Elevators and Moving Stairways
SIC 3534
NAICS 333921
The vertical transportation industry includes the manufacturers of passenger and freight elevators, automobile lifts, dumbwaiters, and escalators. Elevators, as referenced here, are better known in Europe as "lifts" and are used to move passengers and equipment from level to level. They do not include farm elevators (primarily grain storage devices) or aerial work platforms (included under construction machinery and equipment).
According to Buildings, "elevators, escalators, and moving sidewalks are the building industry's equivalent to trains, planes, and automobiles." Although the industry experienced a brief expansion in the latter part of the twentieth century, the beginning of the twenty-first century brought the dual pressures of a downturn in construction and a simultaneous increase in the number of elevator manufacturers worldwide. Greater emphasis was placed on service companies. Large elevator manufacturers swallowed smaller corporations, making the industry increasingly global in nature. The industry subsequently consolidated into just a few major players by the mid-2000s. Otis Elevator Company, later part of United Technologies, founded the elevator industry and was first in the industry for decades. In fact, it wasn't until well into the 2000s that its leadership position was threatened by competitor Schindler Lifts. In 2005, other major worldwide players included Kone of Finland and ThyssenKrupp of Germany, as well as Mitsubishi and Hitachi of Japan.
The state of the elevator industry depends entirely on the health of the construction industry. Although service is an increasingly important aspect of the vertical transportation market, the manufacture of new elevators is dependent on the creation of the new buildings that require them. In the 2000s, the economic emergence of China and other Asian countries shifted the construction industry's focus from Europe and the United States to the rapidly growing construction markets in developing nations along the Pacific Rim. Developing technology included the implementation of multidirectional cabs, high-technology elevator-passenger interfaces, higher speed transportation, and optimal reliability, bringing with it an emphasis on greater environmental friendliness. According to the Freedonia Group, the U.S. market for elevators and escalators was expected to grow 6.5 percent annually through 2007, with most gains realized in residential construction and elevators or moving walkways for the disabled.
Once elevators were technologically able to service large buildings, two distinct categories of elevator construction emerged: electric elevators designed to be used exclusively in high-rise buildings and hydraulic elevators capable of accommodating low-rise buildings of five stories or less.
Hydraulic elevators are relatively slow with a maximum speed of 150 feet per minute (ft/min) or 46 meters per minute (m/min), which is not a disadvantage as long as a building has very few floors. Hydraulic elevators are seen as ideal for smaller buildings because they do not need overhead hoisting machinery. Generally, the elevator sits atop a piston that moves inside a cylinder that is sunk in the ground at a depth equal to the maximum height to which the elevator will rise. So-called hole-less hydraulic elevators rely on power that is transferred via a sliding plunger on the side of the elevator.
Electric elevators fall into one of two categories: gearless traction elevators and geared traction elevators. Gearless traction elevators are quite fast and regularly travel at 400 to 2000 ft/min (120 to 610 m/min). They are powered by large slow-speed motors and are generally installed in high-rise buildings with more than 10 stories. Geared traction elevators travel at a slower rate of speed—a maximum of 450 ft/min (140 m/min)—but can carry up to 30,000 pounds (13,500 kilograms) and have many industrial applications.
It is a given in the elevator industry that passengers often must wait for an elevator car to arrive. Escalators, on the other hand, offer a mode of vertical transportation that is continuously accessible. Depending on design, the "moving stairways" that make up escalators can transport up to 4,500 passengers per hour on a series of steps running in a continuous chain up an incline. Most escalators service floors separated by a 20-foot (6 meter) slope, although 100-foot (30 meter) escalators also are in use. All escalators are powered by alternating current electric motors and move at about 100 ft/min (30 m/min).
A third, relatively small part of the vertical transportation industry is a dumbwaiter. Dumbwaiters are used exclusively as material-handling systems (they do not accommodate passengers) and are widely used for such applications as moving books between floors in libraries or transporting food and medical supplies in hospitals. Dumbwaiters are always operated from outside the system, never from inside a cab. Dumbwaiters are limited to nine square feet of platform area and must be of a height no more than four feet. Any system larger than this is classified as an elevator and is therefore subject to more stringent safety requirements.
In the United States, the agency that regulates elevator and escalator safety, operation, and design is the American National Standards Institute (ANSI). ANSI is an organization of industrial and consumer groups and pertinent government personnel. Under their aegis, on-site safety inspections of elevators, dumbwaiters, and escalators are made by state and local inspectors.
The elevator of the twenty-first century operates on many of the same basic principles first perfected by Elisha Graves Otis back in 1854. An elevator is basically either an open platform or a closed cab powered by a unit that moves it up and down an enclosed shaft through various combinations of pulleys, cables, counterweights, and gears.
While the concept of an elevator-like device able to move heavy loads vertically was investigated by the ancient Greeks (the Greek mathematician Archimedes invented a type of elevator in 230 B.C.), such apparatus of vertical transportation had limited application well into the Industrial Revolution because of seemingly unsolvable safety problems, especially the fact that there was no way known to stop a falling elevator. If the lifting cable or rope used in the operation of an elevator broke, the results were disastrous for the elevator, its passengers, and any freight on board. Demand, however, overrode safety concerns in certain situations. The advent of the Industrial Revolution saw elevator use increase in industrialized countries, especially in the United States and Great Britain. By the 1840s, patents had been granted for steam and hydraulic elevators. Still, the safety question cast a pall on elevators' general acceptance and thus stifled technological development. New buildings remained more or less "stunted," because the practical height of a building was inextricably tied to the ability to vertically move people and freight to the upper floors. Until this could be accomplished quickly and safely, the multi-story buildings and skyscrapers that are the hallmarks of modern urban architecture had to wait.
Vertical transportation embarked on its "golden age" in 1853 after Elisha G. Otis, a 43-year-old mechanic from Albany, New York, dramatically demonstrated an elevator safety device of his own invention. First unveiled at the Crystal Palace Exposition in New York City, the device had been constructed by Otis in a Yonkers, New York factory. Otis's safety innovation consisted of a pair of spring-loaded "dogs," which, if the elevator's lifting cable broke, would engage cogs mounted along the elevator shaft rails, thus halting the uncontrolled fall of the elevator. Scientific American called the device an "excellent" and "much admired" invention. Buoyed by the excited reception, Otis and his son began in earnest to manufacture "safety elevators." In 1857 Otis installed the first commercial passenger elevator in a department store in New York City. This steam-powered elevator rose through the building's five stories in just under one minute, carrying passengers effortlessly to the top floor and conveying the Otis Elevator Company with seemingly comparable ease to an undisputed position as leader of the vertical transportation industry.
Once Otis had shown the way, advances in elevator technology paralleled the increasing demand for higher buildings and skyscrapers. Elevators became faster, safer, and more capable of carrying heavier loads, and the steam elevators of the nineteenth century gave way to the electric and hydraulic elevators of the twentieth. Otis Elevator Company introduced the first escalator at the 1900 Paris Exposition, but development of this alternate approach to vertical travel did not begin in earnest until the 1920s. Prior to 1950, escalator use was generally restricted to stores and transportation terminals such as airports. After the middle of the century, however, they became increasingly popular features in schools, offices, public buildings, and other buildings where large numbers of people had to be moved among a relatively low number of floors.
In the 1980s the vertical transportation industry saw stability in Europe and a boom in Asia, but began to level off in the United States. The world market expanded in the latter part of the...
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