Siemens construction union
The Siemens-Bauunion ( SBU for short ) was a subsidiary of Siemens & Halske AG and Siemens-Schuckert-Werke GmbH founded in 1921 for construction purposes . It was brought into being in order to be able to offer construction tasks from a single source. Previously, the parent company had to outsource all services (such as major projects) to other companies. The major projects of the Siemens-Bauunion included, for example, the construction of the Siemensbahn , construction work for the West Tangente in Berlin and the subways in Berlin and Athens , the Trans-Iranian Railway in Iran and the construction of the first kilometers of motorway in the 1930s. The end of the Siemens-Bauunion came in 1972 when the company was transferred to Dyckerhoff & Widmann AG .