Pre-industrial era
The earliest known reference to an elevator is in the works of the Roman architect Vitruvius, who reported that Archimedes (c. … See more

Round-trip time calculations
History
In 1901, consulting engineer Charles G. Darrach (1846–1927) proposed the first formula to determine elevator service.
In 1908, Reginald P. Bolton published the first book devoted … See more

Manual controls
In the first half of the twentieth century, almost all elevators had no automatic positioning of the floor on which the cab would stop. Some of the older freight elevators were controlled by switches operated by pulling … See more

Most elevators are built to provide about 30 to 40 years of service, as long as service intervals specified and periodic maintenance/inspections by the manufacturer are … See more

Some people argue that elevators began as simple rope or chain hoists (see Traction elevators below). An elevator is essentially a platform … See more

Elevators can be rope dependent or rope-free. There are at least four means of moving an elevator:
Traction elevators
Geared traction … See more

Anti-crime protection
The anti-crime protection (ACP) feature will force each car to stop at a pre-defined landing and open its doors. This allows a security guard or a receptionist at the landing to visually inspect the passengers. The car stops at … See more