Students of urban history tell us that two things have shaped the modern city.
One is the telephone.
The other is the elevator.
Both were invented at roughly the same time, but the telephone, being relatively cheap, came into widespread use before the elevator did.
Before the telephone, businesses had to be clustered together in the middle of town so that the owners could meet and talk without having to go very far. Having telephones meant the person you were talking to could be a kilometre or two or three from where you were sitting. The telephone contributed to urban sprawl long before the automobile allowed people to live in the suburbs and work downtown.
But it soon became obvious that there were advantages to being close to those in similar businesses, so they clustered in the core area.
As the cities grew that core became congested and the only way you could get more office space was if you built tall — tall enough to make using the stairs impractical. So we have elevators.
That let the genie out of the bottle. Buildings went up, and up, and up. Now, a building under construction in Jeddah, Saudi Arabia, will be 167 storeys tall. That's a thousand metres. A kilometre.
There are really very few buildings taller than about 500 metres because of limits imposed by elevators. Traditional elevators hung on steel ropes can only rise around 500 metres before the weight of the rope itself becomes too burdensome.
All this was spelled out in a recent paper written by Antony Wood, executive director of the Council of Tall Buildings and Urban Habitat, and by Dario Trabucco, a researcher in building technology at a university in Venice, Italy.
The authors discuss a new elevator system that has no cables, no ropes. It travels by using electric linear induction motors, the same kind of contactless energy transfer that powers the magnetic levitation trains seen in some high-speed rail systems in China and Japan.
This mag-lev system means the passenger cabins can move independently of each other in a shaft, which in turn means multiple cabins can be working in one shaft at the same time.
Even more interesting is that these cabins can travel horizontally, potentially even diagonally. The induction motors pivot to follow the power track while the floor of the cabin remains level.
"The difference between an elevator and the car, or even a train, becomes less clear — as does the difference between a building, a bridge and an entire city," the authors write. "Instead of descending from your 50th-floor apartment to the street in an elevator, then taking a taxi or the subway to another building across town and going back up to the 50th floor, you might instead have a door-to-door ride between buildings, at height, in a single vehicle."
Such a system has been developed by the German firm Thyssenkrupp, which has been testing it in a specially built tower.
The company calls its system MULTI and it will be installed in a new office tower in Berlin that is due to be completed by 2020.
One can't help but ask if the world is really ready for this.
The answer, say Wood and Trabucco, is "probably not right away.
"In the short term, we can expect to see systems like carbon-fibre-roped...elevators in some of the very tallest, most high-profile (and expensive) buildings."
They point out that at the moment the systems are far more expensive than the conventional alternatives. Building owners won't use them until they can save — or earn — lots more money by building systems like those designed by Thyssenkrupp.
At the moment, say Wood and Trabucco, the tall-building industry has no standard data or recommendations to guide designers. That's why their organization is studying design possibilities of ropeless systems in order to develop some engineering guidelines.
Korky Koroluk is an Ottawa-based freelance writer. Send comments to firstname.lastname@example.org.