Rope drive tensioned by an idler pulley, but this system was not used in the UK and each loop was tensioned between its two pulleys by one of them being movable. Rope drives were also cheaper than belts, around a quarter of the price. The rope drives were placed in a large diagonal shaft at the side of the building, usually windowless and distinctively visible from outside the building. Rope drives required a larger such shaft than comparable belt or shaft drives. As the open shaft represented a channel for transmitting fires, unlike the narrow holes of a shaft drive, it needed
Elevator poor energy efficiency. Gearless traction machines are low-speed (low-RPM), high-torque electric motors powered either by AC or DC. In this case, the drive sheave is directly attached to the end of the motor. Gearless traction elevators can reach speeds of up to , A brake is mounted between the motor and gearbox or between the motor and drive sheave or at the end of the drive sheave to hold the elevator stationary at a floor. This brake is usually an external drum type and is actuated by spring force and held open electrically; a power failure will cause the brake