When designing any rope operated equipment, designers should consider the relevant National and/or International Standards which refer to acceptable sheave and drum diameters based upon the application, industry, etc. The diameter of sheaves and drums together with the tension, are normally associated with overall service life of the rope and in ‘simple terms’ the larger the diameter the longer the service life, although consideration should also be given to the anticipated modes of rope deterioration which will also significantly affect the service life. Typically, the diameter of sheaves and drums for crane applications are 16 to 28 times the nominal rope diameter.