ESCON fun theory:
Going Up: Get Double-Decker Elevators...

Extremely tall “superscrapers” are going up in cities all over the world. One in Changsha, China — the Sky City, a 2,750-foot high-rise — and another in Jeddah, Saudi Arabia — the kilometer-high Kingdom Tower — are expected to surpass Dubai’s record 2,717-foot Burj Khalifa. And in 2013, as many as 24 skyscrapers approaching 1,000 feet may be completed.

These buildings need special elevators. Engineers at long-time elevator manufacturer Otis are responding with a number of innovations, including the super double- decker elevator that can serve two floors at once. Conventional double deck elevator systems with two cars connected at a fixed distance are no longer able to accommodate the new buildings being constructed. But the super double deck elevator has a flexible middle that can adjust to buildings with different floor heights. Otis also has implemented computerized dispatch, replaced steel ropes with polyurethane-coated belts and traded bulky motors for smaller gearless drives, eliminating the need for a large engine room