MEEB: Vertical Transportation: Escalator Design

MEEB: Vertical Transportation: Escalator Design

First operated in 1900 at the Paris Exposition

Two types of arrangement, criss cross and parallel arrangements

criss cross = from side elevation the up and down escalators form a cross or X shape

it has two modes, spiral and walk-around which applies to whether you can board the next escalator up adjacent to the landing or if you have to walk-around to the opposite end

Most common of the two

takes up less room

Parallel = escalators face in same direction, from side elevation, up and down escalators are in line with each other (one is hidden by the other)

two modes, stacked (walk-around) and spiral

requires more floor space, used less often

General escalator guidelines

Centrally locate in main line of traffic

Mark escalator destinations clearly to avoid confusion of traffic.

1. provide well marked escalators with sufficient traffic carrying capacity.

2. provide collecting space at intermediate landings so that pressure can be relieved

3. provide a physical divider at intermediate landing turnaround points that guides riders away from the discharge point and provide adequate space (and time) for riders either to leave at that level or to follow the guide around and continue the trip.

4. Provide a slight setback for the next escalator so that the necessary 180 deg turn can readily be negotiated.

Newels = moving rail extensions at top and bottom landings

8 feet past landing for 32 inch units

10 feet past landing for 48 inch units

Escalators are reversible to accommodate traffic requirements

Standard designs

Inclination = 30 degrees from horizontal in all of United States

Vertical clearance = 7 feet clear

maximum linear speed = 125 fpm (per ANSI/ASME 17.1, verify)

Industry standard linear speed = 100 fpm

Size (between balustrades) = 32" and 48"

Width (refers to tread width, typically referred to as tread depth in stair design) = 24" tread for 32" size, 40" tread for 48" size

Approximate Maximum Rises:

unit size type supports max. rise

32" standard, supported at ends only = 24 feet

48" standard, supported at ends only = 16 feet

32" standard, supported at ends & center = 30 feet

48" standard, supported at ends & center = 20 feet

32" heavy, supported at ends only = 24 feet

48" heavy, supported at ends only = 18 feet

32" heavy, supported at ends & center = 40 feet

48" heavy, supported at ends & center = 20 feet

(note:these are general and vary with manufacturer)

Special designed units available up to about 60 foot rises

BUT

as rise increases, loads on all drive components including chains and sprockets increase sharply

heavier equipment requires increased truss width, wellway size and balustrade decks.

Rises above 25 to 30 feet (depending on unit width) drive motor won't fit inside the truss and requires a separate machine room below the truss.