Many of us who have ridden inside an elevator since its invention 160 years ago are accustomed to hearing its ominous hums and creaks, as well as stories of malfunctioning elevators that cause people to be stuck inside for hours. So, the idea of hopping into a cable-free elevator in a mid to high-rise building can sound both thrilling and nerve-wracking. That idea is soon to become a reality for global transportation manufacturer ThyssenKrupp, who is set out to test the first units of their cable-free MULTI elevator system once the testing tower in Rottweil, Germany is complete by the end of 2016.

MULTI's design is derived from the company's TWIN control system and safety features. Deemed as the world's first cable-free elevator, MULTI includes a multi-level brake system and multiple self-propelled cabins that can be incorporated within the same elevator shaft.

Operating on a circular system, the elevators will be able to move vertically and horizontally in a loop at a speed of 5 m/s, powered by new linear motor technology similar to that of the Transrapid magnetic-levitation train. Passengers would have access to an elevator cabin every 15-30 seconds with a transfer stop every 50 meters.

ThyssenKrupp states the MULTI system will improve transportation efficiency and increase capacities up to 50 percent, considering projected urban population trends. At the same time, MULTI could also help reduce the building's overall energy supply needed to power the elevators by 50 percent. This would also reducing the for escalators and additional elevator shafts to be built.

MULTI also uses smaller 6 sq.m shafts than standard elevator systems, which quite evidently, creates more usable space in the building. According to the company, current elevators and escalators occupy up to 40% of a building's floor area.

The ideal building height for the MULTI system to operate is at least 300 meters, but its cable-free design could potentially allow architects to create new buildings that have different heights, forms, and functions -- which would otherwise be restricted by the height or vertical alignment of current elevator shafts.