Elevators--Perception Going Up

Elevators have an unusual relationship with the macabre.

Really, stick with me here. Some of people's most irrational fears are exploited by an elevator: heights, enclosed spaces; decapitation; a terrifying free fall (see The Tower of Terror).

There's more. Have you ever seen The Shining? (Yes, of course you have.) Little Danny Torrance envisions elevators unleashing waves of blood to recolor the walls of a haunted hotel. In similar bloody remembrance, let's not forget The Departed's brutal homicides (graphic) . Heck, they made an entire B movie about a killer elevator.

In real life, many structures skip numbering the 13^th floor or designating a 13^th floor button in elevators.

I don't know about you, but elevators can be an inconvenience for me-at most. Ugh, I have to make boring small talk/listen to terrible elevator music. Elevators are an essential part of building design however and the likelihood of an elevator malfunction is rather low. Despite their customized prevalence throughout the world, and the idiosyncratic nature of their name (yes, Britons we know it's called a lift), elevator designs vary minimally and are cursed for their perceived shortcomings.

Remarkably, Italy has over 900,000 elevators installed within its buildings, meaning there is one elevator for every 67 of its citizens. By comparison, the USA has the second most, but with one elevator for every 445 of its people. It makes some sense that Italy has the most, if only because Roman scientist Vitruvius was reputed to have invented a vertical ascension mechanism in 236 B.C. Elevators appeared in variation through the rest of history until the early 19^th century when hydraulic systems began appearing in Britain and the United States. Though modernized with better safety protocols, smaller parts, and worldwide popularity, elevators designs have remained largely unchanged since the traction design was invented shortly thereafter.

Elevators are essentially limited to four types:

• traction hoists employ high strength cables, a counter weight, and an electric motor
• hydraulic pistons and their associated pumps push hydraulic elevators skyward
• a hybrid traction-hydraulic elevators has an attached counterweight, but still relies on the linear power of hydraulics
• climbing elevators are self-powered and are reserved for towers, masts, and other exceptional structures

Structures with just a handful of stories are best served by traction-hydraulic elevators, while skyscrapers and other tall buildings tend to use traction designs.

Depending upon the traffic pattern and the demographic the elevator serves, some very intuitive functions are built into the devices. In halls where multiple elevators serve riders (also called an elevator bank), cars are concentrated at lower levels in the morning, and at higher levels in the afternoon to better accommodate the flow of traffic. In Jewish communities, elevators on the Sabbath may run automatically-opening at every floor, to accommodate those who observe electrical prohibition on that day. Emergency patterns are common in nearly every lift and allow firefighters, police, and medical personnel to select the elevator's actions.

Many peculiar structures incorporate specialty elevator designs. Notably, in skyscrapers extending dozens of stories, a skylobby will be built. Here high speed elevators directly take passengers to an intermediate floor providing riders with access to a new elevator bank. Another interesting case is the Gateway Arch in St. Louis that uses a tramway with enclosed, self-leveling cars to account for the structure's unique shape, and the elevators that serve the Eiffle Tower's concave legs function similarly.

Finally, those who perceive elevators as unsafe or dangerous need to have a look at the safety record of elevators. In 1852, Elisha Otis debuted the safety elevator which would not fall if the traction cable broke. Brake pads grasp the vertical running rails, slowing the elevator if it descends faster than which it was intended. In fact, until the 9/11 attacks, the only record of a traction elevator in absolute free fall was in 1945 when a plane struck the Empire State Building, severing the cables. Hydraulic elevators are much more likely to fail, but mostly because older designs excluded a failsafe and relied upon a single cylinder to support the elevator.

So it's 5:30 p.m. on Friday. You just packed your desk and are so ready to end your workweek. You arrive at the elevator bank and hit the call button so you can take your ride from the 67^th floor to the lobby and get on your way home. Ugh, of course the elevator is going up. All the elevators are going up! Clearly there is a conspiracy to keep me here as long as possible!

A more common complaint is a bias against riders travelling downwards from high floors after work. Riders in high floors will complain that elevators servicing their floor will most often be travelling up, while riders in lower floors will receive the benefit of elevators already on their way down. The truth is that it's only the perception that some floors receive better service.

If someone were to observe an elevator's ascending and descending pattern for a long period of time, they would count an equal number of passes in each direction. However, it's more common for riders to approach elevators at need and be subjected to waiting. Assuming the elevator distributes its passengers evenly, the elevator will be more likely to be coming from the bottom of the building for riders on high floors simply because the elevator spends more time where there are more floors. The same is true for riders on low floors, who can expect to travel downwards on an elevators first pass, just because they are unlikely to encounter the elevator in the slim interval where it is below their floor and then ascends. It's called the elevator paradox. Make sense? Perhaps the graph on the above right helps.

So, not only have we debunked the ideas that elevators are unsafe, we've also eliminated the supposed rider bias the snobby executives often complain about.

What can I say? HUSH looks out for the little guys when it comes to elevators.

Resources

(Images credits: Wikipedia; Pseudo Paranormal; Time Marches On; P. Seale; Elevator Bob's; Unsuck DC Metro)

Wikipedia - Elevator; Elevator Paradox