The Big Thrill
September 01, 2002
Appeared in Consulting-Specifying Engineer
The thrill of riding up a huge mountain of steel, momentarily hovering at the top, then breathlessly descending down a steep angle at speeds in excess of 60 miles per hour just can't be beat, especially for thrill seekers. Or taking part in a full-sensory, 3-D time travel adventure while hurling through outer space, out of control, can be an experience of sheer ecstasy.
But in order to make it all possible, a significant amount of forethought, planning, coordination and creativity must go into the electrical designs that power such unique venues.
"What makes it so exciting, fun and challenging is designing for attractions that have never been built before," notes Rob Tanner, P.E., a project manager with GHT Limited, Arlington, Va.
Whether it's cost-effectively ensuring electrical redundancy for optimized life safety on rides and attractions; working with inspectors to approve projects that may fall outside the realm of building codes; or tucking away wiring and panels so that they don't interfere with the guest experience, such designs can be quite the challenge.
"It's a niche where if you have experience, you are much more valuable," explains Ken Lucci, P.E., Lucci & Associates, Camarillo, Calif., whose clients include Universal Studios and Knott's Berry Farm. "The firms that haven't had the experience underestimate the difficulty with these projects and the little twists, turns and hurdles that always come up."
Safety, Number One
First and foremost, when it comes to powering amusement and theme parks, are issues of life safety. Thus, one of the engineers' major tasks is to work closely with the ride vendors to determine exactly which points of power require emergency backup, explains Dan Christman, P.E., an account executive with GRGV Consulting Engineers, Orlando. This process is particularly crucial because backing up an entire facility could be cost prohibitive.
At the same time, large theme parks often have their own dedicated medium- or high-voltage substations and distribute power themselves. So, by utilizing redundant feeds, reliability can be built in, according to Hisham Barakat, P.E., vice president of entertainment for the Syska Hennessy Group's Los Angeles office.
Another consideration is designing life-safety systems that don't compromise the guest experience. "Since rides aim to give people the feeling of danger, you're not going to have walkways all over the place," says Christman, who's done quite a bit of work with Disney, Universal Studios and Busch Entertainment. "So you have to be able to move the ride to a safe stopping place where people can safely egress [if there is a power outage]."
This also involves positioning piping or conduit in places where they will be hidden from view. "Even conduit that's 30 feet up needs to be painted to match the ceiling," Christman adds.
Similarly, manholes must be strategically located so that a service vehicle and crew can gain access during park hours or, if necessary, wiring can be dug up without affecting park attendance, claims David Eagleson, vice president of Forrec Ltd., a Toronto-based theme park design and consulting firm.
In addition to the big rides, backup power is sometimes also a requirement for the more computer-sophisticated attractions. For example, Christman has designed "four-dimensional" theaters that take viewers on an adventure via a visual experience combined with special effects such as buzzers, water sprayers and leg ticklers in their seats. But if the power goes down, it can be extremely difficult to get all those elements back in sync. Therefore, uninterruptible power supplies are often specified.
In Search of PQ
Besides power reliability, quality of power must also be high on the electrical engineers' list of concerns, especially since rides and attractions run on many motors, often installed with variable-frequency drives (VFDs)— which can produce harmonics.
"We try to use surge suppression wherever practical and possible to separate VFDs from one another, and to arrest surges before they reach the rest of the distribution system," explains Christman. "But at some point, there's a cost tradeoff. We can't put surge suppression on every VFD, but that's part of our job, to figure out what makes sense."
Another way to trap harmonics is to specify a harmonic zero-sequence filter, suggests T.K. Wong, P.E., a senior associate with the sports & entertainment division at the Syska Hennessy Group, Los Angeles. Although this technique doesn't eliminate harmonics, it will inhibit their impact on adjacent loads.
But probably the most common approach for dealing with harmonics, according to Wong's colleague Barakat, is to size the neutrals and transformers with sufficient copper.
"We're doing more copper every time we turn around," GHT's Tanner jokes.
Yet another power quality issue is grounding, which can be rather difficult in a geographic location such as Florida.
"With sand, you may have to go to 100 feet before you find the level of resistance you need," he explains. "But by chemically treating the sand, you can increase the resistivity."Energy Efficiency Anyone?
With all the flashing lights, special effects, motors and backup power requirements, the issue of energy conservation at amusement parks can be somewhat controversial.
"Theme parks and energy savings don't go hand in hand at all," claims Barakat. "Most of them are 24-hour facilities and the most you're going to be able to do is to control the lighting by using compact fluorescents and dimming controls."
But Jeff Jafazade, P.E., MBA, president of IDA Engineering, Dallas, begs to differ. "I don't agree with that. I think you can save energy in everything that you do, and the payback can be pretty good for amusement parks."
Tanner also points out the actual amount of energy consumed by all the lighting is a lot less than it seems. "With all the flashing, switching, blinking and dimming, energy use is not as horrible as people would think when they see all the lights in the park."
And as the International Energy Conservation Code is adopted by more and more cities, increased energy-efficiency standards may eventually be put upon parks, predicts Jafazade.
Of course, the issue of dealing with code officials and different jurisdictions can be a whole other can of worms, especially for amusement parks, which often don't fall under any specific code category.
"Often codes don't specifically address rides, so we have to find capsules of codes from other facilities and apply them," explains Tanner.
This often involves lots of code research, as well as working extensively with creative show designers who want to build extravagant attractions but, in all likelihood, have little concept of what constitutes a safe building design. "Our challenge is to dump their talent into modern-day building codes," says Tanner.
It's also important to note that this process is not just challenging for designers; it's a tough job for code officials as well.
"The authorities having jurisdiction are in a difficult spot because we are designing very unusual things," says Christman.
So in order to ease the permitting process, Christman typically makes an extra effort to keep the AHJs informed as the design solidifies.
Lucci takes a similar approach. However, he points out that sometimes a project can last more than three years and then there may be turnover in the building department.
"Most of the time everybody is on the same page, just as long as the political climate doesn't change drastically," he says.
Another variable is the fact that there can be significant variations among codes, especially when comparing code requirements between small parks in rural areas and major theme parks in southern California.
However, one thing that all codes are very strict about is that all equipment must be UL-listed, which is often a problem when dealing with foreign manufacturers. In such cases, owners must bring in third-party testing agencies in order to certify the equipment.
Yet another problem that can emerge, both with domestic and foreign ride manufacturers, arises when the delivery instructions aren't accurately communicated. "Equipment can show up unannounced or on trucks that are too large to gain access to the site," explains Ed Slingluff, vice president of estimating for Morrow Meadows, an electrical contracting firm located 20 miles east of Los Angeles in City of Industry, Calif.
Consequently, equipment orders and site specifications must be very well explained, adds Slingluff.
The Ever-Changing Park
Once the building team is working with ride vendors, it's possible to address issues of electrical design, power reliability, power quality and conforming to code requirements. But what about cases where a park expansion has already been commissioned, but rides and attractions are still being developed?
"It's very rare that parks have all the vendors lined up [at the beginning of a project], so it can be very difficult to design," notes Barakat. "Consequently, you really need time at the end of the project for troubleshooting."
And the same goes for shows, notes Tanner. "Show vendors typically don't start designing until you're already in construction, so it makes it real tricky at times."
One way to deal with this is to design with as much flexibility and expandability as possible.
"Flexibility is really key for amusement parks because things can change instantly," claims Jafazade. "We typically design for 25% future capacity."
Because there is so much uncertainty with these kinds of projects, engineers also find it difficult to determine a fair and equitable fee for services rendered, notes Lucci. "Even though amusement parks are a lot more fun than other projects, business-wise, it's a greater risk."
But for those engineers who have done a few of these projects, or at the very least, have applicable design skills gleaned from working on museums, high-end hotels or theaters, the experience of designing amusement and theme parks can be a very enjoyable one, especially when there is fun and excitement involved.
"The opportunity to be part of a themed park attraction typically brings out the kid in all of us," concludes Christman.