Due to the number of stairs that needed to be climbed to reach the top, buildings of over six storys were a rarity until the 19th century when the development of passenger elevators - along with advances in building materials and techniques - enabled the construction of taller and taller buildings. As skyscrapers continue to reach ever higher, elevators are required to carry more people further, faster. Mitsubishi already has the first problem licked with the development of elevators able to carry 80 people at once. Now it has tackled speed with technologies that enable ultra-high-speed elevators to travel at more than 60 km/h (37 mph or 1,000 meters a minute).
The various technologies that Mitsubishi has developed to be incorporated into the world's fastest elevators include:
- a single motor with two grouped three-phase winding coils and parallel drive systems that feature a built-in converter to regenerate electricity and cut power consumption by over 30 percent
- hydraulic driven clamp-type disk brakes
- lighter traveling cables enabled by encasing a wider diameter steel core in a lightweight sheath material
- a new active roller guide to reduce vibration from the guide rails and wind at ultra-high speeds
- streamlined aerodynamic car cover with a sound insulating cage.
- safety gear shoes constructed from fine ceramic to provide high resistance to heat, abrasion and shock and provide stability even if high frictional heat when the safety gear is activated
- air pressure control to minimize rapid changes in atmospheric pressure
Mitsubishi says these technologies are being incorporated into elevators for the 632-meter (2,073 ft) Shanghai Tower currently under construction in China.