Reliable data communication underground

Belden supplies FiberINTERFACES from Hirschmann for use with tunnel boring machines from Herrenknecht

The Katzenberg tunnel, which is scheduled to go into operation by the end of 2012, is part of the rail link between Karlsruhe and Basel. For its construction, two identical tunnel boring machines (TBMs) from Herrenknecht were used to drill twin 9,385-meter tubes through solid rock. Each of these machines is 230 meters long and weighs 2,500 tons. Since the data communication equipment used in combination with these TBMs is subject to rigorous requirements, Wayss & Freytag Ingenieurbau, the responsible engineering company, opted to implement an optical Profibus network. As active components they chose OZD Profi 12M FiberINTERFACES from Hirschmann, which have a proven track record in the industrial environment.


While the tunneling machines bored into the mountain, all connections to the mouth of the tunnel had to be extended on an ongoing basis. This applied to conveyors, rails, pipes and power lines as well as data communication technology. Initially 2 kilometers long, the fiber optic cables were gradually extended to a length of 10 kilometers in order to keep up with the progress of the TBMs. Both ends of the cable were equipped with FiberINTERFACES to transmit the Profibus signals. On the two TBMs and in the control room at the mouth of the tunnel, these components also acted as a link to the local PLCs.

The hardware design used for the OZD Profi 12M FiberINTERFACES means they are capable of operating in extreme conditions. Their resistance to shocks, extreme vibrations and high temperatures has ensured reliable data communication during the construction of the Katzenberg tunnel. Available with a range of certifications for Ex environments, the FiberINTERFACES also provide maximum electromagnetic compatibility (EMC), fast ring redundancy, and a redundant power supply. Diagnostic LEDs ensure easy setup and fast on-site maintenance. In addition, alarms can be signaled centrally via a potential-free contact.