A system of ropes or chains hanging beneath the elevator car and counterweight that equalises the changing rope weight distribution as the car travels through the full hoistway height.
Full Definition
In tall buildings the suspension ropes on the car side get longer and heavier relative to the counterweight side as the car descends, creating an imbalance that grows with travel height. Rope compensation counteracts this by hanging a set of compensation ropes (or a compensation chain) from the underside of the car and counterweight, running through a loop at the pit. As the car descends and gains more suspension rope weight, the compensation loop transfers equivalent rope weight to the counterweight side, maintaining traction balance. Compensation becomes necessary above approximately 30 m of rise (EN 81-20 assessment). In very high-rise installations compensation ropes are themselves tensioned by a guided compensation pulley in the pit (compensation rope tensioning device). The compensation system must be designed so that its natural frequency does not coincide with the elevator's drive cycle frequency, avoiding resonance.
