the dome ribs that serve as tracks for controlling the chandelier's movement.|
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|Expertise and Equipment Galore:
The Venetian’s chandelier required a classic mechatronics project
• 32 individual winch machines (16 lift/16 traverse, eight per chandelier
• 16 support tracks
• 640 total motor horsepower
• 1.5 miles of wire rope
• Over 1,800 individual pulleys
• 15,000 bolted connections
• 20 tons of steel to construct the tracks and supports
• Chandelier weighs 2,100 lb
• 40 individual high speed computers running cooperatively
• One human operator