Nordhausen - On December 20, 2022, the plant engineers at Schachtbau Nordhausen received a new contract worth millions from Vattenfall GmbH: the bottom outlet valves at the Bleiloch Dam in Thuringia, Germany's largest reservoir, are to be replaced. These have become obsolete after 90 years of operation and are now being replaced. The biggest challenge here is that the conversions are being carried out at full dam pressure. This is comparable to open-heart surgery. In addition to the technical expertise of the valve manufacturer, the decisive factor in the award of the contract was above all the installation concept of the shaft builders.