A new German system of prestressing is reported to be successfully combining the advantages of both the wire and bar methods. Before concreting, the exact position of the live anchorage is maintained by means of a temporary mounting plate against which the anchor bolt is held by a round centering nut. This is done to insure that the tensioning load will be applied axially to the bolt. After the concrete has hardened, the temporary mounting plates and centering nuts are removed and replaced by the permanent anchor plates alone. Tension can then be applied after hand-tightening the anchor bolt nut to the zero position. The tensioning jack is held in position by a nut tightened on to an extension piece, which passes through the body of the jack and is screwed on to the projecting portion of the anchor bolt. The position of the jack in relation to the anchor plate is maintained by three centering pins which are seated in corresponding holes in the anchor plate. The extension of the cable is controlled by measuring the movement of the cylinder of the jack by caliper rule. To insure that the cable cannot be overloaded the hydraulic pump which operates the jack is fitted with an automatic pressure-release valve and a pressure gauge calibrated to correspond to the tension applied. The relationship between pressure and tension can be read off directly which avoids the danger of errors as a result of on-site calculations.