A pair of elevators

The eccentric engineer: How the elevator shaft came before the elevator

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The story of one inventor who foresaw the future of buildings, and another who brought the idea to birth.

Not all great engineering inventions come out of the blue. Sometimes it seems inevitable that a ‘thing’ will be invented soon and those with foresight can prepare for it. That’s just what industrialist Peter Cooper was doing when he built his Cooper Union for the Advancement of Science – now one of the USA’s leading engineering colleges.

The original plans for the building in New York contained something of mystery. Cooper insisted that an empty shaft run the entire height of the building, accessed at each floor by doors. This might have seemed a little reckless to many. Certainly, walking through those doors would get you to the basement quicker than the stairs – but the arrival might be your last. Cooper, though, could see the future. As buildings got taller, he was betting on the invention of the elevator.

Of course, there had been lifting devices before. Cranes and winches had been in use for millennia for lifting materials from mines, and loading and unloading ships. Archimedes invented an elevator using a man-powered capstan and pulleys in the 3rd century BC. In the 11th century, Andalusian astronomer Ali Ibn Khalaf al-Muradi included an elevator mechanism in his ‘Book of Secrets in the Results of Ideas’, though this was little more than a type of windlass that could already be found in medieval castles and cathedrals. However, very few of these were ever designed to carry people.

There were perhaps two main reasons why the passenger elevator had been thought of, but not built, before the mid-19th century. First, very few tall buildings existed before the 19th century – certainly not ones that required regular access to the upper floors by large numbers of people. Obviously, there were other reasons to build one. Louis XV of France had a personal elevator – his ‘flying chair’ – installed in Versailles so he could travel to his mistress’s bedroom out of sight of the prying eyes of courtiers. Ivan Kiblin had installed a similar device in the Winter Palace in St Petersburg in Russia in 1793, involving a screw mechanism attached to a chair, enabling the aged and rather large Catherine the Great to access the upper floors of her palace.

Yet for most people the stairs were just fine, particularly when it comes to the second reason why ‘flying chairs’ hadn’t taken off. Elevators were dangerous. Being suspended in a shaft by a single cable attached to a winch mechanism was putting a lot of faith in a small amount of technology. Winches regularly failed, the cables parted and the load plummeted to the ground. This seemed like an excellent reason to take the stairs.

Fortunately for Cooper, just as he was planning his Union, a former wagon driver and amateur engineer, Elisha Otis, was having a revolutionary thought. Life had been hard for Otis and all his business ventures had failed, usually due to factors far beyond his control. In 1851, aged 40, he got a job converting an old sawmill in New York into a bedstead factory and was faced with a huge clearing-up job. He thought about installing hoists to help clear the upper floors, but these often failed, sometimes catastrophically, so his mind turned to making them safe.

With his two sons he began designing a ‘safety elevator’. His wonderfully simple device consisted of an old wagon spring attached under the roof of the hoist platform and connected to the lifting cable above. Normally the tension in the cable kept the spring closed, but were the cable to snap the spring would open, engaging saw-toothed ratchets on both sides of the lift shaft and bringing the elevator to a stop.

The 1853 World’s Fair offered an ideal advertising opportunity. In the New York Crystal Palace, Otis had himself hoisted high in the air on his elevator platform. With great showmanship, he then ordered the hemp rope holding him aloft cut with an axe. The crowd gasped, but the platform only dropped a few inches before locking securely in place.

Otis’s business was also secure and, from then on, orders doubled every year. As the safety elevator went on to prove itself as the safest form on transport on Earth, so the skyscrapers of New York could begin to grow.

However, despite already having an elevator shaft, the Cooper Union would not be the first building to get Otis’s machine. Cooper had assumed the most efficient shape for the shaft would be cylindrical and Otis’s elevators were square. It would be several years before Otis had the time to design a bespoke elevator for the Cooper Union.

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