The Swiss manufacturer's remarkable claims are based on the potential of its recently launched synthetic elevator rope. Named SchindlerAramid, the rope is made from high-tensile synthetic fibres and is designed to completely replace the steel cables most commonly in use today. Aramid has no steel core or sheath, consisting of 300,000 individual filaments (1,000 filaments are spun into yarns, then strands of eight yarns are wound in to strands, and 30-34 strands twisted into a rope), yet it is said to be as strong as steel rope and virtually friction-free. It thus weighs far less than its steel equivalent, reducing the size of drive required to hoist the elevator and the need for compensating chains.
There is more to Aramid than its lightness and low-friction operation. Built into the strands are electricity-conducting carbon fibres which are used to permanently monitor the rope for wear and stress. Diagnosis of the rope condition can be checked on site or remotely and, in the worst-case scenario, the lift can be immediately ordered to make an emergency stop to avert a tragedy.
Schindler is just one of the big names in the elevator sector shouting about new faster, higher, stronger products. Another, the Otis Elevator Company, has developed the Gen2 system for low- to medium-rise buildings – the first system to use flat, coated steel belts to hoist the car.
The belt, the heart of the new system, comprises 12 woven high-tensile steel strands encased in a black polyurethane sleeve 30mm wide and 3mm thick. This shape makes it stronger, more flexible and more durable than steel cable, out-lasting it by two to three times. It may look thin but each belt can lift 3,600kg, and as the Gen2 system uses a minimum of thee belts per lift, each system can lift 160 68kg people. The belt is also much more pliable than traditional cable. It will bend around a sheave only 100mm in diameter, approximately 20% the size of that required by steel rope technology, allowing for much smaller winding gear. Another benefit is that the system uses a gearless machine one quarter of the size of traditional systems, which is installed in the actual elevator shaft, along with the controller and drive mechanisms, obviating the need for a motor room.
Gen2 is available in eight- and 13-passenger models, each incorporating a standard communications link that provides continuous diagnostic and performance data, and a passenger voice connection. The elevators can travel at up to 1.6m per second.
Gen2 was not built for speed. Alta from Finnish manufacturer Kone, on the other hand, has been designed for exactly that. The company tentatively claims that Alta is 'believed to be the world's fastest and most powerful elevator system so far.' The largest version of the system can transport up to 70 passengers at the phenomenal speed of 17m per second.
Alta has been designed for what Kone calls the next generation of tall buildings, up to 500m high. At the heart of the design is a 'magnum' version of Kone's EcoDisc hoisting machine, first developed for Kone's MonoSpace elevator. It is based on a permenant magnet synchronous motor in combination with frequency control and low-friction gearless construction.
The use of EcoDisc negates the requirement for a lift motor room, in most instances, as the slim hoisting gear is installed in the elevator well directly on to a guide rail, with the controller built into the door frame on the highest landing. Kone also says that the technology uses only half of the power required by a conventional comparable system, saving thousands of kilowatt hours annually. EcoDisc has been so successful for Kone that the company says that over 60% of all of its elevator systems sold now contain EcoDisc. It has recently been specified on such prestigious projects as the 200m-tall 88 Phillip Street, Sydney, Australia, and City Point, the second tallest office tower in the City of London, UK.
Kone's Alta elevator also employs the Traffic Master 9900 GA group control system, which uses genetic algorithms to optimise the routing of elevator cars. In heavy traffic, fuzzy logic prioritises cars' movements in milliseconds to give the most efficient use of energy and time.
As the global population continues to grow, the only way to provide the demand for residential space is to build upwards. In the next few decades it is widely predicted that the first tower over a mile high (or or 1.6km) will be built. With this type of construction comes a whole host of logistical problems, but it looks like elevators won't be one of them. The challenge to architects has been laid down: to build a structure tall enough to out-do the elevator designs.
In the not so far future, elevators may not be limited to buildings. Otis – on its web page with the poem 'Twinkle, twinkle little star, was that an elevator car?'– cites a NASA report detailing the concept of a space elevator that hums along a thin diamond fibre extending 35,000km into space, to a point called a geosynchronous orbit. Otis vice president, John Thackrah, comments that based on the company's current capabilities for creating transportation systems for skyscrapers several miles high, a space elevator may be more fact than fantasy. 'Today we have the technology to create elevator systems for a five mile-high tower. We could apply technology that we are working on for today's existing market to the NASA concept within the next 10 years.'
Thackrah concludes: 'The NASA concept doesn't just scrape the sky, it breaks right through it. But who knows. There was a time when people couldn't imagine a mile high building or a man on the moon.'
'Bing bong. Going up. Top floor penthouse with views over the Sea of Tranquility'. It could be closer than we think.
Source
World Architecture
