A render of the Multi elevator shows how cabins can move in vertical loops, as well as horizontally, due to the cable-free design.
A century and a half ago, the invention of the passenger elevator triggered an urban revolution. All of a sudden, buildings taller than four or five storeys could be built and the result was skyscraper cities, like New York.
Today, those same elevators are proving a hindrance to ever-taller towers, a few of which will soar into the heavens. That's because their basic design hasn't changed – a single cabin suspended by cables in a vertical shaft. The bigger and taller the building, the more elevator shafts you need, to the point the shafts' "footprint" can eat up 40 per cent of a tower's space.
Germany's ThyssenKrupp, one of the world's biggest industrial companies, claims it can overcome this problem with the first cable-free elevator, unveiled late last week. Called the Multi, it will be powered by magnetic levitation, or maglev, motors and allow several cabins to zip along a single shaft in a continuous, flowing loop. Think of it as a vertical subway, with cabins coming every 15 seconds or so.
The system would even allow the cabins to move horizontally, in a zig-zag pattern, or on inclines, giving architects the freedom to design exotic buildings that break away from the now-standard tall and skinny format. "We are calling this a revolution," says Patrick Bass, ThyssenKrupp Elevator's research and development executive vice-president and head of product strategy. "Elevators were an enabler for tall buildings, then they detracted from them. Multi will change that."
Developers might have to wait a few years before they place their orders. The Multi system, whose development costs are about €40-million ($55.9-million), exists only in digital form and the first working model won't roll skyward until 2016, when ThyssenKrupp builds a test tower in Rottweil, Germany. But the basic components already exist. They include the maglev technology, which has been around for decades and has been used in high-speed trains, with decidedly mixed results, and the "traffic control" system, which will prevent the elevator cabins from forming vertical traffic jams and smacking into one another.
ThyssenKrupp, with 160,000 employees, was formed in 1999 when Thyssen and Krupp, the steel and armaments companies that built Hitler's formidable heavy weapons, merged. The group is still best known as a steel maker, but steel is a tough business, with the Asian manufacturers coming on strong, so the company has been diversifying and using R&D to move up the value chain.
Elevators are one business where ThyssenKrupp sees enormous potential, as hundreds of millions of people move into cities and city planners encourage the construction of exceedingly tall buildings to accommodate the masses. The company is one of four major players in the elevator industry, though it's still far behind the leader, Otis, which is named after the 19th-century American elevator pioneer Elisha Otis and now owned by United Technologies.
Mr. Bass says ThyssenKrupp first contemplated the Multi innovation a couple of years ago, when it realized that just raiding the collective parts bin would get half the job done. Additional inspiration came from German developer Frank Jendrusch, who wants to create very tall buildings with their own wind- and solar-power supplies. "He realized that traditional elevators were taking up so much space and wanted a new approach," Mr. Bass says.
The market for elevators is expanding by about 5 per cent a year as cities grow and new ones are built, with an emphasis on height, not width. ThyssenKrupp says the market for all types of elevators is worth about €46-billion a year and should reach €59-billion by 2019.
Research from Credit Suisse, McKinsey and the Council on Tall Buildings and Urban Habitat, among other sources, suggests buildings are being fed growth hormones. Between 2000 and 2013, the number of 200-metre-plus buildings rose by 318 per cent, to 830. In 2014 alone, as many as 90 buildings over 200 metres were completed, of which 13 are in the super-tall category – more than 300 metres.
In 2000, the average height of the world's 50 tallest buildings was 325 metres. Last year, the average was 390 metres.
Soon, buildings of 300 metres will look stunted. The tallest building on the map is the 163-floor Burj Khalifa tower in Dubai, standing at 829.8 metres. It has 57 elevators. Not to be outdone, Saudi billionaire prince Al-Waleed bin Talal is building the cloud-piercing, one-kilometre-tall Kingdom Tower on the Red Sea, near Jeddah. It will contain 59 elevators, consuming an enormous amount of space.
In theory, the tallest towers could make do with one, or just a few, of the ThyssenKrupp elevator systems, running like shuttle cars. Since the elevators could also move horizontally, they could be shunted off the continuous loop and into a "garage" for cleaning and maintenance.
ThyssenKrupp is not revealing the expected cost of the Multi elevators, but the company says the price isn't really the point; it's the savings, as less space for elevators translates into more space that can be sold or rented.
Eric Reguly