For Elevator Makers, The Sky's the Limit

摘要

Two thousand years ago, the Romans used elevators-powered by pulleys, levers, and slaves-to raise gladiators and wild beasts into the Colosseum for death-match spectacles. Since then, elevator technology has been largely based on the same mechanics, with electricity-propelled cables, rather than teams of rope-hauling humans, providing the lift. These days, however, an engineering revolution is going on. Driven by a boom in megatowers the Romans could not have imagined, the global giants that dominate the industry are engaged in technological one-upmanship.