Elevators: Technical Showcase

Author: Michael Vogel

Aug 25, 2021 Innovation / Industrial Inspection

Elevators make life easier, sometimes even more impressive or oppressive. But there’s one thing they all need to be: safe.

They turned the housing hierarchy on its head. Before there were elevators, going up the stairs to your apartment meant you descended socially. In a multi-story building, the wealthy usually lived at the bottom, while poor people or service personnel lived at the top. The elevator first made penthouse apartments on the top floor attractive.
By now, it’s no longer possible to imagine a world without elevators. They carry people and loads – and have also become a testament to technological prowess. The elevators in the Burj Khalifa skyscraper in Dubai, for example, climb to extreme heights – 504 meters for the main elevators. In the Shanghai Tower, a striking skyscraper in the coastal city of Shanghai, there’s an emergency elevator that bridges 578.5 meters. Manufacturers and operators are also competing to break records when it comes to speed. The fastest elevators are currently whizzing through the Shanghai Tower and the Chow Tai Fook Centre in Guangzhou, also China. Both installations reach more than 70 kilometers per hour. At this speed, the cabin pressure has to be equalized, otherwise passengers feel uncomfortable.
Through the shaft at 70 kilometers per hour
While elevators usually remain hidden inside buildings, outdoor passenger elevators offer an entirely different perspective. In Europe, this can be experienced to the extreme in Switzerland. The Hammetschwand Lift in the canton of Lucerne is 153 meters high. Once at the top, it offers a magnificent view over Lake Lucerne. The elevator has been in operation since 1905. However, the world record holder among outdoor passenger elevators is also located in China, more precisely in the Wulingyuan area, a Unesco World Heritage Site. There, the glass elevator called “Bailong” climbs a 326-meter-high cliff.
Elevators must of course function reliably at these heights and speeds. Accidents may have been considered acceptable in the 19th century, but not for a long time now. This applies not only to the extreme elevators of this world, but to all the countless installations that do their duty in apartment buildings, shopping malls, office buildings, and industrial plants. Elevators must be inspected before commissioning and at regular intervals during operation. This requires experts such as mechanical engineer Dirk Blettermann, who heads the Elevator and Materials Handling Technology Department at DEKRA.
“In EU member states, putting an elevator into circulation, i.e. the first inspection after completion of construction, is carried out in accordance with European law by an appointed authority – this can be DEKRA or the elevator manufacturer itself,” says Blettermann. Next, the Operational Safety Ordinance takes effect in Germany. “Based on that, experts assess additional national regulations and environmental conditions,” explains the engineer. These include, for example, emergency plans, emergency escape instructions, or access to the building. “Only after this inspection can an elevator go into operation for the first time.”
The passenger comfort can be monitored via app
DEKRA isn’t only active in Germany, but other European countries. In addition to testing, the company also offers precise, non-contact measurement methods that can be used to monitor elevators’ passenger comfort – via app. In the EU, Austria comes closest to the German model of operational safety regulation. “However, the interval between the two main inspections in Austria is twelve months, whereas in Germany it’s 24 months, interrupted by an intermediate inspection,” says Blettermann, citing a difference. Unlike in Germany, the periodic inspections in Austria also don’t include weight testing or electrical measurement. “EU member states such as France, Sweden, or Denmark, on the other hand, have periodic inspections of passenger and freight elevators primarily carried out by maintenance companies, and only to a much lesser extent by independent third parties,” he adds.
In Germany, Blettermann estimates that 80 percent of all elevators in need of inspection are passenger and freight elevators. In addition, there are “machines that lift people over a height of three meters,” he says. “These also count as elevator systems that require monitoring according to the German Ordinance on Industrial Safety and Health. Examples include facade elevators for window cleaners, access systems in wind turbines, and construction site elevators.”
Paternosters have a special charm
And finally, there’s the third and smallest group among elevator systems, the paternosters. Blettermann estimates that there are perhaps a hundred of them in Germany. In the paternoster system, several doorless cabs permanently circulate through two parallel elevator shafts. They’re relics of a bygone era and are no longer allowed to be built for safety reasons. Existing installations, however, enjoy the right of continuance. Germany’s most famous paternoster probably operates in the high-rise building of the Axel Springer publishing group in Berlin, because celebrities visiting the publisher’s editorial offices regularly ride it. David Hasselhoff is said to have sung “I’ve been looking for freedom” in the paternoster there.
Recently, Dirk Blettermann put the paternoster in Chemnitz City Hall back into operation. “To be able to do so, an engineering office, working with the assigned maintenance contractor, first had to adapt the technology to the status quo,” he says. The brake, drive, and control system had to be renewed. A light barrier now monitors whether anyone is in danger of getting trapped by one of the cabs. The Chemnitz paternoster is an example of an elevator installation entirely to Blettermann’s taste: It’s one of those two percent that “deviate from the standard”, as he puts it. Despite his long career as an expert, it was his first paternoster inspection on this scale. “So I requested my birthday as the inspection date, and the operator agreed.”
Some elevators are remembered in particular for their unusual ambiance. In Berlin’s DomAquarée district, for example, you can ride through an aquarium with fish and corals in a transparent cabin. The aquarium is a good eleven meters in diameter and 16 meters high. In comparison, the elevator in the Eiffel Tower rises not vertically but at an angle from the base to the second floor. The advantage of these inclined elevators is that they can adapt to the changing angles of inclination of the tower pillars. On the other hand, a thrill of a completely different kind is created by high elevators with glass floors. One example is located in the Sky Tower in Auckland, New Zealand: The view falls unobstructed down the elevator shaft. And a cabin in London’s Southside shopping center even appears to run entirely without a floor. When the adrenaline drops back down, however, you realize it’s an optical illusion – a 3D floor painting of the elevator shaft, created by artist Andrew Walker. A special operational test wasn’t necessary here.