Escalators

Escalators are conveying devices that are used to move people vertically on individual, linked stairways. In installing escalators in a building, many things must be taken into consideration. The most important factors are the height to be climbed and the distance available to run the unit; since they determine the pitch and length of the escalator. Other design factors include:

• location
• physical requirements
• traffic pattern
• safety precautions

Components of escalators include top and bottom landings, trusses, tracks, handrails, and steps. Unlike an elevator, a disabled or powered down escalator can still be used as a conventional flight of stairs. So building managers can shut them down without adversely inconveniencing the users in the building, unlike an elevator.

Features

The average speed of an escalator falls between 1 ft. to 2 ft. per second, or .3 m to .6 m per second. The angle of ascent of an elevator is usually around 30 degrees to the horizontal. The max vertical ascent is usually around 60 ft., or 18 m. At a 30% incline, that means the elevator truss length would be 120 in., or 36 m, long. Step width can vary from 16 in. to 40 in., or 40 cm to 1 m. The standard step width is 32 in. or 80 cm. Escalators are usually powered by AC induction motors and usually run at one speed.

Moving Walks

Like elevators and escalators, moving walkways are used to move people. They are also known as moving sidewalks and are called “travelators”  in the United Kingdom. Much like escalators, moving walkways use a conveyor belt to transport people. However, moving walkways move people and goods horizontally, or on a lower angle of incline to the horizontal than an escalator. They are often found in large airports where people have luggage and have to walk a long distance between various sub terminal buildings. Moving walkways are often installed in pairs, for movement in each direction. They usually run about half of walking speed, around 1.4 mph or 2.2 kmph and can be from 27 in. to 56 in., or 67.5 cm to 140 cm wide. They are usually powered by AC induction motors. Moving handrails, like those found on escalators for code and safety reasons, are optional on horizontal moving walkways.

Types

Moving walkways come in one of two basic styles: pallet type or moving belt. Pallet type moving walkways are built from a series of connected metal plates that are joined together to form a walkway. Pallet type moving walkways are essentially flat elevators. This type of moving walkway has a metal surface, although they are available with a rubberized tread bonded on top of the metal plates. Moving belt walkways are essentially human conveyor belts. Moving belt walkways are typically built with mesh metal balls, which is a rubber surface over metal rollers.

Specifications

All three types of these people movers require extensive architectural and structural engineering support since they are heavy and need a stable base. Elevator shaft ways have to be strong and straight and are usually framed with girders or at least reinforced concrete. Elevator shafts can be the most problematic part of a building’s construction process. There are modular elevator units that come enclosed in their own shaft and everything else one needs for an elevator. But these are usually limited to 100 ft., or 30 m, tall and still require a stable base pad to stand on. When adding an elevator to an older structure, especially a wood-framed structure, a separate steel and concrete combination elevator shaft and fire stairwell addition is usually built on to the side of that building. These refit jobs are a good place to install a modular elevator and do away with the extra expense and engineering effort that a custom built shaft requires. Horizontal people movers need a good solid, usually reinforced concrete base. All of these types of movers require high voltage, high current power feeds, at least 440 VAC 3 phase power.