Poetry in Motion
If you are planning a trip to Las Vegas, I suggest you visit one show where the industrial technology will impress you just as much as any of the other attractions the strip might offer—at least if you’re an engineer. KÀ, by Cirque du Soleil at MGM Grand, is unlike any other show you may have experienced.
If you are planning a trip to Las Vegas, I suggest you visit one show where the industrial technology will impress you just as much as any of the other attractions the strip might offer—at least if you’re an engineer. KÀ, by Cirque du Soleil at MGM Grand, is unlike any other show you may have experienced. It is an epic story of Asian legend with battles, romance, and storms at sea. The plot ties the individual scenes together, but that’s not the point. It’s all about action, acrobatics, and automationon a massive scale that is nothing short of spectacular, even by Las Vegas standards.
Jim Tomlinson, head of automation for KÀ, tried to put it into perspective: “You have to think of what this production cost as being equivalent to doing every show on Broadway in New York at the same time. Designing it all began with the director’s concept of the action, and engineers had to figure out ways to fulfill thatvision. It all happened in three years from a blank sheet of paper to opening night in February, 2005.”
Coming into the theater is like walking onto a Borg ship, or something from The Matrix . It’s all very industrial looking, and huge. Large complexes of towers and catwalks hang above the audience, decorated with people climbing around and swinging from ropes. There is no stage, just a big pit with smoke and balls of fire erupting from below. Behind there are lots of black equipment, more catwalks, and hanging pipes. The proscenium opening is about 110 by 100 feet and the theater seats 1,950 on one main floor, so the whole space is really big. If you watch CSI on CBS, you may have seen some of the pit, since one of the recent episodes was filmed there.
What makes it all the more impressive is the fact that this production was entirely purpose built, down to the seats. They began with a completely gutted interior and built everything just for this show, and Cirque du Soleil plans to have it running ten performances each week for at least ten years with an option for five more. While that may seem like a long time, their shows Mystere, and O, also in Las Vegas, opened in 1993 and 1998 respectively. Neither shows any sign of slowing.
Tomlinson oversees daily operation and makes sure everything comes off without a hitch. Like anyone else in charge of a large industrial plant, he has his hands full with all that machinery. Much of the equipment was designed by Stage Technologies, Ltd., a company that specializes in stage automation, winches, and flying effects. Their control hardware uses Siemens and Delta Tau Data Systems, 30 of them, driving 206 axes of motion. Networking the PLCs is Profibus and Profisafe, with Stage Technologies’ Nomad controller and Ethernet tying it all together.
Moving performance surfaces
All the major scenes take place on moveable surfaces. There are five lifts behind the pit wall that can move individually or together. These use technology typical of stage lifts in any theater, but most of the large scale action takes place on two truly unique moveable performance surfaces: the tatami deck and the sand cliff deck.
The tatami deck is 30 by 30 feet and positioned towards the back of the space in the center. It was built by Show Canada, and can move forward horizontally over the abyss a distance of 46 feet toward the audience on giant triple-extension drawer tracks, while supporting 20,000 lb. The movement is effortless and perfectly smooth using a rack-and-pinion mechanism driven by 75- and 150-hp motors. Its weight is estimated at 75,000 lbs.
The sand cliff is more difficult to describe. It is positioned in the center of the stage space, and when in its normal flat, horizontal position, the tatami deck is behind it and the five stage lift sections surround it around the front and on its ends. The sand cliff is a large steel, aluminum, and wood structure 25 by 50 feet and 6 feet deep and was built by TomcatUSA in Midland, TX. The structure rides up and down on a unique gantry or bridge crane that runs vertically instead of horizontally.
Two vertical columns guide the hammerheads and torsion tube, which can be raised using four, 75-foot long, 12-inch bore, single extension hydraulic cylinders. At the center of the torsion tube is a horizontal arm which extends forward under the sand cliff structure. At its end is a Rotek lazy-susan bearing, the same as is used on a tower crane, to allow the deck to rotate 360°. Moreover, there is a wrist at the end of the arm that can tilt the whole deck, lazy-susan and all, 100° forward.
With those movement options, the sand cliff can be flat, spin around, or tilt forward, all at the same time. At some points in the show, it stands straight up vertically; other times it’s straight up horizontally. It moves up or down at a speed of 2 fps, tilts at a speed of 2.5° /second and rotates at 2 rpm. Seeing something that massive move at those speeds is truly impressive considering that the deck structure weighs 80,000 lbs. and the whole assembly has an estimated weight of at least 280,000 lbs. In the course of the show, it moves 35 times. One of those moves requires 1,250 gallons of hydraulic oil in one minute. During the show, there are two rigging technicians inside the sand cliff to make sure all the artists and scenery attached to it are safely anchored when they need to be.
At one point, the sand cliff begins in its horizontal position, but tilts and turns with several artists on its surface. As they struggle to keep from sliding off, archers appear in the audience with large bows to shoot “arrows” at the surface. When an arrow “hits,” it’s actually a rod shot out of the surface of the deck. As more arrows hit the surface, the artists try to hang on for dear life as the cliff takes its full upright position. Eventually they all fall into the pit, landing on airbags below the stage level.
The hydraulic drive systems are monumental. Five twin-head 250-hp pumps do the heavy lifting with additional units for the peripheral stage lifts and smaller devices. Given the high speed of the stage moves, there are large banks of hydraulic accumulators to supply the hydraulic flow and a reservoir of 4,000 gallons of vegetable-based hydraulic oil.
Tomlinson’s staff of 23 technicians maintains and tests the equipment during the day, and there are two performances each evening, Tuesday through Saturday. During the shows, 80 artists are performing, supported by 100 people backstage, including eight automation technicians. Five operate computers, two roam backstage for specific cues or emergencies, and one is in training. A production like this attracts people from various backgrounds. Some begin as stage hands and develop automation skills. Others have mechanical experience at theme parks or come into the business from more conventional industries or engineering school. Tomlinson himself was working at Tomcat at the time they built the sand cliff and joined the KÀ team during its installation. His background has experience with industry and showbiz. “I have been involved in many forms of live entertainment, special events, and television for over 40 years, with some industrial controls experience mixed in along the way,” he says. “This job is like others I have had, but the machinery is unique.”
The action depends on the appearance of danger, but actual injuries are very rare thanks to a constant awareness of safety. Since so many artists are hanging from cables, the winches and harnesses are of paramount concern and inspections are constant. With the pit floor 120 feet below the catwalks, it’s easy to understand why. All the technicians, men and women, are generally young and quite fit given the amount of climbing that is part of life backstage.
“Safety is our first concern, then the integrity of the show,” says Tomlinson. “Profisafe is used between several PLCs and distributed I/O modules that handle all the e-stops, safe edges, and safe-stop commands in our system. E-stops are rare. I think they have been hit in passion only four times in two years, including over 900 shows and the rehearsal period.”
Even though this is Las Vegas and a showbiz production, the problems Tomlinson and his staff work with are familiar. While we were touring backstage, technicians consulted about mundane issues such as a broken spring in an edge sensor and a leak in a pilot pipe up near the roof. Another was trying to juggle schedules to work in a day off. Getting ready for that night’s show, the action was busy.
As a final test of the sand cliff mechanism, I watched an impressive moment as it was run through all its paces and moved on every axis. “We call that the tumble dryer,” Tomlinson noted. “That way if anybody left a screwdriver in there, it’ll fall out.” The sand cliff takes a bow at the end of the show in its own way. While the artists are standing on the lift below, it rises high up with one character waving to the audience. It’s as if it wants to give everybody a good look at the mechanism and its massiveness.
Peter Welander is process industries editor. Reach him at PWelander@cfemedia.com .