Report KD 652 and KD 653 about the VIRYA-3.6 and the Polycord transmission have been replaced by report KD 693. The tittle of KD 693 is: Calculations executed for the 4-bladed rotor of the VIRYA-3.5 windmill (lambda design = 4, stainless steel blades) meant to drive a centrifugal pump through a Polycord transmission with an accelerating gear ratio 2.5 : 1 and a vertical shaft in the tower.