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
Lifting bag a hazardous operation with high risk of entanglement in an uncontrolled lift or sinking. If a single bag is insufficient, multiple bags may be used, and should be distributed to suit the load. There are also lifting bags used on land as short lift jacks for lifting cars or heavy loads or lifting bags which are used in machines as a type of pneumatic actuator which provides load over a large area. These lifting bags of the AS/CR type are for example used in the brake mechanism of rollercoasters. The volume of the bag determines its lifting capacity: each litre