ESCALATOR

The term “escalator” was developed by the Otis Elevator Company to describe the
moving stairway systems they began producing at the turn of the twentieth century. Otis
Elevator main tained exclusive use of the term until the 1930’s when “escalator” was
declared to be in the public domain.
Elevators provide quick and easy access over long vertical distances and thus were
necessities in the high-rise building type that began to evolve at the end of the nineteenth
century. The escalator provides both vertical and horizontal displacement, usually in an
open environment, making it more appropriate in buildings where only a few floors need
to be connected. The funicular, or inclined elevator, was the predecessor of both the
vertical elevator and the escalator. It evolved into use where the vertical distances were
great and intermediate landings were usually not required such as a ski lifts. Pittsburgh,
PA once boasted fourteen funiculars to move people around the hilly city and they remain
an integral part of the transportation system in Naples, Italy and other parts of Europe.
The predecessor to the modern escalator was the flat stepped “Seeberger” escalator
introduced to the public at the Paris Exposition in 1900. The design necessitated
passengers step off or on the upper landing at an angle to the direction of travel creating a
safety hazard. The “Reno” type, patented about the same time as an “endless conveyor or
elevator,” consisted of a series of slightly inclined flat platforms on a conveyor. A Reno
type escalator installed in the 59th Street Station of the New York subway system at the
turn of the century remained in use until 1955. Both the “Reno” and “Seeberger”
escalators included continuous rotating handrails and were manufactured by the Otis
Elevator Company.
A much earlier moving stairway system, patented in 1859, was the Ames revolving
stair. Its demise was the equilateral treads that forced passengers to awkwardly jump off
and on at right angles to the direction of travel as the tread rotated around the gear.
Other early 20th century improvements to the design of escalators included flat steps
with cleats or combs, and boarding areas parallel to the direction of travel. Developments
during the mid-century include metal treads (instead of wood), glass balustrades, sleeker
lines, and safety enhancements. A late 20th century innovation was the development of
the radial configuration.
Related to escalators are moving walks, both horizontal and inclined designed to speed
the movement of passengers over long distances. Early types, such as the one introduced
at the 1893 Chicago World’s Columbian Exposition, were refined conveyor belts.
Modern moving walkways, incorporating much of the technology used in escalator
design, are familiar sights in airport terminals. Inclined moving walkways are often found
in retail establishments to enable shoppers to move shopping carts from level to level.
Elevators were a key design feature in department stores, museums, concert halls, and
other early 20th century building types built to satiate the need of the burgeoning middle
classes to spend and to be seen. Escalators continue to be used to create opportunities for
enticing shoppers in department stores and shopping malls to view enticing merchandise
displays.
The construction of extensive underground and elevated commuter rail systems in
British, European and American cites contributed to the need for experimentation in the
Encyclopedia of 20th-century architecture 784
development of machines to facilitate the transport of large groups of people over
relatively short distances. Escalators enable the management of people in transportation
centers by dispersing surges of users into a uniform flow and quantity. Moscow boasts
the fastest speeds, about 200 feet per minute for escalators traveling into the deepest
subway tunnels. Speed is limited to 100 feet per minute in most other countries for safety
reasons.
During the first half of the 20th century, banking halls were often located on the
second floor in new high-rise buildings. Escalators provided easy access to the banking
hall from the street allowing patrons to observe who was going in and out, whom they
were with, and, what they were wearing. Today lobbies of grand hotels and convention
centers perform the same function; they allow guests to see and be seen during their
leisurely ascents or descents while adorned in their finest garments and jewelry. The
escalators in the lobby of the PSFS (Philadelphia Saving Fund Society) Building
(Philadelphia, PA) originally transported patrons to a banking hall that was recently
converted to the ballroom of a luxury hotel.
Escalators also provide excellent opportunities for viewing monumental architectural
spaces such as those in the East Wing of the National Gallery of Art (Washington, D.C.)
or panoramic views of the natural environment. Architects often use escalators as design
features within large open spaces. They can be arranged in crisscross or parallel
configurations creating bold aesthetic statements.
The process of designing spaces for escalators includes extensive analysis of a
building’s function, the number of occupants, peak periods of use, and knowledge of how
people traverse through space as individuals and in groups. Adequate queuing distances
must be provided at both the top and bottom of landings to allow for large numbers of
people to embark and disembark in an orderly fashion. This is particularly important in
rail facilities when the platform edges may be located near the escalators. Subway
stations feel grossly oversized during much of the day, except at rush hour when they
seem barely adequate to safely contain the passengers in the space.
Escalator configurations (tread width, angle of travel, speed, and design features) are
standardized by code to ensure passerby safety and to make the process of incorporating
escalators into a design less difficult for architects and engineers. Safety requirements
minimize opportunities for innovative aesthetic modifications to escalator systems.
Balustrades, the most prominent feature, may have tempered glass (clear or tinted),
bronze, or, stainless steel safety panels. Panels may be etched with designs to enhance
their appearance or to tie the escalator to the building’s design theme. Handrails may be
colored or lights may be mounted under them to emphasize this feature. Trusses (the
structural support) may be exposed such as at the Zurich Trade Fair in Switzerland or
clad in mirrors, ornamental metals or decorative stone.