Riding high.

Elevators are about to go where no elevator has gone before--sideways.

Otis Elevator Co. is developing Odyssey, a new system that allows an elevator to move horizontally as well as vertically. The point: to be able to build bigger buildings, bigger even than the 460 m (1,509 ft) World Financial Center under construction in China.

How will an elevator that moves sideways help architects build bigger buildings? The answer is suprisingly simple, and requires no radical changes in current elevator technology.

An elevator cab (the box-like structure that carries people) is raised and lowered on thick steel cables that fit around a pulley (a wheel at the top of the elevator shaft). The pulley is connected to a motor. When a passenger enters the cab and pushes a floor button, the motor turns the pulley. The pulley moves the cables forward or backward, lifting or lowering the cab. The process is aided by a counterweight, connected to the opposite ends of the cables, that balances the load of the cab.

Odyssey works the same way, but the new system also allows the cabs to move sideways on motorized wheels (see diagram). This simple change means that multiple cabs can share the same shaft. They make room for one another by moving to the side, much like one train waiting for another to pass before proceeding through a tunnel.

Architects would like to build skyscrapers with fewer elevator shafts to make more room for offices, an important factor in both the design and cost of tall structures. The 415 m (1,362 ft) World Trade Center in New York City, for example, has 239 separate elevator shafts in its twin towers that take up 21,000 square meters of space. Odyssey would cut that space to 6,300 square meters.

In addition, elevator cables can safely lift cabs only 670 m (2,200 ft). Odyssey will allow people to ride much higher in the same cab since it can move sideways from one pulley system to another.

Otis contends that Odyssey will allow architects to erect buildings as tall as 1,000 m (3,281 ft) and still transport people up and down quickly and conveniently. The company is testing the new system and hopes to install it in buildings before the year 2000.

FAST FACT

In 236 B.C., the Greek mathematician Archimedes refined a hoisting device operated by ropes and pulleys--the same idea that is behind modern elevators.

FAST FACT

In 1852, Elisha Graves Otis installed the first passenger elevator in a retail store in New York. Today, elevators move the equivalent of the world's population every three days.