Electronic Components/Escalator Design.


QUESTION: Dear Deirdre


Escalators, like moving walkways, are powered by constant-speed alternating current motors and move at approximately 12 feet (0.300.61 m) per second. The typical angle of inclination of an escalator to the horizontal floor level is 30 degrees with a standard rise up to about 60 feet (18 m).

1. Is the Angle of inclination of 30 degree standard to the Horizontal floor and standard rise of about 60 feet standardized in all escalator designs  while manufacturing ?. i.e. Can the Angle of inclination differ to 45 degree or standard rise to say 80 meters
or speed vary i.e.  2-3 feet (0.61 m - 0.91 m) per second ?.

2. Is the Load carrying capacity (weight of the Riders) in a escalator set to a maximum limit ?. i.e. Every Escalator designed
has a maximum load carrying capacity similar to a Elevator device ?

In this case, how safety of the passengers is ensured if overload happens ?. what is the overload protection mechanism
inbuilt within the escalator ?. As soon as there is a overload of
extra weight, the escalator device stops moving upwards (Step Up Motion) or downwards (Step Down Motion) ?.

3. In events of electric power breakdowns where escalator comes to a standstill, how passengers safety is ensured as they is a chance of losing balance while moving up or down ?. Is the escalator machine battery powered up in case of mains power failure ?.

Awaiting your reply,

Thanks & Regards,
Prashant S Akerkar

ANSWER: Question 1. An escalator is designed individually for each installation. So the length and angle can vary depending on the needs of a particular building.

Question 2. Escalators can be self-limiting. It is a fairly simple calculation to determine how many people will fit on the escalator, the average weight of people, and to design the escalator to support that number of people, as well as some safety margin. That is why you never see a "maximum load" placard on an escalator - it will easily handle the number of people who fit on it.

The major malfunctions with escalators are usually some type of control issue - including changes in speed or direction. These aren't typically caused by overload, but by control system failure.

Question 3. It's fairly easy to design a gear-based system that will simply lock when power is removed. A worm type gear-reduction system will automatically lock when power is removed, and I expect this is the sort of mechanism used in escalators. While I'm not certain, this is how I expect they are designed. The same arrangement is used for tuning machines on musical instruments - such as guitars - precisely because they lock in position when the source of power is removed from the driving gear.


---------- FOLLOW-UP ----------

QUESTION: Dear Deirdre

Thank you.

1. if a Comparison between Escalator and Elevator Systems is done in terms of  Manufacturing, Installation, Maintenance Costs, Escalators will
be more expensive (i.e. Cost incurred for Manufacturing, Installing and Maintenance) than Elevators ?

2. Can we implement Escalators in already built structures viz Shopping Malls, Departmental stores, Buildings, Airports, Metro Rails etc.

Awaiting your reply,

Thanks & Regards,
Prashant S Akerkar

Escalators and elevators have different purposes. Escalators take up more floor space, but allow larger numbers of people to move between floors more quickly. There are dedicated up and down escalators. A separate escalator needs to be installed between each floor.

An elevator permits fewer people to select between multiple floors. To handle a greater number of people, multiple elevators may be installed.

In case of a power failure, an escalator is typically safer - they can still be used as stairs if the power fails.

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Deirdre Hebert


I can answer most questions regarding electronic components, what they are and how to use them.


I worked for a number of years in the electronic component testing industry, designing and building automated test equipment for the electronic manufacturing industry.

Numerous technical manuals for the equipment we built.

UNH, CCAF and others

Past/Present Clients
General Electric, Motorola, Ford, Sensonor and others.

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