Escalators: Facts and History
Escalators are another way to move people from one level of a building to another. An escalator is essentially a set of moving stairs. Each step is connected to the next step by two heavy roller chains. These chains drive the steps in an up-and-down direction. Each step has axles with rollers on each end. The rollers rest on metal tracks inside a steel frame called a truss. The truss rests between two floors like a steeply slanted ladder.
The steps lie flat at each end of the escalator to make it easier for passengers to get on and off. As the steps travel up or down the escalator, they automatically rise so that they look like staircase steps. Near the end of the ride, the steps automatically flatten out again.
Hidden under the floor at the top end of the escalator is a set of sprockets. A sprocket is a wheel with projecting teeth, like the gear wheel of a bicycle. The teeth of the sprocket catch the links of the roller chain and drive it round and round, pulling the steps along their rails. The sprocket at the top end of the escalator is driven by an electric motor beneath the floor. The chains run over pulleys at the bottom. These pulleys steer the chains properly and keep them tight.
At each side of the moving steps is a protective wall called a balustrade. On top of the balustrade is a continuous handrail, made of a moving belt of rubber. It moves along with the steps, at the same speed and in the same direction. Handrails help passengers enter, ride, and exit the escalator.
The first escalator was patented in the United States in 1859, but no one used this invention commercially. However, a number of inventors developed escalators after 1890. At first escalators were crude and unsafe by today's standards. Most of them were not successful.
In 1892 a patent was granted to Jesse W. Reno (1862–1947) for an "inclined elevator." A rider on Reno's escalator needed good balance. The flat-surfaced moving platform transported people upward at a 30-degree angle. Passengers needed to lean forward like skiers racing uphill. Because the handrail did not move, passengers had to keep moving their hands as they were carried up. Moving handrails and other safety features were added later.
In 1899 an inventor who worked with the Otis Elevator Company built the first step-type escalator. He also coined the term "escalator," which is a combination of the Latin word scala, meaning "steps," and elevator.
Today's escalators all travel at about 100 feet (30 meters) per minute. The fastest escalators ever built ran at 180 feet (55 meters) per minute, slightly more than 2 miles (3 kilometers) per hour and slightly slower than an average walking pace. The world's highest escalator lifts passengers to a height of about 200 feet (60 meters), roughly equal to the height of a 20-story building. This escalator operates at a station of the Moscow Metropolitan Railway in Russia.
Visitors to Hong Kong's Ocean Park can ride the longest outdoor escalator system in the world -750 feet (230 meters). The shortest escalator -a mere five steps- is tucked away in a private garden in Saudi Arabia. Spiral, or helical, escalators are a design breakthrough now being used in imaginative and elegant buildings.
Moving sidewalks are another way to move many people in public places such as airports, railroad terminals, and shopping centers. A moving sidewalk is basically a collapsed escalator where the flattened step treads move as a level or slightly inclined surface.
The steps lie flat at each end of the escalator to make it easier for passengers to get on and off. As the steps travel up or down the escalator, they automatically rise so that they look like staircase steps. Near the end of the ride, the steps automatically flatten out again.
Hidden under the floor at the top end of the escalator is a set of sprockets. A sprocket is a wheel with projecting teeth, like the gear wheel of a bicycle. The teeth of the sprocket catch the links of the roller chain and drive it round and round, pulling the steps along their rails. The sprocket at the top end of the escalator is driven by an electric motor beneath the floor. The chains run over pulleys at the bottom. These pulleys steer the chains properly and keep them tight.
At each side of the moving steps is a protective wall called a balustrade. On top of the balustrade is a continuous handrail, made of a moving belt of rubber. It moves along with the steps, at the same speed and in the same direction. Handrails help passengers enter, ride, and exit the escalator.
The first escalator was patented in the United States in 1859, but no one used this invention commercially. However, a number of inventors developed escalators after 1890. At first escalators were crude and unsafe by today's standards. Most of them were not successful.
In 1892 a patent was granted to Jesse W. Reno (1862–1947) for an "inclined elevator." A rider on Reno's escalator needed good balance. The flat-surfaced moving platform transported people upward at a 30-degree angle. Passengers needed to lean forward like skiers racing uphill. Because the handrail did not move, passengers had to keep moving their hands as they were carried up. Moving handrails and other safety features were added later.
In 1899 an inventor who worked with the Otis Elevator Company built the first step-type escalator. He also coined the term "escalator," which is a combination of the Latin word scala, meaning "steps," and elevator.
Today's escalators all travel at about 100 feet (30 meters) per minute. The fastest escalators ever built ran at 180 feet (55 meters) per minute, slightly more than 2 miles (3 kilometers) per hour and slightly slower than an average walking pace. The world's highest escalator lifts passengers to a height of about 200 feet (60 meters), roughly equal to the height of a 20-story building. This escalator operates at a station of the Moscow Metropolitan Railway in Russia.
Visitors to Hong Kong's Ocean Park can ride the longest outdoor escalator system in the world -750 feet (230 meters). The shortest escalator -a mere five steps- is tucked away in a private garden in Saudi Arabia. Spiral, or helical, escalators are a design breakthrough now being used in imaginative and elegant buildings.
Moving sidewalks are another way to move many people in public places such as airports, railroad terminals, and shopping centers. A moving sidewalk is basically a collapsed escalator where the flattened step treads move as a level or slightly inclined surface.
