A WELCOMED LIFT : New Computer Technology Keeps Elevators on the Up and Up, Cuts Waiting Time

When his law firm moved into the brown office tower at the corner of Century Park East and Santa Monica Boulevard in Century City, attorney Paul R. Fine knew the big advantage of his new address--half the 26-story building’s offices have a view of the pastoral Los Angeles Country Club golf course. But he was also aware of a major drawback.

“The elevators here were something of a joke,” he recalled. They often took a minute or more to come when called, and when they finally did show up, sometimes there would be two or three cars at once. Elevator service was so bad that visiting clients made nasty remarks.

Fine and other tenants complained about the elevators, and when a new company took over management of the 14-year-old building in 1986, it undertook a $1.2-million modernization of the entire elevator system. The electrical relays that had dispatched elevator cars to calls were torn out and replaced with computerized controls that constantly calculated the best distribution of elevators up and down the building. Faster closing doors and computer-controlled hoisting motors moved passengers more quickly once they were in the cars.

$2.5 Billion in Sales

Altogether, average waiting time for an elevator dropped from 59 seconds to 29 seconds, while average trip time has gone from 13 seconds to eight, said Charles W. Altmaier, vice president and director of special projects for Chicago-based JMB Property Management. The modernization not only stopped the grumbling of tenants but also helped JMB raise rents while increasing occupancy of the building, he said. In competing for office tenants, he added, “You can’t afford to have these big, glaring deficiencies.”

The use of computer technology is allowing manufacturers to design new elevators and refurbish old ones to move people a little quicker and a lot more efficiently. The improvements save time for passengers and have boosted business for elevator makers. Since 1983, worldwide sales have grown 36% to $2.5 billion at Otis Elevator, the market leader in the elevator industry and the only major elevator maker to release financial figures.

Bringing the nation’s old elevators up to date has become a $2-billion annual business, compared to roughly $1 billion a year in new elevator sales, and Los Angeles is the fastest-growing major market. “We’re practically rebuilding all the elevators in the United States,” said George R. Strakosch, a consultant and author on elevator technology issues.

The new, “smart” elevator does not go up or down any faster than the automatic elevators in use for the past four decades. Rather, the advantage of replacing the old electrical relay controls with computer chips lies in shaving seconds here and there from the moment a passenger pushes a call button.

Most of the fancy computer programming consists of calculating up to 10 times per second the best way to allot elevator cars to passenger calls, thereby cutting waiting time by up to a third. One of the simplest tricks, previously near impossible with relays, is to assign a call to an elevator that already has to stop at that floor, even though another car may be slightly closer.

When the smart elevator shows up, weight sensors and more calculations determine how long the doors stay open and even how fast they close--slower if the elevator is stuffed and passengers have to squeeze in, faster if it is near empty. And once under way, a smart elevator that filled up in the entrance lobby will not stop on the second floor in a futile attempt to take on more passengers.

“There’s no sense stopping for a hall call when the car is full. So we bypass the hall call. The person in the hall doesn’t know,” said Joseph C. Walker, product manager for gearless elevators at Farmington, Conn.-based Otis Elevator, a subsidiary of United Technologies.

Smart elevators can be programmed to give special priority at certain hours of the day to a floor with different traffic patterns from the rest of the building. During meal times, two elevators of New York’s World Trade Center serve only the Windows on the World restaurant on the 107th floor.

On the way to the top of skyscrapers, maximum speed for smart elevators is no faster than for automatic elevators: about 18 m.p.h. This speed limit is not legal or mechanical, but human. At high speeds, ears begin to pop, and “If you accelerate too fast, your pants fall down. There’s a comfort level,” said Donald W. Brooks, vice president for new products at Toledo, Ohio-based Schindler Elevator, a subsidiary of Lucerne, Switzerland-based Schindler Holding, one of the world’s largest elevator makers.

At the end of a ride, programming can foil the mischievous child or juvenile adult who presses buttons for every floor just before leaving the elevator. In some smart elevators, if the total weight of all occupants is less than 300 pounds and four or more stops are requested, the elevator automatically cancels all the requests. Anybody left inside must start pushing buttons all over again.

Finally, if a smart elevator feels mechanically or electrically indisposed, it can even call a mechanic for help. “You can dispatch someone to fix an elevator before the owner of the building knows its broken,” said William S. Lewis, a partner of Jaros, Baum & Bolles, a New York consulting firm.

Marginal Savings

None of these advances, however, has turned up a way to increase elevator capacity at 9 a.m., when hordes of impatient commuters mob office building lobbies. Rush-hour capacity is what architects use in determining the number of elevators a new building needs. Eliminating a single elevator shaft can make thousands of square feet of floor space available for rent in a skyscraper.

Yet the biggest benefits from smart elevators have gone to employees who sneak out to the bank or a coffee shop at 3 p.m. and try to race back before the boss notices. That is because the programs that decide which elevator to send to which floor can do the most good when a few passengers are scattered up and down a building.

During rush hour, elevators function predictably, rising slowly through stops at all or most of the floors and coming quickly down again for another load. There are few opportunities for saving time through complicated mathematical decision-making. So savings in shafts have been marginal.

Using microprocessor-controlled elevators only occasionally enables a developer to avoid installing an entire shaft, Lewis said. If the number of tenants in a building calls for 7 1/2 elevators, “Yesterday you would have put in eight and now you put in seven.”

Yet even while the gains to developers from high-tech elevators have been minimal thus far, owners of existing buildings pay as much as $250,000 per elevator to have machine rooms torn out and cars replaced.