Anyone traveling through the Gotthard on the way to Italy rarely thinks about the technology that goes into this structure. One component: switch cabinets. The Gotthard road tunnel is one of many exciting projects in which the VX25 enclosure system from Rittal is already being used. The quick and easy assembly of the VX25 made it possible for the Swiss company MB Systembau AG to install and seamlessly replace outdated enclosures in no time at all - even while the tunnel was in operation.
Around 6.5 million vehicles pass through the almost 17-kilometer Gotthard Tunnel every year. "While traffic technology systems and tunnel radio have been regularly modernized, the power supply in the Gotthard tunnel is still original and needs to be replaced due to its age and for safety reasons," says Roland Suter, co-owner and project manager of MB Systembau. The Swiss company manufactures individual switchgear and control systems and planned and implemented the modernization of the power supply in the Gotthard road tunnel. A special requirement of the system operator: the replacement was to be carried out without shutting down the system and without interrupting operations. MB Systembau had to master the replacement in the Göschenen and Airolo depots as well as in the 15 technical centers of the Gotthard road tunnel. Five of these are located in the tunnel, two in the pre-tunnel and at the portals and four on the Gotthard Pass, which are not or only partially accessible during the winter.
The VX25 offers a whole range of advantages over its predecessor. The range is more flexible, there are fewer parts for multiple functions.
Moving into the tunnel
MB Systembau installed 248 control cabinets with a total length of 200 meters as part of the project, and well over 100 kilometers of cable were laid by InfraTech. In order to ensure a smooth just-in-time replacement, the technicians installed and wired the control cabinets in their own factory. "We checked the wiring and tested the communication connections during a factory test," says Suter. Every possible operating and fault message that could reach the command center was also checked. Once the sample system had been successfully accepted, the control cabinets were then moved into the tunnel one control center at a time. "There were systems in the old structure that were no longer needed," says Suter. "We dismantled these first." The team then made space for the new VX25 cabinets. "The VX25 offers several advantages over its predecessor," says Suter. "The range is more flexible, there are fewer parts for multiple functions. Whereas with the predecessor TS 8 everything had to be screwed into place, the VX25 now allows doors and side panels to be simply hung into place. This allowed us to remove the doors on site with minimal effort, giving us optimum access and space to sort and connect the cables."
Step by step, the team switched the power supply to the new distributions. For motorists, the switchover was only noticeable when the normal power supply was switched, as the lighting was only covered by the emergency power supply for a short time.