By BASF Jr. Scientist Russel Andres, Riverview, MI
Prior to 1870, no one built
He used this invention successful y for moving the
skyscrapers, because no safe
debris in his building. However, he did not market
and convenient method of
the new elevator or mention it to his superiors.
accessing the upper floors
Only after his bedstead business folded did Otis
existed. There were primitive
form an elevator company. However, for the most
Inventor of the
versions of elevators available,
part, people stil did not trust elevators. To gain
but they often proved
publicity and customers, Otis built an elevator and
unreliable and even deadly.
demonstrated his new safety system at the 1854
Elisha Otis, an inventor and an owner of a multi-
New York Expo. He stood in the elevator and
story bedstead factory, found himself wishing
had a man cut the cable that supported the elevator.
for a reliable "moving platform" so that he could
The crowds watched in horror, but Otis's safety
transport debris to the attic of his building.
system worked perfectly, and the elevator only
Using his understanding of physics, he realized that
dropped a few inches. Otis was completely unharmed.
if an elevator fel , its downward velocity would
After that, so many people bought his elevators that
exponential y increase every second. For example,
his business doubled yearly. Shortly afterward, in
if the elevator car fel for 2 seconds, its downward
1870, the 13-story Equitable Life Building was
velocity would be 64 feet per second; but if it fel for 5
erected, a building that used Otis' elevators ...
seconds, it would be fal ing at 160 feet per second!
and that many consider to be the first skyscraper.
Such speed would mean injury or death of the
As we can see, Otis' knowledge of science and
passenger upon impact, so he had to invent a
engineering real y "raised" the bar on safety.
safety system for the elevator that would stop the
car as soon as it began to fal .
The elevators of that time used a steam-powered
winch to pul a cable connected to the elevator car
to raise it up and down. The car was kept stable
with vertical, rail-like guides which kept it from
tilting or swinging while in use. Otis' modification
added a rod and several levers that used the
tension of the cable to hold in springs and ridged
cylinders in the wal s of the elevator car. If the cable
broke, the springs would then be free to extend the
cylinders outward, where they connected with Otis'
other modification: an improved guide rail. He had
changed the guide rails to have built-in ratchet
teeth to hold the cylinders.
Now, if the elevator fel , the ridged cylinders would
lock into the guides and could stop the elevator
Otis demonstrates his elevator at the 1854 New York World's Fair.
the second it began to fal .