Tech-Info 11: Rope lifetime in dependence on the sheave groove diameter

According to ISO 16625 the groove of a sheave should have a diameter, that is 5% to 10% bigger than the rope diameter. During the operating time, the rope diameter will decrease. With this decreased diameter the rope will dig itself into the sheave groove and will reduce the groove diameter. Therefore, with the installation of the rope it should be considered, that the groove diameter of the sheave is at least 1% bigger than the measured rope diameter. A sheave with a too big groove diameter cannot support the rope well and leads to increased surface pressure (between sheave and rope). Consequently the lifetime of the rope decreases steadily with an increasing groove diameter. If the groove diameter is too small, the rope will be squeezed and the lifetime drops extremely.